The Figure Below Shows the Results of a Series of Observations

question 150

Multiple Choice

The figure below shows the results of a series of observations and experiments on tail length in male African widowbirds. The black bars represent manipulated tail lengths by researchers (they actually added length to the tail feathers of the experimental birds) . From the black bars on the figure, we see clearly that the male birds that have been artificially manipulated to have super-long tails are very good at attracting mates, approximated by the number of active nests for each male. Why then are the male tails we see in nature (open bars on the figure) so much shorter?

• A)Males with really long tails in nature will eventually evolve, the researchers were simply showing the next step in the evolution of the trait.
• B)The sampling of males in nature was incomplete, they probably exist but were not found.
• C)If males in nature had the most successful tail length from the experimental study, they wouldn't be able to fly well enough to escape predation.
• D)If males in nature had really long tails, then there would be more individuals with really long tails.