For centuries, various cultures have fixated on the rare four-leaf clover, a tradition that "began when superstitions, myths and legends were strong," reported the New York Times in 1990. "According to English folklore, if someone dreams of clover, it means a happy marriage filled with wealth and prosperity." According to another way of thinking, "the clover has magical qualities, because it is in the form of a cross, which was supposed to guard the possessor from evil spirits." How did the four-leaf clover get associated with magic and luck? No doubt because of its rarity. After all, you can knock on wood any time, but finding a four-leaf clover takes considerable effort. White clover naturally grows three leaflets per leaf in about 9,999 out of every 10,000 plants.
Recently scientists have begun to explain why the four-leaf brand is so rare. The theory, as in so many other genetic cases, is that leaf count reflects a combination of factors. "The genetics have to be there," said Wayne Parrott, a plant geneticist at the University of Georgia. "Then if the genetics are there, the environment determines whether the four leaves show up or not." But Parrott said that even after his studies, he's still not sure what triggers the growth of that extra leaflet.
Part of what makes searching for the cause of the fourth leaf so complicated is that each clover plant has four copies of each chromosome, instead of the standard two in animals. Each pair comes from a different ancestor species, a sort of genetic swapping that is impossible in animals but happens without much fuss in plants, where species hybridize much more easily. Usually, hybrids are sterile, since chromosomes need to pair up perfectly for cells to replicate, and chromosomes from different species don't match up quite right. But plants can occasionally leapfrog this problem by duplicating their entire genome, ending up with four copies—two matched pairs—of each chromosome.
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(Score: 1) by oldmac31310 on Wednesday February 15 2017, @03:46PM
Nothing of any value here.
(Score: 1, Informative) by Anonymous Coward on Wednesday February 15 2017, @04:17PM
The comments aren't so great either.
(Score: 2) by bob_super on Wednesday February 15 2017, @05:50PM
But at least, so far, the fonts all match.
Some people do manage to make a lot of money despite having no content to back a clean look.
(Score: 3, Funny) by Anonymous Coward on Wednesday February 15 2017, @05:15PM
I used to find four-leaf clovers fairly often in the school yard as a kid, being too shy to play in the reindeer games. One day I even found a five-leaf clover. A class-mate held it up and loudly proclaimed, "5 leaves are bad luck!" and promptly tore off one leaf, handed it back to me, and said, "There, I fixed it for ya! Four!" I was dumbfounded. An early encounter with a Trumpling.