Evolution and the Ocean
Where can you see results from the world’s oldest and biggest migration? Just hike two miles down Damnation Trail south of Crescent City. You will see sea stars purple, orange and red, all in the same individual. Sea anemones sport aquamarine and purple. They look more like flowers than animals, hence the name. And, yes, sea cucumbers resemble orange and yellow vegetables.
These animals seem so unusual that we name them after more familiar animals. They look weird because they got left behind. Maybe these circular sea animals didn’t know which way to turn to get to land, unlike animals we are familiar with left and right sides, like ourselves. Isopod crustaceans made it to land as pill bugs. The very similar amphipods, though, only made it from ocean to groundwater. They never became terrestrial like pill bugs, probably because their more vertical body shape would have made them top-heavy on land.
Half a billion years of migrating to once lifeless land has largely ended. Land insects and flowers and marine crustaceans and seaweed became so dominant that boundary markers say “No newcomers allowed.” These major groups can’t be out-competed on their home turf. It’s why seafood is crustaceans and mollusks, not tasty insects. It’s why we eat vegetables, not seaweed.
