Neanderthals cold-adapted? Ribcage reconstruction may hold the answer | Hacker News Reader

Neanderthals cold-adapted? Ribcage reconstruction may hold the answer

phys.org

54 pointswglb49 comments

I wonder if adaptation to cold in Neanderthals included torpor during the winter. That could at least provide an alternative explanation for their eradication/dilution by Sapiens, despite the evidence they had greater physical strength and larger brains than the later. The newly arrived Sapiens learned to raid Neanderthal shelters in the winter, while they slept and were mostly defenseless.

> larger brains than the latter

What matters though is how efficient were the H. Sapiens brains.

I read somewhere, long ago, that larger brain is not necessarily better "intelligence" .. maybe a survey of primate brains.. pointers welcome

From the little I've read and watched regarding animal intelligence, it's typically mentioned that the brain-to-body size ratio is more important/correlated to estimated intelligence than brain size alone. It seems to help explain things like the outsized intelligence of certain smaller animals (e.g. corvids), but it also seems to only be a partial explanation.

Makes more sense to dedicate larger share of body-mass to brains the smarter the brain is. So I don't think it is that the big brain makes them smart, its that smart brains can make up for being a bigger burden so they grow larger.

That's a fascinating idea.

The article claims that while Neaderthals had some cold adaptations they were not exclusively so. So your idea is very far fetched.

Humans can exhibit some mild torpor like behavior in extreme winter conditions. We are not ‘exclusively’ cold adapted lifeforms. Even if the Neanderthals had more adaptations for surviving in northern climates that does not mean they are exclusive polar specialists like the arctic fox or the polar bear.

There's one paper from 2020 suggesting that Neanderthals may have torpor (there's some evidence in bone growth patterns suggesting that they basically just... stopped during winters).

That being said, Homo Sapiens likely could have directly out-competed Neanderthals even without this hypothesis. While Neanderthals almost certainly could overpower Homo Sapiens, we've yet to find any evidence of projectile use amongst Neanderthals, especially bow and arrow. There's also some evidence suggesting that Neanderthals biomechanics/skeletons would have severely restricted their ability to use throwing spears.

The spread of Homo Sapiens tends to coincide with local changes in climate transitioning from forest to grassland environments, which would have further favored the the apparent range advantage that H. Sapiens had.

That's what we've found so far anyways.

There are still many uncertainties about how sapiens outcompeted and interbred neanderthals. How hard was it for them to find food in winter? Less food could also explain slowed growth. Why did they not invent spears or bows? Maybe they were accurate enough with stones.

"we've yet to find any evidence of projectile use amongst Neanderthals, especially bow and arrow"

Interestingly, the same is true about their contemporary Homo sapiens sapiens competitors. There is no evidence of use of bows and arrows in Europe until way after the Neanderthals died out.

Don't forget the part about spear throwing.

> There's one paper from 2020 suggesting that Neanderthals may have torpor (there's some evidence in bone growth patterns suggesting that they basically just... stopped during winters).

Do you have a link for that. It would be fascinating if true and would easily explain how they were out competed to Homo Sapiens.

There is just one warm-blooded Primate, the Lemur, which experiences torpor. So there is precedent within the order taxon.

I think the paper referred by GP is this one: https://www.sciencedirect.com/science/article/abs/pii/S00035...

Is this fiction, fantasy, or some far off prediction based on science?

Sapiens barely like sapiens who look different, I’d bet they killed or outcast them just like what happens today.

Sapiens in Europe went extinct roughly the same time that Neanderthals in Europe went extinct, or shortly thereafter. Careful DNA testing has not been any to detect any DNA signature that carried from 30,000 BC to the present population. All humans, of all species, seemed to have gone extinct at some point. It is known that Europe was colonized by Neolithic farmers who expanded out of Turkey about 17,000 years ago, this group had DNA that is still found in the modern population. But none of the older DNA seems to have survived. Therefore it is not clear that Sapiens eradicated or diluted Neanderthals in Europe. They all died out.

But then, where did the people the Neolithic farmers mixed with come from?

That mixing of Sapien and Neanderthal genes, which survives in the modern population, occurred in the Middle East, in the Caucus mountains, and in modern day Turkey. But of the Sapien DNA that we have from Europe before 30,000 BC, we cannot find any trace of it in the modern population.

There are people with Neanderthal genes, so it cannot be true, that they all died out.

Maybe some European fairy-tales have much deeper roots in history than we think? Perhaps the original sleeping beauty was a Neanderthal lady kidnapped as a bride while in torpor, by an invading Sapiens group. Things like that happening back in the ice age could help explain both the remnants of Neanderthal DNA in our genomes and provide an foundation to the folk tale.

The ancestors of pretty much all Europeans could only have come in contact with the Neanderthals in the Middle East so there probably was too much movement and mixing etc. for something like that to survive.

However it’s hypothesized that during the neolithic farmers immigrating from Anatolia/etc. lived alongside the hunter gatherer communities for quite a while. The types of environments preferred by hunter gatherers didn’t have the soil suitable for early agriculture.

But there probably was still quite a but of friction and violence. Also both groups were very different phenotypically, Western Europeans had very dark/black skin and often blue eyes while the middle eastern immigrants had pale skin and dark eyes.

>It is known that Europe was colonized by Neolithic farmers who expanded out of Turkey about 17,000 years ago, this group had DNA that is still found in the modern population. But none of the older DNA seems to have survived.

This is not true. Western Hunter Gatherers preceded Neolithic farmers from Anatolia and their genes survive in the modern populations of Europe.

>But none of the older DNA seems to have survived.

if we share 98% of our DNA with chimps from a million years ago, what does it mean to say that none of some older DNA seems to have survived?

More or less the same as you just did? i.e. these were independent branches just like chimps and humans.

Albeit there was some mixing even in the areas settled by Anatolian farmers. According to current estimates the WHG population was very low to begin with and they continued living alongside farmers for quite a while (due to both groups preferring different environments/soil types) so it probably was more gradual rather than direct replacement/genocide.

I wonder what adaptions humans could develop to survive overheating in a wet bulb szenario. Some thermal shutdown of metabolism or almost all muscles could make those temperatures surviveable?

The only thing to do is hvac management. We don’t have enough time to accumulate sufficient favorable mutations across the population given the speed we are affecting the earths climate.

Do thinner people fare better than obese people?

Based on my experience gaining and losing weight and the amount I sweat when I'm heavier, I'd guess yes.

Square cube law would say so. The more surface area per volume to dissipate heat the better.

The inverse can be seen in arctic animals that are basically baubles to conserve heat.

Not a genetic adaptation like OP is considering, but if you're a big westerner and spend a lot of time in a tropical country you're likely to lose weight.

Edit: tried to find some peer reviewed evidence to back up my anecdote but came away empty handed. Still i stand by my claim. :)

Low hanging fruit probably would be smaller body sizes, and early onset baldness in both sexes.

I expect housing & behavioral adaptations would carry the most weight. E.g. you'd want to dig a basement in a moderate weather season, so you'll have somewhere survivable in the hot season. And of course have redundant backup power for A/C if you can afford it.

Some of the adaptations camels use could theoretically be useful, like dropping temperature at night & letting it rise throughout the day, tolerating higher temps overall, etc. But I doubt there's time for humans to naturally evolve those abilities very far in the next several thousand years.

Many orders of magnitude too few time to adapt naturally to the coming climate crash.

This is wrong thinking about evolution. The potentially beneficial mutations are already out there in the population. They gain dominance in the population after a large die-off of folks who don't have them and the remaining survivors reproduce.

Yeah but the selection for who survives is going to be based not on a specific gene, but on membership in the group with the will and power to kill for the remaining arable land.

The selection is going to be based on wealth, not on genes.

That's pretty much it yes.

Wealth as an abstraction can fall apart too

Not all potential traits are going to be present in the population. If this were true nothing would go extinct as there would be enough diversity in this theoretical population to see some individuals with the right combination of traits.

It it somewhat more likely to happen when you have say a flask of bacteria where they grow logarithmically by the hour in terms of generational time and have much simpler single cell systems vs us poor multicellular well differentiated humans that are waiting until our thirties when reproductive systems start failing to have our 0.6 kids or whatever the rate is in western countries where diversity is already quite low due to a lack of significant african demography in most populations out of africa. Even in places with significant african background population numbers, social history means these alleles have not yet dispersed across the population homogeneously and are maintained in their demographic subset.

I think given the option of a mass die-off, and moving into your still-habitable back yard, most people would take the latter.

Migrating north (or south, in the southern hemisphere). Which is going to increasingly collide with the man-made borders preventing people from doing so.

This is in the back of my mind as my spouse and I ponder emigration.

Evolution will select for humans intelligent enough to buy air conditioners.

Do air conditioners matter if you don't have crops or livestock?

See the CO2 fertilization effect:

https://en.wikipedia.org/wiki/CO2_fertilization_effect

What about rain and temperature?

Bergmann’s rule: animals in colder climates have larger bodies than members of the same species (or subspecies) in warmer climates.

Allen’s rule: limb lengths vary according to climate. Limbs are longer in warmer climates.

Both rules observed in human populations over time.

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

Tangent: Can anyone recommend a piece of fiction about Neanderthal life, or about their encounters with Sapiens?

I know there’s Asimov’s “Ugly Little Boy”.

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