descent with modification; changes in the hereditary characteristics of groups of organisms over the course of generations
Unlike engineering, biological evolution can only occur through
change of what is already present
Charles Darwin
naturalist on the HMS Beagle, published "Origin of Species"
small scale evolution
changes in gene frequency in a population from one generation to the next
large scale evolution
Descent of different species from a common ancestor over many generations
natural selection
Greater reproductive success among particular members of a species arising from genetically determined characteristics that confer an advantage in a particular environment