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# Bio 1M: Evolution by natural selection ## 1 Evolution - The theory of evolution has replaced the theory of special creation in science. - The theory of special creation asserts that each species is a unique “type”, created by God. - The theory of evolution asserts that species have changed throu...

# Bio 1M: Evolution by natural selection ## 1 Evolution - The theory of evolution has replaced the theory of special creation in science. - The theory of special creation asserts that each species is a unique “type”, created by God. - The theory of evolution asserts that species have changed through time (evolved). - Does this mean that scientists don’t believe in God? — Can scientists believe in God? -... -... -... -... ## 1.1 Change through time ### Fossils - A fossil is a physical trace of an organism that lived in the past. - Fossils can be dated using (complicated) radiometric and geological techniques. - Fossils provide information about the history of life. - The fossil record refers to the collection of all known fossils. ### Extinction - Many fossils have been left by organisms that are no longer around. - We say such organisms are extinct. - Extinction is one piece of evidence that species are changing. - In a very limited way. - How convincing is it as support for the theory that species got here by gradual evolution? ### Transitional forms — Fig 22.22 - When a species disappears from the fossil record, a similar species often appears. - This often happens in the same geographic area — Fig 22.22. - Consistent with species evolving: changing through time. ### Vestigial traits - A vestigial trait is a structure that has no function, but is similar to functioning structures in related species. - Examples? ### Directly observed evolution - Although much evolution occurs very slowly, some kinds of evolution can be, and have been, observed on faster time scales. - Ground finches — Fig 20.8 - Tuberculosis - E. Coli — Fig 1.17 (Note: The list of examples under "Vestigial traits" and some discussions under "Does this mean that scientists don’t believe in God?" are incomplete as indicated by the dashes. The references to figures suggest that there are accompanying images or figures that are not included in this text).