The Dolphin Trail . . .the path of interdependence
By Ed Ellsworth
This is the beginning of an article on the physical anatomy, communication, creativity, and evolution of dolphins and other Cetaceans. The Dolphin Trail is the evolutionary path that the land-based ancestors of marine mammals took to evolve back into the ocean. Evolution in the waters of our planet have led to the successful survival of the dolphins. The dolphins and orca are the most evolved of the whale families, and their trail leads us to the rivers, to the lakes and to the oceans.
Most of us are familiar with evolution as described by Charles Darwin. Most people learned that life evolved from the ocean and moved on to the land. The trail led from fish to amphibians to reptiles, to more evolved animals like mammals. Over generations, evolving species DNA has been able to adapt to changing environments to keep surviving.
What many people don’t know, is that some life evolved back into rivers, lakes, and the ocean. Millions of years ago, many land-based animals entered the water, eventually to become dolphins and whales of the Cetacean Family. The dolphin family tree actually goes back over 20 million years, and whales over 40 million years!
Other marine mammals like manatees, seals, sea lions also came from land-based ancestors. Hippos, polar bears and other animals spend a great deal of their time in the water. One advantage of water life for them is that there is more food there. Another is that they would be safe from land predators. This may have required sudden adaptation to flooding due to a previous global warming.