Is Man Still Evolving?

YES! All living things change over time in the same exact way. If not, Earth would now be populated by only one form of life—bacteria that first formed 3.5 billion years ago and all members of the strain would look and behave exactly alike.

According to an article online in the New York Times, scientists from the Beijing Genomics Institute report that Tibetans evolved a set of genes that have helped them breathe at altitudes where oxygen levels are low. They say their studies of local human genomes indicate that natural selection chose the advantageous genes as recently as 3,000 years ago.

The same article explains why many people of Asian descent get red-faced when they drink alcohol. They have inherited a variant gene that rapidly degrades alcohol to a chemical that is not intoxicating but makes people flush. Natural selection chose the gene because drunkenness posed a serious threat to the Asian group’s survival.

Everything about any living thing was determined by the genes it inherited from other living things. Sometimes when copying its genes to pass on to the next generation, mistakes occur that change these genes. If the changed (variant) genes are not too harmful to the offspring receiving them, the next generation will have individuals with different traits whose variant genes can be passed to the next generation and so on.

In time, the population will be composed of individuals having multiple variations of the same gene producing very different biological responses. Natural selection chooses the variation that favors the group’s survival.

Should you want to know more about evolution, global warming, and how scientists explain how our universe began, read my other essays and book, Settled Science.

Source

Adventures in Very Recent Evolution, by Nicholas Wade, New York Times Online, July 19, 2010