History of Antarctica revealed in octopus DNA | Hacker News Reader

History of Antarctica revealed in octopus DNA

science.org

61 pointspseudolus31 comments

Using animal genetics to study other phenomena is one of my favorite techniques!

We’ve got a lower bar for when humans started wearing clothing, for example, because about 120,000 (+/- 50,000) years ago body lice genetically diverged from head lice to the point that they could no longer mate.

That's so interesting! Do you have other examples?

And a reference would be great!

Reference and abstract: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3002236/

Clothing use is an important modern behavior that contributed to the successful expansion of humans into higher latitudes and cold climates. Previous research suggests that clothing use originated anywhere between 40,000 and 3 Ma, though there is little direct archaeological, fossil, or genetic evidence to support more specific estimates. Since clothing lice evolved from head louse ancestors once humans adopted clothing, dating the emergence of clothing lice may provide more specific estimates of the origin of clothing use. Here, we use a Bayesian coalescent modeling approach to estimate that clothing lice diverged from head louse ancestors at least by 83,000 and possibly as early as 170,000 years ago. Our analysis suggests that the use of clothing likely originated with anatomically modern humans in Africa and reinforces a broad trend of modern human developments in Africa during the Middle to Late Pleistocene.

About 40k years ago we start to see people's toes scrunched up from wearing moccasins.

For curiosity of the reader and myself. How are the genetic markers isolated in a way that it can without of a doubt explain an iceshelf collapse?

I think an article like this should go more in depth. I am just wondering because it doesn't explain the process.

I also don't disagree with the worrisome amount of greenhouse emissions.

This is neat, but I'm not sure how it "warns" us of anything. Were the octopus harmed by the interbreeding in some way? Also, how does the existence of a past event predict the future? I get climate models, but this genetic evidence would also exist if the planet were getting colder.

the warning is - yes, oceans were 10 meters higher, not long ago..

To quote the article:

"The new octopus genome data, she adds, “is pretty convincing evidence that a full collapse happened.” The findings reinforce the importance of understanding how modern climate conditions are affecting the West Antarctic Ice Sheet, Dutton says. “This is telling us that we need to take this bigger picture seriously.” Continued ocean warming—driven by greenhouse gas emissions—could destabilize the submerged portion of the ice sheet. To lower the chance of another collapse, she says, “We can’t just kick the can down the road and wait to make emissions cuts for another 5 years, another 10 years. It really demands that we do it now.”

Emissions in the modern sense were not the cause of this. But, it happened. Is Dutton making the claim that emissions are the cause now? I'll accept all of Dutton's claims, except that one; there is no basis for that claim. Lower the chance of another collapse? By how much? Would that have actually helped 100,000 years ago? I make the claim that Dutton is suffering from hubris.

You drive a car of type Model Z. Someone, looking at a crash of a Model Z which was going 50 mph, discovers a design flaw that is particularly acute when the car is driven faster than 70. Do you:

* adjust your driving behavior in accordance with whatever bayesian impact the new data has?

* psychoanalyze the person doing the research, or decide that nothing that happens at 50 mph could tell you something about the behavior at 70 to reassure yourself you can ignore the new data?

Your call...

I do wish that was a reasonable argument. Closer: I drive a "Model Z". In the past, someone discovered a crushed Model Z. Does driving a Model Z more than 50 mph cause crushing?

There are indeed multiple sources of emissions, many not at all needing human intervention at all.

Luckily, we can generally measure natural emissions vs human emissions and find how much of it is being caused by us. Incidentally, due to where various gasses are trapped, many natural looking emissions are still our fault, this is frequently discussed in talks and papers about runaway climate change (note that I mean talks and papers from scientific authorities, not Facebook and fox)

You claim that CO2 causes runaway climate change?

You might want to read the summary for policy makers

https://www.ipcc.ch/report/ar6/syr/downloads/report/IPCC_AR6...

Start with A: Observed Warming and its Causes and move onto b: B. Future Climate Change, Risks, and Long-Term Responses

C02 increases directly increase trapped solar heating.

There are other gases and other factors.

Re: GP comment

* Is Dutton making the claim that emissions are the cause now?

The journalist writing the Science article alludes to the fact that now (present time) Antartic sheet loss is being driven by warming oceans caused by greenhouse gas increases. With no quote marks it's unclear what Dutton had to say on this.

* I'll accept all of Dutton's claims, except that one; there is no basis for that claim.

It's not apparent that is a claim that Dutton made.

* Lower the chance of another collapse? By how much?

See IPCC reports.

* Would that have actually helped 100,000 years ago?

No. Actions taken today would not alter past history.

It's also not the case that ice sheet collapse 100K years ago was related to human or animal gas emissions, unlike today.

* I make the claim that Dutton is suffering from hubris.

You're free to do that. It's not a convincing claim.

Either the journalist writing the article was using Dutton as a source accurately, or Science is not a reputable source of news. This is mutually exclusive.

I took the story prima facie. And, if the story (journalism) is accurate, Dutton is indeed suffering from hubris. Someone brought up the collapse 100,000 year ago in a direct comparison. It was either Dutton or the journalist. If I take Science as an accurate source, it was Dutton. Or it was not Dutton, then Science is not reputable (are they adding implications and misquotes?). If that is the case, why the HN story? HN curated it (that is, HN readers) so I have to give credence to Science magazine (because I give credence "to the crowd of HN contributors"). Again, both sides cannot be argued at the same time.

As to reading the summary for policy makers: the IPCC is a political organization, not a scientific one. Why would its publications that are for policy makers be of interest to me? I need a condensed version of science, not policy. The IPCC doesn't have anything to do with the claim -- (except CO2 causes global warming which the IPCC doesn't actually claim, but does imply, as best as I can tell). Either Dutton made the claim, or Science made the claim -- they have to back it up and defend it. I made no claim EXCEPT that Dutton is suffering from hubris. Which I just backed up and defended.

Yea the verbiage is sensationalist. But sea level rise is more than an existential threat, it would reshape everything.

Here is what the octopus genetics tells us is possible (to repeat):

https://m.youtube.com/watch?v=VbiRNT_gWUQ

reshape everything < existential threat.

Sorry, but it is a pet peeve of mine that existential threat bas become a buzzword devoid of meaning.

If you have a house of cards and someone starts swapping them out for other random things, most of which do not work, then reshaping everything == existential threat. Our environment is in an incredibly delicate balance in some locations, and we don't know how losing some species might have larger domino effects.

If they're rare creatures, maybe the effect won't be large. But who knows?

I think your response reinforces my point. I understand existential threat to mean human extinction threat.

Humans can outlive the destruction and change of basically every environment on earth. We can live in swamps and blistering deserts.

What do you think existential threat means?

They might either mean that the (current line of) humanity will not continue

Millions will die.

For the latter, I contend that millions die every week as the status quo, so I don't see events that might kill 10s or even a few hundred million as an real existential threat.

Remember what happened during COVID? Now imagine the "essential" workers are all dead or too busy fighting for the last scrap of food. The food trucks no longer turn up. The hospitals aren't running. You might survive, but our technological civilization of billions won't.

I think the subtext implied in the respondents tone is that they don’t consider millions or even billions of people dying off as existential.

I thought I was pretty explicit in saying exactly that.

Many countries lost more than 10% of their population in World War II in the span of just a few years. Some lost more than 50% of the working age men. Even that wasn't an existential threat.

It all boils down to what hides behind that word, "existential". Slavs and Jews definitely considered what happened in WW2 an existential threat for instance, but you seem to be arguing that only threats to the entirety of humanity qualify as existential, a view that many others here don't agree with, probably because it gives off the impression that things like the extinction of entire cultures and millions or billions of people are discounted by using a restrictive definition. It seems however that neither view matches the use of the concept of "existential risks" in contemporary discourse, which are understood to be "risks that threaten the destruction of humanity's long-term potential". That's a much lower bar to clear and by that standard, we're clearly collectively cutting the branch we're sitting on, though probably not indeed jumping off the cliff of an absolute total annihilation of the human race.

I might surprise you but our current population is not a prerequisite for technological civilization. At 4 billion people died, that would only set us back to 1970s population.

An existential threat to us is, as the name implies, a threat to our existence. Unknown domino effects which may or may not have changes so large that it causes massive swathes of humans to die off, forever changing the future of our species, seems to fit that description.

How much more does it need to be existential to you?

A credible chance of extinction without unknown unknowns.

I see it as an existential threat to our technological civilization. Humans, like cockroaches, will survive. It's just not going to be a place you'll want to live in.

Existential threat by definition is a threat to people's or humanity’s existence or survival. It comes from the Latin root existentia meaning survival.

Reshaping coastlines and raising temperatures probably won’t kill off humanity. But it will change virtually every aspect of our society and potentially kill of technological civilization as you say.

Therefore it’s more than an existential threat of destroying humanity. I meant it how it’s meant to use used: the range of possibilities major sea level rise far exceeds the risk of extinction or the end of humanity, it possesses a range of possible outcomes that would reshape society itself and change inconceivable numbers of things beyond the possibility of merely wiping out the species.

I hear the Islands of California can be quite lovely in the spring, and the Florida banks have excellent fishing if you don’t mind the super hurricanes.

"The average temperature of the planet was about 0.5°C warmer than it is today—and climate projections predict it will be again within decades. The global sea level was also 5 meters to 10 meters higher than current levels. Many scientists believe the collapse of the West Antarctic Ice Sheet and consequent melting could have been a primary reason."

So there's a good chance the inevitable 0.5°C warming will be followed by a massive raise of the ocean waters. That will have some interesting effects on the society. No wonder Mark Facebook and probably most of the other billionaires are building bunkers.

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