Journey of Life - Seas of Life 15
Steve travels back 3.8 billion years to when life began. Journeying round the oceans, he explores life's first laboratory and discovers how the incredible variety of sea creatures arose, from the first microbes to hagfish and dolphins.
Reptiles, amphibians, birds and mammals like us, all these land animals share a common ancestor-- a fish. But that's not the end of life's long journey through the seas. Ultimately some land mammals developed a taste for seafood and returned to the oceans to hunt.
Over time their legs gradually became flippers. And from an ancestor like this, they would become the most charismatic creatures in the seas.
Today the result of that evolutionary chain of events are the cetaceans, that's whales and dolphins. These are bottlenose dolphins, the most widespread dolphins in all of the seas. People just love them. I think we identify more with this animal than any other sea creature. Yes, we do, don't we? For their size, dolphins have the second biggest brain on the planet only a human's is bigger.
Sorry guys.I beat you. Yes.
And we are just starting to find out how clever they really are. Using sign language we are now able to communicate with trained dolphins like these. Some can understand more than two thousand different sentences.
I'm sure we identify and admire the dolphins because they are so intelligent. But perhaps we should identify more with the smaller cold sea creatures as it's directly because of them and the way they evolved that we are the creatures we are -- that we're multicellular , that we've got eyes, a backbone, an internal skeleton, two pairs of limbs, a jaw, a heart, a digestive system, a sense of smell, touch and taste, a head and a brain. It's all down to three and a half billion years of evolution in the spectacular seas of life.
Next week on the Journey of Life, I'm going to discover how life conquered the hostile land in a story which leads from the sea to the desert. |
