Genetics

The book I read to research this post was Genetics for Dummies by Tara Rodden Robinson which is a very good book which I bought from kindle. This book is a good introduction to this subject and while some of it was a bit beyond my grasp it was nonetheless an interesting book. DNA was only discovered in the 1950's but genetics has come a long way since then. Many of the great genetic discoveries were done with living things like fruit flies and plants. Mendel grew plants all his life and cross pollinated them and kept records. In his lifetime he had no idea how important his discoveries were. His book was published after his death. DNA is made up of recessive and dominant genes which combine in such a way that in some characterisics like a mother having twins they can even skip a generation. In the case of a genetic illness a person with a mild illness can combine their genes with someone else also with a mild form and produce a severe form of it in someone. Some animals like rats have very diverse DNA but others like cheetahs have DNA so similiar so can do a skin graft from one animal to another without any problems. If a disease of epidemic proportions wiped out one cheetah all would probably be at great risk. If human DNA was laid end to end it would be 6 feet long and contains 100 trillion cells in its length. A recent development in genetics has been its use in solving crime. Any kind of body fluid can be traced back to its owner but they need a suspect or database in order to find the culprit. Another recent development has been the discovery that certain viruses can make you much more susceptible to illnesses like breast cancer.