MELC 17 EVOLUTION

• evolution - change of characteristics of a species over several generations and relies on the process of natural selection
• charles darwin's theory of evolution states that evolution happens by natural selection
• the theory of evolution by natural selection first formulated in Darwin's book "On the Origin of Species" in 1859
• natural selection - individiuals in a species show variation in physical characteristics. this variation is because of differences in their genes
• macroevolution - refers to large-scale changes that occur over extended time period, such as formation of new species and groups
• microevolution - refers to small-scale changes that affect just one or a few genes in populations over shorter timescales 
• the ast shore-dwelling ancestor of modern whales was Sinonyx, a hyena like animal