evolution theory

[Aditi Bhattacharya]

Can we reason the fact that during the start of life on earth there was first the development of physical traits but then it started to get diminished and the mental traits grew... i.e. organisms evolved to become more intelligent rather than growing in size? 

[Strange]

13 minutes ago, Aditi Bhattacharya said:

Can we reason the fact that during the start of life on earth there was first the development of physical traits but then it started to get diminished and the mental traits grew... i.e. organisms evolved to become more intelligent rather than growing in size? 

I see no reason for that. Some things have evolved to become larger and some smaller. Some have become more intelligent and others haven't. Organisms evolve to match their environments.

[Aditi Bhattacharya]

25 minutes ago, Strange said:

I see no reason for that. Some things have evolved to become larger and some smaller. Some have become more intelligent and others haven't. Organisms evolve to match their environments.

Then why is it that the intelligent species are not the physically strongest ones?

 

[Strange]

5 minutes ago, Aditi Bhattacharya said:

Then why is it that the intelligent species are not the physically strongest ones?

 

Perhaps because they can use their intelligence to survive, instead of relying on strength.

Why should they be the strongest, if they don’t need to be?

[Aditi Bhattacharya]

2 minutes ago, Strange said:

Perhaps because they can use their intelligence to survive, instead of relying on strength.

Why should they be the strongest, if they don’t need to be?

But still having physical strength can add as an extra benefit

Edited November 5, 2018 by Aditi Bhattacharya

[Strange]

4 minutes ago, Aditi Bhattacharya said:

But still having physical strength can add as an extra benefit

But it also has a cost: increased size, need for more food, etc. And there are benefits to being small. Or fast.

Not every animal can be the largest (or the strongest, or smallest, or fastest). Each species finds its own niche in the environment.

[Aditi Bhattacharya]

Though it comes at a cost , but if a species with superior intelligence and dominant physical traits is synthesized then there wont just be any competition for survival...

22 minutes ago, Strange said:

But it also has a cost: increased size, need for more food, etc. And there are benefits to being small. Or fast.

Not every animal can be the largest (or the strongest, or smallest, or fastest). Each species finds its own niche in the environment.

Though it comes at a cost , but if a species with superior intelligence and dominant physical traits is synthesized then there wont just be any competition for survival...

[Strange]

I can’t see that there is any benefit to either crows or humans (as a couple of examples) becoming stronger. 

What predators do humans have to fight off? What other benefit would there be to being bigger or stronger? The main killers in most of the world are things that are microscopic (parasites, bacteria, viruses). 

Being stronger wouldn’t help with farming animals or crops. 

So where is the survival advantage?

[mistermack]

In the sea, the most intelligent creatures ARE generally the bigger ones. Even with sharks, the great white is reckoned to be one of the most intelligent fishes.

On land, the most intelligent creatures happened to evolve up in trees, which limits size. There was a giant ape that went extinct, but we don't know much about it, or it's intelligence level.

Humans have increased in size a bit, since our ancestors left the trees. But it's skill with weapons that have made us a dominant predator, and that takes the evolutionary pressure off the physical strength characteristic. 

[Strange]

3 minutes ago, mistermack said:

In the sea, the most intelligent creatures ARE generally the bigger ones.

Interesting point. (If true - I’m not sure how we can be sure - and it would depend on the definition of intelligence, I suppose.) I wonder if it says something about the water vs terrestrial environment.

As a possible counter-example, octopuses are thought to be pretty intelligent. 

[studiot]

1 hour ago, Aditi Bhattacharya said:

Can we reason the fact that during the start of life on earth there was first the development of physical traits but then it started to get diminished and the mental traits grew... i.e. organisms evolved to become more intelligent rather than growing in size? 

Surely this is a self fulfilling prophesy?

How could an 'organism' with purely mental traits evolve first?

 

And physical traits needed for survival have changed.

The requirement to breath a non oxygen atmosphere for the first 3,000 million years of evolution for instance.

Strenght is another interesting one.

Which is stronger? An animal that can run or fly away, or the animal that would win any fight with it?

Edited November 5, 2018 by studiot

[mistermack]

4 minutes ago, Strange said:

As a possible counter-example, octopuses are thought to be pretty intelligent.

They are. And on land, the elephant is also considered up there as one of the most intelligent. It's a bit hit and miss really. Why intelligence develops seems to be a bit haphazard. In a lot of cases, it seems linked to communal living, but not all, as the octopus illustrates.

[Phi for All]

3 hours ago, Aditi Bhattacharya said:

But still having physical strength can add as an extra benefit

Only in special circumstances. Humans are wonderful runners, with lots of stamina and speed, but when you add more muscle for strength, it slows us down. The extra benefit of more strength could make us more vulnerable in situations where running away is a better choice. Every species has to deal with a vast variety of situations, and as others have mentioned, added strength comes at a cost. If a bird gains more muscles, it might make them too heavy to fly, rather than make them faster fliers.

[CharonY]

2 hours ago, Strange said:

Interesting point. (If true - I’m not sure how we can be sure - and it would depend on the definition of intelligence, I suppose.) I wonder if it says something about the water vs terrestrial environment.

As a possible counter-example, octopuses are thought to be pretty intelligent. 

There is no universal scale to that. Most sea mammals are arguably more intelligent than fish and they range in size from otters to blue whales. While the largest fish is smaller than a blue whale, every size in between is also covered. The general misconception in OP is probably that there is a uniform selective pressure towards increased (physical) strength. Whereas the optimization is toward reproductive success. Essentially one can imagine a genotype moving towards local fitness maxima rather than an absolute maximum. 

[mistermack]

On the question of intelligence, one factor that seems to be operating is that warm blooded animals on average seem to go higher in the intelligence scales. Of course there are bound to be exceptions, but if you look at mammals vs lizards, or birds vs fish, the warm blooded ones seem to display a bit more. Even in fish, the great white is often referred to as one of the most intelligent fish, and it also has a degree of warm-bloodedness. A big brain is quite energy hungry, but for us humans, the energy burnt in the brain gets circulated and contributes to the maintenance of our body temperatures at 37 degrees. In hot weather, the same heat can be difficult to cope with, and it may be that we evolved the bare skin and sweating partly to compensate for some of the brain heat that we constantly produce.

[CharonY]

1 minute ago, mistermack said:

On the question of intelligence, one factor that seems to be operating is that warm blooded animals on average seem to go higher in the intelligence scales. Of course there are bound to be exceptions, but if you look at mammals vs lizards, or birds vs fish, the warm blooded ones seem to display a bit more. Even in fish, the great white is often referred to as one of the most intelligent fish, and it also has a degree of warm-bloodedness. A big brain is quite energy hungry, but for us humans, the energy burnt in the brain gets circulated and contributes to the maintenance of our body temperatures at 37 degrees. In hot weather, the same heat can be difficult to cope with, and it may be that we evolved the bare skin and sweating partly to compensate for some of the brain heat that we constantly produce.

There is something to that. The brain is energy hungry and roughly speaking, organisms with a higher metabolic rate (which is related to higher body temperature) tend to have larger brains (adjusted for body size). While insufficient to posit intelligence per se, it implies that being able to maintain a high metabolic rate increases the size potential, which in turn might enable more options to develop intelligence.