Isotope analysis
A recent development in forensic science is the isotopic analysis of hair strands. Hair has a recognisable growth rate of 9-11mm per month or 15 cm per year. Human hair growth is primarily a function of diet, especially drinking water intake. The stable isotopic ratios of drinking water are a function of location, and the geology that the water percolates through. Sr, Sr and oxygen isotope variations are different all over the world. These differences in isotopic ratio are then biologically 'set' in our hair as it grows and it has therefore become possible to identify recent geographic histories by the analysis of hair strands. For example, it could be possible to identify whether a terrorist suspect had recently been to a particular location from hair analysis. This hair analysis is a non-invasive method which is becoming very popular in cases that DNA or other traditional means are bringing no answers.
Facial hair
Great apes such as orangutan males seem to have facial hair as well. In chimpanzees and bonobos, facial and body hair become sparser in adulthood due to the aging process, which is in stark contrast to humans, whose facial and body hair become stronger. Because infant great apes have thicker "facial" (as well as body) hair than their older counterparts, it is not androgenic but part of the fur complex. The sensitivity to androgens seems to have been acquired by humans on the gene KRT37 relatively recently.