The study of our appearance and characteristics seems to be merely common sense. After all, we, as humans, have the ability to reason that we received traits from both our parents. This basic concept is known as the study of genetics. To give a brief description, genetics consists of the structure, functions, and inheritance of genes. The theory that living organisms inherit traits from their parents is not new. In fact, it has been speculated for several centuries. These early theories, however, did not have the information and technology available today. They once believed in the idea of "blending" This meant that the characteristics of both parents would be blended together in the offspring. To give more insight into this idea, say a red flower and a blue flower self pollinated. According to the blending theory, the offspring would be purple. An Austrian monk would later discover that this idea was not accurate.
Gregor Mendel was testing parental inheritance in pea plants in the mid 1800s when he noticed that the blending theory did not apply to living organisms. He used pea plants to test inheritance since they were easy to cultivate, the pollination could be controlled, and there could be a great array of varieties (seeds, for example, could either be spherical or wrinkled). He pollinated the first generation (or F1) and noticed that the offspring only sowed one of the two potential traits from the parents. Mendel determined that the trait that was apparent in the plant was dominant and the trait that did not appear was recessive. He then self pollinated to create the second generation (F2). Surprisingly, the F2 generation showed a 3:1 ratio of offspring, or one quarter if the children expressed the recessive trait. This discovery refuted the blending theory since it was thought that the blended traits could never be separated.
After sever years of research, several things were discovered by genes. New alleles can arise in genes by mutations. The products of genes interact to produce a phenotype. In fact, many environmental factors, like light, temperature, and nutrition can effect the gene's action. Sometimes, the phenotype is the result of the effect of several genes or the environment show that inheritance is quantitative. A good example of this is our mice on the Pikani lava flows (as you will read later on). Each chromosome carries many genes, and these genes are known as being linked. They are often inherited together. Linked genes can recombine by crossing over in prophase I of meiosis. Then, they become recombinant gametes and they have new combinations of linked genes. The distance between two genes on a chromosome is proportionate to the frequent of crossing over between them. This is what genetic maps are based on.
Evidence suggests that DNA may be the make up of genes. The DNA molecule is in the shape of a helix, which was first seen by x-ray crystallography. DNA is composed of nucleotides, which contain one of four bases: adenine, cytosine, thymine, and guanine. The amount of adenine equals the amount of thymine and guanine equals the amount of cytosine. Because of this, scientists Watson and Crisk proposed that DNA is a double stranded helix. The strands are anti-parallel and the bases are held together by hydrogen bonds. The bases fit together like pieces of a puzzle; adenine and thymine fit together parallel from each other. The same is true for cytosine and guanine. This double helix accounts for genetic information, mutation, and replication. To close, genetics is the back bone of our existence. The characteristics that make us human were passed down from our parents. We hope this basis overview of genetics will help you understand Dr. Nauchman's research and discoveries.