See Inside August 2010

Rainbow Cells

Biodiversity was the first step toward complex life

Witnesses were absent for the comings and goings of the first life some four billion years ago, but scientists are pretty sure the typical Earth creature in those days consisted of no more than a single cell. That doesn't mean the planet was a dull sea of sameness. Single-celled creatures may have acquired genetic diversity early on.

Here's why. When cells divide, mistakes have a way of creeping into genetic material. Variants that enhance a cell's ability to survive and reproduce become more common over successive generations. This basic fact of evolution applied to the early Earth. “Variation is necessary for there to be evolution by natural selection in the first place,” explains Andrew Hamilton, a philosopher of science at Arizona State University. “Biodiversity originated at the point that there was variation on which selection could operate.”

This is only a preview. Get the rest of this article now!

Select an option below:

Customer Sign In

*You must have purchased this issue or have a qualifying subscription to access this content

It has been identified that the institution you are trying to access this article from has institutional site license access to Scientific American on
Click here to access this article in its entirety through site license access.

Share this Article:


You must sign in or register as a member to submit a comment.
Scientific American Holiday Sale

Scientific American Mind Digital

Get 6 bi-monthly digital issues
+ 1yr of archive access for just $9.99

Hurry this offer ends soon! >


Email this Article


Next Article