## Recent human evolution

In the year 2000, the well-known palaeontologist Stephen J. Gould declared that no change has taken place in humans for 40,000-50,000 years, and the evolution of humans is only slight or has already ended. On the other hand, it is obvious that variability still exists at the biological level and the environmental conditions in which people live are different, so selection can still affect us. An example of recent human evolution is a mutation in the LCT1 gene, which ensures the activity of the lactase enzyme until adulthood. People without this mutation often suffer from lactose intolerance. The mutation spread sometime between 4,500 and 7,500 years ago, around the time when farming probably appeared in the northern Balkans as a means of subsistence. Carriers of the mutated LCT1 allele were favoured because they could consume more dairy products. However, some recent studies indicate that this positive selection may have occurred later and originally spread from Russian shepherds. There are many places in human DNA where similar changes can be observed by bioinformatic analyses, for example, the EPAS1 and EGLN1 genes, which are related to the adaptation to high altitudes of Tibetans, or mutations in genes related to pigmentation and reactions of the immune system.