3 ms·

> biology will create constraints. If you're male, you may be able to bench 200kg, but probably not 500kg unless your biology allows it. On evolutionary timefr

by czl 2y ago

> biology will create constraints. If you're male, you may be able to bench 200kg, but probably not 500kg unless your biology allows it. On evolutionary timeframes what biology allows can evolve and the hard limits are due to chemistry and physics. > there are costs to developing large brains. The benefits would not justify the costs, over evolutionary history. > Large brains come with a significant metabolic cost. They would only have evolved if they provided a benefit that would outweigh those costs Google "evolutionary spandrels" and you will learn there can be body features (large brains of whales) that are simply a byproduct of other evolutionary pressures rather than direct adaptation.

trashtester 2y ago
> Google "evolutionary spandrels" and you will learn there can be body features (large brains of whales) that are simply a byproduct of other evolutionary pressures rather than direct adaptation. If you're a 10-150 ton whale, a 2-10 kg brain isn't a significant cost. But if you're a 50kg primate, a brain of more than 1kg IS. For humanoids over the past 10 million years, there are very active evolutionary pressures to minimize brain size. Still, the brain grew to maybe 2-4 times the size over this period. This growth came at a huge cost, and the benefits must have justified those costs. > On evolutionary timeframes what biology allows can evolve and the hard limits are due to chemistry and physics. It's not about there being hard limits. Brain size or muscle size or density is about tradeoffs. Most large apes are 2-4 times stronger than humans, even when accounting for size, but human physiology has other advantages that make up for that. For instance, our lower density muscles allow us to float/swim in water with relative ease. Also, lighter bodies (relative to size) make us (in our natural form) extremaly capable long distance runners. Some humans can chase a horse on foot until it dies from exhaustion. I'm sure a lot of other species could have developed human level intelligence if the evolutionary pressures had been there for them. It just happens to be that it was humans that first entered an ecological niche where evolving this level of intelligence was worth the costs.
- czl 2y ago
  > Also, lighter bodies (relative to size) make us (in our natural form) extremaly capable long distance runners. Humans' ability to run long distances effectively is due to a combination of factors, with the ability to sweat being one of the most crucial. Here are the key adaptations that make humans good endurance runners: a) Efficient sweating: Humans have a high density of sweat glands, allowing for effective thermoregulation during prolonged exercise. b) Bipedalism: Our two-legged gait is energy-efficient for long-distance movement. c) Lack of fur: This helps with heat dissipation. d) Breathing independence from gait: Unlike quadrupeds, our breathing isn't tied to our running stride, allowing for better oxygen intake. Lighter bodies (relative to size) plays a role but there plenty of creatures that have light bodies relative to size that are not great at long distance running.
- czl 2y ago
  > Still, the brain grew to maybe 2-4 times the size over this period. I read somewhere that the human brain makes up only about 2% of body weight but uses 20% of the body’s energy. While brain size has increased over time, brain size does not determine intelligence. The brain’s high energy use, constant activity, and complex processes are more important. Its metabolic activity, continuous glucose and oxygen consumption, neurotransmitter dynamics, and synaptic plasticity all play major roles in cognitive function. Intelligence is shaped by the brain’s efficiency, how well it forms and adjusts neural connections, and the energy it invests in processing information. Intelligence depends far more on how the brain works than on its size.

by czl 2y ago

trashtester 2y ago

> Google "evolutionary spandrels" and you will learn there can be body features (large brains of whales) that are simply a byproduct of other evolutionary pressures rather than direct adaptation. If you're a 10-150 ton whale, a 2-10 kg brain isn't a significant cost. But if you're a 50kg primate, a brain of more than 1kg IS. For humanoids over the past 10 million years, there are very active evolutionary pressures to minimize brain size. Still, the brain grew to maybe 2-4 times the size over this period. This growth came at a huge cost, and the benefits must have justified those costs. > On evolutionary timeframes what biology allows can evolve and the hard limits are due to chemistry and physics. It's not about there being hard limits. Brain size or muscle size or density is about tradeoffs. Most large apes are 2-4 times stronger than humans, even when accounting for size, but human physiology has other advantages that make up for that. For instance, our lower density muscles allow us to float/swim in water with relative ease. Also, lighter bodies (relative to size) make us (in our natural form) extremaly capable long distance runners. Some humans can chase a horse on foot until it dies from exhaustion. I'm sure a lot of other species could have developed human level intelligence if the evolutionary pressures had been there for them. It just happens to be that it was humans that first entered an ecological niche where evolving this level of intelligence was worth the costs.

czl 2y ago
> Also, lighter bodies (relative to size) make us (in our natural form) extremaly capable long distance runners. Humans' ability to run long distances effectively is due to a combination of factors, with the ability to sweat being one of the most crucial. Here are the key adaptations that make humans good endurance runners: a) Efficient sweating: Humans have a high density of sweat glands, allowing for effective thermoregulation during prolonged exercise. b) Bipedalism: Our two-legged gait is energy-efficient for long-distance movement. c) Lack of fur: This helps with heat dissipation. d) Breathing independence from gait: Unlike quadrupeds, our breathing isn't tied to our running stride, allowing for better oxygen intake. Lighter bodies (relative to size) plays a role but there plenty of creatures that have light bodies relative to size that are not great at long distance running.
czl 2y ago
> Still, the brain grew to maybe 2-4 times the size over this period. I read somewhere that the human brain makes up only about 2% of body weight but uses 20% of the body’s energy. While brain size has increased over time, brain size does not determine intelligence. The brain’s high energy use, constant activity, and complex processes are more important. Its metabolic activity, continuous glucose and oxygen consumption, neurotransmitter dynamics, and synaptic plasticity all play major roles in cognitive function. Intelligence is shaped by the brain’s efficiency, how well it forms and adjusts neural connections, and the energy it invests in processing information. Intelligence depends far more on how the brain works than on its size.