“Where” usually refers to a place, but can on occasion also refer to a time. As in the question: “Where did it all begin?” Each new road evolution takes has its own beginning, its own time and its own place, so where do we go to look for these beginnings?
Apes might be considered the end-point of evolution. Specifically so because humans are included in the term ape, just as gorillas, orangutans and chimpanzees (the great apes). So where do we go to find the beginnings, the time and the place? Do we go all the way back to the very beginning, the first step in the chain, or do we pick a place where evolution took a new turn? That also might be termed a beginning.
The closest beginning would be where Apes finally diverged form monkeys. This is according to the fossil record somewhere in the beginning of the Miocene era 23 million years ago. The place Africa and Asia. Shifting climate and moving tectonic plates had made the rest of world hostile to monkeys and so their development occurred in these areas.
The changes themselves were small. Fewer vertebrae, sinus cavities, changes that allowed apes to walk bipedally. In the end this is what allowed them to live successfully on the ground.
But these changes in a way were only fine-tuning. Rather a late step, but not the most important step in the ultimate success of the apes. The real key to success lay in an adaptation that apes share with monkeys and other primates. I’m talking of course of opposable thumbs.
Opposable thumbs made it possible for Apes to start using tools. Chimpanzees for example will use a stick to fish ants out of ant-hills for consumption. And it is this ability to use tools that no doubt stimulated the apes brain pushing them to ultimate success.
But how did primates develop opposable thumbs. We need to go back to another beginning. This time 65 million years back at the end of the mesozoic era. Primates were primarily arboreal and they needed to be able to climb. Predators lurked on the ground so they were limited to food found in trees. Transporting and manipulating food such as nuts and fruits required nimble hands. Eventually those more successful at doing this were most likely to pass on their genes to the next generation. Eventually this led to very agile hands and feet sometimes with both including opposable thumbs.
But primates are only a step on the way. A specific branch of mammals that finally became successful after the demise of the dinosaurs. But mammals had been in existence for a long time already. Different from dinosaurs in that they were warm blooded and sometimes gave live birth, how did they develop?
The first known mammal was Morganucodon watsoni, a small animal (2-3 cm) that looked like weasel and of which fossils have been found in all geographical areas.
The mammals were precipitated by the mammal-like reptiles. Just how much they were like mammals is not known only that they had no scales and their skin was more like that of mammals. How did these animals evolve into actual mammals? There is no clear fossil record, but it probably happened about a few million years after the mammal-like reptiles appeared 285 million years ago.
We are now nearing the very beginning and as we get further away from the apes I’m speeding things up. About 340 million years ago the early reptiles evolved into the mammal-like reptiles. 350 million years ago these early reptiles evolved from the first fish leaving the sea. Fish themselves came into being probably about 510 million years ago.
I think I have gone back far enough now. The trip all the way to the very beginning is too long. But I think it is clear by now that the evolution of apes involves many places and many times. Each place and time a new beginning that allowed the development of specific traits that eventually led to the apes success.
Maybe one day the evolution of man will only be only one of the many beginnings in the ongoing story of evolution.
Sources:
http://anthro.palomar.edu/earlyprimates/first_primates.htm
http://en.wikipedia.org/wiki/Apes
http://www.earthlife.net/mammals/evolution.html
