If there is evolution, is there any evidence for it at the genetic level?
The answer is yes. Scientists who have been studying genetic changes occurring in the human genome over the last 15,000 to 100,000 years, have found that over this relatively short period of time the human genome has changed by as much as 10 percent.
Evidence withing the Human Genome
A scientific study identifies small, gradual changes (microevolution) that demonstrate species divergence from a common ancestor millions of years ago (macroevolution). The study makes human-to-human comparisons throughout the complete human genome instead of comparing a human to mice or chimpanzees. By this procedure humans can be seen changing over time, due to our ancestors being exposed to – among other selective pressures – different climates as they spread across the globe.
Evidence for Change
Early humans had problems digesting lactose after the age of one. Lactose is an enzyme found in milk. Befor the domestication of animals (about 20,000 years ago) humans could not digest milk after infancy. But some time after humans began migrating and domesticating animals, humans began to develop a gene that allowed us to tolerate consuming milk into adulthood. In other words as humans have populated the world, there has been strong selective pressure at the genetic level for mutations that allow digestion of a new food source or tolerate infection by a pathogen that the population may not have faced in a previous environment.