Print Page   |   Contact Us   |   Sign In   |   Join ASA or sign up
Sign In


6/21/2018 » 6/23/2018
“Bioethics and Being Human,” Deerfield, IL

Call for Papers for “Being human in a technological age,” Pretoria, South Africa

“Will the Machines Take Over? Human Uniqueness in the Age of Smart Machines,” Seattle, WA

7/27/2018 » 7/30/2018
2018 ASA Annual Meeting

8/13/2018 » 8/14/2018
“Our Place in the Cosmos?: Humanity, Spirituality, and the Awesome Universe,” Saskatoon, SK

original human population size
Moderator(s): Randall D. Isaac
Thread Score:
1 |
| 3
Thread Actions

7/13/2012 at 5:00:49 PM GMT
Posts: 141


  You raise many important issues to discuss. Let me focus here on one of your original issues that started this topic. You state that " In any case a single individual will always be responsible for getting a new gene going that will make the new organism substantially different than the others." But I think what Craig and Keith and I were trying to say is that while it is true that a mutation, or small set of mutations, can occur in one individual and eventually propagate to 100% of the population, such mutations in complex organisms seldom, if ever, define a species or subspecies of the type that might differentiate humans from non-humans. Of all the characteristics that biologists and paleontologists use to identify a "human", I don't think there is any single one where they would define a precise value above which is a human and below which is non-human. In other words, the transition from non-human to human is more than a single, or several, generation's worth of changes. It may be more helpful to think of a continuum in each characteristic trait.

 As a result, if one differentiates human from non-human in purely biological terms, then the notion of a "first human" or a "first couple" is hard to sustain in light of our observations and understanding. That leaves a spiritual definition, which is an interesting option and which raises its own set of questions.

7/13/2012 at 10:12:04 PM GMT
Posts: 12
the first human
Re K. Miller and R. Isaac (7/13, 5pm)

Thank you for your thoughts Keith. I know some of your work so I’m very pleased that  many highly qualified scientists are participating in these forums.

I can understand that, as you say, "the genome of a species is a population genome that includes all the genetic diversity within that interbreeding population.” In the case of humans then, the first human would have been the first individual of a species to inherit a mutation that gave it certain characteristics that were significantly different from the rest of the interbreeding population. Among several unique characteristics it possessed, the most important and defining characteristic was its ability to relate to God. All those to whom this and the other unique characteristics were passed on constituted the subspecies we call humans. All together they had the genome that defines humans. That genome had enough variability to include the individual genomes of all of its members. But there was a first person to have these characteristics and the particular genes that produced those characteristics. He had other characteristics that were shared by all other humans (say, a certain moral awareness) and then some other characteristics were not shared by all other humans (such as the shape of his nose). He also had characteristics that were shared by the entire species, including the non-human primates (say, bipedalism and the same reproductive organs and capacities). The shared human characteristics resulted from genes that produced them which were likewise shared by all other humans. The characteristics he possessed that were not shared by all other humans resulted from genes sequences not shared with all other humans.

I think Randy’s recent comments will help to bring us to a better understanding and possibly some agreement. First of all, we need to consider what it takes to be human. Traditionally it was considered to be intelligence. Man is the rational animal. No animal can reach our intelligence.  But I think the defining characteristic must rather reside in the area of spiritual and moral awareness. We will sometimes hear accounts of people who seem to have absolutely no moral awareness. A true psychopath, if he or she has truly never had any moral awareness, could still be very intelligent but would not be human. I don’t think that there are truly any such people in the world unless, perhaps, God wanted us to live among some others who are not truly human. I think all people are given some moral awareness and then they have the opportunity to make choices that will remove that awareness or to let it continue. Romans 1 seems to indicate that all people have a spiritual awareness as well, an awareness of God, which they can suppress as well as their moral awareness.

Now we don’t really know whether at least some higher animals have some kind of moral or spiritual awareness. If they do, then God must deal with them in some special way very different from the way he deals with us. So I think the defining characteristic of humans must be in their unique moral and spiritual characteristics. They are aware of the ought, they are at some time in their lives aware of God or at least the possibility of God’s existence, and they can relate to God in some ways that animals cannot.

I cannot more clearly define the moral and spiritual differences. But I think it suffices here to say that humanness consists in certain moral and spiritual characteristics not possessed by any other animals.

The second point we need to be aware of is that these characteristics must be passed on genetically. Somehow God gives us this awareness by giving us a certain mental ability. To think that these abilities can be passed on to all humans without involving genetic changes raises difficulties. How does everyone who is human happen to have these characteristics, these mental abilities, without this coming from their genetic makeup?

Thirdly, then, there must be a first human who has the genetic makeup that gives him or her these abilities, this moral and spiritual awareness.

We don’t have a gradual continuum between being aware of God and not being aware of God, between our awareness of right and wrong and not having that awareness, between knowing what God means and not knowing. So again, I would claim that there must be a first human (and then a first human couple) from whom these characteristics of humanness came.

Last edited Saturday, July 14, 2012
7/17/2012 at 1:54:41 AM GMT
Posts: 141
Dennis, this is a good discussion and there is much more to be said. But it may be after the annual meeting before we get to it. Meanwhile, I just saw this interview "A Conversation With Chris Stringer
A Bone Here, a Bead There: On the Trail of Human Origins" on the NYTimes online and thought it was quite interesting and relevant to this discussion.

Last edited Tuesday, July 17, 2012
7/17/2012 at 4:28:01 PM GMT
Posts: 1

Hello Dennis, from another Dennis. Welcome to the ASA.

Between Craig, Randy and Keith you've had good answers to your original questions, but I fill in a bit here and there.

One thing to note is that "new" mutations are not the only way to produce novelty in a population, nor the most common way. It is far more common to have recombination of previously existing mutations (genetic variation in a population) into new combinations. For humans and chimpanzees, for example, many of the differences we see between our two genomes were likely present as alternate alleles in our common ancestral population. These differences then sorted down to our two modern populations unequally - an effect known as incomplete lineage sorting.

Another thing to note is that single mutations do not, in general, produce large effects. Many mutations, combining and recombining over time in a population, can shift averages. When we compare the human and chimp genomes, for example, scattered small differences are the rule, not the exception. Yet these differences combine to give the differences we see.

I've written about these issues in more detail over on the BioLogos site (search under my name as an author search) and look for the "Understanding Evolution" series.

One last comment about your statement that "God-awareness" is either there or not there - what about our own development from infants to adults? Did we not become aware of God gradually through that process? Would not a similar progression be possible for our species over time?



7/17/2012 at 10:28:58 PM GMT
Posts: 12
Was there a first human?
re R. Isaac and D. Venema

The references you both gave may help me to understand the details of current views of evolutionary processes a little better. Thank you for these references. I’ll be looking at them shortly.

Randy, I know you have much to do for the annual meeting, so I’ll be interested in whatever continued comments you want to make when it’s over. Thanks for taking so much time already.

I know it is not as simple as mere single mutations producing radical changes. I suppose that it’s just easier for me to think in those terms since it gives a clear idea of how changes can occur. Dennis, I don’t see that the more complicated and more realistic processes you mention (combination, recombination, incomplete lineage sorting, etc.) really make a difference to my claim. Maybe after I look at your references I will. But for now doesn’t it seem that whatever genetic changes and recombinations we need to produce the necessary and sufficient conditions for humanness (God-awareness, moral awareness, etc.) we still end up with some in a breeding population who will have those characteristics and others who will not. Those without those characteristics will either eventually become extinct as they are selected out of the population by natural selection or they will form another species. (Here I’m just assuming the simple definition for a species of all members of an interbreeding population.)

Concerning your comment about God-awareness being an awareness a child gradually develops, Dennis, I would think that the child certainly may develop this gradually and yet only be responsible before God at some discreet point in the process. That is, at some point the child is aware that God is there and God is someone to whom they ought to respond spiritually. Before this point the child might have some more vague awareness of God, but this is not certain. If they do at some point have only this vague awareness, then they are not truly aware of God as God until they are aware of how they ought to respond to God. I may be wrong here. It may be that God considers the child to have their humanness actualized at some point at which the child is merely aware of God’s existence and is aware of some other relationship with God. But I would claim that one is not an actualized human but only a potential human until one of these points.

It is not as though this understanding can be used to justify infanticide, for example, since God sees a person as one through time. God sees the infant as the same person who will someday have moral and God-awareness. God does so because both are the same person. I am the same person I was as a new-born and even as a fetus once I was given sentience. The same awareness persists through time and constitutes the identity of a person. Nevertheless, humanness occurs at a discreet point. Before that point of moral awareness and God-awareness, one has no greater awareness than that of the other animals. At least one might say that any greater awareness up to this point does not make any difference.

Now the primate that is just on the verge of God-awareness but doesn’t quite possess it in it’s life may be the parent of a primate which does possess God awareness. But because the first primate is not the same person as the second, because it is cut off from this distinct awareness, it is not human. Only the second primate is human. So again, it seems to me that humanness is something one either has or does not have.

I’ve mentioned my indebtedness to your work in one of my earlier comments in this discussion, Dennis. Thanks again for your added comments. I’ll get to your study on the BioLogos web site shortly.

7/17/2012 at 11:17:52 PM GMT
Posts: 7


 There is a major aspect to your questions that I did not address in my earlier post. One assumptions you seem to be making is that their must be a physical (biological) component to being human in a theological sense (that is be able to be in communication with and image God). I believe that this in only the case in that there must be certain intellectual capabilities (self consciousness, empathy, awareness of past and present, creativity, logical reasoning, etc.) in place so that a creature has the potential to be in conscious fellowship with God. However, those mental capacities are not what make us God’s image bearers. It seems clear to me, that what defines our image bearing is relationships. That is we image God in that God has chosen to establish a relationship with us, and that relationship then extends out to other humans, and to the entire creation. The image is relational, not biological. It is not a consequence of our biology, but of God free grace in putting us in relationship.

Because of this understanding of being made in God’s image, I think that it is futile to try to discern the beginning of humanity in a theological sense from the fossil and anthropological record. I don’t see why there need be any biological difference at all between those individuals that God revealed himself to and made His image bearers. Becoming human was not a speciation event -- it was a divine act of grace.

I do not think that it is possible to define the beginning of the image of God through anthropology. It is also not a biological function that we can identify and that a person might lose through injury or genetic defect. We are images of God only because God is in special relationship to us.

All the best,


7/19/2012 at 5:32:30 PM GMT
Posts: 12

Hello again Keith,

I said that humans must have certain physical capacities, that there is a minimum of intellectual abilities necessary for humanness. I agree with you that this is only a necessary and not a sufficient condition to have humanness. Any organism lacking these abilities and the genetic code needed to produce these mental abilities cannot be human unless God somehow miraculously intervenes to allow such abilities. Yet one who has these intellectual capacities is still not necessarily human. One may have the capacity to be aware of God and still not be aware of God should God not choose to allow one this awareness. This awareness need not be anything like what we might think of as a religious experience. It could be nothing more than the awareness that God could be there and that one has a moral obligation to this God should this God exist. This is more of a moral awareness though we might also call it a spiritual awareness.

So yes, it seems that God does have to specially act to give us our humanness, the image of God, and having all the right mental abilities is not enough. I could be wrong, but it does seem to me that this kind of moral awareness cannot result from mere physical capacities of the brain. I would certainly claim this of human consciousness (as well as animal sentience insofar as we can assume that animals do have sentience). J. P. Moreland, for example, develops an argument for God’s existence from human consciousness. No increase in complexity or in new arrangements of complex neural parts can produce consciousness in humans any more than making Star Trek’s android, Commander Data, more complex can actually give him consciousness. To claim otherwise is a category mistake. What I am questioning concerning moral awareness is whether, given human consciousness, this awareness can result naturally from some feature of human intelligence which in turn results from our complex brain structure. As I say, I don’t think it can.

You make the point that it would thus be very difficult to determine from studies in population genetic or archeology when the first humans came to be. But even if the characteristics I’ve suggested to be sufficient for humanness are genetically determined—that once we are physically made a certain way and behave and think accordingly, we must be human—it would still be just as difficult to say when the first human came on the scene. Might one in the line of common ancestors for the chimp and human line have been human? I claimed earlier that humans and non-human primates might have interbred until one line was left and the other became extinct or that both became distinct species. If all it takes to be human is a sense of God’s existence (or an awareness of the possibility of God’s existence), and an awareness of the obligation to relate to this God in a certain way (worship, obedience, etc.), and maybe a more general moral awareness also, then it seems very possible that the first human could be very early. I had mentioned the Upper Paleolithic Revolution as a likely starting point for humans because it seems that here the artifacts and other evidence indicate clearly modern human behavior whereas for any previous primates we can hardly tell the difference between their behavior and artifacts and that of any other higher animal. And I still think this is the more likely point at which humans appeared. But as I say, if we truly consider humanness to consist of moral and spiritual characteristics like those I’ve suggested, the first humans could have existed much earlier.

You have suggested some other characteristics such as creativity, logic, etc. which might put some rough limits as to when humanness could begin. But as you say, with this it is "futile to try to discern the beginning of humanity in a theological sense from the fossil and anthropological record.” I’m not sure if you are saying that to be human in a theological sense requires one to be in relationship with God. It should at least require the potential of relationship with God, that one may choose that relationship and God may allow it. But certainly those who refuse this relationship are (and were) no less human than those who choose it.  

You say, "I don’t see why there need be any biological difference at all between those individuals that God revealed himself to and made His image bearers. Becoming human was not a speciation event -- it was a divine act of grace.” Well, so long as they all have those minimal mental abilities and yet they still have that relationship with God (or, as I suggest, even the potential for that relationship), they certainly should all be considered human even though they be of different biological species. If there ever were more than one biological species of humans, then all must have become extinct except one.

Last edited Thursday, July 19, 2012
7/20/2012 at 10:34:13 AM GMT
Posts: 21
As far as the biological question of past population sizes, Dennis Venema has covered the methods used to estimate them in the latter part of a paper on the Biologos site ( You may find that useful to look at.

7/20/2012 at 4:13:23 PM GMT
Posts: 12
Thanks for the reference. I still haven't gotten through all of the other references that have been suggested but I hope to soon.

7/28/2012 at 11:30:30 PM GMT
Posts: 7


 I will make only one comment.

 You stated: "But as you say, with this it is "futile to try to discern the beginning of humanity in a theological sense from the fossil and anthropological record.” I’m not sure if you are saying that to be human in a theological sense requires one to be in relationship with God. It should at least require the potential of relationship with God, that one may choose that relationship and God may allow it. But certainly those who refuse this relationship are (and were) no less human than those who choose it."

 Yes, I believe that being human (having the image of God) is based upon God's relationship to us.  We are human in the theological sense because God has graciously chosen to be in a special relationship with us.  However, that does NOT mean that it is dependent on our response.  We are God's image bearers regardless of whether we acknowledge or respond to that relationship or not.  That is why there is an historical redemptive story - God pursues those with whom He has established a relationship.

Our biology is NOT the basis of our humanity (except in the sense of possessing certain mental and social capabilities).  A creature capable of interacting with God could have as easily been evolved from the dinosaurs.  I think we place far to much emphasis on our biology in understanding our unique status before God and the rest of creation.

All the best,