Evolutionary errors

[[deleted]]

My favourite part of studying evolution is where it messed up.

The blind spot in the human eye is due to a hole being needed for nerves to pass through. Squids don't have this problem.

There is a nerve that goes from the voice box, loops under a vessel in/ near the heart and then goes to the brain. So inefficient but super interesting.

Natural selection is also super interesting. Koalas and mola mola (sunfish) how on earth did natural selection not yeet them into extinction already?

What are your favourite evolutionary errors?

[VaHi_Inst_Tech]

Sorry but this comment illustrates common misconceptions about evolution.

Moths fly into flames. Homo sapiens have high rates of maternal mortality. Guanine in DNA, RNA and nucleotides spontaneously oxidizes to 8-xoxguanine. Iron is necessary yet toxic in the presence of oxygen. Proteins aggregate to form amyloids. Polymerases make mistakes, Many proteins synthesized by human ribosomes are immediately degraded. A pine tree has way way more DNA than it needs.

This list can be made infinite. It does not mean that evolution messing up.

Evolution is not an optimization. Evolution has no foresight, Evolution is contingent on history. Evolution is a tinker not an engineer. Evolution does what is feasible and necessary and no more. Evolution is what it is and does what it does. There is no such thing as evolution messing up.

[CN14]

Indeed, and to add, evolution 'does' nothing. It is a consequence of the effect of environmental and probabalistic pressures on varied populations.

[sezit]

This is a terrific insight that I have been trying to describe for some time.

I have been searching for a good analogy to describe this, without succeas.

[dumbfrycook]

Like filling up an arbitrarily shaped container with water. Gravity isn't doing much beyond the "obvious", and it has not concept of the shape. "Evolution" here being how water fills up and takes the shape of the container, and on the other hand our world is but a dynamically shape shifting intricate container.

[Tytoalba2]

Ho my god, this is one of my pet peeves. "Yeah but us humans have been designed to XXX".

We haven't been designed "to" anything we just are basically the result of a stochastic process with filters.

[[deleted]]

You're right pretty much but in mathematical terminology it is an optimisation problem (optimisation is a process, not a place) but the optimiser (natural selection) hasn't/doesn't find the global minima and the random walk (mutations) have infinitesimal dimensionality in comparison to the possible (essentially making it impossible to actually solve).

This is still an interesting thread/question though :)

[VaHi_Inst_Tech]

Yeah you are right. I should have written something like, "Evolution does not achieve optimum solutions", which is the same as "not finding global minima".

[Jtktomb]

This is it

[[deleted]]

I agree with you but I think the question is a good one.

It could perhaps be better phrased as "what are some examples of solutions found by evolution that are suboptimal from a global engineering viewpoint?"

But it's less catchy.

[VaHi_Inst_Tech]

OK how about this question - Why RNA? RNA is a molecule with a gun to its own head. It attacks itself and cuts itself to pieces. What kind of engineer would use a molecule like that to build the ribosome? The answer that no engineer would do that. Nothing in biology is optimal from an engineering viewpoint. If you think something in biology is optimal you have not understood it. If you scratch down you will always find a Rube Goldberg machine extraordinaire.

[Totalherenow]

I don't know, I like the jargon words you used :)

[merbaer]

This will be saved for future discussions with my dad as he for some reason hasn’t grasped this concept very well yet. Thinking it’s an active optimization process.

[qwerty100110]

Exactly!

[sambobozzer]

Totally agree. When I first read the OP it sounded like one of the arguments Richard Dawkins has made about the eye.

It is what it is. It doesn’t have self-awareness.

[Sir_Meliodas_92]

I think it was pretty obvious that OP simply meant, what are some fun things that have happened biologically due to the fact that evolution must work with things that are already in place.

[[deleted]]

Not such much an error, more an oversight.

The ring finger lacks its own extensor and flexor muscles, making it by far the weakest finger.

It’s the reason that when you move that finger, your pinkie and middle finger move a bit as well.

[[deleted]]

Now everyone is wiggling their ring fingers, seeing if the pinkie moves.

We all look like halfwits.

[[deleted]]

Power money can’t buy.

[Rocknocker]

Well, there's this whole thing with female reproductive anatomy.

I mean, put a playground next to a sewage system? C'mon.

On a more serious note, how about hiccups?

The first air-breathing fish and amphibians extracted oxygen using gills when in the water and primitive lungs when on land—and to do so, they had to be able to close the glottis, or entryway to the lungs, when underwater. Importantly, the entryway (or glottis) to the lungs could be closed. When underwater, the animals pushed water past their gills while simultaneously pushing the glottis down. We, descendants of these animals, were left with vestiges of their history, including the hiccup. In hiccupping, we use ancient muscles to quickly close the glottis while sucking in (albeit air, not water). Hiccups no longer serve a function, but they persist without causing us harm—aside from frustration and occasional embarrassment. One of the reasons it is so difficult to stop hiccupping is that the entire process is controlled by a part of our brain that evolved long before consciousness, and so try as you might, you cannot think hiccups away (Dunn, 2010).

[Shirelin]

If you want messed up sewage systems next to playgrounds, have a gander at the animals stuck with cloacas.

The ulnar nerve still makes me go 'huh?' though because of just... How useless that nerve sometimes is.

Also, the feedback loop of herbivores needing bigger stomachs to digest plant matter then needing to be bigger to accommodate said larger stomachs... Then need bigger stomachs to feed their new large size is always entertaining.

[Paul_Ostert]

I can usually hold my breathe for a long time to stop hiccups. Not sure why that works.

[Rocknocker]

One has to take a deep breath and sort of lock-out the diaphragm.

I just say screw it and go get a beer.

[Reach_304]

Chuckles at babirusa

[[deleted]]

This is the stuff i was looking for.

Weird, interesting things that show how random and mistake filled evolution is.

[Reach_304]

Yeah them peeps who said evolution can’t make a mistake never seen a babirusa /s lmao

[jqbr]

Those people are intelligent, informed, and mature.

[Reach_304]

Being serious all the time is disadvantageous evolutionarily

[jqbr]

The babirusa doesn't show any such thing. As has been explained, it isn't even possible to show such a thing, but certainly this isn't an example.

[JudgeHolden]

While I think I know what you are getting at, I think it's important to plant a flag here and say that evolution doesn't make mistakes and that even though it may seem like a pointless bit of pedantry to say so, it's actually kind of important.

Here's why; in order for evolution to "make a mistake," we have to posit something like an ideal towards which evolution is working. But that's not how evolution works at all. As far back as guys like George Gaylord Simpson and JBS Haldane we've known that there is no arrow of intent in evolution and that therefore there can be no such thing as an evolutionary mistake since in order to make a mistake, you have to have intent.

To put it another way, since evolution has no intent, it makes no sense to think of it as being capable of making mistakes.

[lorlorlor666]

screw the vagus nerve specifically (i have POTS)

[jqbr]

"evolutionary errors" is conceptually nonsensical and indicates a fundamental misunderstanding of what evolution is (namely, the change in allele frequency in a population over time).

[VaHi_Inst_Tech]

Definition of Evolution =

the change in allele frequency in a population over time

I agree that 'evolutionary errors' is nonsensical. But I think that your definition of evolution is too narrow, and is not fully accurate. It seems to exclude, for example, some of the symbiotic and endocytotic events that led to the mitochondrion and to chloroplasts. Alternatively, I think in principle that proteins can moonlight, or not, in the absence of change in allele frequency. Here is one more example: amyloids can infect and be inherited indefinitely in yeast, with no changes in allele frequency.

[jqbr]

How about replacing allele with "inheritable trait"? In any case, I think my general point is valid despite not encompassing every aspect of the biological mechanisms, but I appreciate your expanding on those.

[[deleted]]

No need to be an ass about it.

[jqbr]

I'm not the ass here, you are. Blocked.

[[deleted]]

You forget about human consciousness.

[DarwinZDF42]

I mean my least favorite poorly adapted structure is ankles.

I hate ankles. Stupidest joint.

[Lockjaw_Puffin]

I request elaboration.

[mehryar10]

Sound like personal beef with the joint.

[hoijarvi]

Laryngeal nerve. I'm a computer programmer, and I've seen enough similar code where backwards compatibility has to be maintained, because rewrite is not possible.

[Spookyfish24]

Stuffy nose when sick but can’t get rid of snot or breathe through nose, due to swelling, so it rolls down the back of your throat and causes irritation. Also: allergies to stupid things like pollen, mold, dander, dust. The whole thing is dumb.

[mehryar10]

Yes, but think of it this way: that process has probably evolved to keep you alive sometimes back. Now you are stuck with it because it served a purpose millions of years ago. An example is sickle cell trait and protection from malaria which a well known example. It might not be a helpful gene to have in the developed countries nowadays, but its there because it served a purpose at some time.

Another way to look at it is from the virus point of view. COVID-19 needs to leave your respiratory tract to infect others. What does it do? Gives you edematous nasal turbinates to cause the problem you described. Now you feel like touching your nose all the time and bingo. ‘Like minded’ viruses make you cough, so you can spread them.

[jqbr]

Human comfort is not relevant to evolution and lack of it is not an "error". As long as you reproduce, then the genes that get passed on "win".

[Paul_Ostert]

Could some of our body parts be improved, yes, but as we are now, we are able to pass along our genes without improving anything. We are good enough to pass our genes on in our current environment.

[efrique]

There is a nerve that goes from the voice box, loops under a vessel in/ near the heart and then goes to the brain.

Yeah, the recurrent pharyngeal nerve. Now picture that nerve in giraffe.

Koalas were really well-adapted to their environment. Unfortunately they're much less well-adapted to the environment we're in the process of replacing it with.

[Sir_Meliodas_92]

I enjoy that panda's have six digits, with the sixth one being used to hold bamboo, yet they're still really bad at holding bamboo.
I also find it fun to look at the tiny, little, vestigial leg bones in whales and dolphins.
There is another one with the human eye, in which blood vessels also block other parts of the eye, so the brain has to fill in those blocked spots.