DNA

Rebuilding the genomic architecture of evolution

thegcatblogLeave a comment

Beyond mutations in the genome

Although genetic variation is, in itself, often considered to be one of the fundamental underpinnings of adaptation by natural selection, it can appear through a number of different forms. Typically, we think of genetic variation in terms of individual mutations at a single site (referred to as ‘single nucleotide polymorphisms’, or SNPs), which may vary in frequency across a population or species in response to selective pressures. However, we’ve also discussed some other types of genetic-related variation within The G-CAT before, such as differential gene expression or epigenetic markers.

Continue reading →

Scanning for causes: an introduction to genome-wide association studies

thegcatblogLeave a comment

Understanding genetic determinants

You’ve probably been exposed to one news headline or another in the recent past (let’s say the last 5 years) that reads something like “SCIENTISTS DISCOVER GENES THAT CAUSE (X).” X, of course, varies massively based on the study itself (and sometimes the bastardisation of said study by media): it can include describing medical conditions such as cancer, autism or congenital diseases; behavioural traits, such as sexual preferences; or broad physical traits, such as the classic problem of the inheritability of height. Unsurprisingly, you may think that trying to find the genes responsible for some traits should be either a) super easy, or b) super hard, depending on your own philosophical preference or the trait in question. So how do these studies come about, anyway?

Continue reading →

What’s yours is mine: evolution by adaptive introgression

thegcatblog4 Comments

Gene flow and introgression

Genetic variation remains a key component of not only understanding the process and history of evolution, but also for allowing evolution to continue into the future. This is the basis of the concept of ‘evolutionary potential’ – the available variation within a population or species which may enable them to adapt to new environmental stressors as they occur. With the looming threat of contemporary climate change and environmental transformations by humanity, predicting and supporting evolutionary potential across the diversity of life is critical for conserving the stability of our biosphere.

Continue reading →

Islands of speciation and speciation on islands

thegcatblogLeave a comment

The concept of a species

We’ve spent some time before discussing the nature of the term ‘species’ and what it means in reality. Of course, answers to questions in biology are always more complicated than we wish they might be, and despite the common nomenclature of the word ‘species’ the underlying definition is convoluted and variable.

Continue reading →

Evolutionary clocks out of sync

thegcatblogLeave a comment

Evolutionary time

It shouldn’t come as a surprise to anyone with a basic understanding of evolution that it is a temporal (and also spatial concept). Time is a fundamental aspect of the process of evolution by natural selection, and without it evolution wouldn’t exist. But time is also a fickle thing, and although it remains constant (let’s not delve into that issue here) not all things experience it in the same way.

Continue reading →