1. Evolution of a Species Changes to a gene pool can lead to the evolution of a new species Speciation = members of similar populations can no longer interbreed

2. Geological Isolation = physical barriers divide a population  Over time, the  divided populations may become two species that can no longer interbreed, even if reunited

3. Reproductive Isolation = occurs when formerly interbreeding organisms can no longer mate and produce fertile offspring; 2 types – 1. Genetic Isolation = genes of two populations are so different they cannot produce fertile offspring – 2. Behavioral isolation (ex: one population mates in the spring, another population mates in the fall)

4. Change in Chromosome Numbers = mistakes in cell division lead polyploid individuals (abnormal sets of chromosomes) Polyploids can be sterile, unable to reproduce Polyploids can also reproduce and generate a new species through interbreeding

5. Speciation Rates Gradualism = species originate through gradual change of adaptations Punctuated Equilibrium = speciation occurs in quick, rapid bursts

7. Patterns of Evolution Divergent Evolution = species that were once similar evolve to look differently – Adaptive Radiation = ancestral species evolving to fit into a lots of different habitats

8. Convergent Evolution = very distantly related organisms evolving similar traits

10. Hummingbird moths are night-flying insects whose behavior and appearance are similar to those of hummingbirds. Explain how these two organisms demonstrate convergent evolution and analogous structures. (1 paragraph, 5-8 sentences)