Two-million-year-old Adam and Eve still possible: Dr. Ann Gauger’s model remains viable

A few weeks ago, I wrote a short post titled, Adam and Eve still a possibility?, in which I drew readers’ attention to the work of geneticist Richard Buggs, Reader in Evolutionary Genomics at Queen Mary University of London, who thinks it’s still theoretically possible that the human race once passed through a short, sharp population bottleneck of just two individuals, followed by exponential population growth. Biologist Dennis Venema, professor of biology at Trinity Western University in Langley, British Columbia, has recently written a two-part reply to Buggs, titled, Adam, Eve and Population Genetics: A Reply to Dr. Richard Buggs (Part 1) and A Reply to Dr. Richard Buggs (Part 2). But in a comment in response to a query of mine, Professor Venema conceded that at the present time, science cannot rule out Dr. Ann Gauger’s hypothesis that there was a severe bottleneck around two million years ago, with the emergence of Homo erectus, whom she identifies as the first true human being. When I pressed Professor Venema, saying, “In plain English, what you’re saying is that science can’t rule out an original couple, if they lived more than 1 million years ago,” he replied:

I guess it depends on how reliable you think PSMC methods are as they approach this time frame. The data looks smooth to me out to around 1.5 MYA or so, plus or minus, but the method loses its power as you go back further and further.

In a recent email message, Dr. Gauger clarified her position on Adam and Eve:

I did not settle on an old age for Adam so that the population genetics would work out or because I was seeking to prove two progenitors. It was because I could not understand why God would create Homo species so close to us and not be part of us, and because of morphology. I find species definitions to be tricky things, and sometimes they are assigned because of an agenda. H ergaster and H habilis are disputed for example. But for me Turkana boy is clearly human.

So I arrived at an early date because paleontology. I am aware of arguments for 200k (first modern skeleton), 70 k (Blombos cave, migration out of Africa), or 20-10k to match Genesis.) We will see if any of these dates, as well as the older one, can accommodate a unique origin based on AFS, LD, and several other pop gen statistics. Feel free to pass this on.

Dr. Gauger has adduced evidence that Homo erectus and Homo ergaster (African Homo erectus) were rational beings, who were capable of foresight: they transported tools over distances of 12-13 kilometers, compared to distances of just tens or hundreds of meters for Australopithecus and early Homo (see here). In addition, there is evidence (see also here) that Homo ergaster was able to tame fire as far back as 1,000,000 years ago, and perhaps use it to cook meat as well, although Wil Roebroeks of Leiden University in the Netherlands and Paola Villa, a curator at the University of Colorado Museum of Natural History in the U.S., cautions that we don’t have evidence of regular fire use going back any further than 400,000 years ago. Finally, excavations at the South African site of Kathu Pan suggest that Homo ergaster had a sense of aesthetics. As Dr. Gauger describes it:

…[T]he site has yielded what is termed, the ‘Master Hand-Axe’ which dates to approximately 750 000 BP rendering it the oldest artifact which is indisputably aesthetic i.e. worked for beauty and symmetry, perfectly oriented, and worked considerably beyond the functional requirements of the hand-axe, which could have been achieved with half or fewer blows (see Figure 4-2). The technology which produced it is known as the Acheulian, and the artifacts are thought to be made by Homo ergaster (Homo erectus in Africa), a diverse grouping of early humans commonly imagined as small-brained, small-jawed and robustly built, with heavy eyebrow ridges.

When I look at that master handaxe, I see aesthetics, painstaking care, and a joy in the materials. I see mind.

In a recent comment on Biologos, I expressed reservations about Dr. Gauger’s ancient Adam and Eve scenario:

However, if I were to identify the chief flaw of the ancient Adam and Eve scenario, it would be this: modern human behavior doesn’t appear until 100,000 years ago. Homo erectus may have had foresight (transporting tools over distances of more than 10 kilometers), the ability to control fire (although this is hotly disputed) and even a sense of aesthetics (judging from the elegance of some Acheulean tools), but it almost certainly lacked the capacity for art, religion and science. This means that in some ways it was less human than we are – which means that if we are to believe in Adam and Eve, we have to give up belief in human equality.

It is instructive to compare Homo erectus with modern-day tribes whose lifestyle has been described by some as “primitive.” Members of these tribes have relatively little trouble in adapting to the cognitive demands of civilization, some making the transition in as little as a generation. I doubt very much whether Homo erectus could have done that. And I also doubt whether anyone could have preached the Gospel to Homo erectus.

Finally, in a recent post on The Skeptical Zone, I marshaled evidence indicating that Homo erectus almost certainly lacked the use of language, and that even the Neandertals probably lacked it. What’s more, the human brain appears to have evolved specific traits in the lineage leading to Homo sapiens, which allowed our species to possess a full-blown theory of mind and imagine what others were thinking about them.

For her part, Dr. Gauger is not troubled by the fact that Homo erectus lacked our level of linguistic ability. And in a post on Biologos, she responded as follows to my concerns about the lack of symbolic culture in Homo erectus: “First of all, our full capacity for art, drama, philosophy, religion and language was not present 300,000 years ago. Nor was it present, it could be argued until the Egyptians, the early Greeks, and the Chinese had their cultural flowering.” I agree with Dr. Gauger that early Homo sapiens, who lived 300,000 years ago, lacked “our full capacity for art, drama, philosophy, religion and language.” I think that these abilities appeared 100,000 years ago, with the emergence of modern human behavior (see also here). Dr. Gauger argues that the long lag between the appearance of Homo sapiens and the emergence of behavioral modernity means that we shouldn’t consider Homo erectus subhuman because it didn’t behave in this way. I would argue, however, that the human brain did not stop evolving with the appearance of Homo sapiens. It may have subsequently acquired the traits which enabled us to use language and to possess a full-blown theory of mind.

So the long and the short of it is: Dr. Gauger’s model of a two-million-year-old Adam and Eve remains scientifically viable, but their minds would have been very different from ours. Personally, I wouldn’t call Homo erectus a true human being. The Neandertals I’m not so sure about, for reasons I’ve discussed previously.

I’ll just finish by mentioning the work of Dr. Joshua Swamidass, who is an assistant professor at Washington University in Saint Louis where he runs a computational biology group. In an article titled, A Genealogical Rapprochement on Adam?, he accepts “the genetic evidence in which it appears (1) our ancestors arise as a population, not a single couple, and that (2) we share ancestry with the great apes,” but also proposes that an individual named Adam “was created out of dust, and Eve out of his rib, less than 10,000 years ago in a divinely created garden where God might dwell with them, the first beings with opportunity to be in a relationship with Him.” After leaving the Garden, Adam and Eve’s offspring blended with that of their neighbors in the surrounding towns. “In this way, they became genealogical ancestors of all those in recorded history. Adam and Eve, here, are the single-couple progenitors of all mankind.” Of course, humans today have many genealogical ancestors, not just Adam and Eve. An article outlining Dr. Swamidass’s hypothesis will appear in the March 1, 2018 issue of PSCF (Perspectives on Science and Christian Faith). The important thing for readers to grasp is that genealogical ancestry is not genetic ancestry: “Though scientific discourse focuses on genetic ancestry, genealogical ancestry is germane to the theological claims about Adam.” Adam and Eve are ancestors of us all, because genealogical ancestry becomes universal in just a few thousand years. Dr. Swamidass contends that “Scripture and theology, at most, make claims about genealogical ancestry, but not genetic ancestry,” because when Scripture was written, people had no notion of what genes were. I’m not sure, however, that it’s that simple. The Bible appears to affirm that Adam and Eve were the only genealogical ancestors of the entire human race. As Acts 17:26 puts it: “From one man he made all the nations, that they should inhabit the whole earth; and he marked out their appointed times in history and the boundaries.” I’m also not sure exactly what new trait Adam and Eve were supposed to have possessed, under the scenario proposed by Dr. Swamidass, since he explicitly declares that even the human beings living outside Adam and Eve’s Graden were made in the image of God. It seems the only thing that was genuinely new about Adam and Eve was that they were spiritually fallen. But because genetic information is transmitted only unreliably, Dr. Swamidass argues that Adam and Eve, if they existed, “probably did not transmit DNA to all their descendants, nor did they transmit any identifiable DNA to any of their descendants.” He continues: “This means that Adam and Eve’s DNA is not how the Fall or original sin, if they exist, is transmitted to all of us.” At any rate, Dr. Swamidass’s article is a very stimulating read, which is sure to take the Adam and Eve debate in a new direction.

I’d now like to throw the discussion open to readers – especially those with a Christian background. If you had your druthers, which Adam and Eve would you pick? A two-million-year-old one, who was perhaps a lot dimmer than us, as proposed by Dr. Gauger? Or a Neolithic one, as proposed by Dr. Swamidass, who interbred with other humans that were made in God’s image and likeness, and left descendants all over the globe? Or neither of the above?

I’ll leave you all with a concluding thought: “We are more different genetically from people living 5,000 years ago than they were different from Neanderthals,” according to John Hawks, a professor of anthropology at the University of Wisconsin-Madison. Many of the genetic mutations that have spread through the human population in the last few thousand years relate to “changes in the human diet brought on by the advent of agriculture, and resistance to epidemic diseases that became major killers after the growth of human civilizations.” Civilization seems to have been what’s changed us most. But how has it changed our brains? That I don’t know. Maybe someone can tell me. Over to you.

300 thoughts on “Two-million-year-old Adam and Eve still possible: Dr. Ann Gauger’s model remains viable

  1. Corneel: Could you please specify what you mean by “epigenetic inheritance” here?

    I’m talking about inheritance that is not genetic. “having to do with specific genes”

    Corneel: You seem to be happily including both the chromatin modifications in experimental mice models and gut biota.

    I’m also including cultural inheritance and literally anything that is not directly related to inheritance of specific genes.

    I hope that helps

    peace

  2. fifthmonarchyman: When I think of genetics I think of genes

    Ah, that is where the confusion comes from. But these words have a long history. The words “genes” and “genetics” were coined by early 20th century biologists Wilhelm Johannsen and William Bateson, before it was established that DNA was the hereditary material or that it had protein-coding potential. As the role of DNA in heredity became better known, “genes” and “genetics” acquired their modern meaning.

    I consider genomics to be a bit of a modern show-off term. The only real difference between genetics and genomics is the scale of things. In genomic research, the aim is to examine the entire genome, whereas genetic research can be limited to one or a few genes (or genetic markers or regulatory regions or what-have-you). Genetics is not restricted to coding genes.

    fifthmonarchyman: articles would be helpful if you know of any

    Oof. Where to read up on that? You might consider reading a standard textbook (I like Lewin’s GENES, but that is a bit heavy on the molecular side. Otherwise take Griffiths’ Introduction to Genetic Analysis). If you prefer to read something more proselike on the early development of modern molecular genetics you should consider reading Judson’s “The Eighth Day of Creation”. Perhaps some of the TSZ residents here have better suggestions?

  3. fifthmonarchyman: yep and we post links ………..more than once if necessary

    Yeah, I figured you had read that somewhere, but when I tried to find the source I got the dismissive story. I’ll check out the link, thanks.

  4. fifthmonarchyman: I’m also including cultural inheritance and literally anything that is not directly related to inheritance of specific genes.

    I hope that helps

    Just non-genetic inheritance then? Very well.

  5. Corneel: Just non-genetic inheritance then? Very well.

    Well yes. Except I’m looking at anything that is not related to the actual genes.

    I’m not sure what to call that since you are including other other factors in your definition of genetic inheritance that I would exclude.

    If you are correct It’s a pity that biology no longer has a term for the study of actual genes. Not to say I’m skeptical but I’d still like to see that linguistic tidbit in black in white.

    Oh well, I guess it makes little practical difference if we understand each other here.

    All I’m saying is that red polls share the same genes despite being separate species

    The same would be true of the descendants of A&E and any hypothetical “others” that might have existed at the same time. That is if my Idle speculation is in the ballpark of reality.

    I hope we finally have that all cleared up. These sorts of discussions are often difficult but they can be interesting, thanks for hanging in there

    peace

  6. fifthmonarchyman: All I’m saying is that red polls share the same genes despite being separate species

    Congratulations, you have moved into the realm of mainstream science. Apart from your odd habit of calling the different morphs species, I see no reason to disagree with that.

    fifthmonarchyman: The same would be true of the descendants of A&E and any hypothetical “others” that might have existed at the same time. That is if my Idle speculation is in the ballpark of reality.

    As I recall, this discussion got started by you insisting that what distinguished A&E from the “others” was not merely a theological concept, but some identifiable factor that got passed down to us by non-genetic inheritance. Restricting the definition of genetics to include only coding sequences does absolutely nothing to mitigate the problems outlined in the OP; as long as the “human” factor is encoded in the DNA, the chance of it being reliably transmitted to all A&E’s descendants is really slim.

    fifthmonarchyman: These sorts of discussions are often difficult but they can be interesting, thanks for hanging in there

    If we didn’t like these type of discussions, we wouldn’t be hanging out at TSZ, would we? 🙂

  7. Corneel: Restricting the definition of genetics to include only coding sequences does absolutely nothing to mitigate the problems outlined in the OP; as long as the “human” factor is encoded in the DNA, the chance of it being reliably transmitted to all A&E’s descendants is really slim.

    What problems? It seems to me that the one “problem” in the OP is solved simply by allowing that species are not defined by genetic isolation. That is what should be happening regardless.

    As far as genetic factors from single individuals being transmitted to all humanity. Mitochondrial eve and Y-chromosomal adam conclusively establish that it’s not only possible but it happened at least twice.

    peace

  8. Corneel: As I recall, this discussion got started by you insisting that what distinguished A&E from the “others” was not merely a theological concept, but some identifiable factor that got passed down to us by non-genetic inheritance.

    The reason I favor non-genetic inheritance is simply because I think that it is more prevalent generally in the world than is accepted now. It has nothing specifically to do with humans,

    The trigger for the discussion was when Joe Felsenstein claimed that if A&E existed we should be able to find a gene for original sin.

    I think that is a silly as saying we should be able to find a gene for intelligence or kindness if they run in families.

    I just think there is a lot more going on with inheritance than is captured in our genes.

    peace

  9. fifthmonarchyman: I just think there is a lot more going on with inheritance than is captured in our genes.

    Ever thought about progressing humanity’s store of knowledge by formalising your thoughts into a form that can be used to empirically determine if they bear some relation to reality?

    I.E. write a paper.

    fifthmonarchyman: The trigger for the discussion was when Joe Felsenstein claimed that if A&E existed we should be able to find a gene for original sin.

    Well, that seems reasonable to me. After all, at one point there was no sin. Then there was sin. Something must be inherited that allows sin to happen in subsequent generations, no?

    What is that thing?

    fifthmonarchyman: I think that is a silly as saying we should be able to find a gene for intelligence or kindness if they run in families.

    Scientists have investigated this question for more than a century, and the answer is clear: the differences between people on intelligence tests are substantially the result of genetic differences. Genes account for about half of all differences in intelligence among people, so half is not caused by genetic differences, which provides strong support for the importance of environmental factors. This estimate of 50 percent reflects the results of twin, adoption and DNA studies. From them, we know, for example, that later in life, children adopted away from their biological parents at birth are just as similar to their biological parents as are children reared by their biological parents. Similarly, we know that adoptive parents and their adopted children do not typically resemble one another in intelligence.

    https://www.scientificamerican.com/article/is-intelligence-hereditary/

    You might think that is silly but what you think, luckily, does not influence the world in any meaningful way. The rest of the world works on more then gut feeling.

    fifthmonarchyman: I just think there is a lot more going on with inheritance than is captured in our genes.

    And yet intelligence demonstrably runs in families.

  10. fifthmonarchyman: As far as genetic factors from single individuals being transmitted to all humanity. Mitochondrial eve and Y-chromosomal adam conclusively establish that it’s not only possible but it happened at least twice.

    So you accept then that the Adam and Eve tale as told in the bible is without doubt incorrect?

    You cannot talk about “Mitochondrial eve and Y-chromosomal adam” and hold that the events in the bible are literally true. Or can you?

  11. OMagain: You cannot talk about “Mitochondrial eve and Y-chromosomal adam” and hold that the events in the bible are literally true. Or can you?

    Of course I can.
    I think you are mistaking literally true with woodenly literal.

    It’s literally true that the “sun rose this morning” and will “set tonight” but to understand those phrases in a woodenly literal way is incorrect and just silly.

    Do you understand the difference?

    peace

  12. OMagain: Ever thought about progressing humanity’s store of knowledge by formalising your thoughts into a form that can be used to empirically determine if they bear some relation to reality?

    I.E. write a paper.

    There are tons of biologists doing that sort of thing even as we speak.

    I have my own job and “pattern” hobby as well as obligations with family and friends. Plus I have a tendency to get involved in long conversations with curmudgeons on the internet. 😉

    I have neither the time nor the aptitude nor the inclination to take this sort of thing on. Unless something changes I’ll wait for the actual biologists

    OMagain: Genes account for about half of all differences in intelligence among people, so half is not caused by genetic differences,

    That sounds about right. Half is no where near all it’s only about 50% 😉

    I did not say that everything that makes us human comes from non genetic factors.

    I only said that I don’t believe everything that makes us human can be reduced to our genes

    peace

  13. fifthmonarchyman: What problems? It seems to me that the one “problem” in the OP is solved simply by allowing that species are not defined by genetic isolation.

    Yes, and that would be the end of it, were it not for your claim that the “human” factor, rather than being some theological concept, can be assessed by scientific scrutiny. Yet you cannot tell us what it is.

    fifthmonarchyman: As far as genetic factors from single individuals being transmitted to all humanity. Mitochondrial eve and Y-chromosomal adam conclusively establish that it’s not only possible but it happened at least twice.

    It happened thousands of times. It’s called coalescence. But that happens to coding regions as well, and you insist that it is not genetic sensu FMM.

    fifthmonarchyman: The reason I favor non-genetic inheritance is simply because I think that it is more prevalent generally in the world than is accepted now. It has nothing specifically to do with humans,

    I have the strong impression there are other reasons at play as well, since you think you can find solace in epigenetic inheritance and fail to realise that to make it substitute genetic inheritance, it essentially needs to work in the same way.

    Really, what is the difference between a gene for original sin, or a histone methylation for original sin?

  14. Corneel: Yes, and that would be the end of it, were it not for your claim that the “human” factor, rather than being some theological concept, can be assessed by scientific scrutiny. Yet you cannot tell us what it is.

    For the purpose of this thread “it” (what makes us human) would be decent from A&E.

    I see no reason it could not be assessed scientifically.

    For example if we found a population of humans with Neanderthal Mitochondria that did not descend from Y chromosome Adam it would tend to demonstrate that humanity did not descend from a single couple

    Corneel: It happened thousands of times. It’s called coalescence.

    Then calling it unlikely seems a little bit overblown don’t you think?

    Corneel: I have the strong impression there are other reasons at play as well

    Impressions are sometimes misleading. in this case I just fell that we are more than the sum of our genes

    Corneel: Really, what is the difference between a gene for original sin, or a histone methylation for original sin?

    I would not expect to see a a histone methylation for original sin anymore than a a histone methylation for intelligence or kindness.

    Even though intelligence and kindness run in families

    peace

  15. fifthmonarchyman: I see no reason it could not be assessed scientifically.

    For example if we found a population of humans with Neanderthal Mitochondria that did not descend from Y chromosome Adam it would tend to demonstrate that humanity did not descend from a single couple

    No, it wouldn’t because the “Neanderthal Mitochondria” coalesce with the mitochondrial genomes of other human populations. You would simply be relabeling “Neanderthal Mitochondria” to human mitochondria in order to find a new mitochondrial eve, pushed slightly further back in time. Same goes for the Y-chromosome. Other commenters, like Entropy, tried to tell you this previously in the thread.

    fifthmonarchyman: Corneel: It happened thousands of times. It’s called coalescence.

    Then calling it unlikely seems a little bit overblown don’t you think?

    Heh, I should have seen that coming. The trick is of course in knowing which chromosome will be going to fixation in advance. All extant DNA sequences ultimately coalesce at some point in time. But I am not particularly impressed with wisdom in hindsight.

    fifthmonarchyman: Impressions are sometimes misleading. in this case I just fell that we are more than the sum of our genes

    Nobody disputes that.

    fifthmonarchyman: I would not expect to see a a histone methylation for original sin anymore than a a histone methylation for intelligence or kindness.

    Good! But then the question remains: how is epigenetics going to support your idea that “being human” was transmitted to us from Adam by non-genetic means?

  16. Corneel: You would simply be relabeling “Neanderthal Mitochondria” to human mitochondria in order to find a new mitochondrial eve, pushed slightly further back in time.

    The real point of contention here is not Neanderthals per say but a population with out the capacity for symbolic/abstract thought.

    If we discovered a modern group of humans with Mitochondria from a second population of Hominids that we knew did not have the capacity for symbolic/abstract thought (Neanderthal or otherwise) we would not simply relabel it as human.

    We would assume that the the capacity for symbolic/abstract thought arose independently more than once in hominids. This would falsify A&E.

    Corneel: The trick is of course in knowing which chromosome will be going to fixation in advance.

    Evolution does not have foresight. From a Darwinist’s perspective it would be just a lucky accident that hypothetical Others went extinct and the decedents of Adam did not.

    Corneel: how is epigenetics going to support your idea that “being human” was transmitted to us from Adam by non-genetic means?

    You misunderstood. I did not offer epigenetics as support for anything.

    I was simply asked how “being human” could possibly be inherited by the decedents of Adam absent specific “genes” and I replied

    “epigenetics perhaps?” .

    The fact is that there are other means of inheritance besides the overtly “genetic”. That should not be controversial. Epigenetics is just one possible mechanism.

    peace

  17. fifthmonarchyman: We would assume that the the capacity for symbolic/abstract thought arose independently more than once in hominids. This would falsify A&E.

    And what, exactly, determines this capacity, if not genetic change?

    fifthmonarchyman: The fact is that there are other means of inheritance besides the overtly “genetic”. That should not be controversial. Epigenetics is just one possible mechanism.

    It isn’t controversial, but any other means of inheritance suffers from the same flaw.
    There is no gene for original sin
    There is no histone methylation for original sin
    There is no gut bacterium for original sin
    There is no gut bacterium interaction for original sin
    You get the idea..

    We can subject it to scientific enquiry you say. It’s not genes. What is it?

  18. Corneel: And what, exactly, determines this capacity, if not genetic change?

    I don’t know,

    Earlier in this thread I speculated that it might be the critical period hypothesis coupled with some unknown genetic change. You could throw in epigentics to the mix as well.

    It’s likely to be a mixture of factors providentially coming together in one particular couple at a particular point in history.

    I expect that the precise cause will never be known, If we could determine precisely what made us human we could create humans from other species like Doctor Moreau.

    I just don’t ever see that sort of thing happening.

    Corneel: It isn’t controversial, but any other means of inheritance suffers from the same flaw.

    Not at all.

    The “flaw” is in looking for one individual factor when like for everything else interesting in life the cause is most likely compound and multifaceted and irreducibly complex.

    peace

  19. fifthmonarchyman: Earlier in this thread I speculated that it might be the critical period hypothesis coupled with some unknown genetic change. You could throw in epigentics to the mix as well.

    It’s likely to be a mixture of factors providentially coming together in one particular couple at a particular point in history.

    That doesn’t sound unreasonable. Yes, I’d agree that “being human” is a mixture, compound and multifaceted. It has genetic, epigenetic and cultural aspects.

    But all of those things are not going to coalesce into a single ancestral couple. Suppose this cocktail came together, as you say, in historical Adam and Eve, then there is no way “being human” could be inherited by all descendants of Adam, but not by any of the Others. All the ingredients of “being human” would have been percolating throughout the wider population, unless there was strict isolation of the genealogical line of Adam. And the genetic data indicate the latter is very unlikely.

  20. Corneel: But all of those things are not going to coalesce into a single ancestral couple.

    Why not?

    Corneel: Suppose this cocktail came together, as you say, in historical Adam and Eve, then there is no way “being human” could be inherited by all descendants of Adam, but not by any of the Others.

    I would say that it could and it did happen that way. It would just be impossible via step by step Darwinian processes

    Imagine an irreducibly complex package of 10 factors that came together in A&E. The hypothetical Others would each be missing one or more of the factors necessary for humanness.

    That is the whole principle behind irreducible complexity each and every one of the parts must be present and working in order for the whole to function. If you have 9 instead of ten before A&E you are not a human you are an”Other”.

    Folks like me who find ID to be compelling just don’t think that you can get to an irreducibly complex thing like “humanness” in a step wise Darwinian fashion.

    Corneel: All the ingredients of “being human” would have been percolating throughout the wider population,

    Yes exactly, all the various factors would be there just waiting for a particular couple and a (you say lucky I say divine) spark

    Corneel: unless there was strict isolation of the genealogical line of Adam. And the genetic data indicate the latter is very unlikely.

    Isolation is not at all necessary, all that is necessary is that the combination of the various factors that constitute humanness into an irreducibly complex whole are unlikely.

    Given the assumptions of this thread we would need odds of something less than one in ten thousand.

    Given the long history of hominids and the short history of humans one would expect that humanness is at least that unlikely.

    peace

  21. fifthmonarchyman: Imagine an irreducibly complex package of 10 factors that came together in A&E. The hypothetical Others would each be missing one or more of the factors necessary for humanness.

    That is the whole principle behind irreducible complexity each and every one of the parts must be present and working in order for the whole to function. If you have 9 instead of ten before A&E you are not a human you are an”Other”.

    Yes, I get that. I was more concerned with how the segregation of those factors could be prevented from happening in Adam’s descendants. This is the part that requires genetic isolation and causes a bottleneck.

    fifthmonarchyman: Given the assumptions of this thread we would need odds of something less than one in ten thousand.

    How did you get that number?

  22. Corneel: I was more concerned with how the segregation of those factors could be prevented from happening in Adam’s descendants.

    If the magical humanness spark was unlikely before A&E it would still be unlikely post A&E.

    At the same time A&E descendants would have been very busy making sure that they the A&E Humans were the only game in town either by inbreeding or replacement.

    Corneel: How did you get that number?

    It was suggested that the genetic population never got below 10,000 individuals. The likelihood of humanness would have to be less than that.

    peace

  23. Corneel: I was more concerned with how the segregation of those factors could be prevented from happening in Adam’s descendants.

    Perhaps we are getting even further down the theology/philosophy path now. but I’ll trudge on

    What makes a person human is not the presence of the complex of all the various “human” factors but the potential that they will exist given the natural course of events.

    A mammal is still a mammal even if it has a genetic defect that renders it hairless.

    A fetus is still human even before she has had any abstract thoughts and even if she is brain damaged to the point that she will never have abstract thoughts this side of heaven.

    Get it?

    peace

  24. fifthmonarchyman: At the same time A&E descendants would have been very busy making sure that they the A&E Humans were the only game in town either by inbreeding or replacement.

    Precisely. This effectively isolates the genealogical line of Adam from the Others, and creates the bottleneck that can be detected by its effect on genetic variation and linkage disequilibrium.
    And we have come full circle now. You too will need to come to terms with the findings described in the OP, even though you reject species defined by reproductive isolation.

  25. fifthmonarchyman: What makes a person human is not the presence of the complex of all the various “human” factors but the potential that they will exist given the natural course of events.

    A mammal is still a mammal even if it has a genetic defect that renders it hairless.

    A fetus is still human even before she has had any abstract thoughts and even if she is brain damaged to the point that she will never have abstract thoughts this side of heaven.

    Get it?

    Yes.

    So what “potential” are the Others lacking? I don’t think you can name any.

  26. Corneel: This effectively isolates the genealogical line of Adam from the Others, and creates the bottleneck that can be detected by its effect on genetic variation and linkage disequilibrium.

    How exactly does inbreeding with others isolate the genealogical line of Adam? it seems to me that it would do just the opposite.

    Killing folks who don’t have sex with you does not genetically isolate the line of Adam either as far as I can tell.

    It simply removes competition that is already isolated from your population genetically,

    Corneel: And we have come full circle now.

    you will definitely need to explain your self here. I have no clue what you are getting at.

    peace

  27. Corneel: So what “potential” are the Others lacking? I don’t think you can name any.

    Decent from Adam for one very important one.

    Seriously, If being human requires decent from Adam then hypothetical “others” don’t have it. It’s pretty simple.

    Assuming humanity is a irreducibly complex package available only to decedents of Adam then “others” would have no possible route to that eventuality.

    Just what other specific potentialities are entailed by decent from Adam are another conversation.

    If I was being theological I would say the potential personal relationship with God is one. But we don’t have to go down that road if you don’t want to we could stick with consciousness if you like.

    peace

  28. fifthmonarchyman: How exactly does inbreeding with others isolate the genealogical line of Adam? it seems to me that it would do just the opposite.

    I thought that would be obvious. If the descendants of Adam only interbreed among themselves, they become reproductively isolated from the Others. Same goes for rapidly exterminating them.

    So now your rejection of the biological species concept becomes a moot point. The fact that they can interbreed with the others is irrelevant if this does not actually happen.

    fifthmonarchyman: Corneel: And we have come full circle now.
    you will definitely need to explain your self here. I have no clue what you are getting at.

    Way in the beginning of this thread, you claimed that your alternative species concept solves the problems in the OP. But since it now turns out that your scenario requires reproductive isolation as well, we have returned to the orginal issues laid out in the OP.

  29. fifthmonarchyman: Decent from Adam for one very important one.
    Seriously, If being human requires decent from Adam then hypothetical “others” don’t have it. It’s pretty simple.

    Yes, but decent from Adam is not really a potential is it?

    fifthmonarchyman: If I was being theological I would say the potential personal relationship with God is one. But we don’t have to go down that road if you don’t want to we could stick with consciousness if you like.

    I don’t have any issue with “personal relationship with God” being the inherited human character (though I am a non-believer myself). Like Joe did, I will simply grant you that, but maintain that it is outside of the scope of scientific enquiry. I do take issue with consciousness as an exclusively human potential. In my perception, lots of animals are conscious. Are you sure you mean the same thing as I do?

  30. Here is a more recent example of the sort of expansion that the decedents of Adam might have had among any hypothetical nonhuman hominids alive at the same time.

    http://blogs.discovermagazine.com/gnxp/2010/08/1-in-200-men-direct-descendants-of-genghis-khan/

    quote:

    The greatest joy for a man is to defeat his enemies, to drive them before him, to take from them all they possess, to see those they love in tears, to ride their horses, and to hold their wives and daughters in his arms.

    end quote:

    from the article and originally Genghis Khan

    I would expect that given the smaller population and longer time frame involved it’s not unlikely at all that all hominids alive for the last several thousand years would count Adam as a direct ancestor

    peace

  31. Corneel: So now your rejection of the biological species concept becomes a moot point.

    again why??

    Corneel: The fact that they can interbreed with the others is irrelevant if this does not actually happen.

    If it’s possible it does happen, that is the general understanding when it comes to sex,

    If it’s not possible for one reason or another then I would expect the competition to be eliminated rather quickly.

    Corneel:But since it now turns out that your scenario requires reproductive isolation as well, we have returned to the orginal issues laid out in the OP.

    I have no idea how you got the idea that my scenario requires reproductive isolation when I keep emphasizing just the opposite.

    Perhaps you misunderstand elimination of competition for reproductive isolation for some reason. but I have no clue why you would do so and you haven’t elaborated as of yet.

    Does killing the males in a village and rapeing the females so that the males will have no offspring constitute reproductive isolation in your mind?

    peace

  32. Corneel: Yes, but decent from Adam is not really a potential is it?

    Why not?

    You really need to elaborate.
    Perhaps you think that a zygote is already a descendant before birth I have no problem with that.

    In which case I would say the potential is to be a fully actualized descendant.

  33. Corneel: I do take issue with consciousness as an exclusively human potential. In my perception, lots of animals are conscious.

    Given the philosophical problem of other minds how would you know another organism besides your self was conscious?

    Corneel: Are you sure you mean the same thing as I do?

    I mean consciousness as in possessing a mind. I’m not sure that is what you mean

    peace

  34. here is another example of what I’m talking about.

    Earlier in this thread I talked about inbreeding between Lepomis macrochirus and Lepomis cyanellus sunfish in my pond.

    In my experience one of the interesting things about this particular mating arrangement is that all things being equal over time in a good pond habitat Lepomis macrochirus will dominate and Lepomis cyanellus will subside in a population.

    I think that is because most of the surviving hybird offspring are male and male Lepomis macrochirus are more likely to be the instigators in the inbreeding.

    It all happens rather naturally. I see no reason not to expect something similar in hominids like humans and hypothetical “others”.

    peace

  35. fifthmonarchyman: Here is a more recent example of the sort of expansion that the decedents of Adam might have had among any hypothetical nonhuman hominids alive at the same time.

    You seem to really attach to coalescence in your arguments. Consider this; for all the men that carry the Y-haplotype that traces back to (presumed) Genghis Khan, do you believe that all other DNA sequences in their genome also trace back to the same individual or his primary wife? Of course not, these men have many different ancestors.

    In the same way, absent reproductive isolation, all descendants of Adam are also descendants of some of the Others.

  36. Corneel: In the same way, absent reproductive isolation, all descendants of Adam are also descendants of some of the Others.

    So?

    Just because I have some Neanderthal DNA does not mean I’m a Neanderthal

    peace

  37. fifthmonarchyman: Just because I have some Neanderthal DNA does not mean I’m a Neanderthal

    Heh, it is funny that you can see multiple factors coming together to form some hypothetical irreducibly complex package for “being human”, but fail to realise that it will segregate just as easily in any subsequent generations.

    Here is the issue: The infusion of heritable material from the Others into the lineage of Adam will wreck your hypothetical IC complex, because the replacement of any single factor will render the carrier non-human.
    The only way to guarantee reliable transmission of all the parts of the IC package is some sort of reproductive isolation.

  38. fifthmonarchyman: Given the philosophical problem of other minds how would you know another organism besides your self was conscious?

    Are you going to tell me that only humans are conscious?

  39. fifthmonarchyman: The greatest joy for a man is to defeat his enemies, to drive them before him, to take from them all they possess, to see those they love in tears, to ride their horses, and to hold their wives and daughters in his arms.

    fifthmonarchyman: Does killing the males in a village and rapeing the females so that the males will have no offspring constitute reproductive isolation in your mind?

    fifthmonarchyman: I think that is because most of the surviving hybird offspring are male and male Lepomis macrochirus are more likely to be the instigators in the inbreeding.

    * Penny drops *

    Being human is inherited through the male lineage? Really?

  40. Corneel: it is funny that you can see multiple factors coming together to form some hypothetical irreducibly complex package for “being human”, but fail to realise that it will segregate just as easily in any subsequent generations.

    When you are talking about irreducible complexity “segregation” equals destruction of the whole. Yet we see lots of irreducibly complex things persist over time.

    If you say the persistence of irreducible complexity is highly unlikely given materialistic assumptions folks like me who find ID to be compelling would screen amen, because that is what we have been saying all along .

    😉
    peace

  41. Corneel:
    The only way to guarantee reliable transmission of all the parts of the IC package is some sort of reproductive isolation.

    If that were the case no irreducibly complex things would exist except in genetically isolated populations .

    Is that really the road you want to go down here? I’ll bet you get some grief from your fellow ID critics on that one

    peace

  42. Corneel: Are you going to tell me that only humans are conscious?

    I’m going to say that only those beings that are created in the image of God are conscious.

    When it comes to the animal kingdom only humans (ie descendants of Adam) fit that bill.

    Are you going to try and prove that axiom wrong empirically? I would truly like to see you try to do that.

    peace

  43. Corneel: Being human is inherited through the male lineage? Really?

    I have no idea of the way the inheritance is passed on

    All of Adams male decedents would by definition be the decedents of Adam and Eve so it really does not matter.

    I do know that male humans are more likely to be the perpetrators of the kind of aggressive seed spreading that occurred with Genghis Khan so I see no reason to rule it out.

    peace

  44. fifthmonarchyman: If you say the persistence of irreducible complexity is highly unlikely given materialistic assumptions folks like me who find ID to be compelling would screen amen, because that is what we have been saying all along .

    I am not injecting materialistic assumptions. We were talking about inheritance. So the persistence of irreducible complexity required divine guidance?

  45. fifthmonarchyman: If that were the case no irreducibly complex things would exist except in genetically isolated populations .
    Is that really the road you want to go down here? I’ll bet you get some grief from your fellow ID critics on that one

    Are you going to tell me you know of populations that are segregating heritable variation for irreducible complex traits, like eyes? Nice, please share.

    Your scenario requires the intact transmission of multiple heritable factors to each and every one of Adam’s descendants. Not going to happen until the trait is fixed.

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