The mechanism of microevolution itself. It's a process of subgroup isolation, which is a process of decreasing genetic variability.Admit what? What are you saying? That a population of organisms can diverge from its ancestors so far that they can no longer interbreed? Yes. That the descendants of that population might diverge even further? Yes.
In fact given enough time you might find as many different species as we see on this planet all descended from a common ancestor.
What mechanism exists to stop such diversification?
The mechanism of microevolution itself. It's a process of subgroup isolation, which is a process of decreasing genetic variability.
SPRING BREAK!!!!! WOOOOOOOOOOOOOO!!!!!!!
Sorry, I'm British. Did I do that correctly?
The mechanism of microevolution itself. It's a process of subgroup isolation, which is a process of decreasing genetic variability.
Were you holding a beer and waving it over your head as you did it? In a bottle, mind you...pint glasses aren't suitable!
If so, then yes. Yes you did!
No, but I was on a quest to see as many boobs in as short a space of time as humanly possible, if that counts.
I'd say that isolation increases the rate of evolution, due to small effective population size. Even in very large populations (say, humans) new traits can arise and spread quickly if they offer sufficient advantages (nothing is ever at HWE). It's just easier to go from 1% to 99% in a population of 100 than in a population of 6,500,000,000.Simon39759 said:a) In general, evolution is a consequence of isolation rather than a cause of it. Isolation -> Genetic drift -> The two populations are too different too co-reproduce. If the populations are free to intermingle, there is no reason for such a genetic drift and it makes specification unlikely.
Only for you people obsessed with squishy things!b) Microevolution does not cause reproductive isolation, by definition, because such isolation is a criterion for speciation and speciation defines macroevolution.
I'd say that isolation increases the rate of evolution, due to small effective population size. Even in very large populations (say, humans) new traits can arise and spread quickly if they offer sufficient advantages (nothing is ever at HWE). It's just easier to go from 1% to 99% in a population of 100 than in a population of 6,500,000,000.
Only for you people obsessed with squishy things!On a serious note, this is why I dislike these terms: even within science they have multiple definitions. For example, what you're describing as macroevolution is termed "microevolution" in paleontology. It gets confusing.
Please note that I mean this as a friendly conversational gambit, not as criticism. I'm bored, Fable 2 is annoying me, and this conversation is interesting (well, the parts between people who actually know a thing or two about evolution, anyway).
ETA: My spring breaks were spent looking at geology in various states in the Eastern United States. Of course, the one time we DID end up on a beach in Pensicola Florida....About a week too early, sadly. Never camp in Ohio in March, that's all I'm sayin'.
No, reducing populations DOES decrease genetic variability and his comment on increasing "evolution" is a red herring. Yea, we can increase evolution, for example, by inbreeding dogs to create new forms.Yep.
That was the idea behind my point c.
Randman says that microevolution and isolation decrease genetic variability while, in general, it is the opposite that is true...
My main focus is molecular biology, so super-squishy indeed.
I need to get back to amateur paleontology, especially now that I both have a car and live in a fossiliferous region... I already spotted a local club, but it was close when I checked it out... Next month, hopefully...
My main focus is molecular biology,
Got a chuckle out of the every species is by definition an intermediate stage. See what I mean when you guys focus so much on the theory and verbal proofs of it, that it clouds your ability to look at processes and data by themselves and get a handle on things?
On the other bolded parts, no, there is no evidence it was purely random, and no it does not conflict with front loading. Front loading does not predict all of one species would mutate the same way, etc,.....You really need to take the time to actually understand what men like Pierre Grasse and later, various front loaders, are saying before you assume something disagrees with them.
Why not just take the time to get a handle on what they are saying?
So Simon, how do you explain the cheetah's relative low genetic variability? Shouldn't the cheetah be thriving now as populations are smaller? After all, you claimed smaller populations increase genetic variability.
Some of your comments:It's not:
a) In general, evolution is a consequence of isolation rather than a cause of it. Isolation -> Genetic drift -> The two populations are too different too co-reproduce. If the populations are free to intermingle, there is no reason for such a genetic drift and it makes specification unlikely.
b) Microevolution does not cause reproductive isolation, by definition, because such isolation is a criterion for speciation and speciation defines macroevolution.
c) This isolation actually protect less prevalent alleles and variant that might be otherwise drowned in the more prevalent ones. As such, this evolution is actually increasing genetic diversity.
Or are you confusing microevolution and natural selection again?
In general, evolution is a consequence of isolation rather than a cause of it.
If the populations are free to intermingle, there is no reason for such a genetic drift and it makes specification unlikely.
Microevolution does not cause reproductive isolation, by definition,
This isolation actually protect less prevalent alleles and variant that might be otherwise drowned in the more prevalent ones. As such, this evolution is actually increasing genetic diversity.
Maybe because asking you guys to deal in specifics and not vague assertions is something you yourselves should be doing in the first place.Why does every Id'er seem to be asking simultaneously, for a pokemon like evolution system ( in which each stage is clearly defined, and exact. ) so they can " see " the changes, but also for a endlessly detailed almost, animation kind of evolution, in which we can see every possible step.
Fail to meet these conflicting criteria and automatically creationism wins out.
Why does every Id'er seem to be asking simultaneously, for a pokemon like evolution system ( in which each stage is clearly defined, and exact. ) so they can " see " the changes, but also for a endlessly detailed almost, animation kind of evolution, in which we can see every possible step.
Fail to meet these conflicting criteria and automatically creationism wins out.
Maybe because asking you guys to deal in specifics and not vague assertions is something you yourselves should be doing in the first place.
And sequential speciation as the process originating higher taxa is not really that vague. yea, you can look at species differently, but no matter how you define species, the envisioned process is the same.
As opposed to YOUR view, which is based on a refusal to read widely accepted scientific sources and insists that anyone who hasn't heard of your pet lunatic is an undereducated moron? Including those who actually STUDY the subject?randman said:Got a chuckle out of the every species is by definition an intermediate stage. See what I mean when you guys focus so much on the theory and verbal proofs of it, that it clouds your ability to look at processes and data by themselves and get a handle on things?
When you bother to read what legitimate scientists say, and actually UNDERSTAND what they say (something you demonstrably have been unable to do thus far in all three threads) I'll look into your pet lunatic. Until then, I'll pass.You really need to take the time to actually understand what men like Pierre Grasse and later, various front loaders, are saying before you assume something disagrees with them.
Why not just take the time to get a handle on what they are saying?
HOW WOULD YOU KNOW? You refuse to read posts after any disagreement with you. ANTpogo spent an absurd amount of time gather data to demonstrate that you're wrong and you refused to even acknowledge it. You don't get to demand evidence and then ignore it.Maybe because asking you guys to deal in specifics and not vague assertions is something you yourselves should be doing in the first place.
This is merely them attempting to dictate the terms of the conversation. They want to define the terms (randman has redefined pretty much every piece of jargon he's used), dictate what constitutes evidence (clear transition fossils aren't enough, clear molecular evidence isn't enough, etc), and dictate who is and isn't an expert (anyone who agrees is an expert, anyone who doesn't isn't, no matter what they happen to say).sadhatter said:Why does every Id'er seem to be asking simultaneously, for a pokemon like evolution system ( in which each stage is clearly defined, and exact. ) so they can " see " the changes, but also for a endlessly detailed almost, animation kind of evolution, in which we can see every possible step.
Fail to meet these conflicting criteria and automatically creationism wins out.
They also want dogs to give birth to cats.