Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Yawning has an unexpected influence on the fluid inside your brain

newscientist.com

Post reply on HN
Print view View original

11–20 of 82 posts

Re: Yawning has an unexpected influence on the fluid inside your brain

#11

Post by kgwxd »

MPSimmons wrote: post #4

The contagious nature of yawning is so weird. It has to be evolutionarily advantageous because it's so wide spread, but it's also non-obvious.

Just about all our behaviors are contagious. Scratching, deep breath, emotion, looking in a certain direction, sudden alertness. If yawning were different, that would be weird.

Re: Yawning has an unexpected influence on the fluid inside your brain

#13

Post by rtkwe »

clscott wrote: post #5
MPSimmons wrote: post #4

The contagious nature of yawning is so weird. It has to be evolutionarily advantageous because it's so wide spread, but it's also non-obvious.

A trait doesn’t have to be advantageous to persist just non-detrimental.

Yeah that's (to me) a more accurate framing, also evolution is bad at revisions so even if there are minor disadvantages to a setup so long as it's not affecting your ability to have and raise kids it's basically completely absent as far as evolution is concerned. For example there are some wild inefficiencies in body layout left over from fish body patterns where the nerve from the brain to the voice box wraps down around your aortic arch because the relative position of the throat, brain, and heart were very different in fish so the path it took then was more direct. It happens in humans and most hilariously in giraffes where it goes all the day down their enormous necks.

Re: Yawning has an unexpected influence on the fluid inside your brain

#14

Post by EA-3167 »

clscott wrote: post #5
MPSimmons wrote: post #4

The contagious nature of yawning is so weird. It has to be evolutionarily advantageous because it's so wide spread, but it's also non-obvious.

A trait doesn’t have to be advantageous to persist just non-detrimental.

They can be detrimental too, especially if they're linked to beneficial traits. The test is ultimately whether or not the harm done is sufficiently disadvantageous that it interferes with reproductive fitness. Baldness is arguably detrimental, but it's linked to a bunch of recessive genes that function in other ways, and it doesn't impact us until we're likely to have already reproduced.

That's a simplification, but you get the idea.

Re: Yawning has an unexpected influence on the fluid inside your brain

#16

Post by HPsquared »

MPSimmons wrote: post #4

The contagious nature of yawning is so weird. It has to be evolutionarily advantageous because it's so wide spread, but it's also non-obvious.

It's a bit like laughing. Synchronise the mood of the group. I assume other mammals have contagious yawns too?

Re: Yawning has an unexpected influence on the fluid inside your brain

#17

Post by embedding-shape »

nickthegreek wrote: post #8
MPSimmons wrote: post #4

The contagious nature of yawning is so weird. It has to be evolutionarily advantageous because it's so wide spread, but it's also non-obvious.

I literally yawned as I clicked on this article from my RSS reader. The contagious nature at the mere idea of a yawn is wild.

I yawned as I read the title on the frontpage. Smiled a bit when I read the rest of the comments. Contagious beyond physical proximity sure is wild.

Re: Yawning has an unexpected influence on the fluid inside your brain

#18

Post by CGMthrowaway »

clscott wrote: post #5
MPSimmons wrote: post #4

The contagious nature of yawning is so weird. It has to be evolutionarily advantageous because it's so wide spread, but it's also non-obvious.

A trait doesn’t have to be advantageous to persist just non-detrimental.

It is detrimental though. It is socially impolite to yawn in public.

Edit: why am I being downvoted for this?

Re: Yawning has an unexpected influence on the fluid inside your brain

#19

Post by frisbm »

clscott wrote: post #5
MPSimmons wrote: post #4

The contagious nature of yawning is so weird. It has to be evolutionarily advantageous because it's so wide spread, but it's also non-obvious.

A trait doesn’t have to be advantageous to persist just non-detrimental.

and not even that, I'd narrow it further to not detrimental before and during the prime reproductive periods of a species. After that period, detrimental traits are totally fair game and more dependent on technology, culture, and family care dynamics. Heart disease later in life caused by genetic predisposition to high cholesterol isn't something people generally select for or against in a partner, but its effects happen later in life well after people have children so it passes on.

Re: Yawning has an unexpected influence on the fluid inside your brain

#20

Post by nickthegreek »

kgwxd wrote: post #11
MPSimmons wrote: post #4

The contagious nature of yawning is so weird. It has to be evolutionarily advantageous because it's so wide spread, but it's also non-obvious.

Just about all our behaviors are contagious. Scratching, deep breath, emotion, looking in a certain direction, sudden alertness. If yawning were different, that would be weird.

Most of those can also be done consciously though. Yawning is different. It is more inline with flatulence, crying, or vomiting. Actions that are in many ways, outside of our direct control.
Post reply on HN