I am pretty sure it is Sexual selection.
When was BSE first discovered?
BSE first appeared in British cattle in the mid-1980s. There have been numerous cases detected in other countries. A complete list of countries is available from both the U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA).
Answer:
If a whole specie of organisms has to survive, they should must possess the ability to reproduce and adopt to environmental conditions in better way.
For example: If a disaster occurs or a condition of unfavorable weather occurs, the specie will survive even if only few members remain alive. Because those members will reproduce and regrow the community.
The reason is this that reproduction is not important for the survival of one organism, like organism will still survive even if he do not reproduce, but if a whole specie has to survive and continue, reproduction is most important trait.
Hope it help!
its a theory because its not a fact, its one idea along with other ideas.
