What podcasts say about David Reich
Every statement, with the speaker, the exact quote and the moment it was said.
What David Reich has said on podcasts
28 statements · 15 positive · 6 negative · 2 mixed · 5 neutral
Ancient DNA studies have struggled to detect biological change because sample sizes were too small.
“what's not been successful is learning about biology and biological change. And one big reason for that has been that the sample sizes have been too small.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 1:35
Large samples are required to estimate genetic frequency changes over time precisely.
“To get a high resolution picture of how the frequency changes over time, you need to have very big sample sizes of truly very large numbers of people.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 2:46
Environmental changes create selection pressure for populations to adapt genetically.
“if there has been a change in environment that a population has experienced, for example, people have shifted to agriculture or begun living close to domesticated animals, or moved to a new environment from a cold place to a warm place or a low place to a high place, then there's pressure on the population to adapt to these new stresses, these new needs.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 3:36
Genetic drift and population structure explain about 98% of observed frequency changes.
“98% of it is other factors, especially genetic drift.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 8:07
Natural selection has been widespread throughout the human genome despite explaining little total frequency change.
“Nevertheless, there's so much natural selection as our study thinks has shown, that in fact, it's been rampant in the genome.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 8:29
Periods without migration or admixture provide the best opportunities to detect natural selection.
“The best moments to detect natural selection is when migrations and population admixtures are not happening for a few hundred years.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 9:55
Ancient selection signals are enriched roughly four- to fivefold among immune traits.
“what we found is there was a vast enrichment by about a four or five fold for immune traits.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 13:40
Behavioral selection signals are difficult to detect because many genes each have weak effects.
“Behavioral traits are shaped genetically by very large number of genes of weak effect. And we just don't have the statistical power to detect these very weak signals there.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 15:10
Bronze Age population density and animal contact increased infectious-disease pressures.
“In the Bronze Age, there was an intensification of how people lived with much higher population densities, people living more and more next to their animals and getting their diseases and exchanging their diseases with them and with each other.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 17:56
Tuberculosis becoming endemic may explain a later reversal in a tuberculosis-risk variant.
“a possible reason for this is maybe the spread of tuberculosis maybe becomes endemic in the population 2,000 or 3,000 years ago.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 20:50
Selection intensified during the Bronze Age, making it an evolutionary inflection point.
“the intensification happens like 5,000 years ago, 4,000 years ago. And so it's really interesting, this observation of that being a key point, that being an inflection point”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 25:55
The Bronze Age’s longer duration allowed selection effects to become detectable.
“The Bronze age is not 300 years years, it's 3,000 years. It's the power of compound interest. And you have enough time to begin to see a strong effect.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 28:44
Variants predicting modern IQ-test performance show strong ancient selection.
“we see very strong natural selection for this combination of genetic variants that predicts people's performance on IQ tests”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 30:03
Iceland experienced a small one-century decline in a genetic predictor of intelligence.
“there's estimated 0.1 standard deviation decrease in genetic predictor of intelligence in Iceland just within one century”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 37:39
Chinese schooling-associated variants correlate strongly with their selection trajectories in ancient Europe.
“there's actually a huge statistical correlation, a 5 or 6 standard deviation correlation between the effect size of variance a number of years of school in China today and the trajectory in Europe.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 41:37
Selection reduced genetic predispositions to obesity-related traits by about one standard deviation.
“there is clear selection by about a standard deviation on the scale of modern variation for these traits, reducing about 10,000 over the last 10,000 in this part of the world.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 52:34
Human populations could move many complex traits further toward extreme values.
“I think there's more room at the top for a lot of these traits.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 56:51
Bronze Age selection was probably not caused primarily by population size becoming large enough.
“I think that's not likely to be true”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 1:00:35
No recent genome-wide selective sweep shared by all modern humans was detected.
“right across all the DNA we could look at, we couldn't find anything more recent than four or five hundred thousand years ago.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 1:04:29
Modern humans and Neanderthals may have possessed key cognitive and behavioral abilities 200,000–300,000 years ago.
“it's not obvious that all the toolkit, the cognitive toolkit, the behavioral toolkit, the genetic abilities were not all in place two or 300,000 years ago, and that even Neanderthals had them.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 1:12:46
Neanderthal modern-human ancestry may indicate deeper cultural or biological modernity than expected.
“5% is actually a sign of something much more impactful, that is that somehow Neanderthals are in some sense deeply modern in some ways.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 1:19:55
Some genomic regions make a person closer to Neanderthals than to another modern human.
“in some places in our DNA, we're more closely related to Neanderthals than to each other.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 1:21:59
Neanderthals may be culturally closer cousins of modern humans than genome-wide relationships suggest.
“the actual correct way to think about them may be in an important sense somehow the relations or the close cousins of modern humans.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 1:33:15
Reich’s alternative Neanderthal model is more plausible and explanatory than the standard model.
“this is much more plausible than the model we currently sort of write down. It's probably wrong, but it's just much more plausible. It explains many more things.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 1:45:44
The study identified at least 479 independently selected genomic positions with 99% confidence.
“we find at least about 479 positions that are all independently pushing in the same way. Those positions are 99% confident that they're real.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 2:02:39
About 3,800 genomic positions show selection signals above the study’s 50% confidence threshold.
“By another criteria of more than 50% confident that they're real, we think that about 3,800 positions are all pushing in the same direction.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 2:02:48
Selection statistics above five indicate that essentially all detected signals are genuine.
“once you slide the statistic above 5, essentially all the signals of natural selection are real.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 2:06:09
Ancient-DNA sequencing costs have fallen roughly a millionfold since the late 2000s.
“the drop in cost has been a million fold since the late 2000s and another maybe one to two orders of magnitude from 2010 to today.”
Open the episode · David Reich – Why the Bronze Age was an inflection point in human evolutionListen at 2:09:42
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