Natural selection is one way that evolution occurs. Evolution is the change in allele frequency over time. In this article we will look at the process of natural selection, and a few different types of selection. Note that there can be other mechanisms behind evolution as well, such as the genetic bottleneck effect described here. … Read more
Genetic Diversity – Variation and Biodiversity Ep 2
Genetic diversity is defined as the number of different alleles of genes in a population. Last week we looked at one method of introducing new alleles into a population - by genetic mutation. Today we will look at other ways that genetic diversity can be increased or decreased, and how it can be measured. Increasing … Read more
Mutations – Variation and Biodiversity Ep 1
There is a huge variety of life on this planet. In this series we will look at how all that variation exists, from the DNA level to the population level. Today we are starting off with a source of variation at the DNA level. What are mutations? A genetic mutation occurs when the DNA base … Read more
Crossing Over and Independent Assortment – Cell Division Ep 5
In the last article we looked at meiosis - the type of cell division that produces haploid gametes in the reproductive organs. Today we're going to look at how meiosis can produce genetic variation in the gametes, and therefore genetic variation in offspring after the gametes fuse at fertilisation. We will also finish off by … Read more