Intelligence and evolution

Quick jump to: Human evolution
Quick jump to comments

Intelligence is not a supernatural gift coming from somewhere, and is not a kind of ‘special feature’ in biology. As mentioned before, for the most of the species, the increasing of intelligence is not the most direct and effective way to improve their ability to survive. But, it is not the case of the Primates. We will examine why, in the next paragraph.

The fact is that we perceive ‘intelligence’ as a special ‘gift’ in nature, just because it plays a central role for our specie.
As well, elephants might think that their long trunk is a special gift, and giraffes about their long neck. And they could perceive themselves as the most advanced specie on the Earth, because of their uniquely hugely developed part of their body.
Since today there is only one specie on the Earth which can be defined of ‘human-grade’ intelligence, this fact should suggest us, that in the most of cases, the development of a high grade of intelligence is not necessary to improve the survival chances of a specie. Otherwise all other millions of ‘non intelligent’ species would be already extinct.

In biology, to increase the size of the brain is not a more hard job than to increase the size of any other organ, or part of the body. For the biology, to produce more neuron cells, is not more hard or expensive than to produce more muscle cells for a bigger muscle in the legs, or a bigger heart, or more cellules for a bigger kidney.
Like every organ type, the brain doesn’t get bigger if it is not necessary to the survival of the specie.

The laws of nature prefer always to undertake the easiest and less expensive solution. The way with lower consumption of energy.
Differently than the Primates (which we are), all other species have a much more specialized morphology. They have much more specialized limbs. Limbs are their first and main interface to the environment. Their limbs are their specialized tool to catch food or to escape from predators. Take a look to the limbs of insects, herbivores, carnivores, quadrupeds and birds.
Therefore, the mutations which affect more directly their ability to survive, are the mutations which improve their specialized limbs, and the general morphology of the body.
For this reason in nature there is a so huge variety of type of limbs and body morphology, meanwhile there is only one ‘intelligent’ specie.
Of course, not all mutations needs to be selected. Many are given to the offspring anyway and they contributes to increase the variety of differences among the species.


A brief overview about how the human evolution worked

Now it is clear why it is not a random chance, that the specie which increased more its intelligence is a member of the order of Primates.
The hands of our ancestors (as well those of the modern primates) were not super-specialized to do a single specific task, like the paws of felids and the other quadrupeds. Their fingers could be more easily employed to perform different tasks.

The climate change which gradually turned the African forest into a savanna, selected those mutations which made our ancestors more smart in the ability to use their versatile upper limbs and to stay longer in the straight position.
So, it is how our thumb finger became opposable. The versatility of our hands got improved, but our hands loosed their moderate specialization for climbing on threes and branches.
Our fingers are able to perform a wide range of tasks, but they are not good to do something particular. Our hands can’t swim good, can’t climb good, dig good, etc.
The result of this selection is what we are today, the most ‘intelligent’ but less specialized Primate.

Technically, there is nothing wondering in this process. It was just good luck for us that this climate change happened in Africa, in the right way. If it didn’t happen, we would be still monkeys on threes, and the whole Earth would be much more fine. The same, if the climate change would have been too fast and the selection process had not enough time to reach the present result.
Intelligence is the consequence when the environmental factors exert the proper pressure on a suitable specie. A specie, preferably with a low grade of morphology specialization. It is an ‘evolution’ which may occur, as well not.

The proud biped Homo Sapiens is far from to be a perfect specie even anatomically. Our backbone is even not yet well adjusted to stay permanently in the straight position. This is why pains and problems to backbone are so common to people after the age of 30-35 years, less than the half of the average lifetime. No other animal has such problem. And our backbone will not ‘evolve’ by itself, since no selection is acting on us. Humans today can mate independently by their backbone’s issues along their life. As well our intelligence will not increase more, without a kind of selection process.

As general rule, more specialized is a specie, less intelligence it needs to survive.
None specie develops more intelligence than what it needs to survive in its environment.

For example the eternal dispute between felids and canids (cats and dogs). Both are land quadrupeds, but canids have a less specialized body than felids. Canids have not so effective weapons and agility as the felids, thus they need something more cognitive intelligence to catch food and survive.
Cats have a little less cognitive intelligence than dogs, because cats need some less intelligence than dogs to be effective hunters. But in the other hand, cats use their intelligence in more refined ways. They show more complex behaviors, languages, and they build complex relations with other species and with objects around them. So, the cognitive intelligence is only one aspect of the intelligence.


Notify of
Inline Feedbacks
View all comments