How We Got Here: DNA Points to a Single Migration From Africa | Hacker News Reader

How We Got Here: DNA Points to a Single Migration From Africa

nytimes.com

93 pointsandyraskin62 comments

"However, neither Mallick et al. nor Malaspinas et al. exclude the possibility of multiple out-of-Africa dispersals." (from the commentary).

How is that one wave?

yeah, i doubt the thesis. The egyptians certainly left africa in several waves, and it's unbelievable that there wasn't genetic mixing between egypt and subsaharan africa.

What are exactly egyptians in your case? Much of the mediterranean basin including modern Turkey, Syria, Lebanon, Israel/Palestine, Egypt, and the rest of N. Africa was also settled by "Europeans". Egypt itself went through multiple periods including Persian, Canaanite, and Hellenic periods. Overall you need to be very specific of the period because there was a lot of influx and movement of people and civilizations.

Even in the past 2000 years there were huge demographic changes in Egypt, the Egyptians today are not an entirely good representation of Egypt even 2000 years ago during the Coptic period.

The changes in skin tone, physique and facial characteristics in Egyptian art are quite interesting to see and they represent the changes in the ethnic and demographic makeup of the civilization.

For example late period mummies and portraits show the outcome of genetic influx from Hellenic and Roman cultures into Egypt https://en.wikipedia.org/wiki/Fayum_mummy_portraits, this is even more interesting since Faiyum is quite far from the coast line which shows that demographic changes spanned the geography of egypt.

so, basically you made my point for me.

There's one wave that provided 98% of the genes in modern humans outside Africa. Probably a single traveling group that represents a historical choke-point in the gene pool.

We know there were multiple dispersals out of Africa, but we can trace our ancestry back to a single one.

How does that work? Everyone else died? What about recently discovered groups like the Red Deer Cave People? https://en.wikipedia.org/wiki/Red_Deer_Cave_people

Doesn't evidence exist that groups interbreed, at least Denisovans / Neanderthals / Modern Humans?

I thinks it's "all extent modern humans migrated in one wave", they also bumped uglies with a few other not so modern species along the way.

Personally I want to see more study into mungo man (https://en.wikipedia.org/wiki/Lake_Mungo_remains), that has some potential to upset things.

In 1988, the skeleton of a child believed to be contemporary with Mungo man was discovered. Investigation of the remains was blocked by the 3TTG [ie. Three Traditional Tribal Groups] with the remains subsequently protected but remaining in-situ. An adult skeleton was exposed by erosion in 2005 but by late 2006 had been completely destroyed by wind and rain. This loss resulted in the indigenous custodians receiving a government grant of $735,000 to survey and improve the conservation of skeletons, hearths and middens that were eroding from the dunes. Conservation is in-situ and no research is permitted.

Sounds like the local aboriginal tribes are claiming ownership of remains that predate them, that they never knew were there anyway, and blocking further research. Thanks guys.

I read that as a Roanoke Colony situation.

https://en.wikipedia.org/wiki/Roanoke_Colony

They left, they died, they tried again until they didn't die.

The commentary referenced in the article is far better than the article itself: http://bit.ly/2cWOXmj

[0] short url provided for insanely long paywall avoiding link in the nyt OP

I wonder how this would tie in to the human bottleneck theory. According to this theory[1], somewhere between 100,000 to 50,000 years ago, we had a human genetic bottleck event where there were only about 10 000 individuals left on the planet.

If true, we're one lucky species.

[1]https://en.wikipedia.org/wiki/Toba_catastrophe_theory

Wasn't that discredited? From your link:

> Other research has cast doubt on a link between Toba and a genetic bottleneck. For example, ancient stone tools in southern India were found above and below a thick layer of ash from the Toba eruption and were very similar across these layers, suggesting that the dust clouds from the eruption did not wipe out this local population.

It's fair to say scientists have cast doubt on the theory but I don't think it has been completely discredited[1]? I could be wrong, so any elucidation would be great.

At least it's an interesting thought. Or maybe it's just wistful thinking.

[1]https://whyevolutionistrue.wordpress.com/2011/09/18/how-big-...

Great link, thanks for posting it.

it was worse than that - according to my phd cellular research ex-gf (some rare anemias), at one point there were only 5 women/females from which we all come from. this can be traced in all of our DNA.

I presume it was before homo sapiens, so maybe a million years ago if not more (sorry I don't have any factual details, but girl was super clever and she stated this as a well known fact in their research community).

all the racists of this world should get a bit of education to get perspective (wishful thinking...)

> at one point there were only 5 women/females from which we all come from. this can be traced in all of our DNA.

Mitochondrial DNA, not nuclear DNA. There may have been more ultimate female ancestors at the bottleneck, but only that number have had their mitochondrial DNA propagated.

I can't read the full article. Even with all my cookies cleared it takes me to a subscription page. Same with web search. What's up with this?

You may have read all your free articles for the month. The NYT is a paid subscription newspaper but they offer a handful of articles a month for free.

If you enjoy the NYT and read it often, think about subscribing.

...and how do they keep track of how many articles each person read each month? Oh right, by cookies.

There are other ways. Local storage, indexedDB, WebSQL, browser fingerprinting.

Control your cookies, dump your storage, Scriptblocker, uBlock Origin, and Random Agent Spoofer.

Or just open it in incognito mode / private browsing.

Or just subscribe.

(though private mode is the easiest way)

I was speaking more broadly to what we should all be doing, all of the time.

Your average user has no idea how to do any of that.

Plenty of them use ad blockers, and if the pressure keeps up they'll figure out much of the rest too. The very environment driving this anti-privacy trend is just educating a generation of consumers, in the same way that the very instant people were able to get away from advertising they did.

The article is not especially pay-walled, from what I can detect, using multiple devices. It seems to just use the typical 10 article cookie variable that all NYT articles usually check.

I'd estimate your current machine is behind some kind of network/web proxy that's browsing with a separate session, on your behalf, with a stale cookie that has reached the free article limit attached to its session.

Maybe you're the victim of an A/B test? That's the only other idea I can imagine.

Let me simplify your life a little

http://www.printfriendly.com/print?source=homepage&url_s=uGG...

Don't have the ref. onhand but read recently that African populace shows the greatest genetic diversity in Homo sapiens sapiens.

India comes in at second place, presumably because of larger migration to the subcontinent compared to Europe.

Africa is home to the tallest (Sudanese) and shortest (pygmy) humans. You can think of the entire non-African population as a little inbred offshoot of the main stock.

I recommend E. O. Wilson's "Social Conquest of Earth" as a reference for quantifying the genetic difference within and between populations.

I wouldn't necessarily call them inbred. Whites crossbred with Neanderthals and Asians did the same with some other related Homo genus whose name escapes me.

Doesn't surprise me that both went extinct. If we're still this prejudiced towards each other in the 21st century, I have little doubt that we played a large role in their extinction

Denisovans (Homo Altai / Homo sapiens Denisova).

You make a good point that the emigrants did mix in a peppering of genes from their early-arriving distant cousins. But overall, only a tiny fraction of the available gene pool made it out of Africa.

I often wonder how people reconcile such scientific reports with what religious texts say.

Some weeks ago, while discussing with a colleague about the human tendency for discrimination on any grounds, I'd said "After all, we humans were once apes in Africa". He responded with "Hey, I'm a follower of so-and-so religion, and our religious text says that God made everything within a week. So, please let's not discuss topics that are hurtful to me".

The idea is to interpret the larger point the text is making, and not get hung up on interpreting each detail literally.

As for your point, saying "After all, we're all children of God" means essentially the same thing.

Funny, because in my interpretation of the text (e.g. Genesis 9:3 [1]) god draws a distinct line between people and animals. Saying that we're all apes from Africa is more like erasing that line and acknowledging our kinship.

[1] http://biblehub.com/genesis/9-3.htm

Right, but the question is whether the GP was trying to make common cause with all humans or with all animals.

Thank you. The key point of Genesis is: be fruitful, multiply, and allow your descendants to enjoy the blessings of God. Getting involved in quibbles about the status of other species is exactly the anti-pattern of how to not to get a good outcome from interpreting a sacred text.

To get pedantic, humans were never apes, they share a common ancestor with apes.

And you could reconcile with your colleague, "I'm not disputing God created everything within a week; I'm just saying that all the evidence makes it look like it happened over the course of millions of years. Maybe God had some accelerated process, does your religious text talk about how God went about creation?"

To get extra pedantic we are apes. Taxonomically, humans are in the great ape family Hominidae.

We were, however, never monkeys.

Eddie Izzard points out that the French don't distinguish between monkeys and apes... and then goes on to suggest that the French translation for a line in Planet of the Apes must be interesting: "We are not monkeys! We are apes!"

Ah. Thanks for the correction!

> humans were never apes,

Humans, chimps, and bonobos form a clade; to say that 'humans were never apes' means that you have to make some tough decisions about what 'apes' are and live with the consequences.

http://www.whozoo.org/mammals/Primates/primatephylogeny.htm

Genesis chapter 2 says God formed Man from the dust of the ground. It also says "And out of the ground the Lord God formed every beast of the field and every fowl of the air and brought them to Adam to see what he would call them."

I find this fascinating that apparently all life has the ground in common. Science says no creator, but after a Big Bang, life evolved from sludge with Darwinism from thereon.

Doesn't the two kind of compare?

There are plenty of words written about the subject if you are interested. For example, here is a brief overview of Catholic teaching about creation and science: http://www.catholic.com/tracts/adam-eve-and-evolution

If you would like to read more, you can look up any number of scientists, philosophers, theologians, educators, etc.

Keep in mind that www.catholic.com is a website made by laypeople and not the official position of the Catholic Church. Their answers usually tilt towards the conservative side. Here's a Catholic Review article that shows a position within the Catholic Church that's more critical of the biblical narrative (and more supportive of the scientific consensus):

http://www.catholicreview.org/article/work/catholic-church-h...

This really show that the catholic position is barely an improvement on the baptist creationists. Their only point of disagreement seems to be on the time line.

> I often wonder how people reconcile such scientific reports with what religious texts say.

I'm not convinced anyone does reconcile.

Without intending to derail this thread into a boring old argument, religion isn't really about truth.

Mixture of identity tied up with other issues - the people that critically take a look a this kind of thing don't end up religious. All that's left are people that rationalize it or just don't think about it.

More egregious examples exist.

> "Hey, I'm a follower of so-and-so religion, and our religious text says that God made everything within a week. So, please let's not discuss topics

OK, that's reasonable. Some people are religious, their religion is more important to them than scientific truth, and there's not much use discussing this sort of thing with them as there is little common framework to discuss within.

But

> that are hurtful to me".

What? Why would a topic be "hurtful"? Or "offensive", as you also hear a lot. That's what I don't get.

After I read the Bible the first time I had a discussion with a preacher about a theory of mine, just based on my own observation.

Genesis and Revelations are the two books of the Bible that were not written as observed. Genesis was written by Moses after the Jewish Exodus and Revelations is prophecy.

That leaves significantly more room for interpretation and metaphor, especially when discussing a subject that is so cross-discipline as creation itself. Is Genesis expected to provide cellular and DNA explanations?

I've come to call people who harp on these two books while ignoring everything in between, "Bookenders". It applies to just about anyone who is either obsessed with end-times prophecies or the idea that Genesis itself must be 100% literally interpreted (either to prove or disprove the accuracy of the Bible).

Reading the entire text is really a great exercise in perspective though. Far too few people do it.

> I've come to call people who harp on these two books while ignoring everything in between, "Bookenders". It applies to just about anyone who is either obsessed with end-times prophecies or the idea that Genesis itself must be 100% literally interpreted

Wow. This term deserves to be in more widespread circulation as it describes so many cranks who identify as Christian.

There is a lot of completely irrelevant tedium in the Old Testament outside of the Genesis and the handful of well known books. I've tried to read the whole thing a couple times, but I usually give up on the book of numbers and all the nattering on about hecatombs and priestly ritual.

I found schedule that break it into a daily dose of Old Testament, New Testament, psalms and proverbs. When you hit Leviticus it's hard to keep going but having that break down makes the daily routine a lot easier.

And Australian Bushmen, Polynesians, south Indians show us the multiple waves of migration, but who are they compared to a fancy statistical model made from poorly understood DNA sequences by clever hipsters!

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