Adaptation and natural selection
Adaptation via natural selection is one of the most fundamental components of understanding evolution. It describes how species can continually evolve new, innovative traits and produce the wondrous diversity of the natural world. This process is inevitably underpinned by particular heritable traits often linked to particular genetic variants (alleles). Remember that the underlying genetic trait (the allele) is referred to as the genotype; the physical outcomes of that allele (i.e. how it changes the physiological, behaviour or ecology of the organism) is the phenotype; and the scale of the benefit of possessing that trait is referred to as its fitness. Under the normal process of natural selection, phenotypes which increase fitness are selected for, which results in a shift in genotypes underpinning it.
Continue reading →
The fundamentals of population genetics
Many times in the past, we’ve discussed the importance of genetic diversity within populations as a foundation for adaptation and evolution. It includes both adaptive variation (which encompasses genetic variation directly under natural selection), as well as neutral variation (which is predominantly generated and maintained by non-selective forces such as demographic history and genetic drift). This pool of genetic variation acts as the underlying architecture for evolution by natural selection, and is a critically important component for future and ongoing evolution.
This all sounds important from an academic perspective: that population genetics can reveal a significant amount of information about the processes and outcomes of evolution and provide novel insights into concepts that have been around for ages. But how can this information be applied to real scenarios? With the ever-growing availability of massive genetic datasets for an increasing number of species, the sheer volume of information in existence that can be used is monumental.
Continue reading →