Evolution Chpt. 16-3

Modern Synthesis of Evolutionary Theory Since Darwin’s time, discoveries in genetics have been added to his theory to explain evolution Mendel’s laws of heredity opened the door to a genetic explanation of evolution

Remaining Questions about Evolution Can individuals evolve? Populations evolve when natural selection acts (indirectly) on genes Individuals do not evolve

Remaining Questions about Evolution Does evolution always produce the “fittest” form? “Fitness” is the ability of an organism to survive and reproduce Variation does not always provide the best adaptation Evolution may produce those that “fit” well enough to leave offspring

Remaining Questions about Evolution Is evolution predictable? Scientists cannot predict the exact path of evolution

Microevolution & Macroevolution A change in the genes of populations Macroevolution The appearance in new species over time

Speciation Speciation is the formation of new species. A species is a group of organism that are closely related and that can mate to produce fertile offspring.

Microevolution It is important to look at the process by which inherited traits change over time Natural selection and mutation affect the kinds of genes that will exist in a population from generation to generation

Macroevolution It is important to look at the patterns in which new species evolve Adaptive Radiation: Over time, species may split into two or more lineages (or descendants). After splitting repeats, one species can give rise to many new species.