AnEmpiricalAgnostic said:
Hey shinbits. Let me start off by complimenting you on your post. I respect participants that ask questions instead of simply using their post to evangelize. I see that Jet has already answered the questions very well but I thought Id add some more info in the hopes to make it clearer.
I have a favorite example of how a population might evolve today that I think will bring the answer to this question into focus.
There are people walking around right now (maybe even you) with a mutation called Delta-32. If a person gets a copy of this mutation from their father and a copy from their mother they are born with two copies of it or a
double Delta 32 mutation. The neat thing is that if you have two copies of this mutation it makes you immune to the black plague and AIDS. So there are some people walking around right now with total resistance to AIDS. Now image that the virus that causes AIDS was something that would be spread like wildfire through the air sweeping across the globe and infecting every single person. The only people left alive would be the ones carrying the double Delta 32 mutations. Now every single child born after that will possess the double delta 32 mutation and the entire population will be immune to AIDS. This is exactly how populations, not individuals evolve. It all starts with a beneficial mutation.
Okay. That was actually explained well. I'm with you so far.
Aside from something catastrophic like I mentioned above, mutations can get into the population and spread if they offer some kind of advantage.
okay. I'm still with you.
If an animal develops a mutation that allows him to attract more females (even if its aesthetic) he will have more offspring than the next guy. If a female has genes that give her a wide birth canal she may have more offspring and pass that on better than say a female born with a narrow birth canal that dies during her first labor. Its all about which genes give the higher reproductive success rate. This includes anything that makes you live longer for the same reproductive reasons. More success equals more copies of those genes in the population.
Gotcha. So far, you've been talking about survival of the fittest.
I think you have a little bit of a misunderstanding about how fast this happens. The mutations are usually very small.
No, that's not it. I'm full aware of how long evolution says it takes.
But you may not be fully getting my question.
See, mutations are random.
Correct?
And random mutation is passed on to the offspring. Correct?
Here's where it gets hazy. In theory, the next step, is that somewhere down the lineage, whether it's the very next generation or not, that another mutation will occur, and the prior mutation will be passed on in as well as the more recent one. Correct?
The question now, is on the last part mentioned---How can two or more different organisms, resulting from the same ancestry,
randomly mutate
the same mutations?
See, if the mutations aren't the same, then a population can't evolve simultaneously into the same new species---there'd be a bunch of different ones if the mutations aren't similar.
See, I'm NOT talking about mutations that cause simple variation, in keeping with the same species---I'm talking about mutations that start to cause an entire population to become a
different one. How do
those mutations happen uniformly if they're random? The individuals would have to randomly mutate similar genes, and that would take unheard of luck.
Do u understand me now?