"Anyway, I'm assuming the obvious, that there were apes before there were humans. Therefore, we must have evolved from one of these ape species, correct?"
No. Apes are humans so we couldn't evolve from them. Evolution is not a straight line, it is a tree or bush. But we came from a common ancestor, all the great apes and diverged along different branches, some of them ending in extinction.
Here is a list of relatively close ancestors of apes and humans:
Starting some 80 million years ago:
Tree shrews, Lemurs Lorises Tarsiers Cebids Old World Monkeys
Gibbons Oranutan Gorilla Human Chimps
Chimps branched off after Humans started evolving from the common ancestor of humans and chimps about 7.7 million years ago. Chimps branched about 3.4 million years ago.
Anthropoids branced from ancestral primates about 70 million years ago and apes as a whole about 23 million years ago.
What you have to understand about genetics is that mutations and other content changes in genetic material build up whether expressed in the phenotype or not. Thus, there are many areas of genetic material that can be activated by various type of switch type genes. So if life has been evolving for a billion years, we have a billion years of genetic variations throught the whole system.
I assume you mean that humans are a particular species of ape, as in, a human is an ape, but not all apes are human. Otherwise, you and I have extremely different definitions of what a human is to say the least. You cannot train a gorilla to perform arthroscopic surgery, nor can a chimpanzee expound on philosophy and moral dilemmas. They're very different from us.
Evolution is not a straight line, it is a tree or bush.
True, but if you look at the tip of the highest branch of any tree, you can still trace a single line all the way down to the root.
But we came from a common ancestor, all the great apes and diverged along different branches, some of them ending in extinction.
So what was this common ancestor?
Here is a list of relatively close ancestors of apes and humans: Starting some 80 million years ago: Tree shrews, Lemurs Lorises Tarsiers Cebids Old World Monkeys Gibbons Oranutan Gorilla Human Chimps. Chimps branched off after Humans started evolving from the common ancestor of humans and chimps about 7.7 million years ago. Chimps branched about 3.4 million years ago.
Anthropoids branced from ancestral primates about 70 million years ago and apes as a whole about 23 million years ago.
Let's cut to the chase. It is the period from the point this common ancestor appeared +/-7.7 million years ago to the present that my questions are concerned with. Repeating the analogy given above, we should be able to start at the tip of the highest branch of the tree -- us -- and trace backward in a single line, if not to the root (microbes) then to a thicker main branch (this ancestor). What was this ancestor, and roughly how many basic successful mutations were there between it and us? There are only three possible answers to this question:
1) a specific number;
2) an approximate number;
3) we really don't know.
I don't know how I can make this question any clearer.
What you have to understand about genetics is that mutations and other content changes in genetic material build up whether expressed in the phenotype or not.
Fair enough, but I knew that already. This is stuff taught in basic biology in grade school and high school. Genetic traits skip generations due to various combinations of dominant and recessive genes, etc. But for the purposes of this conversation, I am only concerned with those expressed phenotypes.
Thus, there are many areas of genetic material that can be activated by various type of switch type genes. So if life has been evolving for a billion years, we have a billion years of genetic variations throught the whole system.
That would seem obvious. But I am only interested in this common ancestor of 7.7 million years ago to the present, as in, this ancestor eventually gave rise to this phenotype, which then gave rise to this one, then that one, etc.