WEBVTT
Kind: captions
Language: en

00:00:00.100 --> 00:00:28.100
(Music)

00:00:30.300 --> 00:00:36.880
Thank you very much, good evening, welcome, thanks for coming, and I'll talk to you a little bit tonight

00:00:36.880 --> 00:00:39.960
about mammoths on the Channel Islands and as

00:00:39.960 --> 00:00:44.190
Bryson mentioned there have been
some recent finds on Santa Rosa Island

00:00:44.190 --> 00:00:48.420
and some of the people who did the
excavating are actually standing at the

00:00:48.420 --> 00:00:53.879
back of the room there and they are
they can raise their

00:00:53.879 --> 00:00:58.110
hands there and identify themselves
that's Monica Bugbee and Justin Wilkins

00:00:58.110 --> 00:01:02.550
from the Mammoth Hot Springs site in
South Dakota and if you're ever cruising

00:01:02.550 --> 00:01:06.000
around in the northern Great Plains and
you happen to pass through Hot Springs,

00:01:06.000 --> 00:01:11.580
South Dakota on your way to Black Hills
or Mount Rushmore or Sturgis for a

00:01:11.580 --> 00:01:17.399
motorcycle rally be sure to stop in at
Hot Springs and and go visit the museum

00:01:17.399 --> 00:01:21.720
there where they've actually
constructed a museum over a mammoth dig

00:01:21.720 --> 00:01:27.149
site so how's that for a dedication to
the study of mammoths so anyway we're

00:01:27.149 --> 00:01:31.920
we're happy to have some of the esteemed
mammoth paleontologists in the audience

00:01:31.920 --> 00:01:35.909
tonight and without further ado I'll let
them go ahead and give the talk that I

00:01:35.909 --> 00:01:42.990
was going to give. (laughter) just kidding, anyway.
I'm happy to be here it's always great

00:01:42.990 --> 00:01:48.329
to talk about the Channel Islands to
an audience that is a local audience

00:01:48.329 --> 00:01:51.869
here that knows the Channel Islands and
loves them and appreciates them and

00:01:51.869 --> 00:01:54.869
that's that's a wonderful thing. other
places where I talk about it they ask me

00:01:54.869 --> 00:02:00.390
where the Channel Islands are except in
places like the UK where they say

00:02:00.390 --> 00:02:05.340
they're not in California they're off
the coast of Britain so that's different

00:02:05.340 --> 00:02:11.340
Channel Islands. first of all can
everyone hear me all right? okay and back

00:02:11.340 --> 00:02:16.130
in the control room there is there any
possibility of extinguishing this light

00:02:16.130 --> 00:02:25.310
or dimming it at least or something or
maybe I can go get my sunglasses whoa

00:02:25.310 --> 00:02:38.180
it's very bright yeah ah there we go I'm
back okay is that okay all right so

00:02:38.180 --> 00:02:43.140
Mammoths on the Channel Islands: How and
Did They Get There. we'll talk a little

00:02:43.140 --> 00:02:48.090
bit about both of those things and will
even talk a little bit about why they're

00:02:48.090 --> 00:02:54.240
not there now and that is very
controversial and we'll just jump right

00:02:54.240 --> 00:03:00.210
into the controversy when we get to that
point. one thing too that I wanted to be

00:03:00.210 --> 00:03:04.320
sure to say here is that our studies on
the Channel Islands of mammoths and

00:03:04.320 --> 00:03:08.790
indeed all of the geologic studies that
we've done on the Channel Islands have

00:03:08.790 --> 00:03:14.940
been a group effort I'm with the US
Geological Survey USGS but we also work

00:03:14.940 --> 00:03:21.390
closely of course with the National Park
Service where these islands that we've

00:03:21.390 --> 00:03:27.870
been finding the mammoths are located and
also the Nature Conservancy for parts

00:03:27.870 --> 00:03:33.600
of Santa Cruz Island. The Natural History
Museum of Los Angeles County has been

00:03:33.600 --> 00:03:38.360
very helpful to us in a lot of our
paleontological studies with our smaller

00:03:38.360 --> 00:03:42.570
fossils- marine invertebrates and things
like that- and then I mentioned the

00:03:42.570 --> 00:03:47.940
mammoth site in South Dakota and they
have the coolest logo of all and they

00:03:47.940 --> 00:03:53.940
are represented by people who I
introduced you to already and they have

00:03:53.940 --> 00:03:59.760
had in their past for a long time people
involved in research here on the Channel

00:03:59.760 --> 00:04:04.170
Islands, particularly the late Dr. Larry Akenbroad, who some of you might know

00:04:04.170 --> 00:04:08.880
he made trickling visits to California,
he's a retired Northern Arizona

00:04:08.880 --> 00:04:14.070
University professor who then set up and
dedicated his retirement years to the

00:04:14.070 --> 00:04:19.140
mammoth site in South Dakota and we miss
him a lot but we were trying to carry on

00:04:19.140 --> 00:04:26.960
his legacy with continued studies of
mammoths. so mammoths in North America

00:04:26.960 --> 00:04:33.770
during the last major glacial period the
last of the most recent of the ice ages

00:04:33.770 --> 00:04:41.750
which was about 25,000 to
about 12,000 years ago we had two common

00:04:41.750 --> 00:04:51.680
species of mammoths in North America one
of them the whoops whoa

00:04:52.510 --> 00:04:58.150
let's go back there we go and the laser
pointer is right up above here you got

00:04:58.150 --> 00:05:03.220
to pick it very carefully here because
it's up above the left right buttons. at

00:05:03.220 --> 00:05:10.270
any rate the Columbian mammoth or
Mammuthus colombi is indicated by these

00:05:10.270 --> 00:05:15.100
red dots where the the sites are where
it's been found some of them ranged up

00:05:15.100 --> 00:05:18.700
pretty far north but not very many and
most of our sites are down here in the

00:05:18.700 --> 00:05:22.750
western and southwestern United States
and a big concentration here in Florida

00:05:22.750 --> 00:05:27.670
as well. but the woolly mammoth which a
lot of people associate with the ice

00:05:27.670 --> 00:05:33.120
ages is more of a northern species we
have a lot of sites here in Alaska and

00:05:33.120 --> 00:05:38.110
northwestern Canada and then a lot of
sites in the northern United States, not

00:05:38.110 --> 00:05:42.250
so many sites in Canada which you might
expect to see except for the fact that

00:05:42.250 --> 00:05:47.140
that's where the ice sheets were so or a
major part of the last glacial period

00:05:47.140 --> 00:05:52.300
that was all covered by a big thick ice
sheet so a lot of that part of the world

00:05:52.300 --> 00:05:57.100
what pretty much looked the way Greenland
does today so that's why we don't have a

00:05:57.100 --> 00:06:01.300
lot of mammoth sites there but we have
lots of mammoth sites around it in the

00:06:01.300 --> 00:06:06.370
northern part. so those are our two most
common species of mammoths in North

00:06:06.370 --> 00:06:11.350
America but here in California and
adjacent to the Channel Islands we had a

00:06:11.350 --> 00:06:19.450
third species: Mammuthus exilis, or the
pygmy mammoth which, exilis meaning

00:06:19.450 --> 00:06:23.950
'exiled' meaning exiled to these islands
but not through some punishment/

00:06:23.950 --> 00:06:27.820
banishment or something like that they
did this voluntarily and I'll show you

00:06:27.820 --> 00:06:34.030
how in a little bit here. and one thing
to note here is the present distance

00:06:34.030 --> 00:06:39.580
from the closest mainland locality which
would be slung right around here near

00:06:39.580 --> 00:06:43.930
Oxnard over to the closest Channel
Island which would be east Anacapa is

00:06:43.930 --> 00:06:50.050
presently at about 20 kilometers okay.
multiply that by 1.6 and that's how many

00:06:50.050 --> 00:06:55.510
miles you talking about 30-some miles
something on that order other way around

00:06:55.510 --> 00:07:03.069
thank you I was testing you just to see
how awake you were, very good.

00:07:03.069 --> 00:07:09.649
anyway as you can see 20 kilometers as I
was saying and keep that figure in mind

00:07:09.649 --> 00:07:17.050
because we'll see how that changes when
we go into the past. thank you 14 miles.

00:07:17.050 --> 00:07:22.610
so at any rate mammoth remains have been
found at a number of locations on three

00:07:22.610 --> 00:07:26.809
of the northern Channel Islands: a few of
them on Santa Cruz but only in the

00:07:26.809 --> 00:07:31.879
western part and none of these have been
found in place as far as I know I could

00:07:31.879 --> 00:07:36.589
be wrong about that but I think that's
correct; lots of sites on Santa Rosa

00:07:36.589 --> 00:07:42.259
Island and we'll see examples of those;
and we have a few sites on San Miguel

00:07:42.259 --> 00:07:47.599
Island as well and I'll show you some of
those too. in fact let's start with San

00:07:47.599 --> 00:07:52.339
Miguel Island here's some that are some
of the first that I ever saw this is a

00:07:52.339 --> 00:07:59.139
photograph I took in 1976 and these two
people Diana Johnson and Don Johnson

00:07:59.139 --> 00:08:05.869
were two people that did a lot of work
here in the 1960s on the Channel Islands

00:08:05.869 --> 00:08:09.469
and how many people have seen the
caliche forest on San Miguel Island, or

00:08:09.469 --> 00:08:15.800
have heard of it? that was actually
identified and named by Don Johnson okay

00:08:15.800 --> 00:08:23.959
and that's his wife Diana and they did
this work early in the mid-60s before

00:08:23.959 --> 00:08:28.249
many people were working on the Channel
Islands and Don managed to find a piece

00:08:28.249 --> 00:08:34.789
of Cyprus charcoal near this mammoth
tusks and that's been radiocarbon dated

00:08:34.789 --> 00:08:38.569
at around 18,800 years. that puts us right smack

00:08:38.569 --> 00:08:43.009
in the middle of the last glacial period
remember I said that was about 25,000 years to

00:08:43.009 --> 00:08:47.689
about 12,000 years or so ago well that's
really right in the middle of the last

00:08:47.689 --> 00:08:51.920
glacial period and as you'll see when we
get further on a lot of our mammoth ages

00:08:51.920 --> 00:08:57.649
has kind of fallen to that time span, not
all of them. here's some that we're also

00:08:57.649 --> 00:09:02.180
done not too far away from where those
last two sites are near Running Springs

00:09:02.180 --> 00:09:06.290
in western San Miguel Island but these
were done just a couple of years ago by

00:09:06.290 --> 00:09:11.389
by a couple of us with the US Geological
Survey. this is one of my cohorts Jeff

00:09:11.389 --> 00:09:15.860
Bugatti and he is pointing to some
snails that are right

00:09:15.860 --> 00:09:21.260
near this tusk which is hanging out here
and then in this gully up above there's

00:09:21.260 --> 00:09:27.320
other fragments, other mammoth remains
and more snails. and Jeff has been kind of a

00:09:27.320 --> 00:09:33.860
pioneer in trying to resurrect the
capability of using snails for

00:09:33.860 --> 00:09:37.250
radiocarbon dating. a long time we
thought that they weren't very good, it

00:09:37.250 --> 00:09:41.300
turns out some are not so good but a lot
of land snails and those that live on

00:09:41.300 --> 00:09:45.440
San Miguel Island and Santa Rosa Island
are actually pretty good for radiocarbon

00:09:45.440 --> 00:09:51.890
dating and see these are the numbers
we're getting from here around 19,000

00:09:51.890 --> 00:09:55.640
again pretty close to what we saw in
that last picture but here we've got

00:09:55.640 --> 00:10:00.260
some younger ones so these mammoth
remains apparently are a bit younger

00:10:00.260 --> 00:10:06.140
than these which are lower in a
stratigraphic sense from these others so

00:10:06.140 --> 00:10:11.149
you can see we're spanning a lot more of
the last glacial period here just at

00:10:11.149 --> 00:10:18.170
this one particular site. some of them
are undated but we keep finding them. one

00:10:18.170 --> 00:10:23.019
of the rangers this is Luis Cuevas who's
the head ranger on Santa Rosa Island,

00:10:23.019 --> 00:10:27.890
she actually grew up on Santa Rosa Island as
a matter of fact, and she's pointing to

00:10:27.890 --> 00:10:33.740
this feature right here and a big pile
of river gravel that's exposed in

00:10:33.740 --> 00:10:39.199
Bechers Bay and if we do a close-up:
look at that it's a mammoth tusk. pretty

00:10:39.199 --> 00:10:44.149
beat up and weathering away rapidly and
I don't even know if it's still exposed

00:10:44.149 --> 00:10:50.060
there or not, does anyone know? No. Brandi is
telling me it's gone now ok. but this

00:10:50.060 --> 00:10:55.120
kind of thing pops up every now and then
and we we find them periodically.

00:10:55.120 --> 00:11:01.519
this is now retired Bill Faulkner from
the Park Service here serving as scale

00:11:01.519 --> 00:11:06.890
for the first complete pygmy mammoth
skeleton about 12,800

00:11:06.890 --> 00:11:12.709
years old and one of the
excavators for this was Don Morris who is

00:11:12.709 --> 00:11:16.490
retired archaeologist for Channel
Islands National Park who is also in

00:11:16.490 --> 00:11:20.959
the audience here tonight and keep me
honest on mammoth history here along

00:11:20.959 --> 00:11:24.529
with the two Hot Springs people. I got a
lot of people checking on me here

00:11:24.529 --> 00:11:27.620
tonight
so I'm not going to make any more

00:11:27.620 --> 00:11:32.240
mistakes about metric conversions I can
assure you of that. at any rate you can

00:11:32.240 --> 00:11:38.900
see this a reproduction of this cast of
this over in the Channel Islands Visitor

00:11:38.900 --> 00:11:43.250
Center, just right across the the
courtyard here on days when that's open

00:11:43.250 --> 00:11:46.940
and I believe it's now in the Santa
Barbara County Museum, is that correct? the

00:11:46.940 --> 00:11:54.350
actual specimen itself? and phenomenal
find. this is one of the few times where

00:11:54.350 --> 00:11:58.880
we've really been lucky here in
California to be able to have someone

00:11:58.880 --> 00:12:04.190
discover this kind of a nearly complete
skeleton and it will give you an idea of

00:12:04.190 --> 00:12:07.370
just sort of what the size of these pygmy
mammoths are they are significantly

00:12:07.370 --> 00:12:10.790
smaller you will see another picture
that will illustrate that very

00:12:10.790 --> 00:12:16.180
graphically. and here's our two
superstars from Mammoth Hot Springs,

00:12:16.180 --> 00:12:22.850
South Dakota, from the hot spring site in
South Dakota. Monica and Justin who you

00:12:22.850 --> 00:12:26.300
just saw a minute ago here they are when
they're really doing their work they're

00:12:26.300 --> 00:12:30.320
not standing upright and clean and
showered and well dressed and everything

00:12:30.320 --> 00:12:35.180
this is what they usually look like and
here they are excavating this nearly

00:12:35.180 --> 00:12:39.680
complete skull and it has a pair of tusks
attached to it there's one of them

00:12:39.680 --> 00:12:44.990
sticking out right there this was done
just literally in the last couple of

00:12:44.990 --> 00:12:49.790
weeks and if you are a subscriber to the
Ventura County Star you probably read

00:12:49.790 --> 00:12:53.480
the stories about the discovery and then
there was a follow-up story about how it

00:12:53.480 --> 00:13:01.520
was airlifted out and it's a spectacular
find. and these two young superstars are

00:13:01.520 --> 00:13:06.320
going to be studying this and learning
more about it and we hope to find a lot

00:13:06.320 --> 00:13:10.070
more information about it. what we do
know from a couple of preliminary

00:13:10.070 --> 00:13:14.800
radiocarbon ages it is likely younger
than about 13,250

00:13:14.800 --> 00:13:18.950
years so like the previous
photo that I showed you it's on the

00:13:18.950 --> 00:13:22.970
young side we're still in the last
glacial period but we're really near the

00:13:22.970 --> 00:13:28.370
tail end of that okay and we're actually
getting close to the time when we start

00:13:28.370 --> 00:13:32.960
to see the arrival of humans on the
Channel Islands in those early days as

00:13:32.960 --> 00:13:39.379
well and we'll return to that topic too.
So mammoth ancestry and this is specifically

00:13:39.379 --> 00:13:44.059
mammoth ancestry for North America now
that we're talking about I mentioned the

00:13:44.059 --> 00:13:50.779
Columbian mammoth- here it is right here-
but it had an ancestor called Mammuthus

00:13:50.779 --> 00:13:55.669
meridionalis and this was probably an
immigrant from Asia we don't know but

00:13:55.669 --> 00:14:01.869
we're pretty sure that's the case but
it's been around a long time we have

00:14:01.869 --> 00:14:07.069
dates on this particular species of
mammoths from Anza Borrego Desert State

00:14:07.069 --> 00:14:13.549
Park in San Diego County. anybody been
there? a lot of people, good. and there

00:14:13.549 --> 00:14:19.549
they go back to about 1.8 million years
okay so that takes us way back into the

00:14:19.549 --> 00:14:25.659
Ice Ages to earlier part of that Ice Age
period that we call the Pleistocene and

00:14:25.659 --> 00:14:31.759
that was apparently the ancestor of the
Colombian mammoth (Mammuthus columbi)

00:14:31.759 --> 00:14:37.309
which we think probably evolved here in
North America and that in turn was the

00:14:37.309 --> 00:14:42.049
ancestor we're pretty sure of Mammuthus exilis or the pygmy mammoth which

00:14:42.049 --> 00:14:46.249
evolved on the Channel Islands. And just to give you some size

00:14:46.249 --> 00:14:52.220
comparison here's a scale in meters so
in feet that would be.... I'm not even going

00:14:52.220 --> 00:14:56.239
to try it. not even going to try it.
anyway you can see these were little

00:14:56.239 --> 00:15:00.979
guys. these were little. there you go
thank you. so you can see they were

00:15:00.979 --> 00:15:04.850
pretty little okay so these are the
kinds of guys that you you know wouldn't

00:15:04.850 --> 00:15:10.879
mind you know pet sitting for a while
and in your backyard they were probably

00:15:10.879 --> 00:15:16.399
just as cute in their day as the Channel
Islands fox is cute in its current day

00:15:16.399 --> 00:15:23.269
and so we would have loved to have seen
them but we'll do our best to use our

00:15:23.269 --> 00:15:30.799
imaginations instead. so there on the
Channel Islands, Colombian mammoths

00:15:30.799 --> 00:15:35.659
somehow got out to the Channel Islands
and then through time evolved down to

00:15:35.659 --> 00:15:40.849
the smaller size. why did they evolve
down to a smaller size? well part of the

00:15:40.849 --> 00:15:46.369
reason is that one thing there's no
particular advantage to being large if

00:15:46.369 --> 00:15:49.579
you're out on an island where there aren't
any predators that you have to worry

00:15:49.579 --> 00:15:52.790
about you can be smaller and not have to
appear

00:15:52.790 --> 00:15:58.370
fearsome to a potential predator. But
probably more importantly there's every

00:15:58.370 --> 00:16:04.040
good reason to get smaller because
little guys can find enough to eat and

00:16:04.040 --> 00:16:09.350
you've got limited areas to like an
island for the food resources and things

00:16:09.350 --> 00:16:14.240
like that. The big guys might go hungry
because there's maybe not quite as much

00:16:14.240 --> 00:16:20.120
to munch on out there. So through time
they tend to be selected down towards

00:16:20.120 --> 00:16:24.380
the smaller forms: smaller and smaller
forms. We don't know how long that takes.

00:16:24.380 --> 00:16:30.020
if we know that it happens commonly when
animals migrate to islands and get

00:16:30.020 --> 00:16:35.300
isolated there's a general rule in
biogeography that if they are size of a

00:16:35.300 --> 00:16:39.530
pig or larger they tend to get smaller.
Another good example from here in the

00:16:39.530 --> 00:16:44.390
United States are the key deer in
Florida which you can see if you go to

00:16:44.390 --> 00:16:49.160
Big Pine Key just cruise around some of
the back roads some eventually you'll

00:16:49.160 --> 00:16:54.170
run into them like cohort Randy from the USGS
who's here in the front row and I have

00:16:54.170 --> 00:16:57.710
seen these guys on Big Pine Key and they
are much much smaller than the sort of

00:16:57.710 --> 00:17:03.590
deer that we're used to in Colorado
where we live. But at any rate this is

00:17:03.590 --> 00:17:08.750
probably how the dwarfing process took
place is from limited resources on an

00:17:08.750 --> 00:17:15.500
island every good reason to get smaller
and no good reason to stay large but

00:17:15.500 --> 00:17:20.630
then the question becomes why how did
they get out there in the first place?

00:17:20.630 --> 00:17:26.300
and we know that this was something that
was an island process because we find

00:17:26.300 --> 00:17:31.100
both Colombian mammoths but pygmy
mammoths as well on the Channel Islands,

00:17:31.100 --> 00:17:35.810
but no pygmy mammoths on the mainland.
okay so that tells us that the

00:17:35.810 --> 00:17:43.160
Colombians came out, dwarfed down to the
pygmy sizes, and stayed there and were

00:17:43.160 --> 00:17:47.810
isolated but we didn't have a- whether we
had a reverse process or not we don't

00:17:47.810 --> 00:17:52.220
know but at least it wasn't enough for
pygmy mammoths to somehow get back on

00:17:52.220 --> 00:17:56.420
the mainland because we've never found
any. okay so looks like an island process.

00:17:56.420 --> 00:18:00.560
but the question is how do they get
there. so for years and years virtually

00:18:00.560 --> 00:18:05.930
all researchers appealed to former land
bridges and this is kind of like looking

00:18:05.930 --> 00:18:08.929
at
exploratory maps from the early European

00:18:08.929 --> 00:18:13.970
era and exploration when people thought
that Baja California was an island and

00:18:13.970 --> 00:18:19.160
all kinds of crazy things and there's a
lot of imagination in these things and

00:18:19.160 --> 00:18:22.309
what you're seeing here are some of the
kinds of land bridges that were

00:18:22.309 --> 00:18:27.230
constructed by various researchers who
study these but there's always a bridge

00:18:27.230 --> 00:18:32.870
okay always a bridge coming across here
somewhere or another bridge like this

00:18:32.870 --> 00:18:38.470
you know some of them really quite
elaborate as you can see here a lot more

00:18:38.470 --> 00:18:43.990
electoral districts in the state of
California in those days but at any rate

00:18:43.990 --> 00:18:49.130
some of these are ideas that go back
into the 30s and 40s and 50s but all the

00:18:49.130 --> 00:18:54.500
way up to the 70s as well. however what's
interesting is that there is no

00:18:54.500 --> 00:18:59.990
geological or geophysical evidence at
all, whatsoever, that such land bridges

00:18:59.990 --> 00:19:10.460
ever existed, none, not a shred. okay and
in addition the fact that we find only

00:19:10.460 --> 00:19:14.960
pygmy mammoths and not other mammals. If
there were other land- if there were

00:19:14.960 --> 00:19:19.610
truly land bridges- and there were
mammoths going across to the islands on

00:19:19.610 --> 00:19:24.289
them, why didn't the saber-toothed cats
come along as well? do you think they

00:19:24.289 --> 00:19:29.510
would just say no way man that's going
to be an island someday, I'm not going

00:19:29.510 --> 00:19:34.730
near that. Cats can swim yeah but we
don't like it you know they go right

00:19:34.730 --> 00:19:39.860
after it, of course they would and we'd see a
lot of the other Ice Age mammals

00:19:39.860 --> 00:19:46.429
wandering across as well. why only
mammoths then on the islands? okay? Nobody

00:19:46.429 --> 00:19:49.340
could answer this question and what's
interesting is that the evidence for

00:19:49.340 --> 00:19:53.450
these land bridges- the only piece of
evidence- was just the presence of the

00:19:53.450 --> 00:19:57.500
pygmy mammoths. So people
actually used that as the explanation

00:19:57.500 --> 00:20:01.309
that there had to be a land bridge; all
the geologic and geophysical evidence to

00:20:01.309 --> 00:20:04.940
the contrary, forget about it, we're not going to worry about that, it had to be a

00:20:04.940 --> 00:20:11.090
land bridge because the pygmy mammoths
were there. Okay. Well as it turns out no

00:20:11.090 --> 00:20:15.200
evidence for that and there still isn't
and that's because it didn't happen. Now

00:20:15.200 --> 00:20:24.140
recall that we have this distance
which I will give in metric terms: 20

00:20:24.140 --> 00:20:30.050
kilometers from Oxnard over to Anacapa
but to get to a real Island you're

00:20:30.050 --> 00:20:34.370
looking more at around 30 kilometers or
so to get to Eastern Santa Cruz. Recall

00:20:34.370 --> 00:20:38.540
too we haven't found any mammoths on
Anacapa but on the other hand they're

00:20:38.540 --> 00:20:43.010
very tiny islands very easily could have
been eroded away. but the shallowest zone

00:20:43.010 --> 00:20:50.930
here, okay, the absolute shallowest zone
is around 230 to 240 meters depth, okay.

00:20:50.930 --> 00:20:55.040
let's keep that number in mind, okay,
that's a that's pretty deep water even

00:20:55.040 --> 00:21:00.410
you know for a thing like the Pacific
coast where we we drop off fairly

00:21:00.410 --> 00:21:07.130
quickly, but that is as shallow as it
gets, okay. however things were different

00:21:07.130 --> 00:21:13.310
during ice ages okay. here's the world
as we know it now in North America. The

00:21:13.310 --> 00:21:16.970
main ice sheet that we have that is in
this part of the world is the Greenland

00:21:16.970 --> 00:21:23.120
Ice Sheet. What was left from a much
larger ice sheet is now this little

00:21:23.120 --> 00:21:29.240
Barnes Ice Cap on Baffin Island up in
Canada here but that was once a large

00:21:29.240 --> 00:21:33.830
ice sheet here we call the Laurentide
Ice Sheet and this big thing that came

00:21:33.830 --> 00:21:39.950
all the way down here: Chicago was under
ice, New York City was under ice, a lot of

00:21:39.950 --> 00:21:46.810
Minneapolis, a lot of our upper tier of
states/ large cities were all under ice,

00:21:46.810 --> 00:21:52.010
virtually all of Canada as you can see
here, and here in the western part of

00:21:52.010 --> 00:21:55.640
North America we had another Ice Sheet
called the Cordilleran Ice Sheet. Wasn't

00:21:55.640 --> 00:22:01.280
as thick or as big as the Laurentide Ice
Sheet but still not not trivial

00:22:01.280 --> 00:22:07.310
either. and so we've got a whole lot of
ice here and we had a larger Greenland

00:22:07.310 --> 00:22:11.030
just for good measure and our mountain
ranges in Alaska had bigger glaciers

00:22:11.030 --> 00:22:17.030
plus over in Eurasia we had the Pentoscandian Ice Sheet as well. Where did

00:22:17.030 --> 00:22:21.470
all that water come from? There's only one place
it can come from and that's from the

00:22:21.470 --> 00:22:30.650
oceans. So air masses that would come
across and fall as snow here in the

00:22:30.650 --> 00:22:33.650
northern parts of Canada and farther to

00:22:33.650 --> 00:22:35.480
the
east in the northern parts of Eurasia

00:22:35.480 --> 00:22:42.120
during a cold climate so that the snow
would stay over through the summertime

00:22:42.120 --> 00:22:46.530
into the next winter kept building up
building up building up building up

00:22:46.530 --> 00:22:49.740
building up building up pretty soon you
get to the point where a certain

00:22:49.740 --> 00:22:54.420
critical density is reached then flow on
its own weight and you've got a glacier-

00:22:54.420 --> 00:22:59.220
you've got an ice sheet. okay. That's what
we have right now in Greenland, a little

00:22:59.220 --> 00:23:03.210
bitty one here at the Barnes Ice Cap
which characterized the upper part of

00:23:03.210 --> 00:23:08.280
North America during the last ice age
and in all previous ice ages and there were

00:23:08.280 --> 00:23:13.590
more than 20 of them over the last two
and a half million years. So if all of

00:23:13.590 --> 00:23:18.930
that moisture to build that ice sheet
came from the oceans what's going to

00:23:18.930 --> 00:23:26.180
happen to sea level? It's going to go
down. okay. all right. So what we see then

00:23:26.180 --> 00:23:33.990
in a place like this part of the world
is enormous amount of land area that

00:23:33.990 --> 00:23:39.620
extends out from our present coastline
and you see it right here going from the

00:23:39.620 --> 00:23:45.480
stunning metropolis where I grew up
called Lompoc- it's actually a really

00:23:45.480 --> 00:23:51.630
nice town, not a stunning metropolis but
it's a nice town- and at any rate all of

00:23:51.630 --> 00:23:56.040
this white area that you see here is the
land that would have been created around

00:23:56.040 --> 00:24:02.070
the mainland as sea level dropped and
reached its maximum during the last

00:24:02.070 --> 00:24:08.280
glacial period about 20,000 years or so
ago. Well out here in the Channel Islands

00:24:08.280 --> 00:24:13.410
look what happens there's a lot of
shallow shelf surrounding the islands

00:24:13.410 --> 00:24:19.020
and all of that gets exposed as land and
all four islands get connected into one

00:24:19.020 --> 00:24:26.490
big island that was dubbed Santa Rosae by
Phil Orr of the who at that time was at

00:24:26.490 --> 00:24:31.860
the Santa Barbara County Museum. Now
depending on which sea level histories

00:24:31.860 --> 00:24:39.320
you look at, the actual area that or the
actual depth to which sea level drop

00:24:39.320 --> 00:24:43.960
could have been as high as 95 meters or
as low as 120

00:24:43.960 --> 00:24:47.860
meters, it turns out it's not exactly the
same on each coast because there's other

00:24:47.860 --> 00:24:53.230
other, excuse me, other factors involved
which I won't get into but either way

00:24:53.230 --> 00:24:57.250
you're looking at a significant increase
in land area with all these islands being

00:24:57.250 --> 00:25:05.050
connected. So now what's our distance to
the former ice age Oxnard: 7.2 kilometers,

00:25:05.050 --> 00:25:13.650
okay, not nearly as much, still no land
bridge though. how they gonna do it?

00:25:14.130 --> 00:25:21.430
This is the way they're going to do it.
It turns out my undergrad adviser and

00:25:21.430 --> 00:25:25.570
masters advisor at the University of
Illinois who was a native Californian

00:25:25.570 --> 00:25:31.030
and who worked on the Channel Islands
the one who named the caliche forest was

00:25:31.030 --> 00:25:36.370
fascinated with mammoth, fascinated with
biogeography, and was trying to address

00:25:36.370 --> 00:25:40.180
this question because he knew these
landbridge theories were wrong, couldn't

00:25:40.180 --> 00:25:44.560
possibly be true. He knew the geologic
and geophysical evidence was against it.

00:25:44.560 --> 00:25:50.700
So he started looking through- this was
back in the in the 60s now and early 70s-

00:25:50.700 --> 00:25:56.350
started looking through accounts of
elephant behavior- modern Indian and

00:25:56.350 --> 00:26:00.940
Asian elephant behavior- and seeing what
people had done and they observed how

00:26:00.940 --> 00:26:04.780
they interacted with their environments
and so on and discovered there were a

00:26:04.780 --> 00:26:11.170
number of cases of elephants swimming.
Sometimes forced swims, for example

00:26:11.170 --> 00:26:19.000
during an ocean-going ship having an
accident at sea and then a an elephant

00:26:19.000 --> 00:26:24.700
getting loose and then for its own
survival swimming to shore as much as 30

00:26:24.700 --> 00:26:33.160
miles one way which would be about 45
kilometers. (laughter) so there! okay pretty good huh?

00:26:33.160 --> 00:26:39.430
And so at any rate that was a forced
swim but voluntary swims have been

00:26:39.430 --> 00:26:43.600
documented as well and it turns out
elephants are excellent swimmers and

00:26:43.600 --> 00:26:48.100
both Indian ones and African elephants
and a lot of their relatives like

00:26:48.100 --> 00:26:53.530
manatees so closely related too, okay,
and the stellar sea cow. Anybody heard of

00:26:53.530 --> 00:26:57.400
the stellar sea cow? They're not around
anymore but they were around not so

00:26:57.400 --> 00:27:00.330
long
ago, they certainly were swimmers; related

00:27:00.330 --> 00:27:07.269
vaguely to elephants am I correct? yep,
okay, good, I'm on track. And here's a good

00:27:07.269 --> 00:27:11.529
example right here: Rajan, the swimming elephant of Havelock Island, India. This

00:27:11.529 --> 00:27:16.230
poor guy had had some troubles earlier
in life as you can see and had a lot of

00:27:16.230 --> 00:27:21.279
cruel activity placed on him but has
been adopted by the residents of this

00:27:21.279 --> 00:27:25.600
island. They take care of this guy and
every once in awhile he goes out for a swim

00:27:25.600 --> 00:27:33.279
and does this voluntarily, has a great
time, uses his trunk as a snorkel, and a

00:27:33.279 --> 00:27:40.149
way he goes. So my old advisor documented
this before Rajan was born actually. The

00:27:40.149 --> 00:27:43.419
Origin of the Island Mammoths and the
Quaternary Land Bridge History of the

00:27:43.419 --> 00:27:47.080
Northern Channel Islands, California. He
came up with the mechanism. Finally

00:27:47.080 --> 00:27:54.880
explained why we had elephants- mammoths, that is, their cousins- out on the Channel

00:27:54.880 --> 00:27:59.470
Islands but no other large mammals and
you don't need a land bridge to explain

00:27:59.470 --> 00:28:04.269
it and he also added to this the
evidence of why they went out there he

00:28:04.269 --> 00:28:08.019
actually looked at some of the buried
sand dunes that were cemented it had

00:28:08.019 --> 00:28:13.389
their dip angles which tells us what the
wind direction was, demonstrated that the

00:28:13.389 --> 00:28:17.980
winds were westerly just as they are now
with a lot of lush vegetation out there

00:28:17.980 --> 00:28:23.769
that comes wafting across. These guys
can smell this and they say hey there's a lot of

00:28:23.769 --> 00:28:29.470
good eating out on those Islands let's
go swimming, that's what they did. ok. now

00:28:29.470 --> 00:28:34.510
what happens when you end an ice age
though? What happens to sea level? All

00:28:34.510 --> 00:28:38.409
that water goes back in the ocean, sea
level goes up, and all the sudden they're

00:28:38.409 --> 00:28:44.679
stranded ok and this is when we start to
see some of the kind of dwarfing process

00:28:44.679 --> 00:28:49.240
sometimes take place. So what I'm going
to show you here this looks very

00:28:49.240 --> 00:28:53.980
complicated but it's actually not and
it's easy to to walk you through it. What

00:28:53.980 --> 00:28:59.740
this is is basically a sea level curve
or ice ages and interglacials that are

00:28:59.740 --> 00:29:03.429
in between them. We call the periods in
between ice ages, like the one we're in

00:29:03.429 --> 00:29:09.129
now, interglacials. And this is time on
this axis in thousands of years so

00:29:09.129 --> 00:29:14.290
that's a 100,000 years, 200,000
moving back to about 450,000 years here

00:29:14.290 --> 00:29:19.290
so every time you see a high point we're
in an interglacial and sea level is high

00:29:19.290 --> 00:29:25.390
okay. And every time you see a low point
you're in a glacial period and sea level

00:29:25.390 --> 00:29:29.860
is low so this is essentially how the
ocean is going up and down and up and

00:29:29.860 --> 00:29:35.260
down and up and down and up to our
present level so during the last glacial

00:29:35.260 --> 00:29:40.510
period when all that ice was covering
North America we were in this low point

00:29:40.510 --> 00:29:43.960
right here and you can see that last
glacial period was one of the lowest of

00:29:43.960 --> 00:29:48.010
the lows of the last few hundred
thousand years so it was a big big

00:29:48.010 --> 00:29:56.140
glacial let's say. And these different
cycles here are given numbers I've shown

00:29:56.140 --> 00:30:02.860
the interglacials in red and those are
called stages so this is stage one that

00:30:02.860 --> 00:30:07.840
we're in and so the last glacial period
would have been stage 2 you know the

00:30:07.840 --> 00:30:15.340
most recent of the glacial periods. So
what we see from, well, the photos I've

00:30:15.340 --> 00:30:21.760
shown you already are a lot of stage two
aged mammoths okay and we don't have any

00:30:21.760 --> 00:30:25.270
stage one age mammoths on the Channel
Islands, we haven't found anything younger than

00:30:25.270 --> 00:30:33.640
about 12,800, does that sound right? okay so
we're really sort of at the tail end of

00:30:33.640 --> 00:30:40.570
the stage two at that point but we have
these earlier glacials as well and

00:30:40.570 --> 00:30:46.150
although they weren't maybe quite as
dramatic as the last one maybe this one

00:30:46.150 --> 00:30:50.470
was pretty close they're still not
insignificant and they are still thought

00:30:50.470 --> 00:30:55.690
we're still talking about fairly low sea
level and land masses of the Channel

00:30:55.690 --> 00:30:59.340
Islands that would have been closer to
that big landmass of North America.

00:30:59.340 --> 00:31:07.170
So we're going to take a look at this
last part last sort of glacial-

00:31:07.170 --> 00:31:11.680
interglacial-glacials cycle right here
in a bit more detail so we're just going

00:31:11.680 --> 00:31:16.150
to take that part of the curve and expand
it out a little bit here. So here's the

00:31:16.150 --> 00:31:20.920
last interglacial this was a period of
time when sea level was actually higher

00:31:20.920 --> 00:31:24.570
than it is now and we see evidence of this in places

00:31:24.570 --> 00:31:29.970
like the Florida Keys. Florida Keys are
all coral reef material in their upper

00:31:29.970 --> 00:31:38.730
part that is a coral reef that records
six meter higher level sea compared to

00:31:38.730 --> 00:31:43.590
the present one. Same thing in Hawaii the
Waimanalo formation is a coral reef

00:31:43.590 --> 00:31:49.590
limestone and most of the city of
Honolulu is built on it. okay. So during

00:31:49.590 --> 00:31:55.590
the last interglacial, Honolulu and Key
Largo would have been underwater and so

00:31:55.590 --> 00:32:01.760
would Miami and St. Petersburg and Cape
Canaveral and yep Disney World too okay.

00:32:01.760 --> 00:32:07.409
Disney World might be underwater pretty
soon I'm sorry to say. At any rate so

00:32:07.409 --> 00:32:11.880
that's our last interglacial, and it was
a whopper, it was a sea level was much

00:32:11.880 --> 00:32:16.640
higher and it was much warmer than it is
now and we'll return to that theme too.

00:32:16.640 --> 00:32:22.620
Okay that's stage 5 E: this whole period
in here was our stage five in the last

00:32:22.620 --> 00:32:28.950
graph, we've actually sub divided it into
three sub stages here, E, there's a D there,

00:32:28.950 --> 00:32:35.279
C, a B there and a A here. Clever huh?
Scientists have learned the

00:32:35.279 --> 00:32:40.220
alphabet! okay. all right. And then we have
an early last glacial and then a little

00:32:40.220 --> 00:32:44.580
start of an interglacial that kind of
fizzled and then we go into stage two

00:32:44.580 --> 00:32:49.140
which is our big last glacial state going into the present interglacial. Well most

00:32:49.140 --> 00:32:54.029
of our mammoth radiocarbon ages fall
into stage two there's a few that are a

00:32:54.029 --> 00:32:59.309
little bit older but at this point when
we get into 35 to 40 thousand years a

00:32:59.309 --> 00:33:03.539
lot of our radiocarbon ages are not
necessarily reliable just a small amount

00:33:03.539 --> 00:33:08.730
of contamination can make what is an
infinitely old age appear to be an age

00:33:08.730 --> 00:33:12.809
of about 30 to 40 thousand so we
have to treat those kind of cautiously

00:33:12.809 --> 00:33:18.090
but it does indicate something older
than the last glacial period okay or

00:33:18.090 --> 00:33:22.679
stage two but that's what our majority
of our ages are. So the question is, well

00:33:22.679 --> 00:33:26.520
gee, if we had all these earlier glacial
periods could there have been earlier

00:33:26.520 --> 00:33:33.809
migrations? And actually good old Don
Johnson hypothesized this as well when he

00:33:33.809 --> 00:33:37.920
was describing the whole sequence of
last glacial migration by swimming he

00:33:37.920 --> 00:33:41.490
said possibly this scenario occurred
several times during the Late

00:33:41.490 --> 00:33:46.680
Pleistocene (meaning the ice ages) so this
is something he recognized could have

00:33:46.680 --> 00:33:51.480
happened anytime sea level was low
enough that the distance was shortened

00:33:51.480 --> 00:33:57.180
between the islands and the mainland that it 
was within swimming length. okay? So we

00:33:57.180 --> 00:34:00.720
always wondered about this and we were
always curious about it and we're always

00:34:00.720 --> 00:34:05.340
thinking, gee could we ever find some
geologic evidence of earlier migrations?

00:34:05.340 --> 00:34:11.220
And actually there was a clue that was
given by Phil Orr, guy who named Santa

00:34:11.220 --> 00:34:17.850
Rosae for that ice age mega island in 1960
and he was talking about Santa Rosa

00:34:17.850 --> 00:34:23.310
Island and he was talking about one of
the uplifted marine benches that marks a

00:34:23.310 --> 00:34:29.070
high sea level stand; no it's not like
Hawaii like Honolulu or Key Largo where

00:34:29.070 --> 00:34:34.110
the land is not going up; here in
California the land is in many places

00:34:34.110 --> 00:34:38.730
slowly uplifting and the Channel Islands
are among those so when we get a marine

00:34:38.730 --> 00:34:43.650
bench during an interglacial high sea stand,
with time it gets lifted out of the

00:34:43.650 --> 00:34:48.030
water a little bit, and if you've ever
driven along most of California Highway

00:34:48.030 --> 00:34:52.050
1 from here all the way up to San
Simeon you're driving on that last

00:34:52.050 --> 00:34:57.980
interglacial bench that's been uplifted
out of the water. okay? how about that? So

00:34:57.980 --> 00:35:05.910
anyway what he whoops, sorry, what he said was he was describing some of these

00:35:05.910 --> 00:35:11.820
marine deposits in one of these terraces
"in general a light gray calcareous clay

00:35:11.820 --> 00:35:16.140
containing fossil bones of whales, sea
lion, sea otter, shorebirds, and occasional

00:35:16.140 --> 00:35:21.720
dwarf mammoth." Whoa! That means you're talking about a dwarf mammoth that has

00:35:21.720 --> 00:35:26.340
got to be beyond radiocarbon age and goes all the way back into some part of the

00:35:26.340 --> 00:35:30.800
last interglacial complex because that's
the age of the deposit he's describing.

00:35:30.800 --> 00:35:36.450
okay. So we thought well let's go look at
these sorts of deposits and see what we

00:35:36.450 --> 00:35:42.390
can find, are there occasional dwarf mammoth
fossils there. So we were doing the

00:35:42.390 --> 00:35:49.500
mapping of marine terraces on Santa Rosa
Island over the last few years. These

00:35:49.500 --> 00:35:53.700
brown areas that you see here are some
of the old ones these go back sometimes

00:35:53.700 --> 00:35:59.370
millions of years not many millions but a
couple millions of years but around here

00:35:59.370 --> 00:36:05.820
this whole light, more yellowish color is
the complex of one or two terraces that

00:36:05.820 --> 00:36:13.290
represent those stage 5 high sea stands, you know the 5 E, 5C, 5A, those in that, excuse me, those

00:36:13.290 --> 00:36:18.450
in that time period are all along the
shore there on Santa Rosa. This is what

00:36:18.450 --> 00:36:23.850
they look like: it looks like just a sort
of a flat bench, a Mesa-like one, the upper

00:36:23.850 --> 00:36:30.060
higher Mesa that you see here is an
older marine terrace or terraces but in

00:36:30.060 --> 00:36:35.610
this canyon our exposures of what you'll
see is a wave-cut bench that's got fossils

00:36:35.610 --> 00:36:39.780
on top of it, the sea shells in there that
date to the last interglacial, and they're

00:36:39.780 --> 00:36:45.090
the same species that we find living on
the modern coast today. There hasn't been that

00:36:45.090 --> 00:36:48.480
much time that they've changed or
evolved that much but this is what they look

00:36:48.480 --> 00:36:53.490
like so what we do is we scour exposures
and canyons like these and along sea

00:36:53.490 --> 00:36:58.830
cliffs like these to see what we can
find in there and we were doing this

00:36:58.830 --> 00:37:04.620
collecting these for fossils to try to
date these and they once you get in the

00:37:04.620 --> 00:37:08.820
canyons they look something like this:
this is one of those wave cut benches

00:37:08.820 --> 00:37:13.200
right along in through here that I've
outlined. This is shale which is millions

00:37:13.200 --> 00:37:17.400
of years old and you can see there's an
old sea cliff that's been cut and

00:37:17.400 --> 00:37:21.270
there's a wave cut bench that's been cut.
And this is a wave cut bench of a higher

00:37:21.270 --> 00:37:26.760
terrace and then there's been river
deposits from this canyon that has

00:37:26.760 --> 00:37:31.920
buried all of this. But right along here
I want you to trace that along that wave-

00:37:31.920 --> 00:37:36.600
cut bench. That's from the 80,000 year old terrace and all the

00:37:36.600 --> 00:37:42.510
way out to this sea stack out here, we're
going to go out there. And this is what

00:37:42.510 --> 00:37:45.720
it looks like when you look close up:
there's that shale again. This is in a

00:37:45.720 --> 00:37:50.070
nice low tide. This is the Rincon Formation, the shale, millions of years

00:37:50.070 --> 00:37:54.540
old. But look what we've got here, we've
got a wave-cut bench and there's a layer

00:37:54.540 --> 00:37:58.680
of boulders that are the sort of
boulders that you find sitting on the

00:37:58.680 --> 00:38:03.840
beach over in here, along here, today. They
have little holes

00:38:03.840 --> 00:38:08.370
that have been bored by rock mooring
clams, there's fossils in there, sea otter

00:38:08.370 --> 00:38:15.450
remains, and we're going to look right
here... and guess what we found. A tusk! How about

00:38:15.450 --> 00:38:22.380
that? There it is. There's a tusk. And I
sent a photograph of this to Larry Akenbroad

00:38:22.380 --> 00:38:26.400
because I had been sending him
photographs for years saying I think I

00:38:26.400 --> 00:38:30.300
found a tusk, I think I found a tusk,and  I'd
sent him a picture and he'd say that's a

00:38:30.300 --> 00:38:37.080
whale rib Dan and/or would say that's a
large root cast Dan and there are all

00:38:37.080 --> 00:38:41.850
kinds of things that I misidentified in
my enthusiasm but this time he wrote

00:38:41.850 --> 00:38:44.520
back right away and he said you've finally
done it you found a pygmy mammoth.

00:38:44.520 --> 00:38:50.670
So there it is okay. So here's our
Rincon shale, really old, that's the

00:38:50.670 --> 00:38:56.610
bedrock, its wave- cut benches, this
boundary right through here, and within

00:38:56.610 --> 00:39:01.350
this deposit one of our cohorts at the
LA County Museum, Lindsay Groves, found

00:39:01.350 --> 00:39:09.870
these limpets and other marine
gastropods or snails if you will so we

00:39:09.870 --> 00:39:14.810
know that's that's marine material and
Howell Thomas, his vertebrate

00:39:14.810 --> 00:39:19.230
paleontology sidekick, also at the LA
County Museum found enough fragments he

00:39:19.230 --> 00:39:24.330
was able to actually identify this as a
sea otter with these bone fragments and

00:39:24.330 --> 00:39:29.000
it could even take it down to the
species. ok. now. It's easy to get

00:39:29.000 --> 00:39:34.770
terrestrial fossils mixed into marine
fossils because all you got to do is

00:39:34.770 --> 00:39:39.540
erode them out into the ocean. ok. So on a
sea cliff you know all you got to do is

00:39:39.540 --> 00:39:43.920
have a mammoth who's walking along the
top near the cliff slips, or dies

00:39:43.920 --> 00:39:48.180
naturally, or something, falls into the
surf zone everything gets eroded

00:39:48.180 --> 00:39:53.640
together in with these marine fossils
and you know this can happen. It's

00:39:53.640 --> 00:39:59.340
tougher for marine fossils to get up
onto the land because they have to defy

00:39:59.340 --> 00:40:06.330
gravity to do that. ok. And not too many
of them do that. They you know celebrated

00:40:06.330 --> 00:40:13.050
Jumping snails of Ventura County have
never been verified so at any rate so we

00:40:13.050 --> 00:40:15.360
know that this is a bona fide marine
depot

00:40:15.360 --> 00:40:19.800
and this is a mammoth tusk that was
washed into it now it's interesting

00:40:19.800 --> 00:40:23.310
about this when you look at the
dimensions of this thing, this puts it

00:40:23.310 --> 00:40:28.770
sort of into the range of either a pygmy
mammoth or truth be told it could be an

00:40:28.770 --> 00:40:33.540
immature Colombian mammoth. we really don't
know for sure, but it's one of those

00:40:33.540 --> 00:40:38.250
two. It's no question it's a mammoth
tusk for sure within these marine

00:40:38.250 --> 00:40:44.160
deposits. So I should say this is
probably a pygmy mammoth. But at any

00:40:44.160 --> 00:40:48.810
rate, when could mammoths have migrated to
the Channel Islands? This marine deposit

00:40:48.810 --> 00:40:56.360
it was found in is right here so it's
within stage five... that's five E, C, A...

00:40:56.360 --> 00:41:02.400
this is 80,000 years old okay,
all right, Now because it's 80

00:41:02.400 --> 00:41:06.510
thousand years old or in a deposit
that's 80,000 years old that means it's at

00:41:06.510 --> 00:41:10.890
least 80,000 years because it
had to exist before that marine deposit

00:41:10.890 --> 00:41:14.610
was created. Could be right at 80,0000, or close to it but it can't be any

00:41:14.610 --> 00:41:20.340
younger okay. So you can't have that sort
of a situation in geology or you're

00:41:20.340 --> 00:41:24.630
violating the rules of geology, no one
wants to do that. So we know it has to be

00:41:24.630 --> 00:41:31.620
at least 80,000 years old but
could be older. Well when did it or its

00:41:31.620 --> 00:41:37.260
more likely its ancestors migrate over
to the Channel Islands? Well if you look

00:41:37.260 --> 00:41:41.460
at Stage 5 B here, sea level wasn't
really much lower than it was during

00:41:41.460 --> 00:41:52.080
these high sea stands. 5C was not very low, 5D wasn't very low and we know 5E,

00:41:52.080 --> 00:41:56.070
that's when Hawaii and Key Largo and
Miami and all those places were

00:41:56.070 --> 00:42:00.090
underwater so sea level was much higher
right. So you're talking about swimming

00:42:00.090 --> 00:42:06.120
distances that are comparable to what we have
now or were even greater, okay. So when's

00:42:06.120 --> 00:42:11.490
the most likely time, how about stage six
okay, how about stage eight, how about

00:42:11.490 --> 00:42:18.000
stage 10. Any of those glacial periods are
candidates so we know then that mammoths

00:42:18.000 --> 00:42:23.970
migrated to the Channel Islands sometime
before the last one during stage two so

00:42:23.970 --> 00:42:28.980
we know there had to be at least two
migrations, at least two,

00:42:28.980 --> 00:42:35.550
maybe more we don't know. okay. So how
does that play out? Well if you look at a

00:42:35.550 --> 00:42:40.980
cross section of Santa Barbara Channel
the mainland and the islands out here

00:42:40.980 --> 00:42:44.970
and these are those marine terraces that
I showed you the picture of on Santa Rosa

00:42:44.970 --> 00:42:50.460
these wave cut benches. okay. They've been
forming the last 20 million years on the

00:42:50.460 --> 00:42:55.020
California coast as we've had glacial-
interglacial cycles and we hit a high

00:42:55.020 --> 00:42:59.130
stand to sea and then sea level drops
during a glacial period and the land

00:42:59.130 --> 00:43:05.580
uplifts and the terrace gets run out
of the water. Well this is going on on

00:43:05.580 --> 00:43:10.859
the islands and it's going on on the
mainland so the channel distance here

00:43:10.859 --> 00:43:15.090
used to be greater in the past before
all this uplift took place and then

00:43:15.090 --> 00:43:19.619
through time it's been shrinking so
maybe eventually we will get that

00:43:19.619 --> 00:43:25.230
island who knows okay you gotta you
know bring it up to 240 meters depth so

00:43:25.230 --> 00:43:30.420
that's that's maybe not going to happen
for a while yet. At any rate there was a

00:43:30.420 --> 00:43:36.119
time probably when this distance was
actually beyond the range where mammoths

00:43:36.119 --> 00:43:41.880
could swim. Just too far. And maybe even
during the next low stand of sea, or

00:43:41.880 --> 00:43:47.040
glacial period, it might have still been
too far. At some point and we don't know

00:43:47.040 --> 00:43:52.590
if it was stage 10, stage 8, stage 6 or
even some time earlier but some point

00:43:52.590 --> 00:43:59.460
sea level got to the point where it was
low enough and uplift had taken place on

00:43:59.460 --> 00:44:03.240
the land and on the islands to a
sufficient extent that this distance was

00:44:03.240 --> 00:44:07.500
short enough for where they were finally close
enough they can swim across. And then

00:44:07.500 --> 00:44:11.040
when we get to the last glacial period
which was this whopper okay, sea

00:44:11.040 --> 00:44:15.690
level really dropped, and enough uplift
had taken place, the channel was down to

00:44:15.690 --> 00:44:20.640
that short distance of seven kilometers
or so and easier to swim then even

00:44:20.640 --> 00:44:25.710
before and away they went and that's
where we see a lot of the mammoths that date

00:44:25.710 --> 00:44:29.640
from the last glacial period, both
Colombians and pygmies. Now we don't know

00:44:29.640 --> 00:44:33.570
whether those pygmies evolved during
the course of the last glacial period or

00:44:33.570 --> 00:44:38.720
from the earlier migration, you just
don't know, so this is something that

00:44:38.720 --> 00:44:42.760
Monica and Justin will tell us about
when they get all done with their stuff,

00:44:42.760 --> 00:44:48.430
right? yeah, that's right, that's the
spirit, that's that can-do spirit in the

00:44:48.430 --> 00:44:53.380
mammoth community. But here's another
question: why did they become extinct? And

00:44:53.380 --> 00:44:59.470
there is probably no subject in
Pleistocene paleontology more

00:44:59.470 --> 00:45:05.800
controversial than how the large mammals
of North America, Eurasia and Australia and a

00:45:05.800 --> 00:45:10.600
lot of other places became extinct at
the end of the Ice Ages. And it's

00:45:10.600 --> 00:45:15.640
variable. Some became extinct sooner than
others and it turns out actually some of

00:45:15.640 --> 00:45:20.080
them nearly escaped. There were mammoths
on place called Wrangel Island off the

00:45:20.080 --> 00:45:28.210
northern coast of Siberia that existed
there until 3500 years ago. Isn't that amazing?

00:45:28.210 --> 00:45:33.640
They almost made it, almost made it. So
when the pyramids were built there were

00:45:33.640 --> 00:45:39.820
still mammoths on the earth. Isn't that amazing
to think about? So I feel sorry for those

00:45:39.820 --> 00:45:46.330
guys they almost made it and not quite.
Anyway we know from the geologic record

00:45:46.330 --> 00:45:51.180
on the Channel Islands that mammoths
became extinct on the Channel Islands

00:45:51.180 --> 00:45:56.800
somewhere around 12,000 years or so ago
and perhaps just a little older or something

00:45:56.800 --> 00:46:01.180
on that nature okay at the end of the
last glacial period. There have been

00:46:01.180 --> 00:46:06.610
three major hypotheses that have been
presented. One is impact from an

00:46:06.610 --> 00:46:10.990
extraterrestrial object- a comet or
meteor- and this is an idea that has come

00:46:10.990 --> 00:46:15.790
into vogue just recently. There are a lot
of people that have kind of gone along

00:46:15.790 --> 00:46:22.110
with this concept and I'll talk a little
bit more about it here in a second. A

00:46:22.110 --> 00:46:26.710
more favoured hypothesis is climate
change and sea level rise when we

00:46:26.710 --> 00:46:30.700
shifted from a glacial to an
interglacial climate so that conditions

00:46:30.700 --> 00:46:34.900
were warmer, there would be a loss of
land area so that Santa Rosae would start

00:46:34.900 --> 00:46:39.430
to break into individual islands okay.
All of a sudden you got less land area,

00:46:39.430 --> 00:46:44.110
less in the way of food resources, and so on.
And this idea is favored by a lot of

00:46:44.110 --> 00:46:47.920
people. Here's another one that's favored
by a lot of people that's the arrival of

00:46:47.920 --> 00:46:51.460
humans could be very close to the time
when the first humans were arriving on

00:46:51.460 --> 00:46:55.830
the Channel Islands okay, within a couple hundred years in fact,

00:46:55.830 --> 00:47:01.380
within our uncertainties with
radiocarbon dating. So let's take a look at

00:47:01.380 --> 00:47:07.790
each one of these. That first one, this
has been controversial to say the least.

00:47:07.790 --> 00:47:13.230
Here's one of the groups that has come
up with this. They came up with the idea

00:47:13.230 --> 00:47:21.090
that this large celestial body impacted
on the surface of the earth, brought

00:47:21.090 --> 00:47:27.810
about all kinds of things: wildfires,
ecosystem disruption, the creation of a

00:47:27.810 --> 00:47:31.260
cold period that's referred to as the 
Younger-Dryas, this was a brief period,

00:47:31.260 --> 00:47:35.850
we know this did happen, this cold
period, a brief period where we were

00:47:35.850 --> 00:47:39.750
moving out of the last glacial period,
the last ice age, into the present

00:47:39.750 --> 00:47:44.430
interglacial and then suddenly we had a
precipitous drop in temperature globally,

00:47:44.430 --> 00:47:49.470
or much of the globe anyway, lasted for a full
1000 years and was near glacial

00:47:49.470 --> 00:47:53.810
conditions. More glaciers that actually re-advanced in the mountains in

00:47:53.840 --> 00:47:59.340
Colorado where I live, and this has been verified and
we see it in a lot of geologic records

00:47:59.340 --> 00:48:04.260
and this was also about the time that a lot
of these large mammals became extinct. So

00:48:04.260 --> 00:48:09.600
these guys are saying that all of this
was caused by this impact event and

00:48:09.600 --> 00:48:14.130
they've accrued a lot of evidence that
they present in support of this

00:48:14.130 --> 00:48:18.840
hypothesis. And then there are others
that are the doubters to this theory. In

00:48:18.840 --> 00:48:23.550
fact they've been rather blunt about
this, they have assembled all the

00:48:23.550 --> 00:48:29.010
evidence against it and actually
refer to this as a requiem so so you

00:48:29.010 --> 00:48:32.460
don't see this kind of terminology in a
lot of scientific literature, usually we

00:48:32.460 --> 00:48:36.780
try to be a little more restrained and
you know. But this is amounting to saying

00:48:36.780 --> 00:48:43.380
you know well you guys are you know full
of it here and but in truth these guys

00:48:43.380 --> 00:48:47.940
have worked hard to try to come up with
supportive evidence for this, these guys

00:48:47.940 --> 00:48:54.000
have also worked hard to evaluate that
evidence and quite honestly my feeling

00:48:54.000 --> 00:49:00.240
is that these guys are probably more
closer to the truth than these guys are.

00:49:00.240 --> 00:49:04.860
The jury is still out on this but most of
the evidence suggests a lot of the

00:49:04.860 --> 00:49:08.970
evidence that these guys used is
questionable or can be explained in

00:49:08.970 --> 00:49:11.680
other ways.
So we're going to leave it at that. I'm

00:49:11.680 --> 00:49:15.610
not going to get into this one because
it's quite a quite a mess with the back

00:49:15.610 --> 00:49:20.860
and forth on that but we're just going
to say not likely not likely, not not no,

00:49:20.860 --> 00:49:25.060
but not likely. So climate change and sea
level rise when we shifted from a glacial

00:49:25.060 --> 00:49:31.750
to an interglacial climate, that is
possible. Here's one problem. Remember we

00:49:31.750 --> 00:49:37.780
said that the mammoths had to come over
at least twice, right. Once during the

00:49:37.780 --> 00:49:40.960
last glacial period for sure, we know
that, we see plenty of evidence of that.

00:49:40.960 --> 00:49:46.270
And at some favorable glacial period
prior to that, sometime prior to 80,000

00:49:46.270 --> 00:49:52.420
years ago, we don't know when, could be
stage six 150,000 years ago, stage eight 250,000

00:49:52.420 --> 00:49:57.460
years ago, so we don't know when, but
one of those periods when sea level was

00:49:57.460 --> 00:50:03.100
low. Remember I said too that the last
interglacial period when sea level was

00:50:03.100 --> 00:50:09.900
higher that it would have been after that
migration took place whether it was at

00:50:09.900 --> 00:50:16.150
250,000 years ago or 150,000 years ago
both of those are prior to the last

00:50:16.150 --> 00:50:20.920
interglacial when conditions were
interglacial-like 120,000 years ago.

00:50:20.920 --> 00:50:26.410
Okay well in a lot of places in
California Southern California where

00:50:26.410 --> 00:50:31.810
these red dots are showing up here we
have records of not only a higher sea

00:50:31.810 --> 00:50:37.150
level and then uplift but also the
marine invertebrate fauna within that,

00:50:37.150 --> 00:50:42.760
all the snails and bivalves or clams and
other organisms that are in there, tell

00:50:42.760 --> 00:50:48.790
us that the waters around here were a
lot warmer than they were during the

00:50:48.790 --> 00:50:53.470
current interglacial so things were not sea level is not only higher but

00:50:53.470 --> 00:50:57.940
waters were warmer probably had more El
Ninos or they had a lot of things that

00:50:57.940 --> 00:51:02.200
now live in Baja California or Central
America migrating up in the Santa

00:51:02.200 --> 00:51:06.820
Barbara Channel so conditions were a lot
warmer. Furthermore you even see it in

00:51:06.820 --> 00:51:13.630
fossil pollen that's recorded in a core
that Jim Kennedett at UCSB took right out

00:51:13.630 --> 00:51:18.370
here in the deepest part of the core
that indicates that the vegetation tells

00:51:18.370 --> 00:51:23.760
us it was a much warmer climate as well.
So if sea level was higher

00:51:23.760 --> 00:51:30.360
and conditions were warmer then that
means we actually had, this is the last

00:51:30.360 --> 00:51:36.900
interglacial shoreline right here along
these islands where it's still preserved

00:51:36.900 --> 00:51:41.160
and not all the places but you can see
they're all inland because sea level was

00:51:41.160 --> 00:51:45.780
higher right so what does that mean
about these island sizes. They're

00:51:45.780 --> 00:51:51.900
actually smaller than they are now okay
a sea level was higher all right and the

00:51:51.900 --> 00:51:56.790
waters around here were warmer and then
what did we move into. The first part of

00:51:56.790 --> 00:52:02.250
the glacial period right and then we had
a little, remember, a little failed

00:52:02.250 --> 00:52:07.250
interglacial period and then we moved
into the deep last glacial period. So

00:52:07.250 --> 00:52:13.650
mammoths then survived, came over during
some glacial period, survived the warmest

00:52:13.650 --> 00:52:18.450
interglacial of the last 400,000 years
and then a glacial period that started,

00:52:18.450 --> 00:52:21.870
and then a half started
interglacial period, and then one of the

00:52:21.870 --> 00:52:26.430
coldest glacial periods, and then they
moved into a rather modest interglacial

00:52:26.430 --> 00:52:29.520
the one that we're in now and then they
decided that they had to die because

00:52:29.520 --> 00:52:34.170
they couldn't survive anymore? Doesn't make
sense because they survived an

00:52:34.170 --> 00:52:38.550
interglacial that was more intense than
the present one and where the land area

00:52:38.550 --> 00:52:43.950
was smaller than it was at the end of
the last glacial period and all the

00:52:43.950 --> 00:52:51.890
islands broke up again. So not only did
the old Santa Rosae break up into

00:52:51.890 --> 00:52:56.790
islands, they were smaller islands than
they are now, and somehow they did okay.

00:52:56.790 --> 00:53:00.440
They survived because they we see them
all the way to the last glacial period.

00:53:00.440 --> 00:53:07.410
That's the problem with the climate
change hypothesis okay. Not the idea that

00:53:07.410 --> 00:53:11.490
the idea isn't that it's totally wrong
or anything like that, but it's a problem

00:53:11.490 --> 00:53:17.040
with it, ok. Now another possibility is
the arrival of humans. That is also

00:53:17.040 --> 00:53:23.640
possible. And one of the things we've
learned in studying mainland North

00:53:23.640 --> 00:53:28.440
America is that there are a number of
places where there are bona fide mammoth

00:53:28.440 --> 00:53:34.800
kill sites, ok. Now there are claims that
there are a lot more of them and some of

00:53:34.800 --> 00:53:37.609
them are equivocal, all the ones that you
see here in the little black and white

00:53:37.609 --> 00:53:46.730
dingy colors are kind of supposed
evidence of large mammal kill sites but

00:53:46.730 --> 00:53:51.499
these are all ones that have been
compiled by these two guys who are

00:53:51.499 --> 00:53:57.349
skeptics about the idea that humans were
responsible for the demise of large

00:53:57.349 --> 00:54:02.630
mammals at the end of the last ice age.
But even with their skepticism they

00:54:02.630 --> 00:54:06.920
agree that there are some genuine sites
where there's good archaeological and

00:54:06.920 --> 00:54:12.859
paleontological evidence that there were
kill sites specifically for mammals. So we

00:54:12.859 --> 00:54:16.549
know it's not a question then of saying
well gee humans couldn't have been

00:54:16.549 --> 00:54:19.940
responsible because we just can't
believe they would kill mammoths. That's not

00:54:19.940 --> 00:54:25.730
true; we know that they did, okay, the
evidence is there. But what we haven't found

00:54:25.730 --> 00:54:30.079
is a kill site on the Channel Islands, no one
has ever found it. There were claims to that

00:54:30.079 --> 00:54:35.089
effect back in the 60s and those have
all been debunked okay. Turns out a lot

00:54:35.089 --> 00:54:40.640
of those were reported to be hearts and
actually places where mammoths were

00:54:40.640 --> 00:54:45.440
barbecued by by humans living on the
islands at that time. It turns out they

00:54:45.440 --> 00:54:50.450
are burn sites but they are from naturally
occurring fires okay so we can't count

00:54:50.450 --> 00:54:56.869
those. So it's true we do not hit whoops...
we do not have any bona fide kill sites

00:54:56.869 --> 00:55:01.160
on the Channel Islands as of yet but we
do have them elsewhere so this remains a

00:55:01.160 --> 00:55:06.170
possible hypothesis as well. Here's I
think the one that I kind of favor and

00:55:06.170 --> 00:55:10.759
that is.. okay we're not going to go with
the impact idea, we're not going to go

00:55:10.759 --> 00:55:14.989
with climate change alone, we're not
going to go maybe with arrival of humans

00:55:14.989 --> 00:55:20.329
but keep open that possibility, but how
about climate change AND the arrival of

00:55:20.329 --> 00:55:24.980
humans. Now that's a double whammy. Okay
when you change climate, you diminish

00:55:24.980 --> 00:55:29.569
resources and then you have these
strange creatures arriving. All of a

00:55:29.569 --> 00:55:34.269
sudden you've got a totally different
mix of variables in an animal's survival,

00:55:34.269 --> 00:55:40.910
okay. The jury is still out on actually on
all four of these hypotheses. I don't

00:55:40.910 --> 00:55:44.630
have a strong feeling about any one of
them. If you backed me into a corner with

00:55:44.630 --> 00:55:50.029
a gun and said you must commit to one or
the other I'd say I can't okay it's not

00:55:50.029 --> 00:55:53.080
really
we're not at that state but I'd put my

00:55:53.080 --> 00:55:58.230
money on this at this point probably
this combination. Anyway, so summary.

00:55:58.230 --> 00:56:01.990
Mammoth remains are found on the Channel
Islands and most date to the last

00:56:01.990 --> 00:56:06.820
glacial period. They reach the islands by
swimming during a glacial period when

00:56:06.820 --> 00:56:10.600
sea level lowered and the mainland to island
distance was at a minimum whether in

00:56:10.600 --> 00:56:15.369
English or metric units. It has been
hypothesized that mammoths could have

00:56:15.369 --> 00:56:20.560
made the swim more than once prior to
the last glacial period and we recently

00:56:20.560 --> 00:56:25.359
found a mammoth tusk dating to 80,000
years. This older

00:56:25.359 --> 00:56:29.950
age requires a pre-last-glacial
period migration it was probably during

00:56:29.950 --> 00:56:34.869
an earlier glacial period, we don't know
which one. But even during glacial

00:56:34.869 --> 00:56:38.740
periods, uplift has to bring the islands
and mainland close enough for mammoth

00:56:38.740 --> 00:56:43.570
migration and we don't know when that occurred. Mammoths survived a warmer last

00:56:43.570 --> 00:56:47.770
interglacial period but climate change
and the arrival of humans at the time of

00:56:47.770 --> 00:56:51.160
climate change may have brought about
extinction of the mammals. We don't know,

00:56:51.160 --> 00:56:55.300
that's still a hypothesis that needs
more testing but we'll see what the

00:56:55.300 --> 00:57:00.150
mammoth world tells us in the future.
thank you very much. (clapping)

00:57:09.890 --> 00:57:20.730
Questions? (mumbling) Actually Bryson here is going
to give you a microphone so everyone can

00:57:20.730 --> 00:57:26.160
hear your question. You were saying
there's no geologic evidence for the

00:57:26.160 --> 00:57:30.690
land bridge and was that primarily because
of the depth of the water and with the

00:57:30.690 --> 00:57:36.030
changing sea level there's no way that that...
That's part of it and also, that's right,

00:57:36.030 --> 00:57:41.849
that's part of it and some of it is just
geologic evidence of you know matchup of

00:57:41.849 --> 00:57:46.319
rock types and things like that and 
geophysical evidence which I'm not an

00:57:46.319 --> 00:57:50.670
expert on so I can't evaluate but I took
it from people I trust that there's

00:57:50.670 --> 00:57:55.740
there's good evidence against that and
so on. So it turns out all the land bridge

00:57:55.740 --> 00:57:59.760
ideas were all constructed on the basis
that because there were pygmy mammoths

00:57:59.760 --> 00:58:06.140
out there they had to get out there by
traversing land and not by swimming so

00:58:06.140 --> 00:58:10.980
land bridge idea never had any geologic
evidence all it had was paleontological

00:58:10.980 --> 00:58:14.730
evidence, and it turns out we have another mechanism. And I've got one other quick

00:58:14.730 --> 00:58:20.369
question, so on the kill sites yes for the
mammoths where so it was established that

00:58:20.369 --> 00:58:25.140
these areas where you identified the
kill site truly showed that it was a

00:58:25.140 --> 00:58:30.569
human yes where you could show where there was cut
marks or whatever on the remains so

00:58:30.569 --> 00:58:35.790
definitely human? Yeah and these two guys
particularly Dave Meltzer who is a good

00:58:35.790 --> 00:58:40.470
friend of mine teaches at Southern
Methodist University he's a very very

00:58:40.470 --> 00:58:46.650
careful archaeologist and very cautious
and conservative in how he interprets

00:58:46.650 --> 00:58:52.819
things and his passion is the earliest
arrival of humans in North America and

00:58:52.819 --> 00:58:58.470
so he's aware that there have been
throughout, well past few decades but

00:58:58.470 --> 00:59:04.020
for a long time claims of early human
migrations to North America you know

00:59:04.020 --> 00:59:07.800
going back 100,000 years, 200,000 years just incredible

00:59:07.800 --> 00:59:12.119
claims and he's been very skeptical
about all is and he's done a lot of the

00:59:12.119 --> 00:59:17.500
debunking of what were in some cases
some pretty poor

00:59:17.500 --> 00:59:22.930
accumulations of evidence so when you look
at this and see those sites that he

00:59:22.930 --> 00:59:27.700
agrees are actually human, you're looking at one
of the most critical eyes. He's actually

00:59:27.700 --> 00:59:32.830
looking to eliminate sites and these are
ones that he agrees those are genuine

00:59:32.830 --> 00:59:38.070
kill sites, so there's about a dozen
of them, there might be more by now.

00:59:38.070 --> 00:59:45.100
Justin and Monica do you know? More mastodon
sites yeah. I didn't put the mastodon

00:59:45.100 --> 00:59:47.560
sites up there, at the time they wrote
this paper there were at least two

00:59:47.560 --> 00:59:54.490
mastodon sites, and I think, sounds like
there may be more than that now. Yes

00:59:54.490 --> 00:59:59.920
that's right but I wanted to keep it to the mammoths so that was the reason for

00:59:59.920 --> 01:00:14.530
that. Dr. Muse isn't there... is it on? yeah.
it was there not evidence that both

01:00:14.530 --> 01:00:20.050
Colombians then pygmies were coexisting
there for a later period? Yes I'm glad you

01:00:20.050 --> 01:00:22.830
asked that I was hoping someone would
ask that and I should have mentioned it.

01:00:22.830 --> 01:00:27.940
Yes based on the radiocarbon ages that
actually Larry Akenbroad had gotten

01:00:27.940 --> 01:00:32.890
for a number of the sites on Santa Rosa
Island there's good evidence that we had

01:00:32.890 --> 01:00:38.920
both Colombian and pygmy mammoths out
there at the same time at least roughly

01:00:38.920 --> 01:00:41.980
at the same time you know within a
couple thousand years or what our

01:00:41.980 --> 01:00:50.620
radiocarbon dating allows us to try to
delimit. Now the site that Justin and

01:00:50.620 --> 01:00:54.900
Monica have worked on here has some
interesting characteristics about it

01:00:54.900 --> 01:01:00.520
with regard to this issue. Now the idea
is of course that if you have the

01:01:00.520 --> 01:01:05.740
islands here the mainland here the
Colombians swim out and land on the

01:01:05.740 --> 01:01:11.470
islands, the big guys start dwarfing/
evolving down two little ones, we get a

01:01:11.470 --> 01:01:17.650
small population, okay, and if you have
further migrations before sea level

01:01:17.650 --> 01:01:23.650
rises then you could have Colombians and
mammoths coexisting, or if you had two

01:01:23.650 --> 01:01:28.000
migrations or more you could have
Colombians migrating out, they all dwarf

01:01:28.000 --> 01:01:32.020
down to pygmies, and then during the next
glacial period

01:01:32.020 --> 01:01:36.410
they migrate out again and you've got
pygmies and Colombians together. Now the

01:01:36.410 --> 01:01:40.750
fact that we see pygmies and Colombians
together during the last glacial period

01:01:40.750 --> 01:01:45.950
doesn't mean that that all the dwarfing
took place just during the last glacial

01:01:45.950 --> 01:01:50.510
period but doesn't exclude that
possibility. So it's possible that some

01:01:50.510 --> 01:01:54.650
of the pygmy remains we found out there
that are from the last glacial period

01:01:54.650 --> 01:02:00.890
are actually the ant the descendants of
earlier migrations and then the

01:02:00.890 --> 01:02:04.580
Colombians are the recent arrivals but
then some of them could have also dwarfed

01:02:04.580 --> 01:02:08.600
quickly. We don't know how quickly the
dwarfing process takes place. One of the

01:02:08.600 --> 01:02:14.360
things that Don Johnson hypothesized was
that if they did evolve from Colombians

01:02:14.360 --> 01:02:19.460
to pygmies over an extended period of
time or even rapidly there should be

01:02:19.460 --> 01:02:24.590
some geologic evidence of some
intermediate sized critters, right. That

01:02:24.590 --> 01:02:29.690
makes sense because it doesn't happen
instantly you know. So Justin do you want

01:02:29.690 --> 01:02:33.770
to make a comment about that or Monica
do you want to make a comment about that

01:02:33.770 --> 01:02:43.880
with your recent find? there you go! okay.
We don't know what that means yet and these

01:02:43.880 --> 01:02:47.270
guys are going to study it but what's
interesting is it, correct me if I'm

01:02:47.270 --> 01:02:51.440
wrong Justin, this is one of the first
bona fide finds where you could actually

01:02:51.440 --> 01:02:55.700
make you have enough evidence that you
could actually make some kind of a

01:02:55.700 --> 01:03:06.520
statement than it looks like it's kind
of intermediate as a possibility. right.

01:03:10.760 --> 01:03:20.270
right. so. yeah. So here's the thing to do.
These guys are going to be working on

01:03:20.270 --> 01:03:26.300
this skull that they found, this possibly
intermediate-sized thing, and at the

01:03:26.300 --> 01:03:30.680
Santa Barbara County Museum they'll be
coming to California periodically. Most

01:03:30.680 --> 01:03:34.450
people would prefer to stay in South
Dakota in the wintertime where they live

01:03:34.450 --> 01:03:40.310
but we've managed to entice them into
thinking of coming down here and so

01:03:40.310 --> 01:03:44.510
they'll be doing things and I as I
understand it there might be in the

01:03:44.510 --> 01:03:48.380
future some exhibits at the Santa
Barbara Museum where some of this work

01:03:48.380 --> 01:03:51.800
will be taking place and so watch for
notices from Santa Barbara Museum

01:03:51.800 --> 01:03:58.730
Natural History and Cherry Carlson who
has been following the mammoth research

01:03:58.730 --> 01:04:04.040
with the Ventura County Star might have
an article about this every now and then

01:04:04.040 --> 01:04:08.390
in the VC Star so keep your eyes open
for for that as well she's become a real

01:04:08.390 --> 01:04:13.100
mammoth aficionado so she's been
following all the work that everybody's

01:04:13.100 --> 01:04:17.360
been doing here very closely and done a
good job recording it so if news comes up

01:04:17.360 --> 01:04:21.590
on this she's going to tell you about it.
So anyways does that answer your question?

01:04:21.590 --> 01:04:28.460
Yeah, okay. We have time for one final
question here tonight. Okay. I think you're

01:04:28.460 --> 01:04:35.480
first and... I'm first I have
the mic. Ok. Whose first? I'm back

01:04:35.480 --> 01:04:38.850
here in the back and I've got the mic
okay

01:04:38.850 --> 01:04:44.490
I pretty much put you in the driver's
seat. yep you got it. yeah my question is,

01:04:44.490 --> 01:04:49.590
I've heard that the mammoths didn't do
well when islands were individual as

01:04:49.590 --> 01:04:53.790
opposed to when it was Santa Rosae and
there were more flat area that they that

01:04:53.790 --> 01:04:57.960
mammoths as a whole just don't you know
they don't do well in mountainous

01:04:57.960 --> 01:05:03.300
terrain where there's a lot of
topography. Oh well actually what happens

01:05:03.300 --> 01:05:07.320
is these islands get more topography as
time goes on so in the past they

01:05:07.320 --> 01:05:09.810
actually would have had less topography they would have been flatter

01:05:09.810 --> 01:05:14.310
because it wouldn't have been uplifted
as high and so I don't think that would

01:05:14.310 --> 01:05:18.990
have been a limiting factor quite honestly.
What would have been more of a limiting

01:05:18.990 --> 01:05:24.180
factor is the shrinkage of those islands
for sure, because you lose land you'll

01:05:24.180 --> 01:05:27.480
lose the foods resources that are on
that land. That would be way more

01:05:27.480 --> 01:05:37.200
important. That's true, you have rougher
terrain, yeah that's true enough. On the

01:05:37.200 --> 01:05:42.600
other hand because most of these islands
have been constructed by slow uplift of

01:05:42.600 --> 01:05:46.590
these marine terraces which are by their
nature flat features you still would

01:05:46.590 --> 01:05:50.490
have had a fair amount of fairly flat
terrain it just would have been reduced

01:05:50.490 --> 01:05:55.400
in size. So the amount of area I think
would probably even more of a factor.

01:05:55.400 --> 01:06:02.190
Yeah. There are some questions up front
here yeah would you like to answer I think this

01:06:02.190 --> 01:06:07.190
woman was first and then right over here
this gentleman. During the time that

01:06:07.190 --> 01:06:11.990
humans begin inhabiting the islands can
you talk to us about maybe the number of

01:06:11.990 --> 01:06:16.560
mammoths that would have been on the
islands at the time. Oh my. Do you know? What

01:06:16.560 --> 01:06:31.140
do you guys think, Don, Justin, Monica? This
is really hard to tell. yeah. yeah.

01:06:31.140 --> 01:06:40.380
I can give you a ballpark it less than
present-day Los Angeles, no doubt about

01:06:40.380 --> 01:06:47.640
that. I'll stake my reputation on that.
Over here, sir. I don't remember the exact

01:06:47.640 --> 01:06:52.590
date but I think it was like 120,000 years ago, the water

01:06:52.590 --> 01:06:57.000
level was much higher? yes that's right.
Got it. What was got cause for that rise?

01:06:57.000 --> 01:07:03.180
Ah this is near and dear to my heart. Surely it was before the Industrial Revolution right? Oh yeah.

01:07:03.180 --> 01:07:09.680
Few years before yes the we think
there's been a lot of debate about this.

01:07:09.680 --> 01:07:17.850
Six to eight meters higher you can do it
with one Greenland, one West

01:07:17.850 --> 01:07:24.000
Antarctic Ice Sheet plus part of
Greenland, or all of the West Antarctic

01:07:24.000 --> 01:07:29.130
Ice Sheet and a bigger part of
Greenland's. All the other little ice

01:07:29.130 --> 01:07:33.660
caps and things like that that we have
now would would not amount to much more

01:07:33.660 --> 01:07:39.990
than about a half a meter. The best
evidence we have so far is that about

01:07:39.990 --> 01:07:44.760
two-thirds of Greenland went away during
the last interglacial period so that

01:07:44.760 --> 01:07:51.420
gives you about let's say four to five
meters. To make up the rest you had to

01:07:51.420 --> 01:07:55.350
get rid of all of the West Antarctic Ice
Sheet. So the thinking is that it was

01:07:55.350 --> 01:08:00.180
probably most of Greenland and all of
the West Antarctic Ice Sheet at that

01:08:00.180 --> 01:08:11.460
time now to get to get six to eight
meters. yeah oh no no no no no no no no

01:08:11.460 --> 01:08:19.040
I'm sorry. I thought you're talking about
meters in terms of measurements no okay

01:08:19.040 --> 01:08:26.490
yeah yeah no no no no. This is that whole
cyclicity that you see there is due to

01:08:26.490 --> 01:08:32.760
changes in the Earth's geometric
relationship with the Sun and the amount

01:08:32.760 --> 01:08:37.790
of solar radiation that reaches the
northern hemisphere in summer okay.

01:08:37.790 --> 01:08:42.330
Because remember we said that the you
build up a glacier in that part of the

01:08:42.330 --> 01:08:48.030
world by having conditions cool enough
that the snow that falls in the

01:08:48.030 --> 01:08:51.810
wintertime stays over in the summer into
the following winter and when you keep

01:08:51.810 --> 01:08:55.350
repeating that again and again and again
and again you start to build up a

01:08:55.350 --> 01:09:00.540
glacier. One of the ways you can do that
is if you diminish the amount of solar

01:09:00.540 --> 01:09:06.319
radiation reaching that part of North
America and Eurasia in the summertime

01:09:06.319 --> 01:09:16.980
due to changes in three things. One is
the ellipse.... the whether the Earth's orbit

01:09:16.980 --> 01:09:23.160
around the Sun is more elliptical or
more circular, that has a 100,000

01:09:23.160 --> 01:09:29.609
year cycle. Whether you have a
precession of the equinoxes because they

01:09:29.609 --> 01:09:36.000
due precess the way a top does so that
at times we have, like right now, our

01:09:36.000 --> 01:09:43.109
northern hemisphere winters occur when
we are closest to the Sun but we're

01:09:43.109 --> 01:09:48.810
tilted away from it okay. There are times
when our northern hemisphere winters

01:09:48.810 --> 01:09:57.690
occur when we're farthest from the Sun
and we're tilted away from it so you

01:09:57.690 --> 01:10:03.750
have colder winters, warmer summers. And
then there are changes in the Earth's

01:10:03.750 --> 01:10:10.080
axial tilt okay we're presently twenty
thank you we're presently 23 and a half

01:10:10.080 --> 01:10:15.240
degrees away from vertical but it varies
from about 20 to about 24 okay. When all

01:10:15.240 --> 01:10:20.340
of these things combined in such a way
and those we have a 100,000

01:10:20.340 --> 01:10:23.940
year cycle, 40,000 year cycle, and a
20,000 year cycle. When all three of those

01:10:23.940 --> 01:10:28.680
things combined you have very little
solar radiation reaching northern

01:10:28.680 --> 01:10:34.470
latitudes in summer for extended
periods of time you get ice ages

01:10:34.470 --> 01:10:39.720
initiated okay. And then when the reverse
happens and you have a maximum amount of

01:10:39.720 --> 01:10:43.950
solar radiation in northern hemisphere
summers they all melt and we have

01:10:43.950 --> 01:10:50.220
interglacials okay. Now the way that
these all vary is due to the other

01:10:50.220 --> 01:10:55.200
planets and our relation to them, the
gravitational effects they have on them

01:10:55.200 --> 01:10:58.010
and this is all done by computation and
celestial

01:10:58.010 --> 01:11:03.110
mechanics. It's mathematics that I do not
even attempt to try to understand. But

01:11:03.110 --> 01:11:06.740
it was hypothesized long ago, it's
well-established now as one of the main

01:11:06.740 --> 01:11:13.250
drivers of the ice ages and
interglacials in between and that's

01:11:13.250 --> 01:11:17.080
probably a longer answer than you wanted
but that's the main driver behind it.

01:11:17.080 --> 01:11:27.220
Alright we have time for one final
question. okay. I'm wondering how did the

01:11:27.220 --> 01:11:30.980
paleontologist know where to look? For
example with the latest find how did

01:11:30.980 --> 01:11:35.420
they know where on the island to look
for this skull and my second question is

01:11:35.420 --> 01:11:41.750
do you know approximately how many years
humans and mammoths were coexisting on

01:11:41.750 --> 01:11:46.910
the islands? I'll answer the last one first
and then I'll defer that other one to

01:11:46.910 --> 01:11:53.450
the mammoth paleontologists. We we don't
know that they did coexist. All we know

01:11:53.450 --> 01:11:59.060
is that the radiocarbon ages of the
earliest humans and the latest mammoths

01:11:59.060 --> 01:12:04.550
are getting very close to one another
within our analytical uncertainties but

01:12:04.550 --> 01:12:10.460
they are uncertainties okay. So we do not
have bona fide evidence that they were right

01:12:10.460 --> 01:12:15.200
there at the same time. And what hope
everyone goes away with that

01:12:15.200 --> 01:12:21.290
understanding. We don't know for sure; all
we know is that it is possible, we don't

01:12:21.290 --> 01:12:29.980
know for sure. So that's Part B. Part A:
how do you find a mammoth skull?

01:12:39.580 --> 01:12:45.500
Everybody here now we we look at the
geology that Dan puts together and then

01:12:45.500 --> 01:12:50.740
we go out and we scour those places that
are likely to have dirt of the right age

01:12:50.740 --> 01:12:56.680
okay alright and then we look in that
dirt. Now for a Mammoth's skull we cheat. We

01:12:56.680 --> 01:13:02.389
have Park interns go out and then they
report what they see.

01:13:02.389 --> 01:13:08.059
But no oftentimes the paleontologist
isn't the person that finds the specimen.

01:13:08.059 --> 01:13:13.849
It is he or she is the one that goes out,
documents, excavates, and tells you what

01:13:13.849 --> 01:13:18.169
it's in, and what it means. A lot of it
is just keeping your eyes open when

01:13:18.169 --> 01:13:24.159
you're out doing other things and in
fact that this particular mammoth find

01:13:24.159 --> 01:13:29.419
was discovered by a guy named Peter Leraman who is an ornithologist and who

01:13:29.419 --> 01:13:35.780
was walking the canyon and saw this and
said mmm and it went from there. So a lot

01:13:35.780 --> 01:13:40.760
of these discoveries are made by
serendipity and a combination of

01:13:40.760 --> 01:13:44.809
serendipity and people who have their
eyes open and are thinking about what

01:13:44.809 --> 01:13:50.139
they're seeing so that's that's the
business model for mammoth hunting so

01:13:50.139 --> 01:13:54.070
okay alright think we're done. Thank you.

01:14:02.200 --> 01:14:04.260