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Evolution!
People LOVE to "debate" evolution. But that's silly, and doesn't really solve anything. If you are in a debate about whether or not evolution is a valid theory, you are either debating someone who has little to no idea what what evolution is, or ARE the person who has little to no idea what evolution is. That doesn't sound like very much fun, so let's not do that, okay?
Instead, this thread will be about topics in evolution, because it is much more entertaining to talk about specific cases and ideas than one big overarching theory. The topics will be chosen by whoever has the best topic, with all "lesser" topics being ignored and forgotten.
Now, I'll start us off with what actually made me want to start this thread: randomness. I was reading Mage's post at the bottom of this thread, and immediately thought about genetic drift.
Here is a classic example of genetic drift in a fruit fly population:
Basically, genetic drift states that random sampling has a lot to do with the evolution of small populations. Think about it: say you have a population of four individuals, two males and two females. One female homozygous allele for blue fur, the others all have a homozygous allele for red fur. Mating between blue and red fur produces a heterzygous purple fur creature. We would therefore expect the next generation to have some purple and red individuals, and the one after that to have all three colors represented. Basic Mendelian stuff.
Now, it gets interesting. Lightening strikes the blue female. She's dead, and will never reproduce. Now, all individuals in this population will be forevermore purely red. Note that this is regardless of the fitness of these genes. Blue fur might have been much more beneficial (perhaps these creatures lived in blue grass, and it provided camouflage), due entirely to random events (as opposed to evolutionary pressures) it is RED fur that becomes fixed in the population.
Going back to and contradicting Mage's comment from before, due to genetic drift, having the same selective factors won't guarantee a particular evolutionary outcome, due to simple random events.
So.... Discuss?
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Creationist logic in another context for illustration and/or cheap laughs: Nobody has been back in time to see the Easter island heads being put up, therefore the easter island heads were definitely deployed from space by aliens.
What a load of nonsense. They were clarly hand carved by a prehistoric race of jotun in a last ditch effort to scare away the sea monsters that drove them to extinction.
What a load of nonsense. They were clarly hand carved by a prehistoric race of jotun in a last ditch effort to scare away the sea monsters that drove them to extinction.
Or the only remains of the stone mechas sent to fight the local kaiju. Now we should probably stop before we get banned for trolling.
Evolution!
Having been indirectly reminded of this thread recently, and in the good spirit of the OP to discuss topics of evolution, I have something I want to share.
Lethal parasite evolved from pond scum
It is about a parasite, Helicosporidium, that affects insects. A genomic study has found that its origins are in the algae! As did Malaria, which was apparently found in a previous study.
I find this very interesting because it gives clues about the question of how parasites become parasites in the first place. I am sure parasites have been extensively studied on their parasite-host relations and how infections proceed, but we likely know less about how it all started.
One parasitic topic at a time; I'm still trying to figure out why some moths are now using their probosces for blood!
You just had to tell me this while we're having a moth invasion at home...
Is this what you meant? Russian vampire moths?
http://news.nationalgeographic.com/news/2008/10/081027-vampire-moth-evolution-halloween-missions.html
Related to that, horse-fly females also suck blood for reproduction, similar to mosquitoes. So I guess what flies can do, moths can as well?
Evolution, you're creepy.
I have to wonder for the creationists, would algae turning into a parasite count as one "kind" turning into another "kind"?
It really depends what a "kind" is to a creationist (though I suspect this term is only loosely defined so that they can adapt to the argument at hand...).
What we have here are organisms that drastically changed their lifestyle from self-sustaining photosynthetic algae to host-dependent parasites, along with varying degrees of genetic reduction (as expected, mostly the genes related to photosynthesis and energy production). By all means they evolved into different species. But maybe a creationist would ask for unrealistically more drastic changes, like a transition from algae to animal, to acknowledge it as proof of evolution?
But maybe a creationist would ask for unrealistically more drastic changes, like a transition from algae to animal, to acknowledge it as proof of evolution?
With fossils of every generation in between. Otherwise, God did it.
An image of a link should refute evolution?.... oh wait, a supposed caveman? I think I'm not getting the joke...
Please, we're here to discuss, not let others discuss for us. If you have a point against evolution, elaborate here (you can still use links to back up your argument though).
Quit it with the trolling, you impress no-one.
If you want to argue against evolution, give me one clearly stated argument. Otherwise, find something else to do.
You know, it is actually funny that you came up with cavemen. This enables me to bring up another interesting tidbit for this thread:
Neanderthals were not inferior to modern humans.
Of course the study does not pretend that Neanderthals had a similar degree of education as we have today, but as they say, this "would be like comparing the performance of Model T Fords, widely used in America and Europe in the early part of the last century, to the performance of a modern-day Ferrari and conclude that Henry Ford was cognitively inferior to Enzo Ferrari."
The point is that there is no evidence that the anatomically modern humans were cognitively superior to Neanderthals. Personally I see this as unveiling one of the problems especially in anthropology: we see ourselves as the ones that made it out alive, and assume we must have been better, which of course sounds very coaxing to us. The true story is likely more complex, though.
And the true irony? You are such a modern human, and wrote evolution wrong. Twice.
So I read the article, and as far as I can tell their conclusion is that we are the predominant species as there were more of us in a group.
As we now have a basic understanding of genetics, isn't evolution pretty much proved?
Sadly we don't have genetic material of all the older groups, but we have sequenced some, if not most of the Neanderthal genome. I think it is pretty much accepted that our two groups represent two successive waves of emigrating humans from Africa. Neanderthals and modern humans were by all accounts distinctive human groups.
This is not so easy with the older fossils. It seems like at least some of the earlier human groups in Africa might be just several members of one group:
http://www.livescience.com/40505-earliest-humans-one-species.html
The problem is likely that many anthropologists that find a new bone make a new species based on minor morphological differences to other fossils, discounting a certain degree of phenotypical plasticity (variation within a species).
The genetics thing is unrelated to the fossil stuff. We can watch and understand inheritance and mutation in the modern day.
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