Selina Karim last lab popbio PDF

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Selina Karim 2694784 A Step in Speciation Definitions: Allopatric speciation – results from geographic separation Gene Flow – happens on population level Cladogenesis – species branches off, but original species still exists Anagenesis – same thing, but original does not exist Geographic isolation – populations physically separated by physical barriers Reproductive isolation – behaviors and physiological processes critical for speciation, to ensure species does not mix with another species. (behavioral isolation – 2 members of a species not separated, mating behaviors are too different to mate with one another Sympatric speciation – new species evolve from a single ancestral species while inhabiting the same geographic region. Discussion Questions Part A: 1. It is not uniformly distributed. There is evidence of specific limiting factors where salamanders are not present. There are also arid and semi-arid conditions. Other factors such as human habitation and weather conditions can also contribute to the distribution. 2. Salamanders are present in mountain areas and not valley areas, except in mountainous desert ranges. 3. Due to ancestral relationships, there are subspecies distributed in patterns. The species that are next to each other on the map are more closely similar to each other than those are that more spread apart. 4. The unspotted forms along the coast of California are present except in the southern area. 5. The subspecies E.e. eschscholtzii and E.e. klauberi are similar in their populations, which occur in the same area in southwestern California. Discussion Questions Part B: 1. These populations represent genetic intergrades between subspecies. 2. The eyelids become lighter between the north and south species. The dark pigmentation of the body disappear and some turn into dots. The south has yellow dots on the back, and the tip of the tail becomes lighter. 3. It would be unlikely because they are separated by many miles and geographical barriers. 4. The reason for trying to collect additional specimens from the extreme southwestern California is to see if there were any intergrade specimens or if the two subspecies occupied the same region.

5. The two subspecies are intermixed and have no intergrades. 6. The E. e. klauberi population can be considered a species separate from E.e. eschscholtzii. 7. This specimen is most likely a hybrid between klauberi and croceator. 8. There is a common ancestor which could explain the subspeciation. Even though some of these species are reproductively isolated, they have similarities. The map also shows intergrades between all of the subspecies except two that exist in southern California together. 9. If there was volcanic activity in northern California, it wipe out some of the population and would break the interbreeding between the subspecies. E.e. eschscholtzii and E.e. klauberi do not interbreed. Consequently, these would be isolated populations....