Next time I go to the doctor, I think I’ll get him to give me a test for Toxoplasma. Fifty million Americans have the parasite, so I wouldn’t be the first. And if I was carrying it around in my head, that might explain why it’s so fascinating to me.

I first encountered the strange ways of this single-celled creature while working on my book Parasite Rex, and since then I’ve tried to keep up with new research on what makes it so successful. In January I wrote on the Loom about a potential link between Toxoplasma and schizophrenia.

Continue reading “Toxoplasma on the Brain” →

Two hundred thousand years ago or thereabouts, an African lion killed someone. Along with a meal, the big cat got a wicked stomachache. Today a record of that unfortunate death still survives, in the bacteria that make big cats sick.

The trail of this strange story starts in the 1980s, when scientists discovered that ulcers are caused by bacteria known as known as Helicobacter pylori. H. pylori is found in people around the world, and scientists learned how to recognize the different strains they carried.

Continue reading “Humans As Cat Chow” →

A bunch of good reviews on natural selection in humans are coming out, reflecting the explosion of research on how evolution has shaped our genome. See here and here. Today in Science another good one is out. What sets this one apart from the others is that it comes with a slide show with audio from the authors. As far as I can tell, the show is free. And it’s a pretty clear summary. Check it out. 

Originally published June 15, 2006. Copyright 2006 Carl Zimmer.

The other day I was interviewed on KUCI-FM in Irvine, California, about the evolution of bacteria in yogurt. You can listen to the podcast here. 

Originally published June 14, 2006. Copyright 2006 Carl Zimmer.

Scientists have figured out many ways to study the origin of species. They can build evolutionary trees, to see how species descend from a common ancestor. They can survey islands or mountains or lakes to see how ecological conditions foster the rise of new species. They can look for fossils that offer clues to how long ago species branched off from one another, and how their ranges spread or shrank. Now comes a new trick in tomorrow’s issue of the journal Nature: to test their ideas about how a new species of butterfly came to be, they essentially recreated it in their lab.

Continue reading “Darwin, Meet Frankenstein” →