Life on the Scales - Simple Mathematical Relationships Underpin Much of Biology and Ecology

Science News ^ | 2/23/2005 | Erica Klarreich

[furball4paws]

An article purporting to show simple mathematical relationships in Biology and Ecology.

[sourcery]

Life on the Scales

[furball4paws]

The "genetic" data are derived from the number and types of differences in the genomes of the modern rat and modern mouse. A model of rates of changes for these types is then used to "estimate" how much time was necessary for those changes to have occurred, i.e. 41 million years. Fossil evidence shows 12.5 million years ago modern mouse and rat are present. Certainly they could be older, but 30 million years is a long time.

The best explanation is that there is something wrong with the genetic "model". This paper offers a possible explanation.

i understand your point, but there should be a fossil record of a rat-mouse thing. I don't think that exists.

[furball4paws]

Do you have anything in your pile of stuff Re:rats and mice and the difference in the times for their divergence based on genetics and fossil evidence?

[elfman2]

Sure, if the number of differences is all there is to the genetic model, then that seems too simplistic. After all, wouldn’t some organisms be more vulnerable to environmental changes due to isolation, specialization, or just being at the wrong place at the wrong time and be effected by some kind of cataclysm?

And like the article states, some have higher reproduction rates. I can’t see how that wouldn’t be factored in from the beginning. Well, I guess it’s hard to estimate for some extinct species.

Doesn’t it seem likely that some mutations would be pretty stable, like sub-species of cockroaches and therefore incorrectly imply that they recently split, while others would be more vulnerable to selection from climate cycles or changing predators/competition in a region? For all I know, one of the mutations is the rate of mutation, for better or worse, till irreconcilable differences do they part…

[Ernest_at_the_Beach]

Fractional exponents with a great example ~ scaling...very useful for proper level Math class.

[Ernest_at_the_Beach]

CO see the article on the spacing between trees.

[Junior]

Ping.

[SunkenCiv]

GGG Ping.(?) Yeah, why not, thanks Blam.

Please FREEPMAIL me if you want on, off, or alter the "Gods, Graves, Glyphs" PING list --
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[djf]

I remember something about foxes and rabbits and diffeq.

Not much.

[PatrickHenry]

EvolutionPing

A pro-evolution science list with over 240 names. See list's description at my homepage. FReepmail to be added/dropped.

[furball4paws]

This ain't my bag either. Of course you can only play the DNA modeling game on existent organisms, since you need DNA. So it has a limited application.

So you develop a model. It works pretty good for this organim and not so hot for that one. And then you tinker with it. But I think the major piece is DNA similarity and that points to how much divergence there has been.

This article talks about correcting for size and how "hot" an organism is and bingo the difference is "elininated". Obviously they didn't change the fossil evidence, so they must have made the DNA changes happen faster.

Some evoid type may appear here with the answer if you hang on. I'm sorry my knowledge is so limited in this area and I don't have access to the references in the paper for more details.

[RightWhale]

This kind of scaling is similar to fractal scaling where the power laws resemble fractional dimension. Mandelbrot would see that the forest acts like a single tree.

[gitmo]

The team plans to use its metabolic framework to investigate why the tropics are so much more diverse than temperate zones are and why there are so many more small species than large ones.

Most evolutionary biologists have tended to approach biodiversity questions in terms of historical events, such as landmasses separating, Kaspari says. The idea that size and temperature are the driving forces behind biodiversity is radical, he says.

They will have a hard time describing the high diversity found in the depths of the oceans. Very low termperature, primarily exothermic species, and a remarkably high diversity in sizes of species.

[VadeRetro]

Fascinating! Now I know why my metabolism is so slow. I got too big.

[VadeRetro]

What do you think the average life span of an ancient Eqyptian was? Even in the Middle Ages, I don't think the average man lived past 45 years.

I think life spans were still in the 40s around 1900, very little changed from pre-tech times. Infectious diseases (mainly tuberculosis and pneumonia) were the main killers because there were no antibiotics at all. Heart attack, cancer, and stroke were well down the list of causes of death. Modern surgery of a sort (anesthetic drugs and sterile procedure) existed but was limited by the lack of blood banks. It also wasn't available to many people. Nobody had heard of Alzheimer's.

[PatrickHenry]

I think life spans were still in the 40s around 1900, very little changed from pre-tech times.

Things really changed for the better after acceptance of evolution became widespread.

[VadeRetro]

Actually true, as far as the sequence of events goes. (Somebody could maybe scream about "Post hoc, ergo propter hoc" but they're just jealous.)

[furball4paws]

I think you can pin the big change about 1880 on Louis Pasteur - just happens to coincide with Darwin.

I know this isn't a real Crevo thread, but I'm surprised no creationoids have shown up to say "see the article talks about design and God" (which it does).

[PatrickHenry]

I think you can pin the big change about 1880 on Louis Pasteur - just happens to coincide with Darwin.

In either case, Darwin or Pasteur, the big change in life expectancy followed the increasing application of the scientific method to the field of biology. I think that conclusion is more than mere coincidence, it's inescapable. And it's something we might emphasize in these threads.

The causal relationship seems considerably stronger than the alleged "link" between Darwin and Pol Pot.

[VadeRetro]

Whether or not you needed Darwin to get the last century's worth of progress in medicine, you won't make the next century's progress wearing anti-Darwinian blinders.