Answer:
Mutation
Explanation:
A mutation can be described as any change which occurs in the DNA of an organism. These mutations can be beneficial or harmful for a species of organisms. Mutations are one of the reasons that variations arise among the organisms of a species. If a certain kind of mutation is favored by natural selection, then it can increase in the allele frequency and might completely eradicate the previous wildlife characteristics of a species.
Answer:
<h3>The genes that caused scales to become feathers in the early ancestors of birds </h3>
The first living things on Earth, single-celled micro-organisms<span> or microbes lacking a cell nucleus or cell membrane known as prokaryotes, seem to have </span>first<span> appeared on </span>Earth<span> almost four billion years ago, just a few hundred million years after the formation of the </span>Earth<span> itself.</span>
Methamphetamine is neurotoxic to dopaminergic neurons in the human’s midbrain. It increases the amount of the dopamine in the brain and as a result, produces the euphoria feeling that many people experience. It is also indicated that high-dose methamphetamine use can be neurotoxic to serotonin neurons (with the potential of damaging neurons)<span>.</span>
