The close DNA sequence similarity between men and apes has led some to suppose that a man is no more than a wimpy chimp with a slightly swollen head. Further, it has been suggested, since the difference between men and apes is so trivial, there must be creatures somewhere in the limitless expanse of the universe at least as superior in intellect to us as were are to chimps. So, according to this line of thinking, despite the modest enlargement of the human fore-brain, we have little to be swelled-headed about.
But this reflects a misunderstanding of the difference between men and apes and the significance of that difference.
Both men and apes are mammals, which means that they are built to the same plan. They have liver and lights, stomach and spleen, four limbs, a head and a tail. At the cellular level the similarity of design is even closer: the same membranes, organelles, nucleic acids and enzymes. So inevitably men and apes share much the same DNA sequence, as they do with horses and hamsters, and even with reptiles and fishes, fungi and forest trees.
There is an underlying biochemical unity to the life of this Earth. But that does not make the fangs of a tiger and the molars of a camel functionally equivalent. Small changes in the proportions and slight differences in the elaboration of a basic design can result in fundamental differences in function.
Thus with the brains of man and chimp. In the lobes and their connections the two are largely similar. But the human brain has approximately twice the mass of the brain of a chimp, and there is a many-fold difference between the two in the size of certain lobes. The human brain is thus adapted to functions unknown to the mind of a chimp.
And it is possible for very slight genetic changes to result in qualitatively transformational changes in function. For example, a single-gene mutation that results in one additional rounds of cell division in some portion of the embryonic brain would double the final volume of that part of the brain.
Why, then, it might be said, if the only thing distinguishing a man from an ape is a small collection of single gene mutations, the difference between us is indeed trivial. But that is to misunderstand the evolutionary step that man has made and which no other ape has, or could ever make, so long as mankind exists.
To evolve a larger brain, an organism must have use for a larger brain. The brain is an energy intensive organ, requiring a continuous infusion of glucose and oxygen. A chimp with a brain like that of a human would be at a severe disadvantage. It would want to sit around and think but it would need to work harder than every other chimp to obtain the food necessary to keep its costly brain alive.
The only way such a chimp could survive would be to invent language, create a civilization and its associated technologies thereby raising the chimp living standard while lowering the hours of work.
That is what mankind achieved. And that is what no other species on Earth can achieve while mankind exists because mankind has preempted the resources of the entire planet.
As to the claim that an extraterrestrial intelligence would likely consider the mind of man as feeble a thing as we humans are inclined to consider the mind of a chimp, the answer should be, "give us time."
It took humans about one hundred thousand years to exchange the lifestyle of an ape for that of a yuppie. But most of that transformation occurred, with exponential acceleration, in the last ten thousand years.
Humanity is now at a critical point in its existence. We have technology that can put the entire accumulated knowledge of the species at the fingertips of every one of the seven billion membners of the species. And electronic media allow us to do that at trivial cost. The result could be an explosion in technological innovation the like of which we can hardly imagine and which will either lead us very quickly to self-destruction or grant us the power of gods.
Not only do we have the ability to educate every receptive mind to a point far beyond that reached by Aristotle or Newton, but to build intelligent machines that can outperform the human intellect by orders of magnitude.
This is precisely the transformation that any intelligent civilization created by organically evolved creatures anywhere in the universe must have undergone. It is the transformation from advancement through haphazard accumulation of mutations and genetic rearrangements that yield short-term survival advantage, to the engineered improvement of the organism and its enveloping civilization.
And once evolution is intelligently planned, it likely follows the same course anywhere in the universe. There is now no apparent limit to the advancement of human knowledge and dominion over the planet and beyond—unless we are destroyed by our own technology. But in that case, intelligent life may be a self-limiting phenomenon wherever it arises in the universe, in which case the civilization of humanity is approaching a climax of complexity that will never be exceeded anywhere in the universe.