Chapter 9 - Summary

Genetics and Multicellular Evolution

Careful breeding experiments give us a feel for the ways in which the presence or absence of information in the DNA library will affect the eventual form of the organism. That, for example, if someone has a certain piece of DNA they will have blue eyes, and if they don't they won't. These are the methods of Geneticists.

The study of Genetics develops an awareness that small differences in the DNA of a complex organism can have profound consequences upon its chances in life. Evolution occurs not only in simple single-celled creatures but in multicellulars too: small changes in the DNA affecting the ability of creatures to survive and enable natural selection to operate. Complex organisms produce evidences for evolution that single-celled ones do not. We can dig up fossils showing how life has changed on Earth, we can compare the anatomy of multicellulars and we can compare their "junk DNA" which, although it does nothing in particular, shows remarkable similarities between species - suggesting that we are, in fact, related.

Chapter 10 - Summary

Contemporary Issues

Our understanding of cells allows us to develop biotechnologies that tamper with the essence of Life. These new powers bring a range of ethical concerns. Can we go too far in our desire to control the natural order of the world? Pre-existing institutions of moral guidance provide little useful advice to help us deal with situations that have never been dreamt of before. Unable to turn to the law, the various churches or even to common sense, our only option is to become informed and begin to think for ourselves. Only we can decide what we will do with the power of biological science.