As the third quarter of the school year began the seventh graders learned that many traits are not inherited through simple Mendelian rules. For example, even though dominant traits hide recessive traits, for a variety of reasons, they do not necessarily take over a population and eliminate recessive traits.
The children observed their own fingerprints to learn about polygenic inheritance. They studied blood types to understand multiple alleles. To understand how traits such as color blindness can be traced in a family, they interpreted pedigrees.
During the month of March the kids began a study of evolution. They learned of Darwin’s role in the development of this important theory and the often overlooked contributions of Wallace.
To understand direct evidence for evolution, the kids studied the many fossils in Mr. Pendleton’s collection. The children modeled radiometric dating by shaking up a box of one hundred pennies. They used adding machine tape to make time lines of Earth’s history. Following this, they used their math skills to determine the percent of Earth’s history during which significant organisms had evolved. The story of evolution is a long and interesting history.