Evolution has decreed that it is our brain that determines how we adapt to our environment. It is our strength.

The theory of evolution is based roughly on the survival of the fittest ethos. Traditionally within nature it is the individuals within a species that are able to defend and provide for itself and its' mate that is more likely to be more attractive to the opposite sex and therefore more likely to procreate.

Take a look at a predatorial animal for example. The one with the biggest claws/teeth/whatever is more likely to survive. These traits usually require a considerable degree of energy to maintain. What if that animal suddenly developed the ability to kill using a tool that made killing prey easier and more energy efficient? The bigger claws etc would no longer be such an issue for survival. Members of the species with smaller claws would be as likely to procreate and would require less energy consumption to do so. This results in diluting the gene pool and making this trait less prominent. This is what has happened to humans.

As humans have evolved we have utilised tools and our surroundings to survive to the point where we now rely on them. Physically weaker members of our species have been able to spread their genetic wings as they can provide and survive without these traits, diluting the human gene pool to the extent that our strength and instinct is virtually non existant.

I totally disagree with your assessment. Strong is often not strong. Smart often can't breed. If the whole world was as you say, we'd be nothing but smart monkeys wandering around after oxen.

Mixing it up is our advantage. It is the best way for our species to find good combinations of how to have smart and strong and BREEDABLE all in the same people. You remove one of those options, you'll not get that.

Assume that our intelligence level is sufficient only to provide us with the instinct to want to survive. Assume further that we have not learned to make tools but only to use things in rudimentary ways to aid our survival (eg. to throw a rock to knock fruit from a tree).

How well in the whole scheme of things do we measure up phsically to the majority of other creatures? Is intelligence our only redeeming feature when it comes down to survival?