CDarwin

That would be nice... I'm not totally sure how to do it. When I think of it, I suppose I should add "The earth is warming but the impact of human activity is unknown" as well.

I wasn't there before...

I've been reading some of the global warming discussion on here and the amount of skepticism struck me as interesting. I would therefore like to try and quantify people's feelings on the subject. Bascule's poll (though not itself uninteresting) is a bit inadequate to that task, as it's mainly concerned with making a point. I've tried to be as inclusive as possible as to the range of opinions, based largely on some of the options floated in Bascule's poll thread. I think having a nice picture of everyone's opinions might further discussion in this forum on what is obviously its dominant issue. EDIT: When I look at the poll now, I see I excluded two categories: "The earth is warming and human activity is the only cause" and "Other: Please specify." If you wish to avail yourself of either of those, just post.

I don't think that's what he's talking about.

I'll leave the mechanics to Lucaspa and the like... It has to do with the quality of the water. Axolotls retain larval features and remain aquatic if they can.

Obviously you can link extinctions more clearly to hunting and non-indigenous competitors, these are things that directly kill organisms. Habitat loss weakens populations, so even if it doesn't directly cause extinction in the short run it can set a species up for much bigger problems in the long run from things like hunting and competition. All you're really saying is that there are two levels to protection: protecting the animals themselves from what kills them and protecting populations from what weakens them.

I don't think everyone is talking about the same thing.

You don't need to be a professor to post now or anything, I was just asking. I think people are missing the point of this a little... I didn't intend for this to be a debate as to who qualifies as a scientist. I just meant non-lay people who work in science. The definition doesn't need to be that precise. You're just satisfying my curiosity and that of whoever else cares by posting.

That's obviously going to depend on the individual case. Are you looking for a general rule here? If you want a clear cut example of changing habitat causing extinction, just look at the end of the Permian. The 95% of species that were killed there didn't die by being hunted into extinction, they died because the changeing climate destroyed their habitats. That obviously wasn't a anthropogenic change, though. It is believed by a large number of climate scientists that we are changing the climate of the planet in similar ways now, which should lead to similar extinctions (if perhaps fewer). That might not be what you're talking about though. There hasn't been much citing in this debate, just people refering to their memory. Most places don't give precise reasons for extinctions, but I did find this stating that 100 extinctions a day are due to deforestation. Many of these are going to be of rarer plant species, which are usually highly specialized so they aren't likely to be out-competed by introduced species and too rare and cryptic to be heavily gathered or prayed upon. Here is a list of recently extinct plants. This site should probably be the final word on the matter. It syncs well with what I think everyone has been saying. In theory, habitat destruction should cause extinctions, but it doesn't seem to in large numbers. It may be the result of a time lag. Habitat destructions weakens the genetic diversity of species so that they aren't able to respond when the next crisis comes and thus go extinct.

Any professors?

When would you have liked to live? The warm, sunny Jurassic? The icy-hot Pleistocene? I might like Miocene Europe. It's nice and warm as far north as Scotland, the climate is even and not too extreme, and no meter long dragonflies.

You might want to tell your second example to the muriqui. Now it probably wouldn't understand what you were saying since it's a monkey, but if it did it would note that its kind is teetering on the verge of extinction because of the destruction of its Atlantic coastal forests in Brazil. There are about 500 left. Lion-Tailed Macaques provide a yet clearer example. The only pressure they face is habitat destruction. They aren't hunted and they aren't being competed with by introduced species. There are between 400 and 4,000 of them left. You have to realize that in certain environments many adaptable and widespread species will come out just fine, perhaps even most of the species. The problem is that minority that doesn't come out fine. Arboreal primates are particularly vulnerable to habitat destruction, as they depend on delicate forest ecosystems.

How does one use this thing?

I suppose you decide.

No, you couldn't even say that. Ontogeny does not recapitulate phylogeny as a general rule. You can't equate "primitive molecules" with "immature molecules." Molecular neoteny might be the retention of the the chemicals that lead to the development of immature features like deciduous teeth?

This has probably all ready been done, but its buried so far down the board that I can't find by browsing, so we might as well do another one. Who here actually works in a scientific field? Be honest now. I may wish I was Head of the Max Plank Institute for Evolutionary Anthropology with 3 PhDs, and a D.Sc. from Oxford and but I'm not. But for those of you who aren't presumptuous high school students, give us your field and position, if you will. Education would be interesting too.

Actually a fellow who helped come up with the MRI was a Creationist, Raymond Vaughan Damadian. Behe's made some legitimate contributions to biochemistry too. So even modern Creationists can make contributions to science even if Creationism itself isn't much of one (obviously there were many important Creationist scientists in the past). Actually people will probably just ignore you if you don't actually make points. I can tell you right now that you're not the only Christian on the board, or even in this discussion. I can also tell you that I 'proved them wrong' better in this post than you did in yours, by citing specific facts.

As a justification for conquering the Middle East and making a New World Order and Global Warming and UN tanks and the World Bank and Bilderberg. Bilderberg!

A social science forum group would be good.

Intelligence is the living method for humans. When a snail builds a shell, it doesn't build it using intelligence, it builds it like we do our teeth, by secreting a mineral matrix with specialized cells.

Thank you for finding that, it is interesting from a mechanical standpoint, but it still doesn't really tell me the selective why.

Throughout the fossil record there is a tendency for shelled invertebrates to replace the calcite with the mineral aragonite (orthorhombic calcium carbonate). This is something of a bane for paleontologists because calcite is much less likely to dissolve in water and so thus is more likely to fossilize. That is why the fossil record for Paleozoic corals is better than the fossil record for Cenozoic corrals, the older coral is all made of calcite where the younger corals are aragonite. There are similar tendencies among mollusks. Why was this? The only reason I can think of is that the aragonite would be easier to precipitate out of water. Are there some properties of aragonite of which I'm not aware that makes it better as a shell constituent?

The original topic wasn't "how many limbs can a human control" but "what are the most intelligent non-human animals", so I don't think we can be too faulted for getting sidetracked. The example of the millipede just shows that having a brain that is 'intellectually sophisticated' isn't necessary to controlling ridiculous amounts of limbs. If anything it argues against your statement that humans could control more limbs than any other animal. But if we might digress back to something like the original topic, here's a question that might be relevant. Just what makes a human 'intelligent'? If we can establish that, perhaps we can see why we classify animal A as more intelligent than animal B.

Actually parts of the brain are concerned with processing senses and the size and efficiency of these parts are part of the equation determining an animal's sensory acumen. For example, in animals with good senses of smell, like cats, the olfactory bulb is much larger than in animals with poorer senses of smell, like primates. You can even see this in the Order Primates itself. Lemurs have larger olfactory bulbs than apes, and likewise better smell. Our ancestors probably never had super-sensitive sense organs. Humans and primates in general have excellent vision as far as animals go, though, and can see all three primary colors of light, something most animals can't. The loss of the sense of smell is a progressive thing in primate evolution going back to the earliest anthropoids in the Oligocene. Our ancestors lost their whiskers for probably the same reason they lost their sense of smell: they just weren't that useful for finding fruit in trees. Other than that our sense of touch isn't appreciably worse than your typical mammal. You can't really link the absence of hyper-senses in humans to our 'superior intellect.' The preference for clear, color vision at the expense of other senses is a primitive primate feature.

I see that point, but you understand what I meant. We should evaluate the mental capacities of animals in their own context.