Question about the evolutionary origins of Homo Sapiens

I have heard a criticism of the account of Genesis being that two humans cannot have been the progenitors of the entire human race, because there isn't enough genetic information available in only two individuals to produce a stable community, and other similar arguments.

When the finale of the RDM version of Battlestar Galactica aired, I heard people saying that the 30,000+ humans that settled Earth weren't even enough.

Yet I've seen some scientific papers say "the founding population of Homo sapiens was small, anywhere from 700 to 10,000 individuals".

So... where did those 700 to 10000 individuals come from all at once? Are we to believe that 700 to 1000 pair-bonded couples of the immediate evolutionary ancestor to homo sapiens all had offspring within the same time frame that all had the specific mutations that differentiate homo sapiens proper from it's most recent evolutionary ancestor?

Or is something else meant by the term "founding population"?

And yes, I really am curious about how this is understood to have worked.

Because God willed it.

That's my line, friend. I am trying to see what the Esteemed Opposition has to say.

There is no one binary on/off switch for homo sapiens. You'd have a population of primates who over generations share a number of convergent and favourable traits -- these don't even have to be mutations in the strict sense, although some of them can be --, and a number of the subsequent (!) changes will eventually also close off h.s. as a separate species. (But that too isn't binary; it's clear that our ancestors were able to cross-bread with Neanderthals, for instance.)

Both Genesis and BSG differ from actual natural history by placing a small -- in the case of Genesis, tiny -- population on a world otherwise only populated with extremely distant lifeforms. They end up having the same problem, and in a way, the same solution: God guided them, so he probably thought of some way to make it work that humans can't understand. Though I can't recall Starbuck saving the day in Genesis.

People often say that the bible is not a history book, but then science comes along and proves that certain events or certain places did exist and there's a a bit of truth to it after all. I think the creation story jives just fine with the big bang theory and the theory of evolution. It's just a dumbed down version for people who had no concepts of such things back then. The question is, where did the story come from?

(Note: I'm answering the question as stated. This is not among the 50 or so main reasons why we shouldn't believe the accounts of creation in Genesis literally, if at all.)

Really? Which one?

Good question. The watchmaker argument, of course, assumes that when I find a watch on a beach I should assume the island holds a creature that makes watches. If I found a web under a palm tree, I'd assume the island is inhabited by spiders. If I find a story, my best guess is that humans were involved.

I've been reading stories about space colonies and such cut off from the outside for centuries and about how they died out due to not having enough original individuals and enough genetic diversity. It appears to me that the number of original members they claim is required to breed a viable, growing, long term population is often way too high. I've looked at the numbers of as low as 50 men and 50 women and you can see that with good reproductive planning within a few generations you are not going to have to worry about "marrying cousins" or anything like that.

I'd like to answer my own question.

Which creation story? I was referring to Genesis.

At the point at which the species appeared, it would have been able to continue breeding with homo heidelbergensis, homo neanderthalensis, Denisovans, and possibly other as-yet-undiscovered homo erectus descendants, all of which already existed outside of Africa (the current hypothesis is that there have been 4 or more great migrations out of Africa, starting with homo erectus) when homo sapiens left. Indeed, there is mDNA evidence that this is the case.

If you're now going to argue that this makes those people hybrids and not actually homo sapiens, don't bother; you're assuming a more statically delineated model of speciation than actually exists. Modern humans could probably interbreed with Neanderthals if we could clone them (and there weren't ethical issues up the wazoo, and probably down and sideways too).

Which contains at least two. They're separated by style, language, and clear textual boundaries, and if we are to take them literally so that comparing them to literal scientific accounts becomes sensible, it is worth noting that they also contradict each other on those details that could be used for such a comparison.

And just to complicate things, there's this:

http://www.npr.org/sections/krulwic...ings-almost-vanished-from-earth-in-70-000-b-c

It sounds like you're talking about the Out of Africa theory? If so, that's a theory about early modern humans migrating from Africa to populate the rest of the world. If true, it would explain why Africans are generally more genetically diverse than everyone else.

As far as the gene pool being too shallow, maybe the neanderthal and homo erectus hanky-panky helped out a little.

It was sexless frogs pared with monkeys.

I've never understood the claim that Genesis contains more than one creation story. It seems to me that the so called "second one" is actually just an embellishment or extra detailed version of the earlier one.

Like the original short story version of "Ender's Game" as opposed to the novel "Ender's Game". They still tell the same story.

Or if you hate Orson Scott Card for his beliefs,

The short story version of "Hawksbill Station" as opposed to the novel "Hawksbill Station".

As to precisely what "founding population" means, I *think* that's the population after the Toba super volcano wiped out homo hedielbergensis (and most homo sapiens), a genetic bottleneck. The good news is that our ancestors were geographically well-distributed all over Eurasia and Africa at that point, and the populations probably got back in touch with each other (genetically speaking) within few enough generations that serious genetic damage was avoided (my hypothesis is that there was one last push out of Africa that helped with this, and though it was slowed by the last ice age, eventually led to the colonization of the Americas). It was probably around this time that Neanderthals contributed their genetic material as well.

As for the BSG 30k people isn't enough, well, those critics are just wrong.

The migration out of Africa involved a path moving along the coastline, into Asia and Europe, using the ocean as a refuge against large predators and a source of fish. Following the path selected for humans who like long walks on the beach. That's still considered a primary requirement for fitness when pairing up, since the third of fourth line of any dating profile is always "I like long walks along the beach."

Imagine the tsunami that would have followed.

Again, they differ linguistically and stylistically, which of course gets lost in most English versions; but they also differ in terms of content. Of course, if you assume that they're both really parables that add some details for colour but really want to make more general or even allegorical points, then it's comparatively easy to combine the two, each adding a different message to a set of morals. But if they're to be taken literally, such that they can be compared with a scientific account that literally makes claims about actual specific and distinct events happening in chronological sequence, the differences become irreconcilable. For instance, the first story has humans created before all of the other animals, whereas the second reverses this order; each uses this for a plot point, too, so it's not marginal.

If you want to learn a little bit about the evolution of humans check out these shows.
http://channel.nationalgeographic.com/the-great-human-race/
http://www.pbs.org/wgbh/nova/evolution/becoming-human.html
http://channel.nationalgeographic.c...-human-family-tree/at/genetic-testing-135306/

I've gone to church with what would be called "conservative evangelicals" for more than four decades.

And I can't think of one under 70 years old that actually thinks Genesis creation accounts are to be considered down the line literal recountings of how everything came into being.

Myself?

As I've said, the end of the Bible, Revelations is told in what virtually everyone agrees is symbolism or metaphorically.

It seems perfectly reasonable to believe that the beginning of the Bible, Genesis at least up to the dispute between Abram (Abraham) and Lot is told in the same manner.

It has an elegant simplicity having the Bible bookended that way.

It's true that Creation Account A and Creation Account B differ linguistically and stylistically and in ways which get lost in English translations. But unfortunately for the skeptic, the differences when read in the original language actually give a context that undermines the "two accounts" claims rather than strengthens them.

http://apologeticspress.org/apcontent.aspx?category=6&article=1131

The Old Testament, particularly in its early parts, is composed of multiple sources redacted together. The creation story is merely one place where the sources are joined in such a way that it repeats itself in some form.

There are countless such examples, such as Clarke reworking The Sentinel to become 2001: a Space Odyssey. But in many cases, the difference is not simply greater verbiage or more detailed exposition. In the Clarke example, the basic premise is related, but the two works are actually rather different. Many see the various Genesis stories to be similarly divergent enough to be substantially different and specifically contradictory.

Good. That reading implies that Genesis simply contains no statements that can be compared with a scientific account of the emergence of humanity, since it doesn't address any of the same questions. I agree.

I was specifically referring to the first page of Genesis.

That account completely misses the point. First of all, the differences between these accounts aren't some liberal or skepticist theory. I first learned about it as a Catholic boy in religious school from my priest. Secondly, the account of Prof. Kitchen is apparently written without any knowledge of the stylistic and linguistic differences in play. Stylistic differences, he argues, can result from different intentions and addressees. True, some can. But teachers don't suddenly switch from 2016 American English into Elizabethan just because they change their topic. More importantly, anyone proffering a theory about different intentions creating different styles fir each of the two creation accounts by necessity already agrees that there are two accounts, which is the whole point. Blindly assuming that the opposing view is connected to unbelievers makes Kitchen and his ilk completely misunderstand that point.

Regarding social evolution, there was an interesting Washington Post article on the differences between societies that farmed cereal grains and societies that farmed tubers. Getting to the heart of the article:

The study, published last year by economists at the United Kingdom and Israel doing novel work on archaeological and anthropological evidence, attempts to explain a strange pattern in agricultural practices. The most advanced civilizations all tended to cultivate grain crops, like wheat and barley and corn. Less advanced societies tended to rely on root crops like potatoes, taro and manioc.

It's not that grains crops were much easier to grow than tubers, or that they provided more food, the economists say. Instead, the economists believe that grains crops transformed the politics of the societies that grew them, while tubers held them back.

Call it the curse of the potato.

How crops changed the world

The argument depends on the differences between how grains and tubers are grown. Crops like wheat are harvested once or twice a year, yielding piles of small, dry grains. These can be stored for long periods of time and are easily transported — or stolen.

Root crops, on the other hand, don't store well at all. They're heavy, full of water, and rot quickly once taken out of the ground. Yuca, for instance, grows year-round and in ancient times, people only dug it up right before it was eaten. This provided some protection against theft in ancient times. It's hard for bandits to make off with your harvest when most of it is in the ground, instead of stockpiled in a granary somewhere.

But the fact that grains posed a security risk may have been a blessing in disguise. The economists believe that societies cultivating crops like wheat and barley may have experienced extra pressure to protect their harvests, galvanizing the creation of warrior classes and the development of complex hierarchies and taxation schemes.​

What the theory might be neglecting is that you can't meet your nutritional requirements with potatoes. It's like a corn and bean diet. You'd get pellagra or some other horrible nutritional disease. The problem with many agricultural crops is coming up with a mix that is nutritionally complete. North American Indians had to keep hunting and gathering along with their farming because farming alone couldn't supply all their requirements. As long as a society has to keep hunting, fishing, and collecting wild berries, it can't easily become much more sophisticated than tribal levels.

So the tubers may have been a more productive staple crop, but they couldn't by themselves free people of the need to supplement their diets with hunting and fishing. Wheat and other grains have far more of the essential vitamins, with only choline and vitamins E and K falling into the single digit RDA percentages in a 100 gram serving. Breadfruit is down in the single digits for everything except vitamin B1 and C, and the potato is in the single digits for everything except vitamin C and B6.