The Evolutionary Hotseat

[extro...]

Possibly a provable fact, depending on ones concept of proof.

[Bicho the Inhaler]

[GH]

I guess that's basically what I thought to be true (evolution is a reasonable theory that correlates with observable evidence).

It's interesting to me, though, that people would get so worked up about a one-minute statement that basically says, "Evolution is a theory that correlates with observable evidence, but it's not the only possibility." I can't figure out why this is so important to some people.

Is it just that it's heavily supported by people who use their faith as the reasoning behind it? What if the Emancipation Proclamation had been mainly motivated by Lincoln's faith? Am I just way off base?

[extro...]

[GH]

Yeah, I thought when I read the statement that maybe the book recommendation would have been a point of contention. I find it somewhat interesting that the book is in the school library (I assume that's the "library" referenced in the statement), but encouraging students to look at it would be offensive. That's really neither here nor there.

I'm amazed, still, that it seems so important to some people. I know there are at least a few more of them here. What is it that makes it such a hot button? Is there any non-faith-based reasoning?

[Antrax]

http://www.chick.com/reading/tracts/0055/0055_01.asp
(my favourite quote -- "but isn't losing something the OPPOSITE of evolution?")
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After years of disappointment with get rich quick schemes, I know I'm gonna get rich with this scheme. And quick!

[extropalopakettle]

That entire piece is a classic example of the straw man (in this case, the professor is the straw man, anthropomorphized).

[Antrax]

He's killing me!
_________________
After years of disappointment with get rich quick schemes, I know I'm gonna get rich with this scheme. And quick!

[Chuck]

[Omega Centauri]

The evolution of deep sea animals must be fascinating. There's some weird sh** going on down there. Handling high pressure, no light, sulpher vents, extreme cold, bioluminescence, animals that absorb their mates, and the fact the bottom can be seven miles down.

Its easier to get to the moon than the bottom of the Marianas Trench.

Truly awe inspiring. Just because God doesn't micromanage it doesn't mean it isn't spectacular. I wish more people would understand that.

[Chuck]

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[Zag]

I haven't read the whole thread, so I apologize if I'm repeating.

Mr Evolution Man, tell me why humans lost their fur? Was there some evolutionary pressure that combined tool-using, intelligence, and being mostly bald?

I've always wondered if is wasn't the other way around. That is, some random mutation caused body-baldness, and in the comfortable climes of Africa it wasn't a negative enough trait to prevent reproduction so a sub-species developed.

Then a climate change did occur such that the sub-species would have been wiped out if it weren't for a few of them that were clever enough to make clothing from animal fur. Only those clever few survived to reproduce further.

This reasoning, by the way, correlates rather nicely with an open-minded reading of the Adam and Eve story -- eating the fruit from the Tree of Knowledge of Good and Evil, thereby recognizing that they were naked. I've always wondered if the origin of that story was actually the oral record from people whose great-great grandparents had actually been going around naked and thought nothing of it.

Or have you a better explanation? By the way, I don't buy the parasite explanation -- there would be a lot more bald species if that were the case.

[Chuck]

There doesn't have to be evolutionary pressure to be less hairy. If keeping it is not a great enough advantage then it will eventually disappear. A random mutation is more likely to damage something than to improve it. If damage to some feature isn't a disadvantage to survival or reproduction then it will be passed on to future generations. Over many generations such damage will accumulate causing the feature to shrink, become nonfunctional, and disappear.

This applies to intelligence, too. With welfare and socialized medicine all over the place, a slight decline in intelligence that would have made a primitive ancestor less likely to survive is no longer such a disadvantage. Small decreases in intelligence can be expect to accumulate.

But maybe genetic engineering will become available in time to interrupt this process.

[Zag]

[Chuck]

We have the intelligence to use the fur of other animals so our own is much less important.

[Zag]

[Quailman]

My son just did a project (to learn bar graphing) using animal speeds. He pointed out that the lion, wildebeest and thompson's gazelle all had top speeds of 50 mph. I asked him if he thought that was mere coincidence or if there might be some determining or limiting factor at work. I'm glad he was able to speculate that if the lions didn't run as fast as the prey animals, there'd soon be no lions, and if they ran faster, there'd soon be no prey animals (followed by no lions).

[Chuck]

Also, the speeds of the animals is self adjusting. If the lions become a little faster then more of the medium speed gazelles would be removed from the gene pool allowing only the faster ones to breed. A drop in lion speed would allow more slow gazelles to breed. Faster gazelles would eliminate more slow lions from the lion gene pool and slower gazelles would allow more slow lions to breed. If the changes in speeds are slow then they stay similar.

[Dented Ford]

What about cheetahs?

[GH]

Cheetahs never prosper.

[Chuck]

A cheetah goes after a lot of small prey that might hide or fly away if not caught quickly. A cheetah's prey doesn't have to be faster than the cheetah.

[Samadhi]

No prey needs to be faster than the hunter. They just need to be faster than the prey next to them.
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And he lived happily ever after. Except for the dieing at the end and the heartbreak in between.

[Chuck]

That's true if the prey is a herd animal. A lone bunny needs to be faster than the predator or have a place to hide.

[Chuck]

Also, if multiple predators hunt together then the prey would have to be extra fast.

[raekuul]

Only relatively extra fast. Isn't a snapping turtle a predator?

[Zag]

[raekuul]

True, I'm not very knowledgeable about water predators while in the water. But eventually, their prey will mutate so that only the wounded or unhealthy can be caught with ease. So, if the snapper is lightning, the prey just needs to be a little faster when all things are going okay.

Which is not to say that the snapper couldn't catch it anyway.

[Chuck]

An animal's prey would become faster only if incremental increases in speed had survival advantage. If the predator is a lot faster or very large then a slightly faster prey might just draw more attention to itself. In this case, a prey that is slightly better camouflaged or produces a few more offspring would have a better chance of passing on its genes to future generations.

[Dented Ford]

[Zag]

Right. There are lots of strategies used by prey other than speed. Spines, poison, size, camouflage, hard shell, over-breeding, birthing all at the same time, etc.

[ralphmerridew]

A faster animal requires more food.

[Lepton*]

Three ideas for why humans are furless:
http://www.sciam.com/article.cfm?id=latest-theory-human-body-hair

1. we went through a semi-aquatic phase
2. we lost it when we lived on the savannah
3. parasites (lice, etc)