Why Evolution is True

[n2doc]

From the book "Why Evolution is True" by Jerry A. Coyne

Every day, hundreds of observations and experiments pour into the hopper of the scientific literature… and every fact that has something to do with evolution confirms its truth. Every fossil that we find, every DNA molecule that we sequence, every organ system that we dissect supports the idea that species evolved from common ancestors. Despite innumerable possible explanations that could prove evolution untrue, we don’t have a single one. We don’t find mammals in Precambrian rocks, humans in the same layers as dinosaurs, or any other fossils out of evolutionary order. DNA sequencing supports the evolutionary relationships of species originally deduced from the fossil record. And, as natural selection predicts, we find no species with adaptations that benefit only a different species. We do find dead genes and vestigial organs, incomprehensible under the idea of special creation. Despite a million chances to be wrong, evolution always comes up right. That is as close as we can get to a scientific fact.

more discussion:

http://blogs.discovermagazine.com/badastronomy/2009/04/15/why-evolution-is-true/

[xchrom]

1. 'Despite a million chances to be wrong, evolution always comes up right.'

[BlueJazz]

2. Despite a million chances to be Right, a Lot of People are stupid enough to not believe.

[Juche]

3. All part of God's attempt to test our faith

:sarcasm:

On another note the people who reject evolution tend to do so (from what I've seen) because they are scientifically illiterate and/or because accepting evolution would violate their religious beliefs about a personal creator God, the world being 6000 years old and Jesus dying as a consequence of original sin (there isn't any original sin if evolution was true, so Jesus's death is meaningless). For all intents and purposes evolution destroys the fundamentals of the christian faith because the death of Jesus was supposedly a result of the sins of Adam & Eve. For the most part, after you subtract extremely religious people and republicans from the mix, most people believe either in evolution or intelligent design (which is still flawed, but at least accepts some tenets of evolution).





Point being, you can get a million pieces of scientific evidence proving evolution. If people don't want to believe it because it violates their religious beliefs or if they are scientifically illiterate it won't matter.

[starroute]

4. The real problem is with natural selection, not evolution

Darwin was looking for a completely blind, automatic process to explain evolution -- and he came up with the idea that natural forces inexorably lead to the survival of the "fittest" and the extinction of the less fit.

That notion of the survival of the fittest has always been the weakest part of Darwinian evolution. The very concept is derived from the way humans breed livestock -- which would hardly seem to be a likely model for a theory intended to do away with the need for a divine intelligence. It's also got something unpleasantly mechanistic and even demeaning about it -- which is why many people who are not fundamentalists instinctively feel a distaste for it.

Beyond that, it's never been possible to define "fitness" in any scientific way. And to the extent that natural selection applies at all, it seems to be limited to minor refinements in existing species. It has no ability to explain the appearance of new species -- which may be more a matter of organisms either accidentally or deliberately taking up a way of life to which they're really not well suited and then having to get good at it.

This is not to say that a scientific theory of evolution isn't possible. It will simply have to incorporate a lot of the newer material that is out there around the edges -- ideas about living things as self-organizing systems that to some degree guide their own evolution, about the role of symbiosis and the way in which ecosystems co-evolve, about altruism and other "moral" values as part of what goes into evolutionary "fitness."

When all that happens, I believe that most of the people who currently say they don't believe in Darwinian evolution merely because they don't like the implications of survival of the fittest will be won over. But meanwhile, no amount of arguing as to why evolution is "true" will succeed in making it any more popular.

[Fumesucker]

6. IMO, "fitness" in a biological sense just means..

Whatever traits are most likely to lead to an organism passing on its genetic inheritance to the next generation.

The more "fit" an organism is for a given environment then the more likely it is to pass on its gene sequences.

But usually the more perfectly an organism is adapted to a particular environment the more it suffers when the environment changes, as environments seem wont to do.

I suppose that definition could be thought of as being a bit circular but I don't see it that way.

[Enthusiast]

8. It's more like survival of the

adequate. Like you say, the more specialized a species becomes the more threatened it is by environmental change.

[mike_c]

9. do you have a biological background?

I ask because you discuss evolution rationally, but in a way that few, if any, biologists would accept. For the record, I'm a working biologist and academic scientist, so I'm pretty familiar with that crowd's perspectives.

First, natural selection has NOTHING to do with "survival of the fittest" unless we're talking about population genetics, i.e. multigenerational "survival" (= persistence) of adaptive alleles. In other words, differential reproductive success, with better adapted individuals producing, on average, more offspring than less well adapted individuals. Survival is only necessary for offspring production. Most organisms senesce-- survival beyond the peak reproductive portions of their life histories is irrelevant to fitness.

Second, you're mistaken to conclude that "fitness" is an ill defined concept. From an organismal standpoint, it is defined as the production of viable offspring. It is better expressed as "reproductive fitness," which we often shorten to simply "fitness" for the sake of convenience, but which non-biologists often misinterpret. From a genetic standpoint, it is the persistence and relative proportional growth or decline of specific alleles in populations over time. Alleles that foster reproductive success are "fit." Deleterious alleles are less so.

Third, your contention that natural selection cannot contribute to speciation is not supported by anyone I know. Speciation is something of a red herring among creationists and other detractors of evolution. There are several problems, not the least of which is that the notion of "species" is arbitrary, at best. No successful, universal definition of the term "species" exists at present-- it's a term of convenience, nothing more. Also, natural selection is only one of several mechanisms for speciation. Finally, speciation itself is not a homogeneous process- there are several types, likely with at least partly differing mechanisms.

In truth, the genomes of all organisms living on Earth are continuous elaborations in form and function, but sometimes with observable discontinuities that allow us to distinguish consistent differences separating different "types" or taxa. Think of them as genomic clusters in the universe of all possible shared genomic traits for all organisms living on Earth. What we call a "species" is simply a genomic cluster distinguished sufficiently from its neighbors-- related taxa-- to exhibit observable differences in phenotype, reproductive isolation, etc. Sometimes just spatial or temporal location.

When you consider the genetic continuity of all life on Earth, it's easy to see how natural selection plays a role in speciation. ANY process that fosters the accumulation of genetic differences between related organisms-- that fosters clustering in the universe of possible shared genomic states-- contributes to speciation, including natural selection.

[Realityhack]

14. You are missusing the technical terms. n/t

[Mythsaje]

5. All one has to do to "prove" evolution

is take a look at the way we've manipulated our canine companions for the past several centuries. We bred them for particular traits and evolved them into what we wanted them to be. As evidence goes, it's nearly incontrovertible. And if that isn't enough, all one has to do is catch a virus, get over it, pass it to another person, and get it back mutated just enough that our immune system has to start all over again.

Anyone who denies evolution is an idiot.

[TZ]

12. The problem with that argument is...

that is a form of "directed" evolution and the fundies are big on not understanding the concept of randomness. They say we are too well"designed" to have "randomly" evolved.
Of course they conviently overlooks things like drug resistant bacteria..some of which can be seen to evolve IN ONE PATIENT.
Most of the evolution deniers don't take things logically. Hell I even worked with a biologist who was an evolution denier. Now THAT was an eye opener.

[SlingBlade]

7. 'Tea Bagging' Proves that knuckle dragging ...

spit dripping neandrathls STILL exist, We just call em Neo-Cons these days

Crying out loud, Even a cave man could see it

[steven johnson]

10. Conserved Gene Expression Reveals Our 'Inner Fish'

'God testing our faith' sounds a lot like the psychological mechanism of projection. Clinging to the fairy tales of one's childhood is comforting.

But can you be sure that Allah and Bramha didn't get together to maintain critical DNA sequences? It is certainly revealed in sacred texts.

Creation in Judaism/Christianity, Islam, Greek Mythology, Hinduism,Buddhism

ScienceDaily (Apr. 16, 2009) — A study of gene expression in chickens, frogs, pufferfish, mice and people has revealed surprising similarities in several key tissues. Researchers have shown that expression in tissues with a limited number of specialized cell types is strongly conserved, even between the mammalian and non-mammalian vertebrates.

They found that although the specialized DNA sequences that regulate the expression of the genes seem to have changed beyond recognition over the hundreds of millions of years since the clades parted evolutionary company, the actual patterns of gene expression remain closely conserved.
According to Hughes, "There are clearly strong evolutionary constraints on tissue-specific gene expression. Many genes show conserved human/fish expression despite having almost no nonexonic conserved primary sequence."

"This relatively low divergence of gene expression in brain supports the hypothesis that neurons participate in more functional interactions than cells in other tissues – imposing constraints on the degree of alteration that can be tolerated".

http://www.sciencedaily.com/releases/2009/04/090415193249.htm

[phantom power]

11. I've heard this is a good book.

[callous taoboy]

13. Thank you for posting this. n/t