explain ways in which genetic variation and environmental factors contribute to evolution by natural selection and diversity

natural selection is caused so that an organism can adapt and better survive in their environment.

Explanation:

Natural selection is considered as the key mechanism of the evolution process. It is defined as the differential survival as well as the reproduction of the individuals that is due to the differences in the phenotype. The genetic variations in the species and the various environment factors are generally passed on to the next generation, which is known as the natural selection if any particular trait or features of the species helped them to survive in that environment and also to reproduce. It is caused because the species can survive and adapt better in their environment.

answer; delirium is a common adverse reaction seen when elderly patients take diphenhydramine;