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” →

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” →

Last October, word leaked out that something might be seriously amiss with the embryonic stem cell lines approved by President Bush for federally funded research. Today, the full details were published on line in Nature Medicine. It’s an important paper, and not only because it points out a grave problem with the current state of stem cell research. It also shows how scientists who do cutting-edge medical research are looking back at two million years of human evolution to make sense of their work. At a time when antievolutionists are trying hard to wedge creationist nonsense into science classrooms, this is something worth bearing in mind.

Continue reading “Of Stem Cells and Neanderthals” →