Unit 9: Natural Selection, Evolution & Classification
Objective: Explain how evolution is demonstrated by evidence from the fossil record, comparative anatomy, genetics, molecular biology, and examples of natural selection. Std. 5.1
Evolution is a continuous process driven by natural selection. It is the change in a population's gene pool over generations. Allele frequencies in a population change in response to many things. For example, a mutation may occur, adding variety to the existing gene pool. Or, environmental conditions could change and the organisms with the best suited adaptations to the new conditions will better survive , reproduce and pass on their alleles. Understanding this concept can benefit us in many ways. For instance, scientists study natural selection that occurs in microogranisms which cause diseases in us and in crops. We can treat many bacterial, fungal and viral infections, but sometimes these little critters evolve mechanisms of evading our drugs. They become resistant to them leaving us with no way to fight these diseases.
Objective: Describe species as reproductively distinct groups of organisms. Recognize that species are further classified into a hierarchical taxonomic system (kingdom, phylum, class, order, family genus, species) based on morphological, behavioral, and molecular similarities. Describe the role that geographic isolation can play on a species. Std. 5.2
Objective: Explain how evolution through natural selection can result in changes in biodiversity through the increase or decrease of genetic diversity within a population. Std. 5.3