Graduates in biology or genetics learn Mendel’s laws and Hardy–Weinberg equilibrium as students, and they know, use, and sometimes teach these concepts. However, it is unusual to learn about stocha...
School science descriptions about Mendel and his story are problematic because several statements that are controversial among historians of science are repeated over and over again as if they were established facts. Another problem is the neglect of other scientists working on inheritance in the second half of the nineteenth century, including Darwin, Spencer, Galton, Nageli, Brooks, Weismann and de Vries, who paved the way for the reinterpretation of Mendel’s work in 1900. These problems are o...
Chromosomal crossover is a biological mechanism to combine parental traits. It is perhaps the first mechanism ever taught in any introductory biology class. The formulation of crossover, and resulting recombination, came about 100 years after Mendel's famous experiments. To a great extent, this formulation is consistent with the basic genetic findings of Mendel. More importantly, it provides a mathematical insight for his two laws (and corrects them). From a mathematical perspective, and while i...
Deviations from Hardy-Weinberg equilibrium (HWE) can indicate inbreeding, population stratification, and even problems in genotyping. In samples of affected individuals, these deviations can also provide evidence for association. Tests of HWE are commonly performed using a simple χ2 goodness-of-fit test. We show that this χ2 test can have inflated type I error rates, even in relatively large samples (e.g., samples of 1,000 individuals that include ∼100 copies of the minor allele). On the basis o...
IN college General Biology curricula, the topic of classical genetics is typically followed by consideration of population and evolutionary genetics. After fundamental genetic principles are studied, students are introduced to the Hardy-Weinberg equilibrium as a continuum of Mendelian Genetics in a population context. Population genetics provides a logical segue to the study of evolution. Populations adhering to the Hardy-Weinberg equilibrium provide a reference for studying evolutionary changes...