Show where mutations add genes and whole new traits as evolution requires.
And this is where Randman's strawman version of evolution bites him on the tail end.
You see, mutations work by slow accumulation.
Take the heart, for instance.
It started out as just another place in a circulatory system. One that worked without a heart. Simple convection, no big deal. Simple organism, didn't have the sort of metabolic demands veterbrates put on theirs.
But no heart existed. Under Randman's strawman, a mutation must happen to create a heart.
But that's not how it happened, and not what evolution claimed. Indeed, the appearance of a heart would be a
falsification of evolution, not evidence of it. A heart evolved piecemeal. Starting with the simple muscles already there. One, through mutation, was misplaced. But in such a way that flexing increased circulation somewhat. Even a little bit would give the creature more energy.
And that's where the heart started. A simple muscle. A thickening around a main blood vessel that, when squeezed, forced blood to move. Not very complex, is it? It's still just a muscle, after all. But useful enough to spread through the gene pool. And later get added on. Mutations that increased it's thickness. Made it's movements more autonomic (sort of like spastic twitches)....and so forth.
Randman is asking for the
end product of evolution as the result of one mutation. That's not evolution, randman. I'm not sure what it is. "Cartoon theory" or something.
Lankila:
Actually you are making some statements here that are not proven, and are only assumtions. So I think you may need to study genetics a little more.
Then you should have no problems pointing out
which statements are incorrect, and pointing me to peer-reviewed or even mainstream sources so I can correct my ignorance.
I await your response, as I am eager to fill the gaps in my knowledge.
Not in the slightest. Not at all. Not even close. Thinking PE creates novel structures instantly is horribly, awfully, completely wrong. I don't say this to denigrate you, but to make you understand the depths of your misconception. Everything you think you know about it should be considered suspect.
PE is the application of well-known evolutionary concepts to the fossil record. PE is evolution with a component of isolation. If you isolate a section of a population for (minimum) tens of thousands of years, you create a place where new alleles can spread rapidly that is
also subject to different selective pressures.
Speciation happens far more quickly, because the gene pool is small. Plus it's far more obvious when you compare the now (daughter) species with it's parent. If you didn't have reproductive isolation, the new alleles would spread among the species far more slowly, and the entire population would gradually drift.
The only difference between gradualism and PE is that mutations spread far more quickly through a smaller population. This increases the "speed" of evolution, without any changes to the frequency or ratios of mutations. New traits spread rapidly.
Take a species of Bird. Bird X. That population consists of 2.5 million members. Now, because of a geologic event (or any other isolating mechanism,
including things like shift in mating times because of diet or whatnot of a small set), four thousand birds (Bird X1) can no longer interbreed with the Bird X group.
Now, say a single beneficial mutation appears in the Bird X group. It would take
many generations for that mutation to become solidly established, would it not? Not say it occurs in the Bird X1 group. It would take
much less time to spread through the smaller, isolated group, would it not?
Speciation occurs most often in one of two ways: Either some of the species gets isolated, so that gradual change (and addition) of alleles on both sides cannot be shared, and thus they go their seperate ways.
Or through drift, as new alleles slowly propogate through the population.
In the first case, you have two species you can compare the "end products" (if one doesn't die out). In the second, you don't. The only way to notice speciation is to work out what the species was like
before and compare it to
now. It's also, unsurprisingly, much slower.
Change
accumulates in evolution. Not happens all at once. No "hopeful monsters" are born. No "apes giving birth to a human".
We share a common ancestors with other primates. One step below, in whatever speciation event seperated our anscestors from the others, the two species were similiar enough that it would be difficult to tell them apart. The difference would have been something tiny between the two populations. After that, we divurged, as different changes accumulated.
