If Adam and Eve had specially created egg and sperm cells, can we make a bottleneck work?


(Lynn Munter) #1

This is a fascinating wrinkle to add. I started wondering how many children one could then posit Adam and Eve had, since getting that number as high as possible would create the scenarios most difficult to scientically rule out. I thought the most children any human couple has had was in the low 20s, but Wikipedia has reports of instances in the 30s, 40s, and higher. It’s when you add in extreme life spans then you can really stretch this number.

Of course, in order to get to a really large number, we must also assume that the reports of great patriarchal age applied also to the women, for Eve to live a sufficiently long time to disperse as many of her egg cells as possible into the population. Did the women live as long as the men? Sarah is the only woman whose age at death is mentioned, and at 127 could be either a normally long-lived human or a shorter-lived patriarchal lifespan. And then there’s the question of what portion of Eve’s lifespan she would have remained fertile … did she go through menopause? … Sarah bore a child at the advanced age of 90, but she’d also said she was too old: it was a special miracle from God.

Genetically unrelated eggs and sperm does neatly address the incest question —if all humans born of Adam and Eve were artificially genetically diverse, then perhaps there was no (genetic) reason for them not to intermarry. We could even expand the population diversity further by having Adam breed with his daughters … the limiting factor being the rate at which Eve can go through pregnancies … but Lot’s daughters got in trouble for that, so let’s assume it didn’t happen.

So what rate could Eve have had babies at? Hunter-gatherer societies, as mentioned above, tend to space them out. I once read one child every four years was all that was sustainable, because if you have to be on the move constantly, a four-year-old can walk enough to make carrying a baby feasible. But once you get agricultural (I don’t know how you can read Genesis as anything but agricultural) that rate can go up.

IF Eve lived as long as Adam (930 years) and due to her miraculously good health and divine command (“Go forth and multiply”) or curse (“I will greatly multiply your pain in childbirth”) was able to have a child every year, we’re looking at a starting population of ~900. It could be more with twins, triplets, etc, but it could also be less on account of not all children making it to successfully reproduce. I think trying to stretch it past 1,000 would be more than sobriety could bear; we’re already on pretty shaky thought-experiment ground as is.

A starting population of 1,000 is still not in agreement with the scientific consensus of ~10,000, but you could certainly have a reasonable debate about it if you wanted.

The real question is, is this a good interpretation of the story Genesis is telling us?


#2

Another way to put it is that you would need to introduce some sort of magical source for genetic diversity if the modern population descended from a 2 person bottleneck somewhere in the last 200,000 years.


(Phil) #3

Well, with God anything is possible through miraculous intervention, but I would have to say that scenario seems extremely unlikely. You would really have to stretch the limits of physical reality, as well as add a lot of extra-Biblical miraculous interventions to do so.
Childbirth is dangerous business, especially in primitive societies. Death in childbirth is common, as a journey in an old cemetery will reveal. Also, with childbirth, the physical strain and stretching of tissues takes its toll, and eventually the uterus and pelvic musculature pretty much is shot.
It is interesting that many want to reconcile a literal interpretation so much that they put forth such weird and amazing fantasy additions to what is in the Bible to try to twist it into something that is compatable. I don’t object to someone having a literal concordist type belief, but feel it is better to say that God just did it some miraculous way that we do not understand, rather than saying Adam had mosaic testicles and Eve mosaic ovaries. (interestingly. that is not too far removed from the old fantastic concept of a homunculus, with little men formed in the sperm, with little men formed in the little sperm of the little men etc. so that all humanity was present physically in Adams scrotum.)
Certainly, my thought is, just accept that it is not meant to be literal, and learn what God is saying to you about your life through the scripture, rather than torture the scripture and bring disrepute upon the gospel.


(Lynn Munter) #4

Yep—and then you still can’t let the population bottleneck down to just Noah’s family without going through contortions I can’t even imagine! All of which is unnecessary if you simply recognize that Genesis is talking about the history/mythologized history of a single bloodline. The only time it could conceivably be talking about the entire human population is during the few lines of Gen 1:26–29.


(Lynn Munter) #5

To be fair, I mostly wanted to play with bringing the idea to an extreme in order to test it, and I don’t know if anyone actually is thinking along these lines beyond what @Swamidass said. It would be much easier to argue that Eve had 10 or 20 or even 100 children with artificially distinct genomes than 1,000. But then we have a tougher time reconciling with the scientific conclusions that there was no sharp bottleneck (see the topic I quoted out of).

The homunculus-sperm is a fascinating reminder to us to keep in mind that we don’t necessarily all come to the text with the same ideas!

I apologize for torturing the scripture!


(Laura) #6

I don’t have anything to add to the scientific discussion, but @jpm 's use of the word “torturing” brought to mind a Billy Collins poem that I think everyone who interprets the Bible should read at some point (though it usually makes me think more of Revelation or Psalms than Genesis):

Anyway, carry on. :smiley:


#7

Amen! 


(Lynn Munter) #8

That’s a great one, I like it!


(George Brooks) #9

@T_aquaticus

The whole nature of the Special Creation Scenario (per @Swamidass) is that there is a magical source for genetics (of whatever genetic diversity): God. It’s how we get Adam & Eve out of dust.


(system) #10

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