11 ms·

If all that tissue is not needed, then why did evolution conserve it? It consumes energy, adds size, and increases weight and head size which reduces agility.

by api 11y ago

If all that tissue is not needed, then why did evolution conserve it? It consumes energy, adds size, and increases weight and head size which reduces agility. I really dislike "Chief Wiggum skepticism" that likes to just hand wave away and cheaply dismiss amazing things that might teach us a lot.

deleted 11y ago
[deleted]
awalton 11y ago
> If all that tissue is not needed, then why did evolution conserve it? We don't need two kidneys, two lungs, most of our liver, arms, legs, two eyes, ears, etc. These things just make us better at surviving - more likely to make it out of childhood and to an age where we can reproduce. Turns out, we don't quite need all that matter in our heads either, it just makes it more likely we'd survive some traumatic brain injury. If this guy experienced a TBI with this little brain tissue, there's probably no chance of any meaningful recovery left. Meanwhile we see non-diseased brains recover from injuries that look immediately fatal, like having spikes driven completely through skulls. What we've known is that our bodies are remarkably resilient to many kinds of injuries. This just extends what we know of our resiliency to this class of injury. It's also important to realize that hydrocephalus like this is a "small damage over time" type of injury usually - this patient didn't go to sleep with most of his brain matter intact and wake up with it gone, it was gradually lost over months or even years during his childhood as csf slowly increased in volume, obliterating cells as it went. His brain was just quick enough at rewiring that it didn't kill him outright or leave him permanently seizing or in a vegetative state (as with the other half of patients with hydrocephalus this bad). We should be studying him to learn why his brain was able to keep up with the strain where others aren't.
- api 11y ago
  Interesting, and I generally agree, but the parent post could easily be interpreted as "there's nothing to see here, we already know everything, so no need to look into it."
brazzledazzle 11y ago
>If all that tissue is not needed, then why did evolution conserve it? It consumes energy, adds size, and increases weight and head size which reduces agility. Because evolution is just survival. Fittest doesn't necessarily mean "best", particularly if we're talking about individuals of the species. What genes live on are what worked well enough to be passed on to offspring and didn't happen to get erased from the gene pool.

by api 11y ago

deleted 11y ago

[deleted]

awalton 11y ago

> If all that tissue is not needed, then why did evolution conserve it? We don't need two kidneys, two lungs, most of our liver, arms, legs, two eyes, ears, etc. These things just make us better at surviving - more likely to make it out of childhood and to an age where we can reproduce. Turns out, we don't quite need all that matter in our heads either, it just makes it more likely we'd survive some traumatic brain injury. If this guy experienced a TBI with this little brain tissue, there's probably no chance of any meaningful recovery left. Meanwhile we see non-diseased brains recover from injuries that look immediately fatal, like having spikes driven completely through skulls. What we've known is that our bodies are remarkably resilient to many kinds of injuries. This just extends what we know of our resiliency to this class of injury. It's also important to realize that hydrocephalus like this is a "small damage over time" type of injury usually - this patient didn't go to sleep with most of his brain matter intact and wake up with it gone, it was gradually lost over months or even years during his childhood as csf slowly increased in volume, obliterating cells as it went. His brain was just quick enough at rewiring that it didn't kill him outright or leave him permanently seizing or in a vegetative state (as with the other half of patients with hydrocephalus this bad). We should be studying him to learn why his brain was able to keep up with the strain where others aren't.

api 11y ago
Interesting, and I generally agree, but the parent post could easily be interpreted as "there's nothing to see here, we already know everything, so no need to look into it."

brazzledazzle 11y ago

>If all that tissue is not needed, then why did evolution conserve it? It consumes energy, adds size, and increases weight and head size which reduces agility. Because evolution is just survival. Fittest doesn't necessarily mean "best", particularly if we're talking about individuals of the species. What genes live on are what worked well enough to be passed on to offspring and didn't happen to get erased from the gene pool.