The fruit of evolution model ?

sfs said:

You didn't pick an example: you picked a general statement. Pick one of my specific examples if you want more information.

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lucaspa said:

Read them. They are all easily available either online or in your public library.

What I will do is introduce you to one of my studies and how evolution is used to discover. Juvenissun, what is not usually understood about science is that hypotheses are not tested singly. Instead, they are tested in huge bundles. All except one of the hypotheses -- the "favored" hypothesis or the one lay people think we are testing singly -- are assumed to be true. If, however, they are not true, then the favored hypothesis is not going to "work".

I study fracture repair. Specifically, I study the use of adult stem cells to regenerate bone where so much bone has been lost that repair will not happen -- non-unions. Obviously, I am interested in human fracture repair. But I can't do the experiments on humans for a multitude of ethical and practical reasons. So I need to choose an animal model. Now comes the crucial question: Which animal(s) do I choose as models? Evolution states that certain animals are similar because they share a common ancestor. Because of inheritance, they will share characteristics of that ancestor. As the relationship moves farther apart, they will share fewer characteristics. OK, the original determination of similarity is based on (usually) static characteristics visible to the naked eye: shape of bones, shape of limbs, warm vs. cold blood, fur vs. scales or feathers, etc. More recently, genetics has come into play.

No one ever looked at fracture repair as a basis for deciding similarity or relationship. However, at this stage we make a prediction based upon evolution: since the animals descended from a common ancestor, then the unknown characteristics (fracture repair) will also have to be similar as well as the known characteristics.

So what are the closest relatives to humans? The great apes, especially chimps. They would make good models, but they are too expensive to use in large numbers. From there we go to monkeys, but the same objection applies. The next step would be other mammals, then reptiles, then amphibians, then fish. Mammals are the closest relatives of that list to humans, which brings us to the humble rat, rabbit, and dog as experimental models. As it turns out, the prediction is correct, and it is possible to study fracture repair in those animals and have the results be applicable to humans.

So a current study I have going is to isolate multipotent adult stem cells (MASCs) from an adult rat. I have shown that MASCs are present in humans (as predicted by evolution). The MASCs are expanded in culture (to get a huge number cells, into the hundreds of millions) and seeded into a matrix where they attach. Then I make a non-union defect by cutting out 7 mm from the center of adult rats. This is what is called a "critical sized" defect and will not heal on its own. There is a size in humans where defects will not heal (as predicted by evolution). I place the matrix + MASCs into the defect for 8 weeks and then assay to see whether the defects regenerate the bone. They do.

At this point, because of evolution, I (and the FDA) are ready to try this treatment in humans.

Please note that creationism does not permit this prediction. There is no reason fracture repair HAS to be similar between rats and humans. It MAY be, if the Creator so chose, but you can't predict that. Instead, you would have to test all species to see which one had fracture repair closest to human. Maybe the best model would be fish. Evolution allows a shortcut to choosing animal models. I don't have to check each and every species.

I also want to check the ability of MASCs to regenerate a skin wound. There's no reason a Creator would have to make BOTH wound healing and fracture repair similar. Under creationism, perhaps the best animal model for skin wound healing would be a toad.

But under evolution, both skin wound healing and fracture repair should be similar to that of humans, because of that common ancestry relationship. So I can skip all the time and expense looking at all species to see which one the Creator decided to make skin wound healing similar to humans and use rats again. Because of evolution.

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sfs said:

Using your logic, one could make all kinds of predictions, many of them completely ridiculous. On the one side, we see quadrupedal mammals, and on the other hand, we see bipedal humans. Therefore, even a child could deduce that we should find fossilized quadrupedal humans.

Do you really think this kind of logic is going to be useful in making predictions?

Then why doesn't it? Why don't creationists make valid predictions, if this kind of logic can be applied so usefully? Why is that only biologists, using evolution, seem to be able to do it?

How was the discovery of the fossil fly not a new discovery?

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crawfish said:

Fair enough. I would love to give a detailed explanation but I am no scientist and I know I would fail miserably. One of the things that cemented my acceptance of evolution was talking to a petroleum geologist and a medical researcher, both of whom explained in detail how they used evolutionary theory to build models with successful real-world results. From GIGO, I do know that the likelihood of successful results from bad assumptions is very low; therefore there has to be something to it.

I would love to be able to give their examples, but I know I would fail miserably. I'll leave the science to the scientists on this board.

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crawfish said:

Fair enough. I would love to give a detailed explanation but I am no scientist and I know I would fail miserably. One of the things that cemented my acceptance of evolution was talking to a petroleum geologist and a medical researcher, both of whom explained in detail how they used evolutionary theory to build models with successful real-world results. From GIGO, I do know that the likelihood of successful results from bad assumptions is very low; therefore there has to be something to it.

I would love to be able to give their examples, but I know I would fail miserably. I'll leave the science to the scientists on this board.

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sfs said:

Huh?

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Pete Harcoff said:

APPLIED EVOLUTION:

Evolutionary biology is widely perceived as a discipline with relevance that lies purely in academia. Until recently, that perception was largely true, except for the often neglected role of evolutionary biology in the improvement of agricultural crops and animals. In the past two decades, however, evolutionary biology has assumed a broad relevance extending far outside its original bounds. Phylogenetics, the study of Darwin's theory of “descent with modification,” is now the foundation of disease tracking and of the identification of species in medical, pharmacological, or conservation settings. It further underlies bioinformatics approaches to the analysis of genomes. Darwin's “evolution by natural selection” is being used in many contexts, from the design of biotechnology protocols to create new drugs and industrial enzymes, to the avoidance of resistant pests and microbes, to the development of new computer technologies. These examples present opportunities for education of the public and for nontraditional career paths in evolutionary biology. They also provide new research material for people trained in classical approaches.

APPLIED EVOLUTION - Annual Review of Ecology and Systematics, 32(1):183 - Abstract

Unfortunately for creationists, evolution *is* a useful science. But the common theme from creationists I've noticed when presented with this fact, is that instead of confronting it head on, creationists instead will either ignore it or try to handwave it away. But it's not going away.

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Pete Harcoff said:

Specific "real life" example:

EVOLUTIONARY GENOMICS DISCOVERS AIDS SUPPRESSION PROTEIN

The underlying genetics/genomics research leading this this discover is directly based on evolution and more specifically, the common descent of primates (that's the phylogenetics tree based approach to their analysis):

The potential significance of adaptive evolution and dimerization in chimpanzee intercellular cell adhesion molecules:

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sfs said:

Some examples coming primarily from the study of humans:

The first evidence for large magnitude changes in recombination rate across the genome (i.e. recombination hot-spots), done by measuring the autocorrelation in genetic diversity. Interpreting the result required an estimate of the variation in mutation rate across the genome, which was obtained by measuring divergence between humans and chimpanzees.

Measurement of the mutation rate in humans, again done by comparing the human and chimpanzee genomes.

Realization that human chromosome 2 represents a relatively recent fusion of two previously existing chromosomes, leading to the subsequent discovery of the vestigial telomeric and centromeric sequences.

Measurement of the difference between mutation rates in males and females, done by comparing divergence within families of transposable elements that had been inserted into the X and Y chromosomes. (Strictly speaking, while this analysis was done in an evolutionary framework, I think it really only relied on the human genome being the result of many millions of years of genetic change.)

Estimation of the ancestral population size of humans and chimps, showing that it was substantially larger than the recent human population.

Determination of the ancestral base at sites that are variant in humans, done by comparing humans to chimps, gorillas and macaques. Knowledge of the ancestral base been very useful both for inferring historical demographic changes in the human population, and for detecting and localizing loci where natural selection has occurred recently in the human lineage.

A more general class of very important discoveries: Evolutionary conservation is used all the time for a range of inferences about human genetics and biology. The essential point is that any part of the genome that is nearly the same between a range of species must have a functional role of some sort. This has been used to identify protein-coding genes, regulatory RNAs, and many kinds of regulatory element.

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