Spinal tissue should be the answer.
An example of an dramatic environmental event can be deforestation, or it can be animals losing their homes.
Your respiratory system is the network of organs and tissues that help you breathe. This system helps your body absorb oxygen from the air so your organs can work. It also cleans waste gases, such as carbon dioxide, from your blood.
<span>If the evolutionary survival of homosexuality is due to antagonistic pleiotropy then there has to exist a genetic basis for homosexuality. This is because antagonistic pleiotropy refers to when one gene controls for more than one trait where at least one trait is beneficial and at least one trait is detrimental to the organisms survival. In this case, homosexuality would be the trait that is detrimental to the organisms survival and there would need to exist another beneficial trait that is controlled by the same gene.</span>
