Evolution Research - Main Blog

[Siebert, New York Times, Jan '06]

Extract:

...

Anderson and Mather's resulting 1993 paper in the Journal ofComparative Psychology, entitled "Personalities of Octopuses," was notonly the first-ever documentation of personality in invertebrates. Itwas the first time in anyone's memory that the term "personality" hadbeen applied to a nonhuman in a major psychology journal.

Scientists are not typically disposed to wielding a word like"personality" when talking about animals. Doing so borders on thescientific heresy of anthropomorphism. And yet for a growing number ofresearchers from a broad range of disciplines - psychology,evolutionary biology and ecology, animal behavior and welfare - it isbecoming increasingly difficult to avoid that term when trying todescribe the variety of behaviors that they are now observing in anequally broad and expanding array of creatures, everything fromnonhuman primates to hyenas and numerous species of birds to waterstriders and stickleback fish and, of course, giant Pacific octopuses.

In fact, in the years since Anderson and Mather's original paper, awhole new field of research has emerged known simply as "animalpersonality." Through close and repeated observations of differentspecies in a variety of group settings and circumstances, scientistsare finding that our own behavioral traits exist in varying degrees anddimensions among creatures across all the branches of life's tree...

Full text at:

http://www.gan.ca/animal+news.en.html?neid=72

PDF version:

http://www.udel.edu/anthro/ackerman/animal.pdf

Charles Siebert also appeared on the radio show "Animal Personality" along with Sam Gosling, Psychologist and founder of the Animal Personality Institute at the University of Texas, and Terry Curtis, Vetinary Behaviorist with the University of Florida College of Vetinary Medicine:

http://www.onpointradio.org/shows/2006/01/20060123_b_main.asp

John

Model of an Internal Evolutionary Mechanism
http://members.aol.com/jorolat/index.html

[Richardson et al., Evolution and Development, Jan '04]

Summary:

There is an active debate about how skeletal elements are encoded along the proximodistal (PD) axis of the developing limb. Our aim here is to see whether consideration of the evolutionary morphology of the limb can contribute to our understanding of patterning mechanisms. Of special interest in this context are animals showing reiterated skeletal elements along the PD axis (e.g., dolphins and plesiosaurs with hyperphalangy). We build on previous hypotheses to propose a two-step model of PD patterning in which specification of broad domains in the early limb bud is distinct from subsequent processes that divides an initial anlage into a segmental pattern to yield individual skeletal elements. This model overcomes a major evolutionary problem with the progress zone model, which has not previously been noted: pleiotropy. Parallels with other developmental systems are briefly discussed.

(IA) Full text at: here

John Latter / Jorolat

Model of an Internal Evolutionary Mechanism
http://members.aol.com/jorolat/index.html

technorati tags: Internal+Evolutionary+Mechanism, john+latter, jorolat, proximodistal, evolution, development, axis, developing, limb, evolutionary, morphology, animals, dolphins, plesiosaurs, hypotheses, domains, bud, processes, model, pleiotropy

[Weiss & Buchanan, Evolutionary Anthropology, Sept '00]

Research Article - No abstract is available so I've included some of the highlighted text:

Anthropological geneticists would uniformly count themselves as Darwinians, but our work has been largely restricted to the evolution of genes chosen as markers for reconstructing temporal and geographic history, often intentionally stripped of any other biological content, relying on chance (genetic drift) as the calibrating phenomenon. The rest of biological anthropology has mainly been concerned with the Darwinian evolution of human and primate traits (phenotypes), relying on deterministic adaptation as the calibrating phenomenon...

...Initially, the idea of genes based on the modern synthesis was classically Darwinian: natural selection screened genetic variation and favored the best-adapted. Beginning in the 1950s, advances in genotyping methodology revealed much more variation than had been anticipated...

...To the extent that genetics is at the root of biology, our understanding will be fundamentally incomplete if we do not know how genes affect the assembly, variation, and evolution of a trait...

...Thinking of traits and genes in terms of interaction may be more difficult than thinking of genes as separable components of an engineered structure but, whether we like it or not, may be the biological reality...

...Has our nearly centuryold love affair with genes, driven by the theoretical focus on their presumed biological primacy, led to an exaggerated reductionism in our attempt to understand phenotypes and their evolution?...

Full text at:

http://www.anthro.psu.edu/weiss_lab/papers/WeissBuchanan.pdf

John

Model of an Internal Evolutionary Mechanism
http://members.aol.com/jorolat/index.html

Contents:

1) Researchers evolve a complex genetic trait in the laboratory (Press Release)

Duke University biologists have evolved a complex trait in the laboratory -- using the pressure of selection to induce tobacco hornworms to evolve the dual trait of turning black or green depending on the temperature during their development. The biologists have also demonstrated the basic hormonal mechanism underlying the evolution of such dual traits. Their experiments, they said, offer important insight into how complex traits involving many genes can abruptly "blossom" in an organism's evolution...

..."It's long been known that polyphenisms are controlled by hormones, with the brain sensing environmental signals and altering the pattern of hormonal secretions," said Nijhout. "In turn, these hormonal patterns turn sets of genes on or off to produce different traits. However, we understood only the developmental mechanism, and how it is possible with a single genome in an animal to produce two very different phenotypes," he said...

..."Homeostatic mechanisms tend to stabilize a phenotype such as color and, therefore, allow the accumulation of underlying, covert mutations just as an electrical capacitor acts to accumulate charge. And eventually, these mutations could 'break out' of that constraint to produce a sudden phenotypic change; and one way for them to break out is for a mutation to happen -- for example, one that alters a hormonal level -- releasing all this variation.

Full text at:

http://www.eurekalert.org/pub_releases/2006-02/du-rea012706.php


2) Evolution of a Polyphenism by Genetic Accommodation (Science)

[Suzuki & Nijhout, Science, Feb '06]

Abstract:

Polyphenisms are adaptations in which a genome is associated with discrete alternative phenotypes in different environments. Little is known about the mechanism by which polyphenisms originate. We show that a mutation in the juvenile hormone-regulatory pathway in Manduca sexta enables heat stress to reveal a hidden reaction norm of larval coloration. Selection for increased color change in response to heat stress resulted in the evolution of a larval color polyphenism and a corresponding change in hormonal titers through genetic accommodation. Evidently, mechanisms that regulate developmental hormones can mask genetic variation and act as evolutionary capacitors, facilitating the origin of novel adaptive phenotypes.

http://www.sciencemag.org/cgi/content/abstract/311/5761/650

This is very interesting stuff from my point of view but as usual I don't have a subsciption to Science ('sigh').

John

Model of an Internal Evolutionary Mechanism
http://members.aol.com/jorolat/index.html

Can anyone help me find the 'obscure' paper by JM Clarke that Niles Eldredge refers to on page 64 of "Time Frames"? A scan of the page is available here:

http://members.aol.com/jorolat/trilobite.html

In fact I would be grateful for any information regarding the appearance of the fibonacci series in the lens arrangement of trilobite eyes!

If you know the citation (or better still, have a copy) then please email me or post here.

NB This isn't the paper I'm looking for:

CLARKE, J. M. 1889. The structure and development of the visual area in the trilobite Phacops rana Green. Journal of Morphology, 2:253270.)

Finally, I emailed Niles Eldredge and he said "I've lost touch with it [the paper]--journal such as American Naturalist..". I don't have a subsciption to Jstor but someone did a search of American Naturalist on my behalf but couldn't find anything ('sigh').

John

Model of an Internal Evolutionary Mechanism
http://members.aol.com/jorolat/index.html

technorati tags: trilobite, trilobite+eyes, time+frames, niles+eldredge, fibonacci, fibonacci+series, american+naturalist, jm+clarke, john+latter, jorolat

[Gould, Discover Magazine, May '81 ]

Essay:

Kirtley Mather, who died last year at age ninety, was a pillar of both science and Christian religion in America and one of my dearest friends. The difference of a half-century in our ages evaporated before our common interests. The most curious thing we shared was a battle we each fought at the same age. For Kirtley had gone to Tennessee with Clarence Darrow to testify for evolution at the Scopes trial of 1925. When I think that we are enmeshed again in the same struggle for one of the best documented, most compelling and exciting concepts in all of science, I don't know whether to laugh or cry.

According to idealized principles of scientific discourse, the arousal of dormant issues should reflect fresh data that give renewed life to abandoned notions. Those outside the current debate may therefore be excused for suspecting that creationists have come up with something new, or that evolutionists have generated some serious internal trouble. But nothing has changed; the creationists have presented not a single new fact or argument. Darrow and Bryan were at least more entertaining than we lesser antagonists today. The rise of creationism is politics, pure and simple; it represents one issue (and by no means the major concern) of the resurgent evangelical right. Arguments that seemed kooky just a decade ago have reentered the mainstream.

The basic attack of modern creationists falls apart on two general counts before we even reach the supposed factual details of their assault against evolution. First, they play upon a vernacular misunderstanding of the word "theory" to convey the false impression that we evolutionists are covering up the rotten core of our edifice. Second, they misuse a popular philosophy of science to argue that they are behaving scientifically in attacking evolution. Yet the same philosophy demonstrates that their own belief is not science, and that "scientific creationism" is a meaningless and self-contradictory phrase, an example of what Orwell called "newspeak."

In the American vernacular, "theory" often means "imperfect fact"—part of a hierarchy of confidence running downhill from fact to theory to hypothesis to guess. Thus creationists can (and do) argue: evolution is "only" a theory, and intense debate now rages about many aspects of the theory. If evolution is less than a fact, and scientists can't even make up their minds about the theory, then what confidence can we have in it? Indeed, President Reagan echoed this argument before an evangelical group in Dallas when he said (in what I devoutly hope was campaign rhetoric): "Well, it is a theory. It is a scientific theory only, and it has in recent years been challenged in the world of science—that is, not believed in the scientific community to be as infallible as it once was."

Well, evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts do not go away when scientists debate rival theories to explain them. Einstein's theory of gravitation replaced Newton's, but apples did not suspend themselves in mid-air, pending the outcome. And humans evolved from apelike ancestors whether they did so by Darwin's proposed mechanism or by some other, yet to be discovered.

Full text at:

http://www.stephenjaygould.org/ctrl/gould_fact-and-theory.html

and

http://www.georgealozano.com/teach/evolution/papers/Gould1980.pdf

John

Model of an Internal Evolutionary Mechanism
http://members.aol.com/jorolat/index.html

[Weiss & Sholtis, Evolutionary Anthropology, Nov '03]

Occasionally traits arise that appear to be atavistic throwbacks to the remote past. How can this make evolutionary sense?

As we get older we have a tendency to become nostalgic and think back on old times. We've recently seen a surge of nostalgia for the 1950s; among the remarkable comebacks are the new old diners, like Baby's here in State College (Figure 1). These new-old wonders proffer burgers and shakes like they used to be in the good old days. The decades of change in the competitive fast-food industry seem not to matter at all. The old taste is back! Even Patsy Cline and Elvis are still singing the same songs in the background.

There is a similar phenomenon in biology. Nobody accepts Ernst Haeckel's famous recapitulation argument that, as embryos, we literally go through the adult stages of our ancestors. Nonetheless, many seem to think the evolutionary past can rise again.
Can it?

Full text at:

http://nitrogen.la.psu.edu/weiss_lab/CQ/CQ11_DinnerAtBabys.pdf

John

Model of an Internal Evolutionary Mechanism
http://members.aol.com/jorolat/index.html

'Evolution - Where Darwin meets Lamarck?' places an emphasis on concepts and discoveries consistent with the possible existence of testable internal evolutionary mechanisms and alternative (non-creationist) explanations for 'problem areas' of conventional evolutionary theory.

In their paper "The Spandrels of San Marco and the Panglossian Paradigm" Gould and Lewontin briefly described the European concept of Bauplan ('bodyplan') which, in its 'strong' form, speculates:

"But the important steps of evolution, the construction of the Bauplan itself and the transition between Baupläne, must involve some other unknown, and perhaps 'internal,' mechanism."

An internal mechanism cannot be 'mystical' simply because, if one exists, then it would be testable. This suggests the concept ought to evoke no greater uncertainty than appropriate to the words of Einstein:

"If we knew what we were doing, we wouldn't call it research, would we?".

technorati tags: Baupläne, bauplan, darwin, lamarck, forum, paradigm, john+latter, jorolat