31–40 of 82 posts
Earlier quoted context omitted.
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?
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.
Even the mention of a yawn can trigger it.
Perhaps we are almost always in a state of needing a yawn, but the trigger is seldom met, and seeing or hearing about it is enough to make our brain go "oh yeah I forgot about that".
Perhaps yawning is actually underdeveloped and an ideal human would yawn at regular intervals without any prompting.
Earlier quoted context omitted.
Is that the right criteria? A trait must be completely, 100% disqualifying as a mate or else it sticks around? Our ancestors used to have tails. We no longer have tails. Plenty of people wear artificial tails today and get laid, it's not a 100% disqualifying trait
Natural selection doesn't require 100% disqualifying, it just needs a slight preference and a shit load of time.
Earlier quoted context omitted.
It is detrimental though. It is socially impolite to yawn in public. Edit: why am I being downvoted for this?
Even if yawning in public affected sexual fitness: how long has it been socially impolite to yawn in public? Evolution takes a rather long time in species with long reproductive cycles. Almost all mammals yawn, it would take significant genetic changes to breed that out of us. That doesn't happen overnight.
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.
Earlier quoted context omitted.
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.
> Anecdotal evidence suggests that yawning helps increase a person's alertness.
> Paratroopers have been noted to yawn during the moments before they exit their aircraft.
Earlier quoted context omitted.
is it so detrimental that it leads to a person never finding a mate and reproducing? Maybe for a totally extreme outlier, but probably not
Is that the right criteria? A trait must be completely, 100% disqualifying as a mate or else it sticks around? Our ancestors used to have tails. We no longer have tails. Plenty of people wear artificial tails today and get laid, it's not a 100% disqualifying trait
…Do they? What did I miss?
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.