Well, how to begin. It is common belief that the first 5 books of the Old Testament (or Torah) were written by Moses. Nowadays we know that is not true. These books were written down many hundreds of years after the time of Moses. It is possible that these stories or teachings were first told by Moses and then handed down thru the generations told as various stories by the Hebrew faithful, until they were one day written down to finally be shared with common content. Who knows how the stories changed from the originals after being passed down only verbally, with each retelling containing a bit of the current author's own embellishment.
At any rate, the timeline set up in the book of Genesis regarding the creation, and Adam and Eve, just doesn't stand up to modern day anthropology, which poses a very interesting question...Did mankind start with Adam and Eve?
In my opinion, it most certainly did not, at least not as depicted in the book of Genesis. Mitochondrial Eve is now thought to have lived over 150,000 years ago, and even she was not the first female human, or even the only female of the day to have living decendants. What makes her Mitochondrial Eve is the fact that she is the most recent female to have an unbroken line of mitochondrial DNA that exists today.
By contrast, Y-chromosome Adam lived about 60,000 years ago. Please note that Mitochondrial Eve and Y-Chromosome Adam will likely not be in 1000 years, who they are today, because as male and female lines die out, chains are broken and the most recent becomes, well, more recent.
Okay, none of this procludes the possibility of a Single Adam and Eve that at some point in the history of world, started the first line of homo sapiens. But there is more than one theory on this. There is the multi-regional theory which suggests that homo sapiens arose in different regions of the world simultaneously from lower homonid forms. Then there is the out of africa theory that supposes they rose up from a single line homonid and migrated throughout Europe and Asia. Then of course there is the theory of creationism which tells the history of mankind through tales handed down from generation to generation, whose origin we really don't know for sure.
I tend to lean in the direction of the multi-regional theory.