The Human body’s ability to adapt to different environmental stresses is remarkable, allowing Humans to acclimatize to a variety of temperatures, humidity, and altitudes. As a result, Humans are a cosmopolitan species found in almost all regions of the World, including tropical rainforests, arid desert, extremely cold arctic regions, and heavily polluted cities.
Within the Human species, the greatest degree of genetic variation exists between males and females. While the genetic variation of individuals of the same sex across global populations is no greater than 0.1%, the genetic difference between males and females is between 1% and 2%. Humans of the same sex are 99.9% genetically identical.
By present estimates, Humans have approximately 22,000 genes. The variation in Human DNA is very small compared to other species, possibly suggesting a extremely sharp reduction during the Late Pleistocene (around 100,000 years ago), in which the Human population was reduced to a small number of breeding pairs. I am (the) only Human.