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Rate of Evolution Metrics Observed
eldavojohn notes an article up at Science Daily on research demonstrating that smaller animals with warmer blood evolve faster than larger, colder animals. From the article: "Across species from fish to mammals, they found that rates of protein evolution showed the same body size and temperature dependence as metabolic rate. Specifically, their mathematical model predicts that a 10-degree increase in temperature across species leads to about a 300 percent increase in the evolutionary rate of proteins, while a tenfold decrease in body size leads to about a 200 percent increase in evolutionary rates."
Using the estimated rates, scientists projected evolution to have started about 6,000 years ago. ;)
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I wonder if this has to do with survival rates; shorter lifespan vs longer lifespan, more active vs passive animals, more energy vs less energy?
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Interesting to note that humans have a lower body temperature than most mammals, actually that's one of the reasons we can get leprosy and almost no other animal can carry it, armadillos being the exception, it thrives in cooler temperatures.
more cell division, shorter lifespan, and more more abundant reproduction. All of these mean mutations collect in the population faster. Bacteria evolve much faster than mice, BTW, and they're not warm-blooded since they have no blood. Yet, they reproduce at a much faster rate and the mutations add up faster.
I didn't read TFA, but TFS tells us nothing common sense and a basic high-school understanding of biology couldn't predict as a hypothesis. That someone has gathered evidence to support the hypothesis empirically is pretty cool, though. Even what seems apparent should be tested, or it's not really science.
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I think you have to factor rate of reproduction into this. Whales and elephants don't breed often; that would retard the propagation of genetic changes. Smaller mammals like mice and rabbits tend to breed very often, allowing them to propagate genetic changes faster and more often, making it easier for them to weather (no pun intended) changes in the environment. I don't know how this would factor to "cold-blooded" animals.
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Except that the evidence has tipped heavily in favor of dinos, or at least a large number of families of them, were, in fact, warm-blooded.
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My college buddy's ferret had a fever once. Before it was over she evolved wings, grew a sixth digit on each paw, became super-intelligent and built an interociter which she used to summon a rescue saucer from a race of hyper-sapient star-ferrets.
> So that means the dinosaurs (huge cold blooded reptiles) were an evolutionary dead end?
Dinosaur Spokesman: We had a good what, hundred, two hundred million year run? How long you human critters been around? Two mil? Odds on making it to three?
Done with slashdot, done with nerds, getting a life.
Dinosaurs weren't reptiles. There's more and more evidence that shows that they were warm-blooded. And dinosaurs didn't really disappear. They just look different now. Step outside and look at all those feathered things flying around. Those are modern dinosaurs.
smaller got eaten by bigger, and generally, hot is tastier than cold.
It *does* mean that smaller animals can evolve faster if under lots of evolutionary pressure. Note that since smaller animals tend to breed faster, this is already the case.
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Look asshole, maybe to you a whale/elephant hybrid is "retarded", but to me, it's "fucking awesome".
or, (if you prefer a less vulgar joke)
Man, I really gotta start watching the Discovery Channel more often. I always assumed that whales and elephants didn't breed at all, but "not often"? Wicked!
Yeah, thankfully evolution has not been demonstrated; if it had, we would have stuff like multi-resistant bacteria and animal breeding (which is nothing more than guided evolution).
Now if you'll excuse me, I need to learn more about how the Sun revolves around the Earth...
Using the term "evolutionary rate" is pretty misleading: whats happening is that the genomes are changing faster, but almost all of that change isn't from any selective pressure. Its mostly "neutral drift", things changing randomly in a way that does not impact the fitness of the organism.
It's very important for students to come to an understanding that there is a difference between the incontrovertible fact that 2 + 2 = 4, and the likelihood that birds are one branch of an evolutionary path from a distinct group of dinosaurs. One is intrinsically true, whereas the other has some exceptionally convincing evidence, but too many alternative possibilities to be solidly provable without a time machine and a very dedicated research team.
There are always alternative possibilities, such as Last Thursdayism, the hypothesis that the universe was suddenly created Last Thursday with fully-grown and mid-development life, all of our memories implanted, light and other radiation travelling between stars/galaxies, etc... anything that would give away that it was recent covered up. How? Magic of course. Can't disprove that... hey, it's magic. It is not based on any confirmed evidence, predicts nothing and is unfalisifiable because all of the evidence was magically covered up or is unavailable, so it fails as a scientific theory, as does YEC/ID, Raelianism, panspermia and everything else.
Here's an example of a scientific theory's use in prediction and falsifiability. Humans have 46 chromosomes in 23 pairs. All great apes including chimpanzees have 48 chromosomes in 24 pairs.
Prediction: A chromosome fusion occurred in the distant past after human ancestors had split off from our common ancestor with chimpanzees, specifically:
1) Two chimpanzee chromosomes would be found that had the same banding fingerprint when laid end-to-end as a human chromosome.
2) The same human chromosome would have two centromeres because it was a fusion of two chromosomes that each had a centromere.
3) The human chromosome would contain a telomere inside it, in addition to the ones on each end.
4) All of these extra bits would be in the same order as they would be if there was a fusion, ie the extra centromere would be closer to the end than the extra telomere.
This is nicely falsifiable. If such a banding-matched chromosome wasn't present, or if didn't contain an extra telomere or centromere inside it, or they were present but in the wrong order, this would have presented a problem for common ancestry. So why were they all found to be as predicted?
Have a Google and read about it. I'm sure you'll find plenty of creationist sites that mention this too with rebuttals that are about as scientific or relevant as "Nuuuuh! Does not!" Not being able to make testable, falsifiable predictions such as this one, they can always throw dung from the sidelines.
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