Human Evolution Speeding Up, Study Says

Researchers can examine chromosomes and determine when genetic variations occurred. If a condition within a chromosome is both new and common throughout the population, then researchers assume that natural selection promoted the variation. “According to Charles Darwin's famous theory, evolution happens faster in big populations,” writes John Roach for National Geographic News. The world had less than 2 billion humans in 1900 and 6.6 billion today. New environments, agriculture and culture influence evolution, emphasizing differences among locales: for example, Europeans developed a tolerance for milk, Africans are developing genes that thwart malaria and Asians are developing genes that suppress body odor. More mutations and infectious diseases also emerge in large populations. – YaleGlobal