Light on the DNA means heavy on the metabolism

Posted August 14th, 2009 by kcorliss. Comment (0).

Not only are hummingbirds–as a group–the world’s smallest birds, but they also carry a lighter DNA load than virtually any other animal.

A recent science article in US News and World Report says just that here.

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.

It goes on…

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 creatures, and flightless birds tend to have bigger genomes than fliers.

I’ll leave it to science to determine just what ramifications this finding may present. It looks to be just a curious factoid (other than backing up Szarski’s ideas) to my limited brain.

But once again it seems the press may have overextended its hyperbole if indeed one commenter (Dick Leavitt, if he uses his real name) to this article is accurate:

Contrary to the article’s statement that bats and birds have "the smallest genomes of backboned species," that attribute belongs to certain pufferfishes…

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