Читать книгу The Handy Psychology Answer Book - Lisa J. Cohen - Страница 191

The modern theory of evolution goes something like this: The genetic code for all cellular organisms (organisms made up of cells) is found in each organism’s DNA. DNA gets transmitted from parent to offspring, allowing all the traits that each gene codes for to be passed along from generation to generation. Nonetheless, there is variation in DNA, which means that a variety of traits will be present in any population. Such genetic variation comes in part from the mixing and matching of each parent’s genes in sexual reproduction; each child receives a different combination of his or her parents’ genes. Random genetic mutations also contribute to variation in the gene pool. This means that some genes just change unpredictably as they are passed from generation to generation. Inevitably, some traits are better adapted to the environment than others. The traits that are best adapted to the environment increase the organism’s chances of surviving to pass on the relevant genes to the next generation. In this way nature picks winners and losers via the process of natural selection.