I'm not convinced he's even reached an evolutionary stage equivalent to the Permian just yet. OIM go read this, it's basic enough that you perhaps might grasp something. http://en.wikipedia.org/wiki/Evolution_of_mammals
Since I have to answer my own questions around here, I found 1 synapsid that survived the Permian Extinction, namely Lystrosaurus, and one in the Triassic, namely Cynognathus, however there is no evidence they descended from Dimetrodon.
Crature A evolves into creature B There are some of creature A that did not evolve Creature A dies out What is left?
This is not responsive to what I wrote, to wit: "all mammals are descended from the same basic branch of the tree that spawned dimetrodon" Even if the dimetrodon had no descendants, what I wrote is that we arose from the same branch, namely the proto-mammals. I mean, first, even if Dimetrodon went extinct, that does not mean it had no descendants, just that its descendants were not dimetrodons. More to the point, my recollection is that we are descended not form dimetrodon directly, but from some other member of the same clade under the pelycosaurs (and that both theraspids—which would later evolve into mammals—and dimetrodon were in that same clade). If you look HERE for the "Sphenacodontoidea", it split into two groups, the "Sphenacodontidae" and the "Theraspids". The various kinds of Dimetrodons were Sphenacodontidae, and all mammals are descended from the Theraspids. That said, our common ancestor was very dimetrodon like, minus the sail, like this: Please Register or Log in to view the hidden image!
OIM: The evidence is there. If you're unaware of it, that's your problem, not mine. You don't appear to be actually wanting to learn here. You appear to be posting in bad faith. How disappointing. I said, for example, that alligators have not changed much in millions of years, because their environments have not changed much. Somebody else pointed out that there has been natural selection pressure on them to remain the same. If you want to call this "not evolving", I don't have a huge problem with that. But don't mistake it as any kind of statement saying that it is impossible for alligators to evolve into a different species, given the right conditions and enough time. Given the low chance of fossilisation etc., we'll probably never have direct evidence of this animal. However, I am not a biologist, so you might wish to check all the paleontological literature to determine whether I am right in this assumption or not. Good luck.
So the environment of sharks and alligators hasn't changed at all but the environment of man magically has? And I thought you said environment can't effect alleles because that would be Lamarckian? So natural selection prevents evolution? Cheers. I would like to see that. That would be awesome. However I'm skeptical. Thx...Please Register or Log in to view the hidden image!
I am not a marine biologist, so I can't really comment on how the environment of sharks has changed over millions of years. Also, I am not sure how long the various different species of sharks have existed. You might want to check the biological peer-reviewed literature if you need to know that. Certainly, the environment that produced human beings has changed significantly over millions of years. It is most likely that a hotter period in the Earth's history led to a diminishing of rainforest and an increase in savannah. Proto-humans evolved to adapt to the changed climatic conditions. Correct. The environment provides selective pressure. It does not affect gene frequencies directly. Look up "natural selection" on the internet and you will learn much about this.
OK so crocodiles then. Humans and crocodiles both live on the Earth (same environment) yet humans evolved and crocodiles didn't? And you've already admitted environment doesn't change DNA (Lamarckian evolution). However you've already admitted environment doesn't change DNA (Lamarckian evolution). Please Register or Log in to view the hidden image! Please Register or Log in to view the hidden image! Natural selection will never allow chimpanzees to evolve from extinct Dimetrodons. When pigs fly.
It is not true whatsoever that crocodiles did not evolve, but their outer appearance is still recognizable as similar to ancient ones.
Do you deny that systematic selection over which animals can breed and which cannot can affect DNA? Obviously what he means is that environment does not cause direct changes to the DNA in the typical case *and* that acquired traits are never reflected in DNA. If I shoot a man before he has conceived any children, I do not change the DNA of the human race, in the way of speaking. Ona broader scale, however, I have ended that man's chance to make future contribution to the gene pool and so I have indirectly affected human DNA on a minor scale. Natural selection makes it more likely that certain animals will contribute to the gene pool than others, based on the characteristics of those animals. When those chanaracteristics are genetically determined, those genetic sequences are disproportionately favored in subsequent generations because, subject to some change in the state of the environment, those traits will continue to be selected in subsequent generations and show up with an increasing frequency within the population. Systematic propagation of animals with particular genetic traits can affect the DNA of the species, whether the selection mechanism is "the environment" or any other factor (sexual selection, for example). Some day, they just may. You never know. Please Register or Log in to view the hidden image! Natural selection causes certain traits to become more common within an isolated population. If enough such traits arise in that population, it becaomes a subspecies of the original population. If still more changes occur that render the subspecies unable (genetically, behaviorally or otherwise) to breed fertile offspring with members of the original population, the new population becomes a new "species." As species after species diverges obver hundreds of millions of years, it seems like we could go from a torso and abdomen-having, four-limbed, two-eyed, one nosed, one brained, one-mouthed, warm-blooded lizard like creature to a torso and abdomen-having, four-limbed, two-eyed, one nose, one brained, one-mouthed, warm-blooded hominid. Imagine a game of telephone tag, with each caller relayed the same anecdote to the other over and over, with occasional errors in the facts of the story. Imagine the game lasted 300 million years. How similar do you think the anecdote at the end of the game would be to the one at the start? We all know that the characteristics of a population can change over time. Mutations are real. By what religious mechanism to you propose that DNA be rendered incapable of resulting in speciation?
Not sure I understand your question. If your question is do I deny natural selection, the answer is no. I think that everytime I post it but I still say it anyway haha. That's what I'm not really sure about. A little phenotype variation doesn't mean a new species. I don't say DNA prevents diversity I say it prevents transpeciation.
OIM: I notice that you're arguing in bad faith again, attempting to recast my statements into straw men that you can knock down. In so doing, you are distorting what I have said. That is not an honest method of debate. If you insist on taking a bad faith approach to learning about evolution, then I will no longer bother interacting with you on this topic. I don't want to waste my time on somebody who is deliberately dishonest. Humans and crocodiles do not live in the same environment. You may have noticed that crocodiles live in the water most of the time. They live in swampy, marshy areas. Humans, in contrast, generally live on dry land. Different environments. No. I have said that acquired characteristics are not inherited (Lamarckian evolution). Environmental selection is a different process all together. Do you deny that genes can randomly vary from one generation to the next? Do you deny that when genes are mixed in sexual reproduction, the offspring gets a unique combination of genes, never before seen in any other individual? How so?
