Carl Zimmer is a columnist for the New York Times. He began his career at Discover, where he served as a senior editor from 1994 to 1998. Since then he has published a dozen books, including Parasite Rex and Evolution: Making Sense of Life, and he has written hundreds of articles for The New York Times and magazines including National Geographic, The Atlantic, and Scientific American. In 2003, he started a blog called The Loom, which is now hosted by National Geographic. He is, to his knowledge, the only writer after whom a species of tapeworm has been named.
What is your feature about?
It’s about blood types, and why we have them.
What did you learn that you didn't expect?
I got interested in writing this feature simply to find out why we have blood types. Since scientists have known of their existence for over a century, I was sure that by now their purpose had been discovered. After all, blood types matter a lot to our health – insofar as a mismatched blood type can make a transfusion fatal. I was surprised to learn that, while there are some intriguing clues, no one can say for sure why we have blood types.
Read Carl's feature on Mosaic from 15 July 2014.