Question

An enlarged right ventricle both increases oxygen intake and the risk of pulmonary hypertension. How can natural selection result in an adaptation that produces both positive and negative effects?(1 point) Responses The positive effects outweigh the negative effects in certain environments. The positive effects outweigh the negative effects in certain environments. The positive effects appear after reproductive age in certain environments. The positive effects appear after reproductive age in certain environments. The negative effects appear before reproductive age in certain environments. The negative effects appear before reproductive age in certain environments. The negative effects appear later in life in certain environments.

Answer 1

Natural selection may result in an adaptation that produces both positive and negative effects if the positive effects outweigh the negative effects in certain environments. For example, an enlarged right ventricle may increase oxygen intake and improve athletic performance in individuals living at high altitudes where oxygen levels are low. However, this adaptation may also increase the risk of pulmonary hypertension in these individuals. In this case, the positive effects of increased oxygen intake may outweigh the negative effects of pulmonary hypertension in certain high-altitude environments, leading to the maintenance of this adaptation through natural selection.