AUTHOR: Allen MacNeill

SOURCE: The Evolution List (repost)

COMMENTARY: That’s up to you…

I have mentioned several times in other posts that 2008 is the bicentennial of the birth of Charles Darwin and the sesquicentennial of the publication of the Origin of Species. Hundreds of scientific and cultural organizations are gearing up to celebrate Darwin’s birthday on February 12th, proclaiming it the kickoff for the “Darwin bicentennial year”.

However, in a very real sense, today is the first day of that centennial celebration. On the first of July 1858 two papers and two letters were read to the members of the Linnean Society in London. One of the papers, entitled “On the Tendency for Varieties to Depart Indefinitely from the Original Type”, was written by Alfred Russell Wallace. The other paper and the two letters were written by Charles Darwin, and outlined his theory of evolution by natural selection.

The paper by Wallace had been sent to Darwin, with a request by Wallace that if it were of sufficient merit, would he please forward to the society for publication? Darwin was stunned; he had been working on the very same idea for almost twenty years. Here is what he wrote on 18 June 1858 to his friend, the geologist Charles Lyell, following his receipt of Wallace’s paper:

My dear Lyell

Some year or so ago, you recommended me to read a paper by Wallace in the Annals [a natural history journal], which had interested you & as I was writing to him, I knew this would please him much, so I told him. He has to day sent me the enclosed [manuscript] & asked me to forward it to you. It seems to me well worth reading. Your words have come true with a vengeance that I shd be forestalled. You said this when I explained to you here very briefly my views of “Natural Selection” depending on the Struggle for existence.—I never saw a more striking coincidence. if Wallace had my M.S. sketch written out in 1842 he could not have made a better short abstract! Even his terms now stand as Heads of my Chapters.

Please return me the M.S. which he does not say he wishes me to publish; but I shall of course at once write & offer to send to any Journal. So all my originality, whatever it may amount to, will be smashed. Though my Book, if it will ever have any value, will not be deteriorated; as all the labour consists in the application of the theory.

I hope you will approve of Wallace’s sketch, that I may tell him what you say.

My dear Lyell
Yours most truly

C. Darwin

Knowing how long Darwin had labored on his theory, Lyell and botanist Joseph Hooker prevailed on Darwin to allow them to read his unpublished essay on natural selection (written in 1844) and two letters on the same subject from Darwin to Hooker and to the American botanist, Asa Gray, along with Wallace’s paper at the July meeting of the Linnean Society. Neither Darwin nor Wallace attended the meeting (Darwin was at his home at Down, in Kent, mourning the death of his son, Charles, who had died three days earlier; Wallace was still in the Maylay archipelago), and the joint reading raised hardly a ripple of comment.

Despite their lack of notoriety at first, these papers and letters were the first public presentation of the theory that would fundamentally and radically change the way we view ourselves and the natural world around us.

Here are some links to websites with much more information about this sesquicentennial event:

Happy 150th Birthday Natural Selection!

On the Tendency of Species to form Varieties

How Darwin won the evolution race

Darwin, Wallace and The Linnean Society of London

150th Anniversary of the Darwin-Wallace Papers

The Darwin-Wallace Letters of 1858

Fire the starting gun! The Darwin year begins…NOW!

Previous anniversary celebrations

July 1, 1858: Darwin and Wallace Shift the Paradigm

As always, comments, criticisms, and suggestions are warmly welcomed!

–Allen

AUTHOR: Allen MacNeill

SOURCE: The Evolution List (repost)

COMMENTARY: That’s up to you…

Ever since Darwin, the primary “engine” of evolution has been considered to be natural selection. However, if one takes a closer look at this, it is clear that natural selection is not an “engine,” it is an outcome. If evolution is defined as change in the characteristics of the members of a population over time and natural selection is defined as unequal non-random survival and reproduction (or, more parsimoniously, differential reproductive success), then the underlying cause of the changes that are differentially preserved over time is the real “engine” of evolution by natural selection.

And what might this “engine” of change be? Exactly what Darwin said it was in the Origin of Species: the “laws of variation” of which naturalists of his time were almost “completely ignorant.” That is, given that some variations are heritable and that they can be passed from parents to offspring in the process of reproduction, then it is the processes that cause such variations that are the real “engine(s)” of evolution, including evolution by natural selection.

Darwin was on the right track when later on he sought out the specifics of the “engines of variation” in Variation of Animals and Plants Under Domestication, published in 1868. Darwin suggested that the rate of variation changed over time, in response to specific changes in the environment. For example, he pointed out that the variation between domesticated animals and plants was considerably greater than that found in the wild. This suggested to him that something about domestication – increased food, improved nutrition, lack of predators, etc. – caused an increase in the production of variations that were then exploited by animal and plant breeders.

However, it is now generally accepted that the only real difference between domesticated and wild animals and plants, in terms of variation, is that the conditions of domestication allow more variants to survive and reproduce, rather than causing more of them to be produced in the first place. I do not know enough genetics to say whether or not this is the case, but it seems to me at least that Darwin’s idea is worth empirical investigation. Here are the relevant questions (which may or may not already have answers):

• Is the rate of generation of genetic and phenotypic variation a constant?

If the answer to this question is “yes,” then all we need to investigate is the actual genetic and developmental mechanisms by which such variations are generated. However, if the answer is “no,” then the rate of generation of genetic and phenotypic variations is variable, which immediately suggests more questions:

• Is the increased rate of generation of variations correlated with any identifiable factor in either the genetics/development or the environment of organisms in which such variable rates of variation are observed?

If the answer to this question is “no,” then we may safely assume that the underlying “engine(s)” of variation is/are entirely random, insofar as we can observe it changing randomly over time. However, if the answer is “yes,” then there are more questions:

• Via what mechanism(s) is the increased rate of variation generated, and are the “triggers” for such increased variation endogenous, exogenous, or some combination of the two?

Clearly, the “engine(s)” of variation are prodigious, as it/they have been able over time to modify something as simple as a mycoplasm into an oak tree or a blue whale. Some supporters of “intelligent design” (ID) would dispute this statement, of course, claiming (without any empirical evidence) that “you can’t get here from there.” However, we clearly have gotten here from there; the real question is “how?” There are logically at least two possibilities:

• The process(es) by which the “engine(s) of variation” have produced the necessary variation have operated endogenously by means of a prodigious (and undirected) “random variation generator,” the products of which have been sorted over time by natural selection (i.e. the Darwinian hypothesis), or

• The process(es) by which the “engine(s) of variation” have produced the necessary variation have operated endogenously by means of a less prodigious “non-random variation generator,” the products of which have been sorted over time by natural selection (i.e. the ID hypothesis).

Noticing that the only difference between these two possibilities is the amount of variation and its source immediately suggests a way of testing the two hypotheses: do the currently identified mechanisms of genetic and phenotypic variation produce enough variation to get from there to here, or not? If the answer is “yes,” then the ID hypothesis is unnecessary, and therefore irrelevent to science.

So, the next obvious question is, what are the currently identified mechanisms of genetic and phenotypic variation, and do they provide enough variation to get here from there? The answer to this question will be posted soon -watch this space.

And as always, comments, criticisms, and suggestions are warmly welcomed!

–Allen

AUTHOR: Cornelia Dean

SOURCE: New York Times

COMMENTARY: Allen MacNeill

In an unusual foray into electoral politics, 75 science professors at Case Western Reserve University in Cleveland have signed a letter endorsing a candidate for the Ohio Board of Education.

The professors’ favored candidate is Tom Sawyer, a former congressman and onetime mayor of Akron. They hope Mr. Sawyer, a Democrat, will oust Deborah Owens Fink, a leading advocate of curriculum standards that encourage students to challenge the theory of evolution.

Elsewhere in Ohio, scientists have also been campaigning for candidates who support the teaching of evolution and have recruited at least one biologist from out of state to help.

Lawrence M. Krauss, a physicist at Case Western Reserve who organized the circulation of the letter, said almost 90 percent of the science faculty on campus this semester had signed it. The signers are anthropologists, biologists, chemists, geologists, physicists and psychologists.

The letter says Dr. Owens Fink has “attempted to cast controversy on biological evolution in favor of an ill-defined notion called Intelligent Design that courts have ruled is religion, not science.”

In an interview, Dr. Krauss said, “This is not some group of fringe scientists or however they are being portrayed by the creationist community,” adding, “This is the entire scientific community, and I don’t know of any other precedent for almost the entire faculty at an institution” making such a statement.

But Dr. Owens Fink, a professor of marketing at the University of Akron, said the curriculum standards she supported did not advocate teaching intelligent design, an ideological cousin of creationism. Rather, she said, they urge students to subject evolution to critical analysis, something she said scientists should endorse. She said the idea that there was a scientific consensus on evolution was “laughable.”

Although researchers may argue about its details, the theory of evolution is the foundation for modern biology, and there is no credible scientific challenge to it as an explanation for the diversity and complexity of life on earth. In recent years, with creationist challenges to the teaching of evolution erupting in school districts around the country, groups like the National Academy of Sciences, perhaps the nation’s pre-eminent scientific organization, have repeatedly made this point.

But the academy’s opinion does not matter to Dr. Owens Fink, who said the letter was probably right to say she had dismissed it as “a group of so-called scientists.”

“I may have said that, yeah,” she said.

She would not describe her views of Darwin and his theory, saying, “This isn’t about my beliefs.”

School board elections in Ohio are nonpartisan, but Dr. Owens Fink said she was a registered Republican. Her opponent, Mr. Sawyer, was urged to run for the Seventh District Board of Education seat by a new organization, Help Ohio Public Education, founded by Dr. Krauss and his colleague Patricia Princehouse, a biologist and historian of science, and Steve Rissing, a biologist at Ohio State University.

At the group’s invitation, Kenneth R. Miller, a biologist at Brown University, will be in Ohio today through the weekend campaigning for other school board candidates who support the teaching of evolution. Dr. Miller, an author of a widely used biology textbook, was a crucial witness in the recent lawsuit in Dover, Pa., over intelligent design. The judge in that case ruled that it was a religious doctrine that had no place in a public school curriculum.

After that decision, Dr. Owens Fink said, the Ohio board abandoned curriculum standards that mandated a critical look at evolution, a decision she said she regretted. “Some people would rather just fold,” she said.

But Dr. Miller said it was a good call, adding, “We have to make sure these good choices get ratified at the ballot box.”

COMMENTARY:

Once again Ohio is the battleground in the ongoing culture wars. A similar change in the composition of a state board of education happened in Kansas earlier this year. It will be interesting to see what happens in Ohio, especially in the context of what many are beginning to perceive as a “glacial shift” in Ohio politics, away from religious conservatism and the Republican party and toward a more tolerant and pluralistic libertarianism, as exemplified by Tom Sawyer (even his name resonates in American cultural history). Whether the Democrats can finally become vertebrates and take a principled position on this and related issues remains to be seen…

–Allen

AUTHOR: Christopher Ryan

SOURCE: Evolutionary Psychology

COMMENTARY: Allen MacNeill

The following question was asked on the Evolutionary Psychology list:

“…[W]e look to the EEA for the origins of the design of the human mind (modules, and so on) precisely because the structures in question change so slowly. If, on the other hand, it is demonstrated that complex physiological (and, presumably, psychological) structures can arise and disappear in as few as twenty generations, then of what relevance is the EEA to our discussions here?…Does Gould’s punctuated equilibria theory integrate such rapid evolutionary change? And is it accepted by the folks working in [evolutionary psychology]? If so, why do we spend so much time discussing adaptations that have likely been replaced long ago?”

To which I replied:

Eldredge and Gould, like the vast majority of other evolutionary biologists (beginning with Darwin and including such luminaries as Ernst Mayr) studied animals almost exclusively. It now appears that the equilibrium/stasis pattern that characterizes macroevolution in animals is at least partly an artifact of their developmental biology. Specifically, the hierarchical control of gene regulation in animals via homeotic genes makes possible surprisingly rapid phenotypic change without correspondingly large changes in genotype (i.e. the old “modern synthesis” has been superceded by the new “evo-devo”).

Therefore, it is quite possible (indeed, likely) that relatively slight changes in genetic regulation of development have caused the remarkable changes in hominid phylogeny reflected in the fossil record. This has already been shown to be the case for the FOX-2-P gene, and just last month for the HAR-1-F gene (see “And the winner of the fastest gene award…”), slight changes in both of which have been correlated with significant changes in the human phenotype (both in the direction of greater neoteny, by the way).

So, it is quite possible that humans have changed significantly over the past 40,000 years, and perhaps not just via purely cultural means. It is still an open question just how much of our behavior is affected by our underlying genetics, and how quickly such relationships can change (and under what conditions). And, if new research in epigenetics is any indication, such changes may be even more common and rapid than has been heretofore suspected. Nutrition during early development, chronic stress (including chronic stress in utero), and exposure to certain environmental chemicals have all been implicated in altering gene regulation, and some such alterations have been shown to be heritable (shades of Lamarck!), thereby challenging further the “standard social science model” so vilified by Pinker and other EPers.

Therefore, the EEA for some current “modules” may not date to the Pleistocene, but rather to much later periods, including (but not limited to) events in historical times. Indeed, since relative reproductive success, rather than absolute numerical differences, is the basis for natural selection (and therefore adaptation), it may be that such seemingly cultural processes as warfare, migration (including forced migration via slavery), and religious practices involving both celibacy and increased procreation (via religious prohibition of contraception) may all have played significant roles in the shaping of the human behavioral phenotype via correlated alterations in the expression of genes affecting behavior.

In a nutshell, then, the answer is yes: since humans are animals (like those studied by Eldredge and Gould), it is quite possible that punctuated equilibrium theory is applicable to human evolution, including behavioral evolution, and that further investigations into the relationship between gene regulation, development, and human behavior may yield productive, testable hypotheses about such relationships.

At the risk of blowing my own horn, I have attempted to propose such a hypothesis for the evolution of the capacity for religious experience (see: “The Capacity for Religious Experience is an Evolutionary Adaptation to Warfare”):

“The pan-specific qualities of both religious experience and warfare indicate that they are both evolutionary adaptations. There is considerable variation between individuals with respect to their capacity for religious experience and motivation to participate in warfare. Selective advantages for participation in warfare accrue to both winners and losers as long as the benefits of participation exceed the average costs. These selective advantages, primarily in the form of differential reproductive success, accrue to males when they are on the winning side in a war, and often to females no matter which side they are on.”

“Recent work on the evolutionary dynamics of religion have converged on a “standard model” in which religions and the supernatural entities which populate them are treated as epiphenomena of human cognitive processes dealing with the detection of and reaction to agents under conditions of stress, anxiety, and perceived threat. Religious experience at the individual level is characterized by depersonalization, coupled with submission to a super-individual force; the same is essentially the case for participation in warfare. The capacities for both religious experience and participation in warfare are adaptations insofar as they evolve by means of natural selection operating primarily at the level of individuals who are members of groups in which both kin selection and reciprocal altruism are also operative. It is likely that the overall patterns of supernatural organization exist as the result of coevolution between the memetic content of religious beliefs and the underlying neurological matrix within which such beliefs are maintained and transmitted in the context of specific ecological subsistence patterns.”

–Allen

Evangelists Want Fossil Exhibits Kept Out Of Sight

Robin McKie, science editor
Sunday September 10, 2006
The Observer
http://www.guardian.co.uk/science/story/0,,1868955,00.html

The world’s most important collection of human fossils may soon be hidden from public view - if religious leaders get their way.

In a move that has stunned scientists, senior clergy have demanded that the bones and skulls currently exhibited in Nairobi’s National Museum of Kenya be removed from display to prevent young Africans from being corrupted.

‘It’s creating a big weapon against Christians that’s killing our faith,’ said Bishop Boniface Adoyo, who is leading the hide-the-bones campaign. ‘When children go to museums they’ll start believing we evolved from these apes.’ Not surprisingly, the bishop’s remarks have infuriated scientists who consider the museum’s collection to be unrivalled anywhere else in the world. Its fossils include those of the 4 million-year-old apeman, Australopithecus anamensis, the 1.5 million-year-old remains of the Nariokotome boy, the most complete skeleton of an ancient human ever found, and a series of other bones that highlight crucial phases of our evolutionary past.

Many of these fossils were discovered by palaeontologists Louis and Mary Leakey in areas around Lake Victoria and Lake Turkana and are generally regarded as providing stark demonstrations of how our species was shaped by natural selection.

Their son, Richard Leakey, and his wife Maeve, have continued this fossil-hunting tradition. They too have been dismayed by the bid to suppress the museum’s fossils. ‘The church is being ridiculous,’ said Richard Leakey. ‘Its leaders are out of step. Evolution theory is accepted across the world. This is scientific history and Kenya has the best of this evolutional history. Globally, few can match that claim to fame.’

The National Museum of Kenya is currently preparing to reopen next year after completing massive EU-funded renovations. As part of that work a special exhibit, The Origins Of Man, which displays the key finds around Africa’s Great Rift Valley - considered by many the cradle of humanity - is now being set up.

However, it is this display that African evangelicals say they find offensive, because it promotes Darwin’s theory of evolution. As a result, they are demanding that the display be removed or at least shunted to a less prominent location.

‘When museums put it out there that man evolved from apes, theologically they are affecting many people who are Christians, who believe God created us,’ says Bishop Adoyo, the chairman of the Evangelical Alliance of Kenya, which claims to represent churches of 35 denominations with nine million members.