Study finds hummingbirds have pared-down DNA
Flying with excess baggage is a drag, but hummingbirds have mastered efficient packing. The tiny hoverers have less DNA in their cells than any other previously studied birds, reptiles or mammals, researchers report online August 5 in Proceedings of the Royal Society B. Among hummingbird species, however, genome size doesn’t vary along with body size, suggesting that birds’ DNA was pared down before the diversification of today’s hummers.
Scientists have long noted the link between small genome size and high metabolic rates — a notion first put forth in 1970 by Polish scientist Henryk Szarski. Bats and birds have the smallest genomes of backboned cr