Dolphins have Genes for Smelling

Another curious tale of dead genes involves our sense of smell, or rather our poor sense of smell, for humans are truly bad sniffers among land mammals. Nevertheless, we can still recognize over 10,000 different odors. How can we accomplish such a feat? Until recently, this was a completely mystery. The answer lies in our DNA—in our many olfactory receptor (OR) genes. [...] Our own sense of smell comes nowhere close to that of mice. One reason is that we express fewer OR genes—only about 40...

 Evolution of the Whale

Indohyus was not the ancestor of whales, but was almost certainly its cousin. But if we go back four million more years, to fifty-two million years ago, we see what might well be that ancestor. It is a fossil skull from a wolf-sized creature called Pakicetus, which is a bit more whale-like than Indohyus, having simpler teeth and more whale-like ears. Pakicetus still looked nothing like a modern whale, so if you had been around to see it, you wouldn’t have guessed that it or its close relative...