Pitt Professor's Theory of Evolution Gets Boost From Cell Research [Sudden Origins]

Jeffrey H. Schwartz's Sudden Origins closed Darwin's gaps; cell biology explains how.

An article by University of Pittsburgh Professor of Anthropology Jeffrey H. Schwartz and University of Salerno Professor of Biochemistry Bruno Maresca, to be published Jan. 30 in the New Anatomist journal, shows that the emerging understanding of cell structure lends strong support to Schwartz's theory of evolution, originally explained in his seminal work, Sudden Origins: Fossils, Genes, and the Emergence of Species (John Wiley & Sons, 2000).

In that book, Schwartz hearkens back to earlier theories that suggest that the Darwinian model of evolution as continual and gradual adaptation to the environment glosses over gaps in the fossil record by assuming the intervening fossils simply have not been found yet. Rather, Schwartz argues, they have not been found because they don't exist, since evolution is not necessarily gradual but often sudden, dramatic expressions of change that began on the cellular level because of radical environmental stressors-like extreme heat, cold, or crowding-years earlier.

Determining the mechanism that causes those delayed expressions of change is Schwartz's major contribution to the evolution of the theory of evolution. The mechanism, the authors explain, is this: Environmental upheaval causes genes to mutate, and those altered genes remain in a recessive state, spreading silently through the population until offspring appear with two copies of the new mutation and change suddenly, seemingly appearing out of thin air. Those changes may be significant and beneficial (like teeth or limbs) or, more likely, kill the organism.

Why does it take an environmental drama to cause mutations? Why don't cells subtly and constantly change in small ways over time, as Darwin suggests?

Cell biologists know the answer: Cells don't like to change and don't do so easily. As Schwartz and Maresca explain: Cells in their ordinary states have suites of molecules- various kinds of proteins-whose jobs are to eliminate error that might get introduced and derail the functioning of their cell. For instance, some proteins work to keep the cell membrane intact. Other proteins act as chaperones, bringing molecules to their proper locations in the cell, and so on. In short, with that kind of protection from change, it is very difficult for mutations, of whatever kind, to gain a foothold. But extreme stress pushes cells beyond their capacity to produce protective proteins, and then mutation can occur.

This revelation has enormous implications for the notion that organisms routinely change to adapt to the environment. Actually, Schwartz argues, it is the environment that knocks them off their equilibrium and as likely ultimately kills them as changes them. And so they are being rocked by the environment, not adapting to it.

The article's conclusions also have important implications for the notion of “fixing” the environment to protect endangered species. While it is indeed the environment causing the mutation, the resulting organism is in an altogether different environment by the time the novelty finally escapes its recessive state and expresses itself.

“You just can't do a quick fix on the environment to prevent extinction because the cause of the mutation occurred some time in the past, and you don't know what the cause of the stress was at that time,” Schwartz said.

“This new understanding of how organisms change provides us with an opportunity to forestall the damage we might cause by unthinking disruption of the environment,” added Schwartz. “The Sudden Origins theory, buttressed by modern cell biology, underscores the need to preserve the environment-not only to enhance life today, but to protect life generations from now.”

Schwartz, with his colleague Ian Tattersall, curator of anthropology at the American Museum of Natural History in New York, also authored the four-volume The Human Fossil Record (Wiley-Liss, 2002-05). Together, the volumes represent the first study of the entire human fossil record. Volume 1 was recognized by the Association of American Publishers with its Professional Scholarly Publishing Award. In 1987, Schwartz's The Red Ape: Orang-utans and Human Origin (Houghton Mifflin Company) was met with critical acclaim.

Schwartz, who also is a Pitt professor of the history and philosophy of science, was named a fellow in Pitt's Center for the Philosophy of Science and a fellow of the prestigious World Academy of Arts and Science.

The journal, The New Anatomist, is an invitation-only supplement to the Anatomical Record.

That said, natural selection is the whole game. And that's not random. But I suppose mine is a fringe view.

Not fringe at all. I've long been in the midst of the non-random camp, regarding my own work and that of most of my colleagues.

There are selective pressures we don't yet measure well, but cosmic radiation is a potent stressor on animal cellular division, especially during meitotic and meioitc phase. The problem assigning randomness to this process becomes apparent when we look at phenotypical outcomes---there's huge differences in responsiveness by cellular types (e.g. somatic vs gamete cells), and, when these cells of various types are taken in the context of a multicellular organism, the phenotypical expression is clearly biased, as a result of the physiologic response, and is manifested in terms of adaptiveness.

The point is that stressors are stressors only in as they are measured by the response of the life form. Maybe cosmic radiation is random, I don't know. But the response to it is not, and that is evolution.

Clinicians refer to the same concept as "vulnerability," wherein some patients prosper under the same stress which causes others great distress.

I too could use some explanation of this if you could take the time. Its far outside of my studies (you know how it is, just scrabblin' around in the dirt isn't physics).

I haven't read the actual paper, so all I have to go on is the article here. And there's no telling how accurately it might be describing the paper -- I've long been appalled at the ability of reporters to totally garble things when they attempt to report on science.

But just going by the article, it sounds rather questionable.

The first thing that strikes me is that the guy published a mass-market book first, *then* submitted a paper on it. I have to wonder if the main purpose of the paper is to advertise his book.

In any case, the argument sounds muddled (although again, this could be the reporter's fault). While it's true that environmental stresses can trigger higher mutation rates (and this has been known since the 1960's -- see the citations in my post #35), there's nothing "special" about the resulting mutations, they're just more instances of the kinds of mutations that occur anyway.

Also, the article makes a number of inaccurate claims and implications. If they're the reporter's fault, fine, but if the researcher made them, he's revealing a shocking level of incompetence and his "findings" are likely nonsense. For example, it says:

Why does it take an environmental drama to cause mutations? Why don't cells subtly and constantly change in small ways over time, as Darwin suggests?

Actually, they *do* change in "small ways over time" even without "environmental drama". Despite the cell's error-correction and preventative machinery, mutations do still happen on a regular basis. So the article's line, "But extreme stress pushes cells beyond their capacity to produce protective proteins, and then mutation can occur" is very misleading, since mutations "can occur" and do occur at any time -- they just occur *more often* when the cell is under stress.

And all the article's comments about how some mutations can be recessive in effect and only manifest effects much later (i.e., after many more generations have occurred) applies to *all* mutations, not just ones that might have been induced by environmental stress. If "dramatic expressions of change" can occur due to stress-induced mutations, they can equally occur due to mutations which occur at times not under stress.

The stress has nothing to do with it -- if "dramatic change" can occur in a "hopeful monster" kind of way, as the article implies, then it can happen with *or* without stress. At most, perhaps a case could be made that they might occur more *often* under times of stress, but the same goes for "regular" evolutionary change as well.

So the article's apparent linkage between stress and "big change" is very questionable, to say the least. He has yet to establish that such "dramatic changes" even actually occur. Certainly nothing about the nature of recessive mutations would make "dramatic changes" any more likely or more likely viable (as mentioned in a previous post, small changes are *far* more likely to be viable and advantageous than "dramatic" ones). The only thing "special" about recessive mutations is that they don't reveal themselves immediately (i.e. in the first generation in which they arise), but that doesn't make their effects any larger, any more "dramatic", or any more viable. And they're no more "sudden" than any other kind of mutation, since whenever they eventually manifest, it's as "sudden" a first appearance as that of a mutation which manifests as soon as it first occurs.

The article also says, "Actually, Schwartz argues, it is the environment that knocks them off their equilibrium and as likely ultimately kills them as changes them. And so they are being rocked by the environment, not adapting to it." This is... odd. Yes, they are being "rocked by the environment", but they are *also* adapting to it -- it's not an either/or thing. In fact, the "rocking" creates additional selective pressures on the population, *causing* adaptation to accelerate. They go hand in hand. They can also go extinct, of course, if the "rocking" is too extreme to survive or if the adaptation can not quickly enough adjust to the new conditions.

Even stranger is:

“You just can't do a quick fix on the environment to prevent extinction because the cause of the mutation occurred some time in the past, and you don't know what the cause of the stress was at that time,” Schwartz said.

Um... Where do I start? Even if "the mutation occurred some time in the past", that has *nothing* to do with being able to "do a quick fix on the environment to prevent extinction". So a mutation was introduced into the population as a result of environmental stress... So what? How in the heck does that have anything to do with "fixing" the environment to remove the factor that is causing a population to decline towards extinction? It's not like the population has already adapted to the new environment due to the mutation, or else it wouldn't still be heading towards extinction. Furthermore, the mutation may have done nothing to aid the population in adapting -- it's just a random mutation that's emerging and has yet to be acted upon by selection. It may even *hurt* the population relative to the new environment. So again, why does Schwartz think that the mutation is even relevant in any way when it comes to doing "quick fixes" to save the population from extinction?

If the population is declining due to environmental change X, then removing X and reverting the environment back to its original condition -- the condition that the population was thriving in originally -- should stop the population's decline WITH OR WITHOUT any mutations that might or might not have been induced in the meantime.

Maybe there's more to it than mentioned in the article, but I get the impression that Schwartz has strayed out of his field of expertise, and is making naive mistakes in genetics, population dynamics, and ecology.

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