Question

In 1983 a population of dark-eyed junco birds became established on the campus of the University of California, San Diego. The individual juncos that established the population on the campus came from a much larger population found in the pine forest of the nearby mountains. Juncos have white outer tail feathers but the percent of the tail that consists of these white feathers can vary among individuals and it is highly heritable. Among the campus population, male junco tails were, on average, 25% white, whereas the tails of males from nearby mountain populations averaged 50% white. Biologists have debated about whether the change in the “whiteness” of the male juncos’ tails on the campus was due to natural selection or genetic drift.What data or information would you need to be able to conclude that natural selection was the mechanism that was causing the campus juncos tails to become less white?

Answer 1

To conclude that this variation is due to the natural selection or not we have to confirm the following :
?1. first we have to check and rule out whether this change is due to expression of reccesive trait ( if it is) which appears due to continous inbreeding in either of the population.
?2.if above ruled out we have to check the environmental factors triggring these changes.
?3. we also have to check whether there are further new changes when these organisms are kept in another environmental conditions.
?4. check for penetrance and expressivity of the gene responsible for this change.
?5. finally to find the gene /allele which is mutated and inherting the nxt generation