The evolution of the species only appears to be overwhelmingly cultural as cultural time is something we can all understand intuitively. That the human body is still evolving is a necessity of the way genetics and random mutation in genetic self-replication works. What I find interesting is the ways that human cultural evolution will be selecting for reproductive success based upon the largely symbolic cultural and social human world... that although cultural evolution is, ultimately, such a relatively rapid process - that it is playing back into the longitudinal processes of biological/genetic evolution through influencing human behaviour, survival, mating habits, etc...