#shanenaz

We're doing it again! This time we are biking from Petra in Jordan up to Nazareth in Israel, to raise money for the Nazareth Hospital Dialysis Unit. Last year we raised over £50,000 for the Children's Unit! Nazareth is the largest Arab town in Israel; the people are lovely, and the kids are awesome. Nazareth also treats kids in the West Bank of Palestine who have very limited access to healthcare. They need your help! Go to my sponsorship page to find out more and see what you can do! Maybe even join us..? http://justgiving.com/shanenaz

14 November 2010

Was Adam a real person?

"I'm bringing sexy back."
And is that even a real question? I mean, seriously, is there anyone alive in 2010 who thinks that it is meaningful to consider the historicity of a completely mythical person? We all know that humans evolved from a population of African apes, and there is really no controversy over this, other than in areas of where the population was based, the size of the population, and the various factors that supplied the evolutionary pressures (and the sequence thereof) that led to Us. The basic concept of human evolution as a branch of the Great Apes is scientifically secure. Obviously this means that we can assign pre-scientific stories of human origins to the category of myth, and indeed the book of Genesis in the Hebrew Bible is indeed a book of origins myths, hence the name "Genesis". History, genetics, archaeology, paleontology - all have long since comprehensively proven that Genesis is NOT a record of how the world got to be the way it is.

However, bizarrely, some people still cling to the bonkers notion that this is a history book, and that we need to take it literally. People like my old mentor Norman Nevin. As I have mentioned before on this blog, I like and admire Norman a great deal, but this creationism business is simply crazy talk. Far from adducing scientific evidence to support his strange contention that Adam was historical, Norman engages in some jaw-droppingly poor arguments. It is standard creationist fare, and if you really want to see it ripped to shreds, head over to the British Society for Science Education. This has to stop; it is becoming embarrassing.

11 comments:

  1. ok, so forgive my ignorance, but if humanity did indeed evolve from a population of african apes, was there a "first" human being, and did all other human beings descend from that one being? or is it more likely the case, in your view, that a number of human beings kind of evolved at approximately the same and that it is this collective which makes up our ancestors? i appreciate that i may be misunderstanding several concepts or definitions here - for example what constitutes a new species and how we know when it has arrived..... - but as far as i can tell the answer to my question is pretty important in answering questions about adam.

    secondly, may i observe that your statement beginning "obviously this means" is an utter non-sequitur.

    and finally, this morning i started reading the book you have long recommended - straight and crooked thinking - and i am thus far enjoying it immensely. what i enjoyed even more, though, was that your post here demonstrated at least one example of the crooked thinking that dr thouless seems determined to decry!

    best wishes, and despite my mild mockery above, genuinely looking forward to being educated on the adam stuff.

    :-)

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  2. Out of curiosity, what is your "glass floor" for humanity Shane? At what stage did our ancestors acquire characteristics that made them us?

    (Or at least more us than a chimp is)

    Not a theological question, as it happens. Came across it in "Seven Million Years: The Story of Human Evolution"

    His answer seems to be "I dunno, but this is a cool sub-heading for a chapter".

    What are we looking for? Opposable thumbs? A Theory of Mind? Ascetics? Moral codes? All of the above? None?
    Or do we just measure a cranium and guess?

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  3. And can we all agree that chimps, dolphins and gorillas would be suitable ingredients for a stew

    (If it wasn't for their endangered status? And the fact that they wouldn't taste very nice?)

    Graham

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  4. Hi chaps!

    Jeremy, "obviously this means" is pretty secure. Prescientific creation myths carry no scientific or historical force; they merely illuminate the cultures in which they arise. But that is perhaps an argument for another day.

    A difficulty you seem to be having there is with the notion of "human being" as an ontological category - "human" is really a label we apply to a bunch of critters (i.e. us) that form our population. Back in the olden days there was this platonic notion of the perfect human form; all of us were simply slightly imperfect variants on the theme. What biology tells us is the precise opposite - what constitutes "humanity" is defined by the population itself. In other words, to find out what "human" means, we don't consult some dry definition - we make the definitions up on the basis of what we have already decided fits the class. Subtle, but very important.

    So there was no "first human being" in any meaningful sense, because as you trace the population back, each generation becomes imperceptibly more like the common ancestor between us and chimps & bonobos, and you get to the stage gradually where you stretch the definition so far that you really don't think it's useful any more.

    And so it is now. You are a bit less chimpy than your parents; they are a bit less chimpy than your grandparents and so on and so forth. But there is no discrete rubicon that you cross that suddenly out pops Jeremy, and the chimp parents exclaim, "it's a human!"

    There is also (for Graham here) no "glass floor" - most of the traits that we see and admire so much in ourselves (vainglorious apes that we are) are also present to some degree in our relatives, the other great apes. So it seems reasonable to suggest that they were present in our common ancestor.

    So a new species is really just a population, and under the influence of natural selection (given the constant injection of genetic variation arising from mutations & recombination) and genetic drift, when it diverges into two or more, each population goes its separate way, constantly changing, until whatever labels we humans liked to classify them by no longer become appropriate.

    Each of our genes is descended from a common ancestor, but in general it is a different common ancestor for each genomic region (this is slightly simplistic). So the "Y-Adam", i.e. the last male common ancestor, is a differnet chappie from (say) the FOXP2 common ancestor or "Mitochondrial Eve" and so forth, and they lived (probably) at different times and maybe different places. However, at each point, the human population (and by "human" I mean the lineage that led to us) would have been represented by at least hundreds, and possibly tens of thousands of individuals. Before we hit the Big Time, of course.

    That's what the genes tell us, and it is also pretty clear from looking at our banana-munching pals that many of the phenotypic (as opposed to genotypic) characteristics we used to regard as uniquely "human" are features that have been crafted by evolution as much as our hands or our eyes.

    So where does Adam come into all this? Simple - he doesn't. Adam, as "the first human", never existed, any more than "the first dog" existed, or "the first pine tree".

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  5. thanks shane, i think you've answered my question! not sure i understand quite all of it, and am fascinated by some of the ethical implications for just one example, but am off on holiday soon so will have to chew it over and perhaps ask you some more questions another time :-)

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  6. I like having a few wacky beliefs. And I've explained why I take an evangelical view of Scripture ad nauseum on W&T. If you don't want to believe in Adam, or you have problems with that view of Scripture, don't return to Evangelicalism (-; You can remain within the fold of "Mere Christianity" without those beliefs.

    So I'm not really offering any sort of apologetic here. I think that the question of humanities uniqueness has been addressed by secular thinkers. And I'm not sure that I'd agree with your stance even if I wasn't religious.

    Marc Hauser advances a "humaniqueness hypothesis". There is, in his opinion, a "monumental" cognitive chasm between humans and all other animals. Yes, there are some basic building blocks for human cognitive function in primates and corvids. But the cognitive gap between humans and chimps is wider than the cognitive gap between chimps and earthworms! (his terms).
    He cites: the ability to combine sources of information to form new insights; the ability to use rules and solutions for one problem in a variety of new contexts; and the ability to perform combinatorial and recursive operations.
    Recursion is an important and uniquely human cognitive ability. It allows us to generate a potentially infinite number of sentences from a finite alphabet; to imagine what is going on in another's mind (she thought I thought he thought etc); to make tools that make other tools; and to have episodic memories. This is why chimps are still pushing twigs in the ground to catch bugs, and we build jumbo jets a few thousand years after we invent the wheel.

    Daniel Povinelli, Derek Penn and Keith Hollyoak claim that humans are unique in their ability to interpret the world in terms of "unobservables" like mental states or causal forces. Our ability to represent such forces in symbols, and to systematically manipulate those symbols to make predictions is unique.

    And of course our moral systems differ vastly from the crude altruism of the animal world. As do our aesthetics and our spiritual longings.

    Yes, chimps seem to have a very limited theory of mind. Yes, Kanzi can move blocks around to ask for a banana, and yes the PG Chimps probably realised that their trainers might know some things that they didn't. But Kanzi has never demonstrated any knowledge that the pictures are symbols and chimps don't form propositions about another person's thoughts. They're just on the lookout for snacks.

    So there's a gap that we need to mind. If we can breed enough chimps, we shouldn't worry if someone puts them in a stew. They're not us. They might be tasty. And it would annoy Jane Goodall and Peter Singer!

    Anyhow, there does seem to be a threshold that is crossed. Maybe it just requires a basic ToM etc. combined with recursion. From that point on you can have rapid cognitive development. So I don't think that it's unreasonable to ask questions about a "glass floor". And I don't think that it's just a question for theologians and ethicists.
    Cognitive psychology could give us the 'what', neuropsychology the 'how'. Then palaeontologists can go to expensive conferences to determine if Neanderthals would be eligible to vote!

    (That's a bit of a mess, that argument, because I can't help making fun of anyone who gives PETA any credit, and it's late. But hopefully you'll pick up the gist)

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  10. Goodness me, Graham - posting problems, I see :-) Anyway, let's see if we can make this fairly quick. First off, it is quite simply nonsense to suggest that there is a cognitive "chasm" between us humans and our closest relatives the chimps & bonobos. There is a large difference, sure, but this is perfectly bridgeable, and as I mentioned, we do see a lot of the same qualitative cognitive characteristics in the other great apes as we see in ourselves - for virtually all of these it is a matter of degree, not of type. Language is perhaps the big exception here.

    There is something special about humans - something suggestive of a type of evolutionary arms race. In other correspondence I have referred to a "hump" that humans may well have got over, and then runaway evolution gave us these big brains. Hypothetically, of course.

    You wondered whether this would be the same as the glass floor, but I think that would be to make a mistake. The "hump" is not (necessarily) the core set of characteristics that "make us human", but rather a locus on the selective topology where the gradient part-propelled us to where we are now. As a population. But either way round, you can see that humans did not descend en masse from a single breeding pair, but from a population. Bye bye Adam. And bye bye Noah, incidentally.

    I need to challenge the notion (hey, while we're at it, bye bye Hauser!) that there is a greater difference between our cognitive faculties and those of a chimp than there is between a chimp and an earthworm - that is just daft talk, and I think most primatologists would agree with me here. Although humans are unique, we are perhaps not as unique as we think, and for most of our history we had not invented Jumbo Jets, and it's only in the past 5000 years or so that we've got past stone tools. So we're *good*, but our track record is pretty short.

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  11. I'll be back soon on this topic, (hopefully). Two sources of delay: (1) I'm a wee bit busy with exams and such
    and
    (2) watched 14 year old male students interact at lunch. Realised that if I added two bananas and a milk carton, their behaviour could not be distinguished from the chimps at Belfast Zoo.

    This has caused me to doubt my belief in human uniqueness. We shall see if I can recover from the existential shock.

    Graham

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