You are currently viewing the summary.
View Full TextLog in to view the full text
AAAS login provides access to Science for AAAS members, and access to other journals in the Science family to users who have purchased individual subscriptions.
More options
Download and print this article for your personal scholarly, research, and educational use.
Buy a single issue of Science for just $15 USD.
Summary
It's a rare biologist who manages to catch a glimpse of evolution happening in the wild, but on (page 1934)page 1934 of this issue, researchers report just such a case in Trinidadian guppies. When moved to predator-free pools, the fish grew larger and reached sexual maturity later, all in the space of 4 to 7 years—showing that evolution can sometimes move at top speed.