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New Findings Confirm Darwin's Theory — Evolution Not Random
ScienceDaily is reporting a team of biologists has demonstrated that evolution is a deterministic process, rather than a random selection as some competing theories suggested. "When the researchers measured changes in 40 defined characteristics of the nematodes' sexual organs (including cell division patterns and the formation of specific cells), they found that most were uniform in direction, with the main mechanism for the development favoring a natural selection of successful traits, the researchers said."
Ah, but did this deterministic development mechanism evolve deterministically or randomly?
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The Theory of Evolution is once again mistaken for Natural Selection of Advantageous Traits.
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Hopefully this will be an effective means of shutting up the old saw of "there's no way that 'simple random chance' could produce the creatures of today from the creatures of yesterday!" and all that other nonsense.
O'course, it'll probably be misquoted endlessly by the 'intelligent design' folks, given that--at least superficially--it could be seen to "endorse" the concept of a directed design, rather than being an inevitable consequence of the process.
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Creationist Interpretation : "God came up with something he liked, so he repeated his design; I mean it must have taken awhile to design millions of organisms, He must have recycled ideas somewhere"
Hmm... I don't understand...
From what I picked up in bio, it was known to work as such:
Assume Mutation
(1) If mutation not hindrance, animal likely to live and likely makes babies.
(2) If mutation is boon, animal more likely to live and more likely makes babies.
(3) If mutation is hindrance, animal less likely to live and less likely to make babies
From there, you consider whether or not the mutation is recessive/dominant which determines if the babies get the mutation (then referred to as a trait).
Repeat many many times and you get a separation of a special line.
The proper combination of factors being: mutation = beneficial, mutation dominant, mutated animals screw like proverbial rabbits.
How is this different from the new findings?
Somehow, I feel that this is indeed novel: as far as I understood it, evolution was taken to be the process by which RANDOM mutations are passed on based on how they affect survival and reproduction rates.
This seems to say that the mutations aren't random, but that they are biased into a specific direction - one that is more advantageous to begin with. As an example, this would indicate that instead of there being random variations of the length of the neck of the giraffe, the mutations tend, on average, to favor a longer neck to begin with.
I'd say that's pretty new and spiffy. Did I miss something?
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I think the most interesting thing to come to light in this study is that scientists have identified fourty characteristics of nematode sexual organs.
That it is a deterministic process that will tell how much wood would a wood chuck chuck if a wood chuck could chuck wood.
They might even be able to write a mathematical expression for it.
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This is a link to the paper cited in the article:
http://www.current-biology.com/content/article/fulltext?uid=PIIS0960982207021938
It sounds to me that life has evolved to evolve.
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Evolution is intelligently designed?
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Nobody ever said the selection was random, except for some pinhead creationists who didn't know what they were talking about. Mutations are random, and selection is the process by which those individuals with advantageous mutations survive while those with disadvantageous mutations do not.
-jcr
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You bring up a point that many do not understand. Evolution says nothing about how life or DNA started. It simply explains how once life started with DNA, the process by which it evolves. Similarly the "big bang" theory says nothing about how the universe started. It explains how it expanded and changed from a hot, dense, nearly uniform state to its cold, sparse, unevenly distributed state. There are hypotheses about life starting with an RNA world, or starting with undirected metabolism, but these are completely separate from the theory of evolution, for which we have ample evidence.
Your other point seems to do with the fact that some evidence is not completely explained by evolution. In science, there is always some observation left unexplained, which is why Einstein's theory of relativity and quantum theory superseded Newton's laws. It does not mean that there must be a supernatural explanation for the observations that are currently unexplained.
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Wow, this is a triple convergence of a bad and confusing title, summary and article (which is a summary of the actual journal article) which is unusual even for slashdot.
This really isn't about Darwinian evolution which involves random mutations and selection of the favorable ones. However, there are some characteristics which are neither advantageous or disadvantageous. There is a debate about how many characteristics are "neutral". For example, did large noses appear because they are advantageous (for warming air perhaps) or because they just worked out that way by chance. So the original paper asked this question about worm vulvas and found that nearly all the characteristics that they looked at did NOT arrive by chance but were selected for (i.e. were advantageous in some way).
It is important to note both possible results would be consistent with Darwinian evolution. The only questions being addressed are the mechanism (does evolution go through mostly neutral phenotypes before a favorable phenotype is selected) and the extent that characteristics are neutral. For worm vulvas, it appears that the vulvas that form are biased towards the most favorable ones.
Am not a biologist by trade, but had always thought evolution was at its root a random process. It has the potential to try anything, but known survival traits will always be favored.
We do understand the mechanism by which a trait will become dominant; reproduction of that built-in behavior to offspring. What we don't understand is how such dominance prevents other, competing traits from becoming active.
In the Science Daily excerpt, they mentioned long-necked giraffes, and how if evolution was random we would also see those of the short-necked variety.
This logic does not follow. We would see short-necked giraffes only if their survival let them reproduce. As they would tend not to - being unable to reach the leaves at the top of the tall trees, thus denying them the energy required to either attract a mate or carry offspring to term - this hitherto unknown mechanism would not favor that trait becoming dominant, though like the activities of a good pack rat, the DNA which would allow this trait to exist may continue to be stored, and passed - unused - on to future generations.
Thus, evolution hedges its bets. It may come to pass someday that the short-necked giraffe was more easily able to survive than their long-necked counterparts. Perhaps all trees become shorter. Perhaps some form of brittle bone disease kills the ones with longer necks, and they change their neck length and diet in order to survive. Perhaps they enter into a symbiotic relationship with some other creature that digs up food and leaves it on the ground. Who knows what the future will bring. But should conditions change, the potential for such a trait, still dormant within the species, may emerge to dominance.
This is not meant to introduce any talk of "design" into evolution, but the fact is our understanding of the system remains in the realm of how traits are passed on, not why.
The title of the post is misleading. This is not intended to be a confirmation of the modern evolutionary theory. This paper is about HOW actually evolution of certain aspects of the nematodes happen, not about whether evolution happens or not at all. The modern theory of evolution considers three different mechanisms in which evolution occur: * Natural selection (the only one described by Darwin), which consists in the differential reproduction of organisms (let's just say organisms, to keep it simple) determined by inheritable traits (adaptive traits. * Genetic drift, which consists in the "random" change in the frequency of a gene in a population. * Genetic flow, which consists in the transference of genes among populations. From the summary of the paper: "We propose that developmental evolution is primarily governed by selection and/or selection-independent constraints, not stochastic processes such as drift in unconstrained phenotypic space." Put simply, this paper says that natural selection is the prevailing mechanism in developmental evolution. Sorry about my bad English. Not a native speaker.