1. If our species continues to evolve (and most geneticists believe that this is the case), what kinds of changes do you think might occur?

2. Why do you think some people are apparently more upset about using animals for research and teaching than about using them for other purposes?

3. The fact that the mitochondria in our cells were originally microorganisms that infected our very remote ancestors points out that evolution can involve interactions between two or more species. Most species have other organisms living inside them; in fact, the bacteria in our intestines are necessary for our good health. Some microorganisms can exchange genetic information, so adaptive mutations developed in one species can be adopted by another. Is it possible that some of the features of the cells of our nervous system were bequeathed to our ancestors by other species?