How did two groups of fish separately evolve genes for making antifreeze? | Hacker News Reader

How did two groups of fish separately evolve genes for making antifreeze?

theatlantic.com

91 pointssohkamyung35 comments

From the headline I'd immediately guess many groups of fish were living in above-zero waters adjacent to sub-zero waters containing food. Eventually some of them experienced a random mutation which made them slightly less freezy and earned them free food!

The account of the actual sequence of mutations required was really interesting, though. It's good to see an article go into that kind of detail!

Maybe the mutation wasn't really random? I wouldn't be surprised if at some point we find that the "90% unused brain capacity" is actually doing some long-term adaptation computations and then uses various signals to put that information into reproductive cells...

The "90% unused brain capacity" is a myth.

Furthermore, the brain doesn't control evolution though "thinking", it's powered by natural selection outside the body.

cited by 555 other papers suggesting RNA changes from life experience -https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333222/

so people are working on reproducing this and understanding this process more, to say more clearly: scientists are actively researching how evolution can happen without natural selection

> how evolution can happen without natural selection

This sounds incoherent. What does "natural selection" mean to you?

Modern usage of “evolution” sometimes conflates “change of the organism over time or a lineage between generations” with “Darwinian selection”. Sexual selection is an easy example of evolution that’s not due to Darwinian “natural” selection.

Sexual selection was one of Darwin's key insights. He realized that the 'fittest' in 'survival of the fittest' was not just about living longer.

https://www.darwinproject.ac.uk/commentary/evolution/sexual-...

Sexual selection is literally a textbook example of natural selection.

"Change of the organism between generations" is called "genetic drift" if it's undirected and "selection" if it's directed. The concept of "evolution without natural selection" doesn't really exist.

Selection is how you get organisms that appear to be designed for a purpose. Sexual attractiveness is a purpose.

Epigenetic research isn't going against evolution, it's refining some details.

We are discovering some nonmendelian dynamics of inheritance, but being epigenetic they are only about how the organism can differentially use its genetic library.

was it not clear that I was talking about OP's claim regarding "natural selection outside of the body" when epigenetic is not outside of the body and can result in changes of the offspring, does your response run counter to my observation?

so far all the responses seem to be more about a semantical distinction of the word evolution and natural selection

Well semantics are important, especially in fields that someone is intimate with, and I'm currently finishing a phd in cis-regulation and epigenetics.

When we stress mice and notice a difference in their offspring through epigenetics, this is something that has already evolved in mice. Parts of the parental DNA get "marked" and the mark passes on to the offspring and influences their development, but the mechanism that connects external stress and the marking of the parental DNA is itself a genetic mechanism and subject to evolution.

The offspring whose development was changed because of the parental stress isn't evolved, much like a baby with FASD[1] isn't "evolved" either

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

We are seeing external adaptive pressures that diminish natural selection as an absolute, such as in this paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333222/

Its nice that science is able to adapt to new information.

Natural selection needed to be an absolute to counter state-religion based spontaneous creation.

But its now not an absolute, with worthwhile investigation of how life experience can make its way into zygotes.

Maybe one day we can even prove spontaneous creation, and learn the process for that.

Maybe one day we can prove there's a teacup orbiting Saturn too !

maybe. the consequences being...?

> We are seeing external adaptive pressures that diminish natural selection as an absolute, such as in this paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333222/

That's still natural selection, it's just a different mechanism for it.

> various signals to put that information into reproductive cells

This idea isn't that far-fetched, when considering something like this is possible https://www.sciencedaily.com/releases/2018/10/181022085844.h...

> "90% unused brain capacity"

However, the myth of the 90% unused brain capacity is a myth. Different parts of the brain are always active depending on the environment and the tasks being undertaken at any given moment, due to the brain's structure as a sort of parallel processing machine with specialized areas (speech, visual processing, auditory processing, etc.).

I don't believe (from what we know currently) that there's any mechanism for the brain to change our genetics, but hey, we may find out someday that it does something like that.

Even if not, I'd be completely unsurprised to find out that some of the "random mistakes" or "junk DNA" that we have floating around in our bodies actually reacts in some obscure way to different environmental influences to tweak our gene expression and whatnot.

think about what the fish would have to do -- it would have to realize what the problem was, what change would solve it, and then command its body to make that change, all without the benefit of any scientific knowledge. If we could do those sorts of things, we could solve a host of genetic diseases without medical science.

The central problem for Lamarckism is explaining how the body is supposed to know which changes are beneficial. A blacksmith might develop a strong right arm, but also tennis elbow.

Then how do bacteria or plants evolve?

My assumption would be that the pioneer species, trying to escape predation or searching for new niches open up the niche and then the foodchain follows the "lower" life forms, out of opportunity.

Not really relevant, but too much of a fun fact for me not to share: the partner's name is "DeVries", which I'm guessing has a Dutch origin, and literally translates to "TheFreeze".

(I suspect its etymological origin is more related to Frysia, though.)

Not quite, 'de Vries' in Dutch translates to 'the Friesian'.

No, that would be DeFries.

Exactly, although the word probably derives from that - hence my remark about its etymological origin.

vries means freeze. even though not used like that specifically, you are right in your thought that vries means freeze. "ik vries" -> "i freeze".

friesland's name is disputed though between being founded by a guy named 'friso' and that 'Fries' means 'peoples with curly hair' :D - so much for logic & linguistics :D!

> so much for logic & linguistics :D!

Which is why I didn't want to go into the actual etymology, because the only reason it was a fun fact is because the current meaning of the word is freeze, regardless of what it referred to in the past :)

"Vriesland" is an old spelling for Friesland (Frisia).

I love this stuff. Coolest science to learn and read about. Thank you for sharing it!

Agreed. I also want to thank good scientific journalism writing when I see it. Translating scientific news into a format geared toward a layperson is very difficult, and I thought this author did a great job. I thought his "thralala" neologism was great and made for a better read that was also easier to understand.

Interesting article about some of the mechanics of DNA and evolution.

But I wanted to call out a confusing use of the increasingly ambiguous word “partner” here: “There, she and her partner, Arthur DeVries, studied the notothens”.

What sort of partner? Research partner, clearly. Oh, but with some googling you can find that they are married, so also romantic/life partner.

I appreciate the sentiment behind the takeoff in the use of this phrasing, but it inevitably leads to confusion in communication. Can we come up with a better word that is not so ambiguous? And if not, can we (or at least the editors at places like The Atlantic) try to clarify what sort of partner when the meaning is ambiguous?

Why? This is science reporting, not tabloid journalism. We don’t need to know the marital status, gender preference, dietary restrictions, previous relationships, etc. Good writing about science is plenty. And “spouse” is a fine word if needed.

> We don’t need to know the marital status, gender preference, dietary restrictions, previous relationships, etc.

I agree, but a lot of science reporting and especially TV/movie documentaries are going down the path of "telling a story" and focusing more on the process and characters involved rather than facts. This is particularly true from outlets like the Atlantic, so if GP went in with the expectation of that kind of article I can understand how they got confused.

I agree with you, but then why bring it up at all?

They didn't bring it up.

> What sort of partner? Research partner, clearly.

The fact that the two happen also to be married need not be related to the use of the word.

I directly understood it as both romantic and work partner.

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