Green Evolution, Green Revolution

摘要

The trees and plants that color our continents are more closely related to aquatic microorganisms-unicellular algae, in particular-than they are to the animals and fungi with which they cohabit. The smallest of these algae, called picophyto-plankton, are individually miniscule (less than 2 μm in diameter) but collectively massive in ecological and evolutionary importance. On page 268 of this issue, Worden et al. (1) present the genome sequences of two such microbes, which belong to the green algal lineage Micromonas. Their analyses provide crucial insights into the plasticity of the eukaryotic genome over short evolution-ary time scales and also shed light on the genetic "toolkit" that may have been present in the ancestors of today's land plants and green algae.