Adaptation

Our hand in maladaptation

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Maladaptation

In the previous post on The G-CAT, we talked about the role of maladaptation in the evolution of populations and species, and how this might impact their future. To summarise, maladaptation is the process (or trait responsible for) which causes a reduction in the fitness. As we discussed, this can come about a number of ways – such as from a shift in the selective environment or from fitness trade-offs in traits over time – and predominantly impacts on species by reducing their capacity to adapt. Particularly, this is important for small populations or those lacking in genetic diversity, which are already at risk of entering an extinction vortex and lack the capability to respond well to extreme selective changes (such as contemporary climate change).

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The Bad and the Ugly of evolution: an introduction to maladaptation

Sean Buckley2 Comments

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.

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Rebuilding the genomic architecture of evolution

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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.

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What’s yours is mine: evolution by adaptive introgression

Sean Buckley4 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.

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Islands of speciation and speciation on islands

Sean BuckleyLeave 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.

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