Week 3 Post 2

Evolution and Natural Selection

There are over 67,000 vertebrate species and 1.3 million invertebrate species.

Evolution is the central concept that unifies all of biology.  It is crucial to understanding animal behavior. Biological Evolution is the idea that all life on Earth shares one common ancestor. Descent with modification is the way individuals pass on their traits to their offspring and those traits change over time. It can be monitored from generation to generation by changes in gene frequency (Genes are the main way traits are passed along) to help us better understand the evolutions. Phylogeny is the evolutionary relationships across species, for example, how dogs and cats are evolutionarily related.

Three main processes by which descent with modification occurs are a mutation, genetic drift, and natural selection. Mutation is random and occurs when genetic material is improperly copied or damaged. Some mutations are beneficial (creates new traits or modifies them). Genetic drift is also random. Populations get unlucky or lucky with the traits a specific individual's traits, especially in smaller populations. The individual is usually the most active male or female. Lastly, Natural Selection is one process by which evolution occurs, and is not random. It is basically adaptation. Populations slowly change to better suit their environment through the less effective traits dying off.

Understanding the behavior of animals requires an understanding of how they interact with their animals. And the way they interact with their environment is dependent on their traits and evolution as a species.