How organisms adapt to the environment they live in is a key question in evolutionary biology. Genetic variation, i.e. how individuals within populations differ from each other in terms of their DNA, is an essential element in the process of adaptation. It can arise through different mechanisms, including DNA mutations, genetic drift, and recombination.
Differences in DNA sequences between individuals can results in differences in the expression of genes. This can therefore determine the organism’s capacity to grow, develop, and react to environmental stimuli. However, a growing body of literature reveals that there are other ways organisms can change the way they interact with the world without mutations in the DNA sequence.
The standard approach to quantifying natural selection, developed by Lande and Arnold, does not allow for comparable metrics between linear (i.e. selection on the mean phenotype) and nonlinear (i.e. selection on all other aspects of the phenotypic distribution, including variance and the number of modes) selection gradients. Jonathan Henshaw’s winning submission provides the first integrated measure of the strength of selection that applies across qualitatively different selection regimes (e.g. directional, stabilizing or disruptive selection). Continue reading →
Evolutionary quantitative genetics provides formal theoretical frameworks for quantitatively linking natural selection, genetic variation, and the rate and direction of adaptive evolution. This strong theoretical foundation has been key to guiding empirical work for a long time. For example, rather than generally understanding selection to be merely an association of traits and fitness in some general way, theory tells us that specific quantities, such as the change in mean phenotype within generations (the selection differential; Lush 1937), or the partial regressions of relative fitness on traits (direct selection gradients; Lande 1979, Lande and Arnold 1983) will relate to genetic variation and evolution in specific, informative ways.
These specific examples highlight the importance of the theoretical foundation of evolutionary quantitative genetics for informing the study of natural selection. However, this foundation also supports the study other critical (quantification of genetic variation and evolution) and complimentary (e.g., interpretation when environments, change, the role of plasticity and genetic variation in plasticity) aspectsof understanding the nuts and bolts of evolutionary change.Continue reading →
Online Images: A Treasure Trove of Ecological Data
In the proclaimed ‘information age’, where answers are available at the click of a button or a swipe of a finger, we have become accustomed to the ability to get an almost instant grasp of any topic. Other fields are already making use of this wealth of easily accessible online data, but biologists and ecologists tend to let it slip by. However, this attitude is slowly beginning to change. Some ecological and evolutionary studies are emerging that have used the internet to gather data – through online citizen science projects (e.g. Evolution MegaLab) or databases (e.g. using Google Trends) – but few have used existing data, particularly publicly available data from image repositories.
We were curious to apply the concept of using existing images on the internet to a fascinating visual biological phenomenon: colour polymorphism (or the occurrence of multiple discrete colour phenotypes). To do this, we planned to exploit an existing penchant people have for uploading photographs of animals to the Internet.
Our search phrases included the common and scientific name of the species, as well as a location-specific term
‘Just Google it’ marks an important step in converting ecology to an armchair science. Many species (e.g. owls, hawks, bears) are difficult, time-consuming, expensive and even dangerous to observe. It would be a lot easier if we didn’t have to spend time, energy and risk lives having to observe organisms in the field! Continue reading →
Today, we are pleased to be welcoming a new member of the Methods in Ecology and Evolution Associate Editor Board. Michael Morrissey joins us from the University of St Andrews in Scotland and you can find out a little more about him below.
“I am an evolutionary quantitative geneticist. I am interested in the selection, genetics, and evolutionary trajectories of traits in natural populations. I typically work at the interface of statistics, evolutionary theory, and empirical problems.”
Animals caught on camera by amateur photographers and posted on the web could become an important new tool for studying evolution and other ecological questions, researchers from South Africa have found. Their study – the first of its kind – is published today in Methods in Ecology and Evolution.
Colour polymorphism – when a species has two or more colour types – has fascinated biologists since Darwin. The occurrence of these different colour types often varies geographically, providing a useful way of studying how different colour morphs – or phenotypes – evolve.