I can't help but wonder if the popularity of thornless varieties of these trees is missing something important, and possibly contaminating the gene pools of these species.
Cal Edon wrote:Eleven thousand years is more than enough time for certain kinds of evolutionary change to take place. And again, the gene for thornlessness in Honey Locust is dominant - so even if having or losing thorns has no evolutionary benefit, we should expect thornlessness to be a common trait. But it isn't. Why not?
Perhaps it helps prevent deer from browsing them while young?
"Is this simple dominance, or complex? If there are a number of genes that regulate whether a Honey Locust has thorns, then it depends on the relationship of all of those genes. And do all the thornless Honey Locusts get eaten because they don't have thorns?"
Think about it like this: Say that in the next few years, this drought in the US continues to a point where there is very little for critters to eat in the wild. Those trees with the thorns will have a lower chance of being eaten while the thornless ones will be eaten out of existence (for the most part). After the drought is over and things go "back to normal" the thornless trees make a resurgence to some degree, until another forest food shortage. This would cause the population, over time, to favor the thorny trees even if the trait for thorns is recessive.
I yam what I yam and that's all that I yam - the great philosopher Popeye. Tiny ad:
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