Monday, September 5, 2011

The Genetic Markers of the Flood Bottleneck

Here comes JAR with his usual wrongheaded assertions (no, no evidence here) against the Flood of Noah.
To mention "fossils" when talking about the Biblical Flood is of course simply silly. The Biblical Flood, if it had happened, was far too recent to have anything to do with fossils.
Too recent to have anything to do with fossils? 4500 years isn't enough time? Even though evolutionists claim that fossils are being formed every day in our own time in far more mundane circumstances than the global biblical Flood? Excuse me? The Flood buried bazillions of living things which would have been made into fossils in a lot less time than 4500 years. I've seen discussions, probably creationist of course since evolutionists are committed to not knowing such things, that show the process occurring in a matter of years in caves that drip calcium carbonate. If I find such a discussion I'll post it.
The Biblical Flood myths say that all the critters on land and in the air with the exception of those critters on the fictional ark were killed during a very short period.

If that were true, then every land and air critter living today, plant or animal, would be descended from the few critters on the ark.
Very true and they are.
That would leave a genetic bottleneck marker in EVERY single living species of plant of animal, and the marker would be only a relatively few generations back.

If the Biblical Flood happened, then that marker MUST be there.

It ain't.

Case closed.
I've heard this bit of evolutionist lore many times by now, but I have NEVER ONCE SEEN AN EXPLANATION OF EXACTLY WHAT "MARKER" WOULD POINT TO A BOTTLENECK. Perhaps I merely missed it but I've been looking for some time whenever this subject comes up and all that's offered is this assertion, perhaps some ridicule and choice epithets along with it, BUT NO CLUE AS TO WHAT THE MARKER MIGHT BE THAT WOULD DEMONSTRATE THE BOTTLENECK IN QUESTION.

Now that it's come up again perhaps I'll be motivated to make a more dogged search for such information.

But meanwhile I wanted to highlight JAR's post because of something I just learned about these things that opens up a new answer to the question. I've been rereading Morris and Parker's What Is Creation Science? over the last few days, one of the first books on creationism I read after becoming a Christian, and besides recognizing many points they make that I've made my own in this debate although I'd forgotten their source, I've also run across some points that illuminate some things I hadn't digested and am only now beginning to think about.

One of them suggests an answer to just what WOULD be the genetic indicators of the bottleneck at the Flood and they aren't the sort of "marker" that would jump out at you but something a geneticist today would simply take for granted as the normal state of the genome. Whenever I've gone that far into this part of the debate I find myself wondering about a formerly much bigger genome --polyploidy for instance, which never really fit but now I have a better understanding anyway -- from which it would be easier to imagine descent of all the life forms we see today and extravagantly more varieties before the Flood as well, which certainly must have been the case BECAUSE of such an extreme bottleneck.

No, not a bigger genome, but a different genetic situation along more ordinary lines:

Parker describes how all the varieties of humans and animals are easily accounted for by simple Mendelian genetics combining a given built-in array of genes for various traits. The example he gave was of two parents with "medium" or "average" skin color, expressed as AaBb, with the capital letters representing the darkest and the lower case the lightest, saying that EVERY shade of skin that we see on earth can be produced from those two parents, from the darkest African (AABB)to the lightest Scandinavian (aabb). When you think of every other trait as genetically expressed by the same formula, it becomes clear that an enormous variety of combinations would produce an enormous variety of types or varieties or races -- of people and animals of all kinds -- which would become characteristic of groups as they migrated and became geographically isolated from one another.

And all this incredible variety requires is normal sexual recombination AND HETEROZYGOSITY of the traits.

He also gave this statistic on page 112: "[evolutionist Francisco Ayala] says that human beings are "heterozygous" for 6.7% of their genes, on the average. That means that 6 or 7 times in a 100, the pair of genes for a given trait differ like the genes for brown or blue eyes, or for rolling or not rolling the tongue. Now this may not seem like much. But Ayala calculates a single human couple with just "6.7% variety" could produce 10 to the 2,017 children ...before they would have to produce an identical twin..."

He goes on to say that the whole spectrum of skin color we see today would be easily produced IN ONE GENERATION with just this 6.7% heterozygosity for that trait. Combining that with the same breadth of possibilities for size, hair or fur color, bone type, muscle type, and so on and so forth, would certainly yield an enormous variety of individuals within each created kind or type.

So I figure this 6.7% heterozygosity is what remained on average to all creatures after the Flood, or perhaps it was somewhat more then and has decreased since then. It's still enough to produce enormous variety, everything we see today.

Well, what does a bottleneck do genetically anyway? Doesn't it produce HOMOZYGOSITY for a number of traits? Isn't that what happened to the cheetah -- it has reached the point genetically where most of its genes are fixed and no variety is possible at all. Since the cheetah is of course descended from the cats on the ark, with their already drastically reduced heterozygosity -- perhaps comparable to the 6.7% of human beings -- a later bottleneck would have reduced it even further to the current state of almost 100% fixed loci, so that each individual is almost a clone of all the others, and further variation is as good as impossible.

THERE'S YOUR "MARKER" JAR. Not what you were expecting but there it is. It wouldn't be recognizable in the genome because nobody is looking for it. The average heterozygosity seen today would be accepted as the norm for all human beings for all time. It wouldn't be suspected as a marker of anything, although the basic principle is quite well known.

So instead of the genetic complexities I was trying to imagine to account for the necessity of an enormously greater variety among humans and animals before the Flood, I now appreciate that simple ordinary everyday heterozygosity can account for it all, but presumably there would have been much MORE heterozogosity for a much greater number of genes or traits before the Flood. 100% back at Adam and Eve? 50%?

And to that I would like to add another "marker" of the bottleneck, one of my favorite topics, JUNK DNA -- which makes up something over 90% of the genome. You wouldn't suspect that as a sign of the bottleneck at the Flood, would you, JAR? But if it's what I keep thinking it must be, the record of the genetic death brought about by that bottleneck, as well as all the accumulated death from other causes of course, then its mere existence in the genome is very glaring evidence of the Flood, now to be added to the other marker, the very low incidence of heterozygosity that resulted from all that death. This genetic junkyard or graveyard is a hint at enormously more genetic possibilities at the Creation than exist today.

May I please have my Nobel Prize now?


  1. Prior to writing all that, did you bother to do even a simple google search? I did after reading the first few sentences of your post and was easily able ot find dozens of papers describing what to look for, how rigorous the analyses are, etc.

    one example:
    Mol Ecol. 1998 Aug;7(8):963-74.
    Usefulness of molecular markers for detecting population bottlenecks via monitoring genetic change.

    Or heck, look for yourself:

  2. Thanks for the comment and the link, I did look it up but apparently there is only an abstract available? It's very interesting however, as from talking to evolutionists I'd been getting the impression nobody had anything to say about the percentage of heterozygosity as the important indicator, so it wouldn't have occurred to me to look. The usual response I get is too technical for me but this looks quite readable and informative, although I may not be able to access the whole article. As a creationists I do have to keep in mind that the article would have been written by people with an evolutionist bias, but at least they have the same basic idea I was writing about.


PLEASE just register somewhere, there seem to be many options. A Google account is easy. And give SOME kind of pseudonym at least. THANKS!