I have copied the following from the article on this site under the title of "Modern Synthesis of Genetics and Evolution".
>>>This description would be incomprehensible to Darwin since he was unaware of genes and genetic drift. The modern theory of the mechanism of evolution differs from Darwinism in three important respects:
It recognizes several mechanisms of evolution in addition to natural selection. One of these, random genetic drift, may be as important as natural selection.
It recognizes that characteristics are inherited as discrete entities called genes. Variation within a population is due to the presence of multiple alleles of a gene.
It postulates that speciation is (usually) due to the gradual accumulation of small genetic changes. This is equivalent to saying that macroevolution is simply a lot of microevolution.<<<
This is an outline on current thinking of HOW evolution occured. It does not address the question of WHY it occured. I suggest that it leaves open three possibilities as to why.
1. Through some random process that required no stimultion or design life has evolved to its current form. (Atheism)
2. An intelligent designer set the process in motion and then abscented him/herself from the process. (Deism)
3. There is an intelligent designer manipulting the process in order to achieve a particular outcome. This choice also raises the question of whether there is constant or occasional manipulation.(Theism)
Any of these three WHY's requires an act of faith. I can't see where science can make that choice for us. It does appear to me that when evolution is taught that option 1. is either taught or implied.
I contend that in the teaching of evolution, part of the teaching should be that this is HOW we believe that evolution happened, but that we don't know WHY evolution happened. The WHY should then be part of a class on philosophy or religion, with all points of view being discussed.