Some 40 million years ago there was a primate which was the common ancestor of all the current great apes. The primates were established first in Africa and Asia and then some found their way, somehow, across the ocean to South and Central America. They were restricted to forest areas and were not to be found in northern climes (Europe, N America, Asia). Great deserts and mountain ranges were a major barrier to their spread. They did not reach Australia even though the body of water to be traversed was shorter than that to S America.
Non-human primate range
The appearance of new species of apes was not something that happened across the entire range of the primates. In South and Central America, apes did not evolve. Gibbons and orangutans only appeared in South-East Asia. Gorillas, chimpanzees and the precursors of humans appeared only in Africa.
Knowledge about evolution has exploded in the last century especially now as genetic analysis is getting into its stride. But the common feature with the growth of knowledge is that the questions, too, grow. Why did the ancestors of all apes break away from the parent primate line? What survival advantage led to the gibbons separating from the ancestral ape line to become a separate species? The survival advantages then that caused the speciation of the gorilla ancestors are probably no longer valid now. When a species evolves and a new species appears, the parent species may become extinct, or may well continue down other, separate evolutionary paths. But not all these many paths can be successful. At any given time many of the ongoing evolutionary paths being followed will – and must – be dead-ends leading eventually to the extinction of the dead-end branches. The appearance of every new species must have been because some non-standard individuals, in that place, at that time, exhibited some survival or reproductive advantage over their more “standard” relatives. Clearly the pressures and conditions that caused orangutans and gibbons to appear in SE Asia were not of significance in South and Central America. Neither were the conditions and pressures which caused gorillas and chimpanzees and the species homo to appear in Africa of significance in other parts of the world. Equally the conditions in Africa did not give rise to gibbons or orangutans.
What then were the advantages of being a gorilla – when gorillas evolved – that are now of very little benefit?
The reasons for the splits at A, B, C, D and E are still more a matter of speculation rather than of knowledge.
The current status of a species can only be measured by its numbers. Dinosaurs may once have been of high status and were clearly successful for a long time but – as with every other extinct species – they are all, now, failed species. (Since birds do originate from the dinosaurs then they, at least, represent some very successful current species). If we consider just the surviving ape species (gibbons, orangutans, gorillas, chimpanzees and humans), there is a striking difference in their current status as species.
We have to go back about 40 million years to find a common ancestor. The most striking difference is that which separates humans from all other species – the control of fire. It makes the “fire and cooked meat” theory of human brain development seem very plausible.
Thus, the unprecedented increase in brain size that hominids embarked on around 1.8 million years ago had to be paid for with added calories either taken in or diverted from some other function in the body. Many anthropologists think the key breakthrough was adding meat to the diet. But Wrangham and his Harvard colleague Rachel Carmody think that’s only a part of what was going on in evolution at the time. What matters, they say, is not just how many calories you can put into your mouth, but what happens to the food once it gets there. How much useful energy does it provide, after subtracting the calories spent in chewing, swallowing and digesting? The real breakthrough, they argue, was cooking.
I find watching gorillas (on film) compulsive. When I have seen them in zoos, they are magnificent but deeply tragic figures. They radiate a benign strength which is more than impressive. They are quite intelligent. It is claimed they have an IQ around 40 -50, though applying human IQ tests on them is largely meaningless. Their motor skills develop faster than with human infants and even if some have learned the meaning of some human words, gorillas do not have language. Gorillas are a dying species and, as such, are a failing species. “Conservation” is concerned with the survival and protection of individuals and groups. Though laudable, these efforts only freeze the species within the shrinking habitat they are comfortable with and in the unsuccessful form they have reached.
The gorilla as a species has reached an evolutionary dead-end. I don’t want gorillas to disappear, but to keep them in their frozen, unsuccessful, evolutionary state in zoos or reserves or protected habitats does not seem right either. The conservation practiced today, which makes no provision for the further development of a species, is both unethical and immoral. Other species which adapt and find a role to play in the world of today are not threatened. It is not necessary for a species to find that role within human society as livestock and household pets do. But the survival of livestock and pets is as slaves to humans. Birds and insects remain free of human control but have adapted to varying degrees and continue together with humans. Fish and sea-creatures don’t compete for habitat with humans but do constitute prey. Foxes and rodents and even urban leopards are adapting to continue in freedom and in parallel with humans. It is more difficult for primates. The challenge is to find a way for a species to develop and move forward in the reality of a world dominated by humans. When conservation denies reality and merely tries to go back to some scenario from the past it does no service to any species.
How then can we find a free and meaningful, role for gorillas (or tigers) in a world dominated by humans but which is not an evolutionary cul-de-sac?
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