Humankind struggled to survive during a 100,000 year period during the early Pleistocene, according to researchers who used a computer model to discover a severe population bottleneck in our species’ ancient past.
The bottleneck occurred between 813,000 years ago and 930,000 years ago, and reduced an ancestral human species to less than 1,300 breeding individuals. The issue persisted for 117,000 years, and aligns with a chronological gap in the African and Eurasian human fossil records in that period. The team’s research on the bottleneck was published today in Science.
That’s not something DNA can tell us.
It can – OK, it could – tell us we’re all descended from those 1,300. But it can;t tell us that there were only 1,300. Could have been vast populations all of whose descendants got wiped out.
Not saying that my idea is true, only that it’s possible, given the way that studying current DNA works and what it can tell us. It can tell us who our ancestors were. But not our not ancestors.
Survivorship bias: the curse of bad ‘science’.
800,000 years ago is long before the emergence of modern humans. Homo Erectus still roamed the earth.
Given random mutation and the fact that most mutations are negative for survival it’s likely we are all descended from even fewer that 1,300 individuals. A dozen might be my uneducated guess.
The team posits that the bottleneck may have been due to climatic changes.
Most likely (our traditional enemy is not smilodons or dire wolves, but food scarcity).
This is also why environmentalism has it completely wrong. The Earth isn’t in danger, we are. We should not seek to grovel to Gaia, but to master her for our comfort and posterity. Otherwise we might easily freeze and starve.
Really makes you wonder why the government wants us to grow less food while growing the population by over a million immigrants a year tho. Gonna be a lot of angry fatties, I reckon.
Mitochondrial Eve, Y chromosome Adam. Evolution by random mutation.
Hmmm, if I’d been God at the time I’d have scrubbed the experiment and tried something else.
Climate changes over 120,000 years. Well yeerrs, that’s a few ice ages. The fact that our ancestors survived at all is proof that they had some capability to adapt to their environment, and still fuck. Unlike modern environmentalists.
A quote from an article I have saved, this one that explains the high amount of genetic diseases among Ashkenazi Jews, that shows how they come up with these numbers:
The consortium’s model of Ashkenazi Jewish ancestry suggests that the population’s history was shaped by three critical bottleneck events. The ancestors of both populations underwent a bottleneck sometime between 85,000 and 91,000 years ago, which was likely coincident with an Out-of-Africa event. The founding European population underwent a bottleneck at approximately 21,000 years ago, beginning a period of interbreeding between individuals of European and Middle Eastern ancestry. A severe bottleneck occurred in the Middle Ages, reducing the population to under 350 individuals. The modern-day Ashkenazi community emerged from this group.
As a counter to Tim’s suggestion that these populations might have been originally larger, this evidence from the same article explains why that can’t be true:
By analyzing the proliferation of long nucleotide sequences that are identical in the unrelated individuals in their sample, the researchers determined that a population bottleneck of approximately just 350 Ashkenazi Jewish individuals occurred in central Europe about 700 years ago, followed by an exponentially rapid population increase. The findings suggest that the ancestry of all present-day Ashkenazi Jews can be traced back to this small population.
The link below has a chart that explains the quotes above:
https://systemsbiology.columbia.edu/news/study-sheds-light-on-ashkenazi-jewish-genome-and-ancestry
I did a quick search on population bottlenecks and came up this interesting bit from a Wikipedia article:
A 2005 study from Rutgers University theorized that the pre-1492 native populations of the Americas are the descendants of only 70 individuals who crossed the land bridge between Asia and North America.
https://en.wikipedia.org/wiki/Population_bottleneck
You’ve miss3ed my point. I’m not arguing that there aren’t population bottlcecks. Nor that the size of this one might not be right. Rather, I am insisting that this bottlenexck is the number of people we are descended from, not the number of people alive at that time.
Similar to my prost in the previous thread.
“There are only 100 houses in my town that were built before 1650, therefore there were only 100 houses here before 1650”.
No…. There were 1500 houses, but 1400 of them “died” and did not survive to today.
‘They’re not saying that there were 1,300 humans alive at that time. They’re merely saying that only 1,300 of the people back then have descendants living today.’
I see one of the commenters agrees with you, Tim.
Of course I like this one best. ‘Any fossils over 6,000 years old were planted by Satan.’
Could have been vast populations all of whose descendants got wiped out.
Indeed but then they wouldn’t be part of the ancestral human species of less than 1,300 breeding individuals just as anyone who dies without having children is never going to be anyone’s ancestor.
‘This is also why environmentalism has it completely wrong. The Earth isn’t in danger, we are. We should not seek to grovel to Gaia, but to master her for our comfort and posterity. Otherwise we might easily freeze and starve.’
Pleasant to see someone who thinks like me, Steve.
Pretty much my point, isn’t it?
@ Adolff
Ah, that’s pendantically correct but totally NOT what they want you to believe.
My mother was not just an only child but an only grandchild, my sisters have no children = so if we include those with no descendants, my family is about four times the size of those with descendants = and that’s just four generations.
Secondly it’s not just that over four thousand years an overwhelming majority of family trees will have become extinct: each father/mother only passes on half their genes to the next generation and we share most of our DNA with every other human so the DNA analysis will not tell us from which several hundred related Homo erectus we are descended. So “only 130,000” may, just possibly, be correct but it is much more probably complete and utter bullshit.
a population bottleneck of approximately just 350 Ashkenazi Jewish individuals
Norfolk anyone?
So.. the bottleneck occurred right at the border of two geological epochs ( which are middle Pleistocene, not early anyway..).
Quelle surprise… In this case a magnetic pole reversal, followed by a whopper of a glacial period, so …ummm… yeah.. That might have had some impact here and there…
As for the survivor bias/bottleneck thing..
Due to the way evolution/mutation works and the way mutations propagate ( or actually don’t..) in a population, the only way for any (“positive”) mutation to actually get reinforced enough to have an impact is through a natural or artificial “bottleneck”.
If that bottleneck ( and its associated inbreeding and selection…) isn’t there, any mutation will get “diluted” in the existing gene pool into oblivion, or at best a very rare allele without impacting the population as a whole.
There’s several of these bottlenecks in the evolutionary history of humanity, and you’ll find them for any species you care to look into. It’s just the way Mother Gaia, bitch that she is, works.
The particular bottleneck “researched” here is the most likely point where the distinction between H.Erectus and H.Heidelbergensis was made, with Heidelbergensis being the branch we, and our Neanderthal and Denisovan cousins emerged from.
The one difference between Erectus/Heidelbergensis and us and our cousins is that the two lines were actually closer to true species, since they most likely couldn’t interbreed, given that the lines didn’t merge (successfully anyway.. young lads will be young horny lads..) even after living side by side for several 100.000 years.
But the bottleneck? Nice that they attempted to put a number on it, but as our host says: Our entire existence is the result of a long string of genetic bottlenecks where our ancestors survived some pretty harsh conditions before branching out again.
Didn’t bother to count, but there’s each and every known and recognised geological transition to begin with, of which this research is but one example.
It would have been more interesting if they’d pinpointed a bottleneck that didn’t coïncide with one of the known transitions.
Because then we’d hit actual “Hey… That’s funny…” territory.
This is mere bottlewashing and pin-sorting with new toys.
A 2005 study from Rutgers University theorized that the pre-1492 native populations of the Americas are the descendants of only 70 individuals who crossed the land bridge between Asia and North America.
That’s still cleaving to the scenario of the land bridge & the ice free corridor down to warmer latitudes. A brief window. However there’s archaeological evidence of human habitation of the Americas thousands of years earlier. What seems more likely is at least three migration waves over a period of 8-10,000 years. May even be earlier. If I remember rightly, it was the big cheese from Rutgers’ archaeological department who used his authority to initially rubbish the archaeological evidence because it undermined his own thesis. This is how academic science actually works. But we know that already, don’t we?
All models are wrong, but some are useful. (You know to which models this is a snide reference.)