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A question on evolution

boss1592
Posts: 80
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4/22/2013 4:16:03 AM
Posted: 3 years ago
Wait! Before anything more is said let me quickly clear one thing up, I am not a creationist trying to pick a hole in evolution, I don't doubt the fact of evolution at all. That being said, I've never studied biology at any kind of advanced level, and there are holes in my understanding, and I hope that perhaps a few of the more learned people on here would be willing to take a moment to clear up my ignorance, I would be most grateful. I have one question in particular that has been bugging me for a while.

My question is, I think I have a decent idea of how evolution works on a genetic level, in terms of mutations taking place and those mutations that are beneficial to survival being passed on, but I'm still a little unclear about the issue of adaptability. I've seen examples given, the most well known probably being Darwin's famous finches, where competition over food leads to the development of different shapes of beak to eat different types of food. I understand why that happens, but I'm somewhat unclear as to how it happens, the actual mechanics, if you will, of how the beak changes shape, and how those changes are passed on to future generations.
APB
Posts: 267
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4/22/2013 4:41:05 AM
Posted: 3 years ago
At 4/22/2013 4:16:03 AM, boss1592 wrote:
Wait! Before anything more is said let me quickly clear one thing up, I am not a creationist trying to pick a hole in evolution, I don't doubt the fact of evolution at all. That being said, I've never studied biology at any kind of advanced level, and there are holes in my understanding, and I hope that perhaps a few of the more learned people on here would be willing to take a moment to clear up my ignorance, I would be most grateful. I have one question in particular that has been bugging me for a while.


My question is, I think I have a decent idea of how evolution works on a genetic level, in terms of mutations taking place and those mutations that are beneficial to survival being passed on, but I'm still a little unclear about the issue of adaptability. I've seen examples given, the most well known probably being Darwin's famous finches, where competition over food leads to the development of different shapes of beak to eat different types of food. I understand why that happens, but I'm somewhat unclear as to how it happens, the actual mechanics, if you will, of how the beak changes shape, and how those changes are passed on to future generations.

Well, in a given population of finches, there will be variation in individual beak size. Imagine a Bell Curve, with some birds at either end and most in the middle. If the birds at, say, the large-beak end can access a better source of food, they'll outcompete the guys in the middle and become the majority after a few generations. Then apply the rule again: there will be variation around the NEW average beak size, and if even larger beaks are better then the distribution shifts again. If you've got the same thing happening at the other end of the distribution, you've got 2 lots of finches with differently-sized beaks.

Does that answer your question? If you want to know how it works on a cellular/biochemical level, I will have to dig through my study notes.
boss1592
Posts: 80
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4/22/2013 4:48:38 AM
Posted: 3 years ago
At 4/22/2013 4:41:05 AM, APB wrote:
At 4/22/2013 4:16:03 AM, boss1592 wrote:
Wait! Before anything more is said let me quickly clear one thing up, I am not a creationist trying to pick a hole in evolution, I don't doubt the fact of evolution at all. That being said, I've never studied biology at any kind of advanced level, and there are holes in my understanding, and I hope that perhaps a few of the more learned people on here would be willing to take a moment to clear up my ignorance, I would be most grateful. I have one question in particular that has been bugging me for a while.


My question is, I think I have a decent idea of how evolution works on a genetic level, in terms of mutations taking place and those mutations that are beneficial to survival being passed on, but I'm still a little unclear about the issue of adaptability. I've seen examples given, the most well known probably being Darwin's famous finches, where competition over food leads to the development of different shapes of beak to eat different types of food. I understand why that happens, but I'm somewhat unclear as to how it happens, the actual mechanics, if you will, of how the beak changes shape, and how those changes are passed on to future generations.

Well, in a given population of finches, there will be variation in individual beak size. Imagine a Bell Curve, with some birds at either end and most in the middle. If the birds at, say, the large-beak end can access a better source of food, they'll outcompete the guys in the middle and become the majority after a few generations. Then apply the rule again: there will be variation around the NEW average beak size, and if even larger beaks are better then the distribution shifts again. If you've got the same thing happening at the other end of the distribution, you've got 2 lots of finches with differently-sized beaks.

Does that answer your question? If you want to know how it works on a cellular/biochemical level, I will have to dig through my study notes.

That makes perfect sense, thanks. You don't need to go digging lol, I think that clarifies it enough, although if you wish to then by all means do so, I'd certainly never turn down a chance to learn something