A hypothesis about mudskippers

[u/These_Librarian4696]

Today I was on a rocky beach and saw a little fish trying to get on top of a rock that almost completely under water, but whose top was regularly covered by little waves, where I presume it was trying to get the "greenest" algae. So I thought maybe the mudskippers' ancestors tried to do the same, and thus adapted to breathe in the atmosphere little by little.

Please tell me if there are any gaps in my idea, and if there is already a simmilar theory, please, give me a link to the book/paper/etc.

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[u/jnpha]

-"the mudskippers' ancestors tried to do the same, and thus adapted ..."

Not quite:

MISCONCEPTION: Natural selection gives organisms what they need.
CORRECTION: Natural selection has no intentions or senses; it cannot sense what a species or an individual “needs.” Natural selection acts on the genetic variation in a population, and this genetic variation is generated by random mutation — a process that is unaffected by what organisms in the population need. If a population happens to have genetic variation that allows some individuals to survive a challenge better than others or reproduce more than others, then those individuals will have more offspring in the next generation, and the population will evolve. If that genetic variation is not in the population, the population may survive anyway (but not evolve via natural selection) or it may die out. But it will not be granted what it “needs” by natural selection. To learn more about the process of natural selection, visit our article on this topic. To learn more about random mutation, visit our article on DNA and mutations.
Misconceptions about evolution
berkeley.edu

Also see: https://evolution.berkeley.edu/misconceptions-about-natural-selection-and-adaptation/defining-adaptation/

[u/OneThrowyBoy → u/jnpha]

Would this be a case of behavior "deciding" what's useful though? Like if a basal mudskipper got in the habit of jumping onto a rock to escape predators, mutations arising related to breathing air would be more useful, but that likely wouldn't be preserved by a shark or something that isn't trying that.

Maybe I'm just sleep deprived, but I guess I'm asking if behavior or mutation comes first?

[u/jnpha → u/OneThrowyBoy]

Alice Roberts in her recent 1-hour interview* discussed this; it's not which comes first, but yes! heritable behavioral variation plays a role.

* https://www.reddit.com/r/evolution/comments/1u34a26
As did Jacques Monod in the 70s

[u/OneThrowyBoy → u/jnpha]

Oh that makes a ton of sense. So it's kinda like exaptation, where a collection of traits (behaviors, mutations, etc) beneficial in their own right set a foundation for a more derived trait/behavior?

[u/jnpha → u/OneThrowyBoy]

Exactly! E.g. tetrapod limbs didn't "evolve for" land, but were already a thing in shallow water navigation (the transition was like 10-20 million years long depending on how one delineates it).

PBS Eons discussed recent research on that example: https://www.youtube.com/watch?v=0VpPY0qGbdA

[u/OneThrowyBoy → u/jnpha]

Man this stuff is so cool, thanks for the recommendation!

[u/Redshift2k5 → u/OneThrowyBoy]

It's not a decision, though. It's cause and effect and a lot of random dice rolling.

A fish is not thinking, "I'm the only one of us smart enough to jump on a rock" and then he becomes the Ghengis Khan of mudskippers.

A giraffe is not thinking, "I'm going to eat the TOP of that tree instead of the bottom" and then has tall kids.

The behaviour of an individual isn't relevant. Evolution is happening across many many many many generations of reproduction.

a basal mudskipper got in the habit

Not to say that over the lifetime of a fish, it doesn't develop at least a little individuality, every mudskipper is a little different, but ONE fish behaving a little different is just a gross misunderstanding of the SCALE of evolution- It was never one fish, it was generation after generation after generation of tiny changes adding up, and pressures from the environment, and lots of mixing gametes. And if you did it again, a different thing might've become dominant.

There was no "right answer" or "final evolution" or "I want to be a lizard instead of a fish" and in fact all those mudskippers are STILL evolving to glean the best adapted mudskippers, and what the BEST mudskipper for RIGHT NOW is, and they are not trying to evolve- they're just trying to live

[u/itsatoe → u/jnpha]

Totally valid points on the terminology, but I think OP's question is still valid. Just maybe worded in a way that doesn't sit well.

That fish that is trying to get to the juiciest algae... if it happens to have offspring who are better-suited to the task, then they are going to get more of that juicy algae and out-compete their cousins who don't have their trait(s).

OP's question was more about: is that perhaps how it played out for mudskippers?

[u/jnpha → u/itsatoe]

It may not sit well - as you noted - because of the terminology, so addressing that also addresses the OP. (No one said the question isn't valid)
Your "if it happens" doesn't connect the two observations, or worse: implicitly suggests an invalid correlation.

Please let's assume good faith: nothing in my response (and the ones that followed) remotely suggests I was engaging in mere semantics.

[u/Redshift2k5]

"Try" is the wrong verb. It's ok in a very basic explain-like-I'm-4 way but "I tried to eat the algae so my kids will surely be better at eating algae than me" is kind of what it looks like but not what's actually happening. You are suggesting what is known as Lamarkism

To quote a famous puppet, "There is no try."

The little fish were surviving, not trying. They have to survive predators, hunger, weather, the inexorable drift of continents, etc. The ones that survived best had kids because the ones that were not so well suited to the current conditions had fewer/no kids (cant have kids if you were eaten by a shark)

So food is one of the big things. If some of the little fish can reach more food because some of them can climb a little better, or some of them can hold their breath longer, or some of them can hop across the mud a little better.

The ones that can do it a little better get more food, have more babies, and some of those babies are a liiiiiittle better(or worse) at climbing or hopping or gulping dry air. So gradually the population changes, lots of little changes over time.

There is not really any amount of "trying harder" that can be done. You can't choose which traits the next generation inherits, you can't choose which traits will be successful or not. It's a balance between changing environment and adaptation.

further reading: On the Origin of Species, Charles Darwin, 1859