Slashdot Mirror
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. ;)
Tsunami -- You can't bring a good wave down!
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.
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.
GetOuttaMySpace - The Anti-Social Network
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.
The world's burning. Moped Jesus spotted on I50. Details at 11.
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.
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.
The cake is a pie
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.