In 1983 a population of dark-eyed junco birds became established on the campus of the University of California, San Diego (UCSD)
, which is located many miles from the junco's normal habitat in the mixed-coniferous temperate forests in the mountains. Juncos have white outer tail feathers that the males display during aggressive interactions and during courtship displays. Males with more white in their tail are more likely to win aggressive interactions, and females prefer to mate with males with more white in their tails. Females have less white in their tails than do males, and display it less often. Based on the information given above, which of the following types of selection was most likely initially involved in the evolution of white outer tail feathers in juncos? 1. directional selection
2. stabilizing selection
3. disruptive selection
4. sexual selection
5. None of the above
Since males use the white in their tails during courtship to attract females and females prefer males with more white in their tails, there is a clear sexual selection process in which males with more white in their tails will have a greater reproductive success and leave more offspring and this trait will be selected for and each new generation the white in the male's tails will tend to increase.
1. Photosynthesis produces two products, glucose and oxygen. 2. Respiration will take the products of photosynthesis and convert them into carbon dioxide and water.
