Growing up as I did in the northeast, I always assumed that the really weird life forms lived somewhere else–the Amazonian rain forest, maybe, or the deep sea. But we’ve got at least one truly bizarre creature we can boast about: the star-nosed mole. Its star is actually 22 fleshy tendrils that extend from its snout. For a long time, it wasn’t entirely clear what the moles used the star for. The moles were so quick at finding food–larvae, worms, and other creatures that turn up in their tunnels–that some scientists suggested that the star could detect the electric fields of animals.

Continue reading “Gulp” →

Ernst Mayr has died.

Continue reading “Farewell, Ernst” →

Thanks to the many people who left comments on my recent post about some recent work on the intersection of stem cells and human evolution. I noticed that several people expressed variations on the same theme, one which deserves a response. To recap briefly: a great deal of research indicates that a couple million years ago, our hominid ancestors lost the ability to make one of the main sugars that coat mammal cells, called Neu5Gc. This ancient chapter in our history turns out to have a big effect on current research on embryonic stem cells. When human stem cells are raised on a substrate made of mouse cells or calf serum, they absorb the nonhuman Neu5Gc sugars, which ends up on their surface. Humans carry antibodies to Neu5Gc, and these antibodies attack stem cells raised on animal substrates. As a result, existing cell lines fed on this stuff would likely be destroyed if they were implanted in a person.

Continue reading “Mutants Today and In Days Gone By” →

Recently I assisted the folks at Soundprint with an hour-long radio documentary about how humans are driving evolution in new directions. Here’s the show, available on Real Player.

Continue reading “The Incredible Shrinking Fish and Other Wonders of the Modern World” →