Darwin’s Abominable Mystery
Where did flowers come from?
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Why flowers, anyhow? Plants began to conquer the land more than 400 million years ago and ruled over it for more than 250 million years without producing a single blossom. Why should they have? Flowers are expensive. Sepals, petals, pigments for color, organic compounds for scent: Creating those fancy clothes and complex perfumes takes a lot of stored energy. Instead of manufacturing flowers, a plant could have used those carbohydrates to make more seeds or grow taller, both proven strategies in the competition for survival. Besides, there seems to be nothing in gymnosperms (nonflowering plants) that corresponds to flowers. Angiosperms (flowering plants) seem to have arisen out of nothing, sui generis. Nonetheless, blossoms—from the oak’s minuscule brown nubs to the green spikelets of rice to the multipetaled splendor of the rose—appear on at least 75 percent of all the world’s plant species. The why and how of angiosperms, Darwin wrote in 1879, are “an abominable mystery.” The mystery still has not been fully solved. Part of the difficulty is that flowers have always been fragile and when they die, they fall apart into easily scattered and perishable pieces. The fossil record of early flowers is therefore exceedingly scant. In recent years, however, evolutionary botanists have come to think the living Amborella trichopoda will help solve the puzzle. (via Why flowers exist: The unlikely genetic mutation of the amborella flower.)
via Tumblr http://ift.tt/UsLhiB June 21, 2014 at 11:16PM
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