Adam, Eve, and human population genetics: addressing critics—Poythress, chimpanzees, and DNA identity (Part 1) | The BioLogos Forum

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Rereading your post, I could concede that evolution relies on both competition and mutualism, but it is absurd to deny the reality of both intra- and interspecific competition. It is intraspecific competition that leads to the establishment of territories and to a “floating reserve” of non-territorial males in many bird species, for example.

As for the sea lamprey, it is actually an anadromous fish, which means it can live in both fresh and saltwater. There had been a landlocked population of lampreys in Lake Ontario before the construction of the Welland canal allowed them to invade the Upper Great Lakes. The sea lamprey is almost a parasitoid, in that it often causes the death of the host.

It is also a stretch to say that Lovelock established the basis of modern ecology - most people in the field would grant that honor to Robert MacArthur or to G. Evelyn Hutchinson.

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Roger,

As you can see, your post opened my floodgates - my graduate research was in ecological competition, and thoughts and ideas keep swirling in my head. Here are a few more observations, in no particular order:

The most undeniable form of intraspecific competition is sexual competition between males - we observe it in species as different as bighorn sheep, lions and rhinoceros beetles.

Dawkins is a popularizer, not a serious ecologist; most practicing ecologists would tell you that both intra- and interspecific competition structure communities (along with predation and many other processes, of course). The “selfish gene” model is almost a caricature of reductionism. It is the organism in the entirety of its relationships and interactions that either dies or survives - not individual genes!

[quote=“Relates, post:59, topic:445”]
neither one of them favorites of evolutionists
[/quote]What exactly is an “evolutionist”? Is it the same as an evolutionary biologist, or is it a term of disparagement?

You seem to find it distasteful that the dark Malthusian mechanism of competition (I am paraphrasing one of your earlier posts) is one of the drivers of evolution; I am curious as to whether you find predation equally distasteful?

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Dan, thanks for not being flippant as so many people are. I had a look at your examples. Aside with the difficulty in sometimes having different definitions of species, it still appears that in all these cases, there is a capability to interbreed, even if the organisms do not necessarily choose to do so. So in that sense, the species has not changed, and the greater genetic variability of the parents has simply been narrowed down into less diverse subspecies or groups. The stickle backs are still sticklebacks, the salamanders still salamanders, and the killer whales still killer whales. To use the human example, the difference between the fat-lipped black ugandans and the red-haired thin lipped irishmen, and the heavy browed australian aboriginals is quite significant, and populations isolated (at least for a time) so they in fact did not interbreed, and yet we know they are all the same species. I am rather surprised that no mention has been made of the wolphin. We have even discovered that an false killer whale and a bottlenose dolphin can breed to produce a fertile hybrid. So their breeding would indicate same species by definition, unless the definition of species has changed. In any case, what it does for me is indicate that species are or were much more genetically variable than we supposed.

So what is necessary is to document the kinds of changes that lead a variety of cat to become a dog, or some such thing involving significant differences other than size, shape or color. We know even all the dogs, bred thru intelligent breeding methods, have very many significant different traits, but are still all the same species. This is a good example of different traits not creating different species. It makes sense that any difference in traits in other species that are not more significant than the differences in varieties of dogs and cats, cannot logically be held up as speciation examples.

But what is also significant is that if we have speciation where all that has happened is a loss of genetic options, or a loss of genetic variabiltiy, then the species change is very limited and specific. We would still need evidence that a less complex species has parented a more complex species. ie. a bacteria or sponge into an ammonite or trilobite or some such thing.

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@Daniel wrote:
> Darwin was appalled by social Darwinism - it is simply not fair to tar him with that brush!

Thank you for your replies. Did you miss my understanding of predation above? The fact is that ecology works to adapt species and individuals to their environments so the whole prospers.

The important thing and this is where I think ecology and evolution differ is that for NeoDarwinism genetic mutation produces change. For ecology environmental change produces changes in species. The most notable example is the extinction of the dinosaurs caused by the change of climate of the earth, not by conflict with other life forms. This climate change also opened many new ecological niches which produced many new species as life forms of many kinds migrated and adapted to the new ecological situations.

Thus ecological evolution, as opposed to Darwinian evolution,. sees the changes if the earth’s surface and climate as the driving forces of evolution including our own, not blind genetic mutation.

In terms of Darwin and Dawkins, we are speaking about ideas and not people. The concept of survival of the fittest, the phrase which Darwin did not coin, but did accept in later editions of The Origin did become the ideological basis of Social Darwinism and Eugenics. I do not know about you but Social Darwinism is still very much alive in Libertarian thinking and politics in the US.

Dawkins uses his scientific theory to justify his new atheism. If his understanding of evolution is wrong, then scientists need to speak out against his views. Since some but only a relatively few seem not to do so, I would say that either they do not disagree or they are so influenced by a siege mentality so that they are afraid to do so. In any case it seems to me that it is my responsibility to speak out against error, regardless of who makes it, and I would certainly not underestimate the influence of Mr. Dawkins, Mr. Dennett, and Co.

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Roger,

Maybe we are talking in circles; genetic mutation provides the raw material on which natural selection acts in order to adapt organisms to a changing environment. You can’t say “environmental change produces changes in species” - that’s Lamarckianism! Change in populations will not occur, regardless of changing environments, unless there is a background of genetic diversity (generated by mutation) for selection to act upon. There is no conflict between modern evolutionary theory and modern ecology; as a matter of fact, I teach a 4000 level course entitled “Ecology & Evolution” - and yes, I teach at a CCCU University.

Most scientists I know don’t think much of Dawkins as a scientist, even though you may be right about the “siege mentality”. I think even less of him as an amateur theologian.

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@Daniel

Dan,

thank you for your response. For years I have been saying that Evolution as defined by Darwin has two different aspects, Variation and Natural Selection. Darwinism using modern genetics does a half way decent job of understanding Variation. However Natural Selection does not work based on Malthusian population theory as Darwinism thought. Symbiosis is much better way to understand Natural Selection.

> You can’t say “environmental change produces changes in species” - that’s Lamarckianism!

Now you throw the L word at me. That is not the way to do science. You are right, we have change when the ability to make the change and the need for the change come together.

One problem which the genetic point of view is that there are other ways to solve problems. Humans and other animals as well as plants team up with other life forms to perform the tasks they by themselves are not equipped by their genes to do, like the proverbial sharks and the pilot fish. Humans have billions of symbiots, who are not human, living in our bodies doing tasks our cells cannot do.

As I see it, every new allele is an experiment. If it is the right form at the right time, it leads to great change. Most alleles do not bring great change, but they might contain seeds of significant change. Some alleles just don’t work and never see the light of day or die a quick death.

What it is, is trying to find the right key for the right lock. Now the key is Variation and the lock is the environment or Natural Selection. There are many possible keys, but only one or a few fit the lock. In my opinion that means that Natural Selection guides evolution. It does not deny the role of genetics and other forms of Variation, but ecology decides which allele thrives and which does not.

The good thing about theistic evolution is that we know that there is a key for every lock. All life’s problems do have answers, which is something a non-believer can really say if every thing is based on chance. However there is still the possibility that humans can mess up the works so a serious catastrophe can happen. We are not protected against our own mistakes.

Changes in populations will occur caused by changing environment, because life forms that do not adapt will die out. What does CCCU stand for?

I repeat do not underestimate Dawkins as a brilliant thinker. He is not trying to be a theologian. He knows how to use words to mislead, and for some reason others do not call him on his tricks. He knows what he believes. He keeps his arguments simple, and appeals to feelings when he claims to appeal to reason. We make a serious mistake when we underestimate our opponents.

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John,

Modern biologists no longer rely exclusively on reproductive isolation to define “species” (the biological species concept). They are now entertaining concepts like phenetic and phylogenetic species concepts, and some botanists are re-evaluating the morphological species concept. Conservationists work with ESU’s (Evolutionarily Significant Units). It has long been recognized that different species can and do hybridize, even though the hybrids often have reduced fertility or reduced viability or both.

Actually human population geneticists have known for some time that within-race variation is greater than between-race variation when it comes to humans, to the point that Cavalli Sforza went so far as to say that "race’ is a social construct when it comes to humans (a point I DO NOT wish to debate on this forum, BTW).

I will quote Giberson & Collins at some length with regard to selective breeding: “Macroevolution typically cannot be expedited by selective breeding. To breed dogs with dogs, for example, will result mainly in a reshuffling of information already present within the canine genes of that population. To get a new species there has to be new genetic information, which typically is produced only by genetic mutations over long periods of time…Selective breeding, however, does not accelerate the rate at which genetic mutations occur…There is thus no significance whatsoever to the claim that centuries of selective breeding have failed to produce a new species.”

This is science-fiction, but I can give you a well-documented example of a major evolutionary transition: extinct synapsid reptiles (the ancestors of modern mammals) had the hinge of the jaws run through the articular and the quadrate bones, while modern mammals have the same hinge run through the squamosal and the dentary bones (the articular and the quadrate become the hammer and the anvil ossicles). There are fossil forms of the right age (ex: Diarthrognathus) which have both the primitive and the derived jaw joints. Furthermore, one can see the transformation in the embryonic development of the opossum (an extant fairly primitive mammal). Short of building a time machine, I can’t think of a better example.

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Coalition of Christian Colleges and Universities.

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Dan, you kind of missed the point with this statement, “There is thus no significance whatsoever to the claim that centuries of selective breeding have failed to produce a new species.” That was not my point at all. My point was simply that the breeding of dogs is an illustration of the variation within a species, the great differences in traits one can have without producing a new species. Therefore to create examples out of nature that are similar to the differences within the dog species, as an example of speciation, is simply invalid. That is the point.

With regard to humans, you said, “Actually human population geneticists have known for some time that within-race variation is greater than between-race variation when it comes to humans…” which I agree is well-known, but from a phenological perspective it simply verifies the fact that phenology is very inconclusive scientifically in terms of defining similarities or differences. This conclusion applies specifically to our interpretation of older fossils, for which we cannot have dna evidence.

And yes, some species have been known to hybridize. Of course, that depends on the definition of species to start with. Hybridization also occurs within species, such as corn, cattle, canola. Hybridization does not define the concept of species. So when we have hybridization occuring, it might be useful to ask what the significance of species definition really is, and what criteria we use to define it. In the case of an actual controlled human experiment, the breeding and selection of various types of dogs, would we call the breeding of a great dane and shitzu a hybridization within species or between species… That might help us to decide what terminology we use when applied to species which have differentiated in the wild.

Since we know that phenology alone can be somewhat unreliable, how do we distinguish between things that look like they possibly could be transitional, vs those that we know were transitional? If we look at a small cat and a bear, we can see that a transitional would require larger bones, different teeth conformations, and loss of claw retraction and a shortening or loss of tail. So now we find a lynx… is it transitional? It has some of the traits. We find a wolf… it has some of the traits. Is it transitional? We think not. How do we distinguish? On the basis of jawbones? What about the other characteristics? How do we know that the one synapsids did not diverge into the two, rather than being transitional between the two? (We know that absence of fossils does not prove species did not exist.)

But I guess if you are believer, then the evidence is plain.

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[quote=“johnZ, post:69, topic:445”]
How do we know that the one synapsids did not diverge into the two, rather than being transitional between the two?
[/quote]I don’t understand this; Diarthrognathus is more recent and more mammal-like than previous synapsids.

[quote=“johnZ, post:69, topic:445”]
But I guess if you are believer, then the evidence is plain.
[/quote] This comment is juvenile and borderline insulting; I am not a “believer” in evolution by natural selection, I am a professional scientist with 30 years of experience teaching at the university level who finds the evidence for evolution by natural selection compelling.

[quote=“johnZ, post:69, topic:445”]
If we look at a small cat and a bear, we can see that a transitional would require larger bones, different teeth conformations, and loss of claw retraction and a shortening or loss of tail. So now we find a lynx… is it transitional? It has some of the traits. We find a wolf… it has some of the traits. Is it transitional? We think not. How do we distinguish? On the basis of jawbones? What about the other characteristics?
[/quote] The entire discipline of phylogenetic systematics is devoted to distinguishing primitive from derived characters and assessing their distribution and polarity - you can pick up any textbook of systematics if you care to. The presence of single dentary bones is synapomorphic for mammals, for example.

This whole exchange has been like a game of wack-a-mole. I now regret investing so much of my time in it. For reasons I can only guess at, you refuse to believe that natural selection can result in speciation. I gave you several examples of speciation, and you dismissed them because some of the populations in question still hybridize (that’s not exactly true in the case of lake Washington salmon and some salamanders in the example, but let’ s let that go). I then gave you an example of a classic macroevolutionary transition and you dismissed it, in effect, because I wasn’t there to see it. I was tempted to give you the well-documented transition from terrestrial mammals to whales next, but then I realized that would have been a further waste of my valuable time. Your mind is obviously made up, and nothing I or anybody else says has a snowflake’s chance in hell of changing it. So be it. I hope this exchange is of some value to other readers of this blog. I am through.

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@Daniel,

Thank you for the information. It sounds like a great course and opportunity for you.

Back to the topic we were discussing, evolution appears to me to based primarily on ecological factors, which does not exclude genetic factors. Science is not the dualistic either/or discipline that many think it is.

The extinction of the dinosaurs led to profound evolutionary change. The reason for the extinction was purely ecological. If the climate and topology of the earth had not changed from the Jurassic Period, today would be the time of the dinosaurs and humans would in all likelihood not exist.

This is why it seems to me that the changing ecology is the controlling and guiding variable, but not the only variable, for evolutionary change and human development. There are other reasons too which I could gladly discuss.

Of course much of the problem is an intellectual one, natural/supernatural dualism. The idea that God does not create through the physical, only supernatural.

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[quote=“Relates, post:71, topic:445”]
evolution appears to me to based primarily on ecological factors, which does not exclude genetic factors
[/quote] But there would be no evolution if gene frequencies didn’t change in response to changing environments. Environmental change alone could not cause evolution if there weren’t a background of genetically-based variation for natural selection to act upon.

[quote=“Relates, post:71, topic:445”]
The reason for the extinction was purely ecological. If the climate and topology of the earth had not changed from the Jurassic Period, today would be the time of the dinosaurs and humans would in all likelihood not exist.
[/quote] Actually the extinction was precipitated by an asteroid impact off the coast of the Yucatan.

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@Daniel

Are you saying that the asteroid hit the dinosaurs and killed them off, or are you saying that the asteroid raised a huge cloud of dust that circled the world for years and reduced the temperature so the tropical swamp that formed the dinosaurs’ habitant died out?

I have also read that the asteroid hit speeded up a cooling process which had already begun. It hastened an extinction which may have been inevitable and aided mammals by making it impossible for the dinosaurs to biologically adjust to the new ecology.

Ecology is based on the relationships between life forms, climate, topography, etc. Darwinian Evolution has concentrated on genetics and to some extent competition between species. Ecology includes asteroids, and human climate change, while traditional evolution does not, which is the reason why ecological evolution is better than Darwinian evolution…

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Dan, I apologize for the juvenile remark; it is probably my own frustration at what seems to me to be the inability to see problems, and only to conjure up more explanations that get around the problems. From your perspective, it is perfectly normal and expected to find explanations that get around the problems and difficulties. So to me it seems like a believers paradigm… but I apologize, because I realize that from your perspective the evidence does all seem to fit together and is compelling.

In looking at the pictures of the jaws of the synapsid sequence, it did not seem to me to be compelling. But I can understand how one would thread a story through it.

If I gave you a wrong impression about natural selection not resulting in speciation, I apologize for that also. But there are two problems with such a generalization. First, how is species defined. If defined on the basis of ability to breed, then many species presently classed as different would in fact be the same species. If classed only the basis of “choosing” not to breed, then of course there would be many species which could interbreed. I certainly believe natural selection could form that type of species, but again, how to distinguish that type of selection from the human experiment with dogs, which although they sometimes look like different species are in fact called the same species. The question is not the natural selection from variability to increased specificity. The question is how to gain increased variability resulting in species with increased functions and structure.

I didn’t dismiss your examples because I denied what what was being shown. I disagreed with the examples because of the way the stories about these examples themselves indicated no proof of the speciation (for definition #1 - ability to interbreed), or because the species themselves still interbred.

The smithsonian site said this about whale evolution: " These ancestral creatures were stranger than anyone ever expected. There was no straight-line march of terrestrial mammals leading up to fully aquatic whales, but an evolutionary riot of amphibious cetaceans that walked and swam along rivers, estuaries and the coasts of prehistoric Asia. As strange as modern whales are, their fossil predecessors were even stranger."

It would be difficult to counter theories about whale evolution in a forum such as this, but these sites below indicates that the theory of whale evolution is not as straightforward as it is often indicated. “Refuting Evolution chapter 5: Whale evolution?”, " Whale evolution fraud " The comments section in the second link is particularly interesting.

This site claims pakicetus is an intermediary , " evolution.berkeley.edu/evolibrary/article/evograms_03" but the above site from creation.com shows how the scientist who originally postulated pakicetus admitted his mistake.

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So far my experience of talking to certain creationists here mirrors yours. Don’t be discourage though - I’ve enjoyed following this discussion. I’m sure others will get something out of it too.

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I think it seems like wack-a-mole on both sides, or on all three sides, some times. As humans we get frustrated… which certainly shows our human limitations, either on the aspect of explaining, or on the aspect of understanding. (as in trying to nail down the definition of species… if it is merely being redefined to fit the evolutionary paradigm then it is a self-fulfilling prophecy). I would quit all of this… after all what difference does it really make to daily life? But perhaps God has his purpose in this too, even if we can’t quite figure out what the purpose is.

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[quote=“johnZ, post:74, topic:445”]
The question is how to gain increased variability resulting in species with increased functions and structure.
[/quote]I don’t understand - mutations generate variability. What am I missing here?

[quote=“johnZ, post:74, topic:445”]
It would be difficult to counter theories about whale evolution in a forum such as this, but these sites below indicates that the theory of whale evolution is not as straightforward as it is often indicated. “Refuting Evolution chapter 5: Whale evolution?”, " creation.com/whale-evolution-fraud " The comments section in the second link is particularly interesting.

This site claims pakicetus is an intermediary , " evolution.berkeley.edu/evolibrary/article/evograms_03" but the above site from creation.com shows how the scientist who originally postulated pakicetus admitted his mistake.
[/quote] “Fraud” is a serious accusation that shouldn’t be thrown around lightly. All of the supposedly “incriminating admissions” in the second link could be found in the scientific literature. Here is an excellent refutation of the link: Marmotism: Whale Evolution "Fraud" and Creationist Impotence! I apologize for the belligerent tone and the occasional profanity - if one can get past those, the actual scientific content is very good.

This is to be expected; evolutionary “lineages” aren’t really straight lines, rather, they are like branching bushes. Many groups of dinosaurs “experimented” with feathers (for insulation or sexual display or both), but only one of them gave rise to modern birds. Here is a more complete outline of whale evolution (more complete, that is, than Carl Werner’s obviously edited videos): http://www.talkorigins.org/features/whales/

[quote=“johnZ, post:74, topic:445”]
This site claims pakicetus is an intermediary , " evolution.berkeley.edu/evolibrary/article/evograms_03" but the above site from creation.com shows how the scientist who originally postulated pakicetus admitted his mistake.
[/quote]Pakicetus was originally reconstructed as more aquatic-looking than it really was

, but the whale-like features of the skull are not imaginary.

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I just figured out what really troubled me here - the author of the second link selectively quotes (and edits) the various paleontologists to make it sound as if they had been caught in glaring deceptions. Actually virtually everything they concede in the videos had already appeared in the peer-reviewed literature. And that’s what really bothers me: the continued attempt by some creationists to portray official science as a gigantic conspiracy aimed at deceiving the public, presumably in order to weaken the Christian faith. That attitude, of course, disregards the many devout Christians (Dale Russell, Theodosius Dobzhansky, Ken Miller, Francis Collins, Robert Bakker, Keith Miller, Ken Sytsma) who have also distinguished themselves in the field of evolutionary biology.

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the continued attempt by some creationists to portray official science as a gigantic conspiracy aimed at deceiving the public

The issue is not that they deliberately set out to deceive. The issue is that the public was deceived by their mistaken conclusions. But your sentence is indeed a deception. They were not portraying “science” as a conspiracy. They were portraying evolution as an error. The YEC have no problem with science, but differ with a few of the conclusions.

Mutations generate variability, but almost all mutations are deleterious, not beneficial. At a generational change of 100 mutations with 99.9 % of them being deleterious, how long would it take for a species to become unfunctional?

For any type of evolution, no matter how branched the tree, and no matter how often it is said, “evolutionary lineages aren’t really straight lines, they are like branching bushes”, every branch on a bush can be (must be) traced directly back to the trunk and root. It cannot simply hover in mid-air due to an affinity or a similarity or a desire to belong.

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Selectively editing respected scientists in order to put “gotcha” videos on the internet qualifies as deception. YEC’s have a HUGE problem with science - they think it should be subordinated to their idiosyncratic reading of the first chapters of Genesis. I challenge you to find any YEC’s who are not animated by fundamentalist zeal.