The Genetic Revolution

 from the 1960s, the field of evolutionary genetics has had the greatest influence on human evolutionary studies. Technological developments like the evolution of the polymerase chain reaction (PCR) itself have proven and helped in, for example, in the analysis of ancient DNA from Neanderthal fossils.

Allen Wilson, Emile Zuckercandel and Linus Pauling were the initiators of the use of molecular methods, which examined evolution at the level of DNA and proteins and showed that the relationships between living and extinct primates are both genetic and fossil. Genetics can also be used as a “clock” that compares the extent of genetic differences (mutations) of existing organisms. Since the mutations have an expected rate of change over time, it can be used to evaluate how long species can share a common ancestor.

The molecular clock cannot determine particular dates and should be tested against independent evidence, like the fossil record. However, by collecting interdisciplinary evidence, we now have a strong knowledge of the relationships between humans and apes.

For instance, we already know that humans and chimpanzees are separated from their common ancestors by approximately 4 to 8 AD and that the genetic difference between humans and chimpanzees is minimal to approximately 1.2%.

Genetics also has proven that humans present at this time have finite genetic diversity suggesting a series of population dilemma for example(temporary and severe population reductions and thus genetic variation caused by earthquakes or disease) and a limited set of ancestral genes

 Genetic variation studies show that the greatest diversity is localized in the African population.

This along with evidence from females (mitochondrial DNA) and male (Y chromosome) determine the dates of African origin for our species and our ancestors suggest migrating from Africa around 70-40 ka

besides helping researchers determine evolution, demographic history, and patterns of dispersal, we can also determine areas of the human genome affected by natural selection.

Functional genes, such as those involved in fighting infectious diseases; life story models. Diet. Skin, hair, and eye coloring; human perception; and even language, the genome fields affected by natural selection in humans have been revealed.