>>13831596I don't think this question has a good answer in principle. You could theoretically figure out all the genes that affect the face, consider all of their valid configurations, and calculate the number of possible faces from that, but this leaves at least two problems: one is that environmental factors also influence the development of facial bones (making room for an infinite number of variations), and the other is that different gene combinations can create faces that are practically indistinguishable, even if they're technically unique. A more realistic approach would be to measure the types and ranges of variation for every notable facial feature, but now the result depends on a rather arbitrary choice of the granularity of your facial parameters, and when you consider the fact that your question implies a combinatorial explosion, even small differences in opinion about the appropriate granularities will yield results that differ in many orders of magnitude.
