Jonah
Jonah asked Carl Zimmer:

I just read Microcosm and I particularly wondered, when you said salmonella is really e. coli, and that different e. coli strains have very different genomes- what defines e. coli as e. coli?

Carl Zimmer That's a great question. Microbiologists first defined species like E. coli long before they could look at the DNA of bacteria. So they just observed traits in bacteria, in the same way ornithologists would look at the color of bird feathers. Now scientists are realizing that strains that "look" like E. coli can be extremely different, genetically speaking. They descend from a common ancestor, but they've picked up lots of genes since then.

About Goodreads Q&A

Ask and answer questions about books!

You can pose questions to the Goodreads community with Reader Q&A, or ask your favorite author a question with Ask the Author.

See Featured Authors Answering Questions

Learn more