Evolution of a Species Changes to a gene pool can lead to the evolution of a new species Speciation...
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Transcript of Evolution of a Species Changes to a gene pool can lead to the evolution of a new species Speciation...
![Page 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.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e495503460f94b3c195/html5/thumbnails/1.jpg)
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
![Page 2: 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.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e495503460f94b3c195/html5/thumbnails/2.jpg)
• Geological Isolation = physical barriers divide a population
• Over time, the
divided populations may become two species that can no longer interbreed, even if reunited
![Page 3: 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.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e495503460f94b3c195/html5/thumbnails/3.jpg)
• 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)
![Page 4: 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.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e495503460f94b3c195/html5/thumbnails/4.jpg)
• 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
![Page 5: 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.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e495503460f94b3c195/html5/thumbnails/5.jpg)
Speciation Rates
• Gradualism = species originate through gradual change of adaptations
• Punctuated Equilibrium = speciation occurs in quick, rapid bursts
![Page 6: 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.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e495503460f94b3c195/html5/thumbnails/6.jpg)
![Page 7: 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.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e495503460f94b3c195/html5/thumbnails/7.jpg)
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
![Page 8: 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.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e495503460f94b3c195/html5/thumbnails/8.jpg)
Convergent Evolution = very distantly related organisms evolving similar traits
![Page 9: 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.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e495503460f94b3c195/html5/thumbnails/9.jpg)
![Page 10: 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.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e495503460f94b3c195/html5/thumbnails/10.jpg)
• 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)