Expert: Dana Krempels, Ph.D. - 6/28/2007

Question
Hello,
  I am looking for a list of all of the known species that have existed(from single celled organisms to Homo sapiens) particularly the ones that led to humans.  I know that we don't know of every species that has existed nor the exact line that led to humans, but the more comprehensive the list the better.  Also, if you know of any books, websites, etc. that have good pictures of as many of these species as possible (pics of fossils as well as pictures of what we think these species may have looked like) that would be very helpful. Thanks!!!

Answer
Dear Skylar,

I do not think there is a single list of all the species that ever have existed (or at least are *known* to have existed).  One would have to scour many textbooks about all the different taxa of living things to compile such a list.  But for an overview of human evolutionary relationships and phylogeny, you could start here:

http://www.bio.miami.edu/dana/106/106F06_18.html

There is also a cladogram (a phylogenetic tree constructed using cladistic methods in biosystematics/classification) of human ancestors here:

http://www.bio.miami.edu/dana/pix/human_cladogram.gif

that you might find useful.

The book "Biodiversity" by E. O. Wilson is an excellent place to start learning about the vast biodiversity on earth, which has only about 2 million species described and named, but probably is home to more than 100 million species.

I hope this helps get you started.

Dana