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Pittsburgh Professors Challenge Darwin
Syberghost writes "Darwin's Theory of Evolution comes under an interesting attack from an American anthropologist and an Italian biochemist, according to an article from University of Pittsburgh's school newspaper. In a nutshell, Schwartz and Maresca argue that change is not gradual as Darwin stated, but comes rapidly in response to drastic mutations caused by shifting environmental conditions."
I have read their original research, put this clearly seems to be a new form of Gould's and Eldredge's theory.
On another note, Darwin supports his theory of evolution. He looks like a monkey!
After all, I am strangely colored.
I don't see how this is news.
...when Gould came up with it 20 years ago.
Seriously, is the author of TFA a moron or what? Punctuated Equilibria is not the same as "Science is wrong!!!11one"
The actual article is available from The Anatomical Record Part B: The New Anatomist" volume 289B, Issue 1 , Pages 38 - 46. The abstract's free, although the article itself may require a subscription or university account. The flareup seems to be with this sentence in the abstract (I haven't read more yet): "In evolutionary terms, extreme spikes in environmental stress make possible the emergence of new genetic and consequent developmental and epigenetic networks, and thus also the emergence of potentially new morphological traits, without invoking geographic or other isolating mechanisms." In other words, a change in the environment puts organisms under extreme stress, overloading the ability of various DNA repair mechanisms to counteract DNA damage and mutation, occasionally resulting in novel, beneficial mutations. Several other posters have already said this really isn't anything new, for instance it's known that some bacteria actively mutate their DNA in response to extreme environmental stress. The author (Schwartz) may be hyping his claims some, but really it looks like a case of the reporter going gonzo, and might be a creationist yahoo to boot.
MrFlibbs' highly rated comment above is suggesting that this theory says environmental stresses could lead to simultaneous mutations in different members of the same species, and the species wouldn't necessarily need a common ancestor for each individual gene. That's certainly different from punctuated equilibrium.
There's nothing in the article that leads me to that reading, though, so yeah, either MrFlibb read the actual research and found something more than the article, or this sounds like total crap.
There are no trails. There are no trees out here.
Wasn't this whole debate put to rest in the luria and Delbruck experiments where they showed random mutation leads to resistance not acquired immunity? Basically showing that the enviromental condition doesn't lead to the evolution it's all random.
"As others have noted, this warm-over of punctuated equilibria is a challenge to Natural Selection as the mechanism of evolution, not to evolution itself. "
I'm not sure what side you are on, but it needs to be made clear that punctuated equilibrium DOES NOT challenge natural selection as the mechanism for evolution. Punctuated equilibrium simply refines the time scales over which natural selection works.
If, for example, the Great Rift Valley in Africa warmed significantly over a few hundred thousand years, this is a natural event. And, if that warming caused forest to turn into plains, this is a natural event. And, if that lack of forest cause certain monkeys to develop taller posture and longer gaits so that they could survive in the new climate, this is a natural event selecting better adapted species to survive. Both Darwin's original theory and P.E. are in agreement on the fact that nature selects the survivors; P.E. simply says that it can happen faster than we thought.
P.E. makes total sense from a mathematicall standpoint. Imagine a cartesian plain (landscape) made up of peaks and valley representing the probability of an animal surviving given a certain set of features. Peaks are successful combinations of features, valleys are combinations that would lead to certain death. In other words, each peak is a niche. At the very beginning of life the landscape is open with successful niches. Randomly combining a set of features will put you, on average, halfway between a peak and valley. So long as no other creatures exists at a higher level on your particular peak, you are the most successful and will probably survive. Moreover, at the beginning of time, it is almost as likely for you to make a huge evolutionary jump and land at another successful niche at another peak. But, over time, creatures evolve to their niches and climb higher on the mountain. Over time it becomes mathematically unlikely to jump from one peak to another AND be more successful in that niche than the existing life forms. Creatures tend to become better and better adapted to their own peaks by making small, tuning changes.
When the equilibrium is punctuated the landscape changes suddenly. Successful niches become deadly and vice versa. The probability of successfully jumping from one peak to another increases, and so does the apparent rate of evolution. That's why evolution seems to work in spurts. We see evidence of this happening again and again: the transition of single celled to multicellular, the age of amphibians, the age of reptiles, the age of dinosaurs (different), the age of mammals, etc. Each age represents a time when life jumped from one configuration to another quickly and then spent millions of years honing those features.
Agree. The article contains many misunderstandings. And, by the way, the article states that he is a professor in the department of history and philosophy of science - actually, he is only an affiliated/adjunct faculty member. (I am a phd there.)
Attitudes make the difference between Space and Time: we want to MAX our temporal, and MIN our spatial extension.
This article, in a word, is bunk. The claims this guy is making are goofy and demonstrably misinformed about what evolutionary theory is.
Some basic background:
Punk eek was opposed to phyletic uniformatism/gradualism (which many consider to have been a cheap straw man anyway). This was a debate over macroevolutionary history: the patterns of large scale morphological and species change. Contrary to popular opinion, macroevolutionary change is subject to all sorts of different forces: things like large scale, genetic drift, extinction events, and so on. No biologist claims that natural selection is the only factor in the particular history of life on earth.
This guy is is not talking about things on the scale of punk eek. He's talking about things on the scale of microevolution, and what he's proposing seems to be a form of saltationism. At best, he's attacking a purported gradualism in actual mutation rates (which itself is nonsense: it's mainstream genetics that different species have all sorts of different mutation rates as well as different rates of morphological change). But for all the rhetoric, nothing he says that's actually correct is even slightly revolutionary. At best, he's proposing another mechanism for variation: variation that involves "good tricks" in a certain genomic sequence that environmental stressors can make happen in many different individuals at once. But variation of ANY sort still just provides the raw material for natural selection to work on. And without natural selection at work, mutation would still be just ultimately random garbage. It's only by placing mutations through the sieve of actually being expressed in individuals that any information about the environment can be imprinted onto a given gene pool. That's the only way we know of that random jostling can be transformed into functional movement. For the mutations to somehow "predict" or "will themselves" to happen in certain linked ways that have a non-random purpose requires some other mechanism, and this guy proposes nothing.
And that's me being the most charitable. Most of the rest of what the guy says is just total nonsense. For instance, he implies that cellular repair systems resist mutation (heck, he even speaks about whether they "willingly" resist change or not!). Well... yes. But they fail. All the time. Most everyone reading this has recent and unique several mutations, right now. And that's not even to mention that you'd have to be grossly misinformed about Darwin to think that "Darwins theory" says ANYTHING about genetic mutation. Darwin hadn't a clue what genes or DNA or the rest of it even were! All he spoke about was the differential success of different variations. Of course, what Darwin thought is irrelevant trivia to what is true in biology, but still, this guy is just showing both his ignorance and his obsession with the idea that Darwin is some sort of "high priest" whom he is fighting against.
Now consider this: "according to Schwartz, mutations occur recessively and are passed unknowingly until the mutation saturates the population. Then, when members of the population receive two copies of the mutation, the trait appears suddenly."
Either the reporter got this wrong, or this guy is really misinformed. Mutations can be recessive or dominant. Nothing about them makes them occur "recessively" only. While the scenario he describes can and does happen (recessive traits that don't really start appearing in force in a population until they become near fixed), nothing about it is particularly revolutionary. And something with complex functionality and specification like fully formed "teeth" is not going to evolve completely out of sight, unexpressed, and then burst onto the scene all at once. That, kids, is called saltation, and while big saltationist jumps can certainly happen (and can spring out via the recessive/dominant pathway), they are very very very unlikely to ever hit upon something functional and useful. Remember: only the actual testing