A D MACKAY © All Rights Reserved


Lemurs, Monkeys and Apes - not  all on the same evolutionary tree


In this article I want to propose a new idea: that apes are not directly related to monkeys or prosimians, and similarities in their form are merely features of evolutionary convergence. Instead, I will describe a new pathway for rainforest ape evolution; this idea was first conceived as a result of comparing brain morphology. That research suggested a possible route of rainforest apes evolution from a predatory canid (African hunting dog). This notion may seem preposterous at first, if not insulting to the ego, but I believe this line of evolution is demonstrated by similarities in brain architecture between apes and canids.


Brain architecture follows a linear evolutionary pathway which involves incrementally added faculties. By contrast, other organs like skeletal structures and dentition can change their form profoundly over short periods of time. For this reason, much of the early classification of animals is likely to be erroneous. In the light of a new appreciation of the process of reversion, animals can switch aspects of their form quite dramatically. Consequently, I believe, no longer should animals be classified in groups by similarities as say, the number of toes, the type of dentition, or the way they move about in trees.


Predatory hunting dogs have roamed the savannahs of Africa for at least 30 million years. These animals were perhaps the forerunners of a very successful family of mammals - the Canidae which nowadays includes wolves, jackals, foxes and dingos, to mention a few.


Predatory animals, generally, are much more intelligent as individuals than their grazing or scavenging equivalents, because successful hunting demands group coordination and elaborate repertoires of hunting behaviour.


Wild hunting dogs still exist on the open savannahs of Africa - although man has reduced their populations and distribution to such a dangerously low level that they now face extinction. Aside from this, it is evident that the hunting dog way of life has been successfully sustained for many millions of years without need for change. Another example of stasis. At times, during this period however, there will have been  severe constraints  (perhaps due to overpopulation) on some groups of these animals with the result that some may have needed to change their habitat to continue to survive. Some of these dogs could have changed their hunting grounds to a nearby rainforest habitat and got themselves established there.


To successfully adapt to this new habitat, however, would mean many changes in behaviour and form.


Hunting would need to be carried out on an individual basis rather than in groups because hunting in packs can only occur successfully in a relatively open environment.


Ground-based prey would be targeted first as those living in the trees would be inaccessible.



The First Stages


So how could a group of these canids adapt to an arboreal lifestyle and begin the process of primatisation (taking on monkey-like characteristics)? It might have happened like this.


A hunting dog may have leapt up onto the branches of a tree in pursuit of its prey but could not go any further. While it was up there, another prey animal may have passed by below and the dog was able to drop down and seize hold of it.


A learned manoeuvre like this would be repeated time and time again and others would begin to copy it. The technique would be demonstrated to offspring and the strategy would be passed onto many successive generations.


So already, behaviour patterns of the hunting dog pioneering the new rainforest habitat, will have begun to change quite considerably. Now we can start to think of them as rainforest hunting dogs. They are on their way to becoming a new species because they are developing in isolation from ‘true’ hunting dogs of the savannahs.


Future generations of these animals would produce variations wherein some were able to climb further up into trees and perhaps reach alternative food resources such as snakes, chameleons and lizards. There would be natural selection for those individuals with these abilities over those which had not and, perhaps, individual animals became smaller in size, to fit the demands of the new environment.











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