Re: [asa] Re: Reading Genesis theologically NOT historically

Heya Dennis,

I read over the paper you linked (I assume you offer this up in response to
the 'first human' question in general, not just to Cameron) and I'm
wondering if there's some talking past each other going on here.

One problem jumps out at me in the author summary: "Primate evolution is a
central topic in biology and much information can be obtained from DNA
sequence data. A key parameter is the time “when we became human,” i.e., the
time in the past when descendents of the human–chimp ancestor split into
human and chimpanzee."

So this paper is talking about "when we became human" - but what that means
seems to be radically different from what I mean in this conversation,
possibly what others mean as well. When I talk about there being a "first
human", I'm not talking about, say.. a point where human-ancestors and
chimp-ancestors were no longer able to interbreed. Really, I'm not
necessarily talking about a speciation event (certainly not a strict
biological speciation event) at all. I'm mentioning that if we have a
certain standard for "human" - defined as an individual possessing all of
this specific set of traits/properties at once - then if such an individual
exists at all, if we were to go roll back the tape of life and examine each
individual in turn, eventually we're likely going to arrive at an individual
who first possessed all of those traits. And if possessing those traits are
what we define "human" to be, then we have our "first human". Even if this
"first human" is present in a larger population they are capable of
interbreeding with.

You also say "There is also no point where one could point at one hominid or
a single pair of hominids and say they were the ancestors of us all. For
parts of our genetic makeup, such as our mitochondrial DNA, yes. *In toto*,
no." Forgive me if I am misreading you here, but I take that as saying the
following.

* One particular aspect of our genetic makeup (our mitochondrial DNA, for
example) may be traced back to one hominid or a single pair of hominids.
* But this will be just one part of our genetic makeup. Other parts may be
traced back to a different hominid/single pair of hominids. So to
'completely' describe our genetics, we'd need to talk about a population,
not just one single ultimate human pair.

Do I have you correct on this much?

On Tue, Oct 6, 2009 at 3:41 PM, Dennis Venema <Dennis.Venema@twu.ca> wrote:

> Cameron,
>
> There is no evidence to support the hypothesis that genus *Homo *arose
> more than once. There is also no point where one could point at one hominid
> or a single pair of hominids and say they were the ancestors of us all. For
> parts of our genetic makeup, such as our mitochondrial DNA, yes. *In toto*,
> no. We come from a population, that came from a population, etc, etc.
>
> Your ideas bear little similarity to those of Darwin, much less that of
> modern writers. Darwin understood that variation was continuous: you’re
> modeling variation in discontinuous categories with some sort of
> single-gene, Mendelian model. Your protests to the contrary, there is ample
> evidence that you do not understand even the basics of evolutionary biology.
>
>
> “So instead of recommending me a dry technical article, why not tell me in
> plain language: how do you come up with an interbreeding population of a
> *thousand* okapis that are six inches taller before you have even *one*
> okapi that is six inches taller?”
>
> Have you never heard of a normal distribution? Populations form normal
> distributions for traits that do not fall into discrete categories (such as
> height and weight). The average characteristics of a population can change
> over time under selection by incremental steps. There are many, many genes
> that contribute to continuous characteristics: variation within these genes
> within a population coupled with genetic segregation produces the variation
> we observe. If selection is acting on one side of the distribution then over
> time the allele frequencies will change in the population and the average
> will shift. I would recommend you pick up an introductory genetics text and
> look over the population genetics material therein.
>
> That paper I linked to is not a “dry, technical paper.” It’s cutting-edge
> science that addresses your exact questions with the best techniques
> currently available. If you’re interested in these issues this is where to
> go: Darwin is all fine and well from a historical perspective, but he’s
> hardly current biology. If you want to ask questions as you read the paper,
> by all means, do so. If you’re not interested in reading the paper (or
> other, current science on this issue) then I’ll probably chalk up your
> approach as another datum point for the Dunning-Kruger effect and leave it
> at that. *Vita brevis.
> *
> Dennis
>
>
> On 06/10/09 12:09 AM, "Cameron Wybrow" <wybrowc@sympatico.ca> wrote:
>
> Dennis, my ideas of speciation come from Charles Darwin -- whose works I
> have read with some care (unlike 90% of the biologists on the planet) -- and
> from a number of biologists who champion his writings, including Ken Miller
> and Richard Dawkins, not to mention a whole host of popular science writers,
> many of whom have Ph.D.s in paleontology etc. I've been reading about
> evolution for about 45 years now, so I have a pretty good idea what
> traditional neo-Darwinism says. My example of the okapi-like creature and
> the giraffe is classical; it's in just about every exposition of Darwinian
> evolution I've ever read, and if you don't recognize it, then I'm absolutely
> stumped. Perhaps you are much younger than I, and the way of teaching
> evolution in both schools and popular science books has completely changed
> in the past 20 years. But I doubt it, since Ken Miller and Dawkins still
> treat evolution in this manner, and they are still very much alive and
> kicking. I wouldn't be surprised if they both employ the giraffe example in
> one or more of their books.
>
> But possibly you are not a neo-Darwinian. If not, please say so, so that
> we won't debate over a position that you don't hold.
>
> One of the first requirements of any discussion between people of differing
> specializations is clarifying terms and concepts. I tried to offer some
> working distinctions within which you and I could hold a rational
> discussion. I made them jargon-free, and employed the technique of division
> by two which has been employed in Western logic and teaching since
> Aristotle, and which I assume that any person educated in any field can
> follow. I would gladly accept a modification of my divisions based on any
> defect in my logic (though I don't see how there can be a third option to
> the alternatives "one" and "more than one", when zero and all negative
> numbers are obviously ruled out). However, instead of addressing my
> divisions in the spirit of clarification in which they were offered, you
> play the "you don't understand enough biology, you need to read more
> articles" card, when nothing -- absolutely nothing -- that I said in my
> reply -- if you would read it carefully -- depends on any specialist
> knowledge of biology. My remarks require only the assumptions that: (1)
> Sexual reproduction happens; (2) Trees of ancestors can be drawn up; (3)
> Common ancestors exist. I believe that all evolutionary biologists accept
> these assumptions.
>
> I know that mammals do not reproduce asexually. The very fact that, if I
> held such a view, I would be a complete ignoramus, should perhaps suggest to
> you (unless you think that I *am* a complete ignoramus, which I suppose is
> possible) that I might mean something more intelligent than that, and that
> you may not have read my words carefully enough before objecting to them.
> But just to clarify, and for the record: though of course two parents are
> necessary for reproduction, only *one* of the parents has to possess the
> mutation which gives the new trait to the offspring. Mendel's genetics
> explains why. If a long-necked okapi mates with a regular-necked okapi, and
> if the long neck of the one is a result a gene that it carries, then the
> gene, and hence long-neckedness, can find its way into the future population
> of okapis, as I am sure you must know.
>
> Your criticism of my two-point distinction, followed by your point 3, shows
> either a misreading of my distinction, which could perhaps be my fault for
> being a poor expositor, or a failure in logic on your part, because you
> think that your answer #3 is different from my answer #2, when in fact it is
> merely *a special case* of my answer #2. Read again carefully. The words
> "The current crop of human beings on this planet is genetically descended
> from more than one pair of ultimate parents" are found in both your answer
> and mine. Your answer still falls entirely within my twofold division of
> "one" and "more than one". You have opted for "more than one", and
> therefore have not invalidated my distinction.
>
> I think what may have thrown you is my word "unrelated". Obviously on
> evolutionary assumptions all life forms are ultimately related. By
> "unrelated" I meant, of course, "breaking off from the main stream of
> hominid (or possibly even primate) evolution at two completely different
> points". The larger question I was raising by the word "unrelated" was
> whether you supposed that human beings -- truly human beings, I mean, genus
> homo, not merely hominids generally -- in fact arose *more than once*, via
> *independent pathways*, with the two or more populations later being blended
> to produce modern homo sapiens, or whether you thought that human beings
> arose *only once*.
>
> More important, you do not seem to see my point about the giraffe and the
> okapi. I will try one more time, briefly. You will agree that there was a
> time on earth when there were no mammals, correct? Then the *latest* common
> ancestor of man and the apes did not yet exist, correct? You will also
> agree that there was a time on earth when there were no primates, but there
> were other mammals, e.g., shrews, correct? Again, the latest common
> ancestor of man and the apes is not on the scene yet, correct? You will
> agree that there was a time when there were primates, but not yet the line
> of primates that was to lead to man and the apes, right? So we still aren't
> there. But now, there comes a time when the latest common ancestor of man
> and the apes exists, correct? Call it 4 million years ago, call it 7
> million years ago, I don't care in the slightest when it was. I am making a
> logical point. After that ancestor, the various branches of higher primates
> go off in their various directions (I'm not getting into the details here of
> which of them is evolutionarily closer to which, because it's irrelevant to
> my point). But if I had a time machine, I could, in principle, go back in
> time, and kill off the genetic ancestor from which all of us evolved, thus
> preventing human beings from ever existing. And yes, of course, if on my
> first landing in the past, I find 1,000 interbreeding individuals, I would
> have to kill off 1,000 to prevent contemporary man from arising. But where
> did those 1,000 interbreeding individuals come from? Did they emerge
> spontaneously out of the earth? Did God call them into existence by fiat?
> No, I think you will say, they came from their parents, who were of course,
> sisters, brothers, and cousins of each other, and therefore sprang from
> earlier common ancestors. So then I could say, "I'm too lazy to kill 1,000
> of these things", or "I don't have enough bullets for 1,000", and I could
> take my time machine back further, until I came to the being -- which you
> can classify any way you want in the technical jargon, proto-hominid or
> whatever is the latest label -- which was the common ancestor of them all,
> and if I kill that being, those 1,000 breeding individuals cannot ever be
> born.
>
> If you have trouble accepting an argument, however logical and complete,
> that comes from a "non-biologist", just look at the diagram in The Origin of
> Species (it's the only diagram in Darwin's book), and look at Darwin's
> explanation in the first four chapters of how species are formed. He's
> clear that new species begin with a variation in an individual -- a longer
> neck or beak or better coloration for camouflage or an incipient new organ
> or behavioural trait -- which is then passed down to offspring. (For
> reasons later explained by Mendel; Darwin was fuzzy on the mechanics.) It
> is those offspring which become your "interbreeding population". No
> original daddy (or mommy) with the new trait in question, no subsequent
> interbreeding population with that trait. It requires no advanced biology
> to see that -- only the knowledge of the birds and the bees. If the first
> mutation doesn't occur, you can forget about breeding populations containing
> that mutation.
>
> So instead of recommending me a dry technical article, why not tell me in
> plain language: how do you come up with an interbreeding population of a
> *thousand* okapis that are six inches taller before you have even *one*
> okapi that is six inches taller?
>
> Cameron.
>
>
>
>
> ----- Original Message -----
>
> *From:* Dennis Venema <mailto:Dennis.Venema@twu.ca<Dennis.Venema@twu.ca>>
>
>
> *To:* Cameron Wybrow <mailto:wybrowc@sympatico.ca <wybrowc@sympatico.ca>>
> ; asa <mailto:asa@calvin.edu <asa@calvin.edu>>
>
> *Sent:* Tuesday, October 06, 2009 12:32 AM
>
> *Subject:* Re: [asa] Re: Reading Genesis theologically NOT historically
>
>
> Hi Cameron,
>
> “Obviously there must be a "first" in every biological line.”
>
> Not so, if you mean “first individual” - as your response seems to
> indicate. The only thing obvious here is that you don’t understand how
> speciation works. I’m not trying to be harsh, just forthright. Your ideas
> of speciation are not like any I’ve seen before.
>
> Populations change much more gradually. The change is in average
> characteristics, unless we are talking about rapid speciation due to
> chromosomal duplication, etc, when speciation is through a single pair or
> individual.
>
> “And the five-foot-six ancestor was an individual, not a "population" --
> though of course he or she eventually produced a population (of
> longer-necked okapi-like animals). “
>
> And how, pray tell, did this poor creature do this all on its own? Mammals
> don’t reproduce asexually. The correct answer, even if your ideas were
> correct, would be that it would be through the existing population.
>
> Your thoughts on human evolution are similarly muddled:
>
> “1. All human beings are genetically descended from a single pair of
> ultimate parents (6,000 years ago, 30,000 years ago, 100,000 years ago, a
> million years ago, whenever).
>
>
> 2. The current crop of human beings on this planet is genetically
> descended from more than one pair of ultimate parents, parents who were
> themselves unrelated.”
>
>
> These are not exhaustive.
>
> The correct answer is:
>
> 3. The current crop of human beings on this planet is genetically
> descended from more than one pair of ultimate parents, parents who were
> members of an interbreeding population of at least 1000 individuals. This
> population shares a common ancestral population with a second population
> that went on to be the ancestors of modern chimpanzees. This speciation
> event is estimated to have occurred between 4-7 million years ago.”
>
> It’s late, and I’m off to bed soon, but here’s a paper to read that might
> help. It discusses human population sizes since speciation with chimpanzees
> and gorillas.
>
> Dennis
>
>
> http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.0030007
>
>
> ------------------
>
> On 05/10/09 5:56 PM, "Cameron Wybrow" <wybrowc@sympatico.ca> wrote:
>
>
>
> Dennis:
>
> Your remark below needs to be explained, because as it stands it obscures
> what you are saying, both in reference to biology and in reference to the
> notion of Adam and Eve.
>
> Obviously there must be a "first" in every biological line. If we take
> the classic neo-Darwinian example of the hypothetical okapi-like animal
> which became the giraffe, presumably all modern giraffes can in theory be
> traced back to a *first* okapi-like animal which grew a neck significantly
> longer than the other members of its population, and survived food
> shortages (because it could reach higher leaves), thus leaving more
> offspring, etc. Neither biologically nor logically could there have been a
> "first population" of long-necked okapi-like animals until there was a
> "first individual" of this type. Supposing that the evolution of the
> giraffe began when an animal five feet tall produced a longer-necked
> offspring that was five foot six, the five-foot-six offspring is what is
> normally meant by the phrase "ancestor of the giraffe". The term
> "ancestor" is perfectly justified by common sense: if that five-foot-six
> animal had been eaten by a predator before reproducing, there would have
> been no giraffes -- or at the very least their evolution would have been
> delayed by however long it took to come up with another five-foot-six
> offspring, which would be by no means a certain thing. And the
> five-foot-six ancestor was an individual, not a "population" -- though of
> course he or she eventually produced a population (of longer-necked
> okapi-like animals). So your objection to a first ancestor does not make
> sense. You need to flesh out, in layman's language, what you mean by a
> "population" in this context. Why does a "first population" exclude a
> "first individual"?
>
> Consider these two possibilities, which as far as I can tell exhaust the
> logical alternatives:
>
> 1. All human beings are genetically descended from a single pair of
> ultimate parents (6,000 years ago, 30,000 years ago, 100,000 years ago, a
> million years ago, whenever).
> 2. The current crop of human beings on this planet is genetically
> descended from more than one pair of ultimate parents, parents who were
> themselves unrelated.
>
> Then there is a further distinction to be made between human and
> non-human, which when applied to the first distinction yields four
> possibilities:
>
> 1. a. The single pair of ultimate parents was fully human.
> 1. b. The single pair of ultimate parents were highly sophisticated
> primates, but not yet human.
>
> 2. a. The different pairs of unrelated ultimate parents were fully
> human.
> 2. b. The different pairs of unrelated ultimate parents were highly
> sophisticated primates, but not yet human.
>
> Now:
>
> If 1a is the case, there is no reason why you should object to the notion
> of a first human pair. I therefore presume that you reject 1a.
>
> If 2a is the case, then the human species emerged *more than once* from
> the evolutionary process. This is most unlikely on neo-Darwinian premises.
> Therefore, I presume that you (whom I take to be a neo-Darwinian) reject
> 2a.
>
> If 2b is the case, then either the descendants of the two (or more)
> unrelated primate lines mixed, or they did not. If they did not mix over
> thousands of generations, it was because they could not mix, and then the
> different types of modern human beings (e.g., Australian aborigine,
> Caucasian, Mongoloid, etc.) would not be able to mix, either. But all
> modern human beings can interbreed. Also, after thousands of generations,
> more like tens of thousands, of separation from two originally distinct
> primate species, we would expect at least species-level differences among
> human beings, not mere differences in pigment or hair curliness and so on.
> But no one thinks that different types of human beings today are of
> different species. So clearly the (hypothetical) distinct primate lines
> must have mixed to produce a common human race. But would the lines have
> been able to mix? That depends on how different the two unrelated primates
> were in the first place. If they were as different as, say, a baboon and a
> spider monkey, or a gorilla and an orangutan, or a human being and a
> gorilla, they would not be interbreedable, and then scenario 2b is
> impossible. On the other hand, if the two distinctive primate lines were
> close enough to be interbreedable, then they undoubtedly themselves sprang
> from a common ancestor, in which case 2b is just a slight variation on 1b.
>
> Thus, by elimination, it looks as if you are plumping for 1b.
>
> So, is your notion that the "first pair" from which all human beings have
> descended was *not yet human*, so that human beings did not come onto the
> scene until hundreds or thousands of generations later than the "first
> pair", by which time there would have been a population of them?
>
> Or, to put it another way, are you granting that all human beings did
> indeed come genetically from a first pair, but not from a first *human*
> pair? Just as the present-day population of giraffes came genetically from
> a "first pair" (an okapi-like animal with a long neck crossed with an
> okapi-like animal with a normal neck), though that "first pair" was not
> itself a pair of giraffes? So that the Biblical story is inaccurate, not
> in postulating a first pair of genetic ancestors for all human beings, but
> in postulating that the first pair was *human*?
>
> Cameron W.
>
>
>
>
> ----- Original Message -----
>
> *From:* Dennis Venema <mailto:Dennis.Venema@twu.ca<Dennis.Venema@twu.ca>>
>
>
> *To:* Gregory Arago <mailto:gregoryarago@yahoo.ca <gregoryarago@yahoo.ca>>
> ; George Murphy <mailto:GMURPHY10@neo.rr.com <GMURPHY10@neo.rr.com>>
> ; Dick Fischer <mailto:dickfischer@verizon.net <dickfischer@verizon.net>>
>
>
> *Cc:* muzhogg@netspace.net.au ; asa@lists.calvin.edu
>
> *Sent:* Monday, October 05, 2009 5:52 PM
>
> *Subject:* Re: [asa] Re: Reading Genesis theologically NOT historically
>
>
> Gregory,
>
> The point (biologically) is that there is a first *population*, not a
> first individual. Your logic, if I understand it correctly, doesn’t hold.
> Speciation for humans was a population event, not via a single individual
> or pair, as far as we can tell.
>
> Dennis
>
>
> On 05/10/09 2:26 PM, "Gregory Arago" <gregoryarago@yahoo.ca> wrote:
>
>
>
>
> George Murphy wrote: "Adam IS mankind."
>
> If that is the case, George, and if you accept the logic *there must have
> been a first,* then do you accept that the 'first human' was ADAM, i.e.
> the first of 'mankind' or 'humanity'? If not, then why not? Are you a
> *degree, not kind* guy?
>
>
>
> ------------------------------
> *From:* George Murphy <GMURPHY10@neo.rr.com>
> *To:* Dick Fischer <dickfischer@verizon.net>
> *Cc:* dickfischer@verizon.net; muzhogg@netspace.net.au;
> asa@lists.calvin.edu
> *Sent:* Tuesday, October 6, 2009 12:47:31 AM
> *Subject:* Re: [asa] Re: Reading Genesis theologically NOT historically
>
> 
> When humankind (not just a single individual) is said to be created in
> the image & likeness of God in Gen.1:2, it's quite legitimate (IMO) to
> interpret the following words, "and let them [N.B.] have dominion over the
> fish of the sea, and over the birds of the air, and over all the wild
> animals of the earth, and over every creeping thin that creeps upon the
> earth" (NRSV). I.e., humans are to be God's representatives in ruling the
> other creatures of the world. The word "emissary" is really too weak for
> this. But more importantly, there is no suggestion that oen human being
> is commissioned to be an emissary to other human beings. So the point
> remains, there is no canonical texts that says - ot implies - "that Adam
> was God’s emissary to mankind." Adam IS mankind.
>
>
>
> Shalom
> George
> http://home.roadrunner.com/~scitheologyglm<http://home.roadrunner.com/%7Escitheologyglm>
>
>
>
>
> ------------------------------
> Looking for the perfect gift?* Give the gift of Flickr!* <
> http://www.flickr.com/gift/>
>
>
>
>

To unsubscribe, send a message to majordomo@calvin.edu with
"unsubscribe asa" (no quotes) as the body of the message.
Received on Tue Oct 6 17:19:21 2009