[In Depth] Do genomic conflicts drive evolution?
Two billion years ago, an early cell swallowed an energy-producing microbe, giving birth to the mitochondria that are the hallmarks of all eukaryotes. Evolutionary biologists now think that was just the start of the influence that the cell's "powerhouses" have on the tree of life. Mitochondria, which can exist by the scores in a eukaryotic cell, have their own set of genes, which can replicate and mutate faster than the cell's better-known complement in the nucleus. Yet both genomes code for products that have to work together in the mitochondria. Researchers are now finding hints that cells' efforts to keep nuclear and mitochondrial genes in sync could play a major role in evolution. At a recent meeting, biologists suggested out-of-sync nuclear and mitochondrial genomes may explain many biological puzzles—from why some female birds prefer the reddest mates to the evolution of new species in both plants and animals. Author: Elizabeth Pennisi