Evolutionary Genetics Topic Room

 

Evolutionary genetics examines the relationships between organisms.  These relationships are often described visually using phylogenies.
Evolutionary genetics examines the relationships between organisms. These relationships are often described visually using phylogenies.

"Evolutionary genetics" is a somewhat redundant expression. After all, Charles Darwin understood that natural selection required an inheritance mechanism, although it took nearly a century to reconcile his ideas with those of classical genetics. Moreover, much of the reconciliation between Mendelian genetics and Darwinian evolution involved advances in population and quantitative genetics.

Those articles that are part of the evolutionary genetics topic room can be arbitrarily divided into five main categories: phylogenetics; mutation and molecular population genetics; the genetics of speciation; genome evolution; and evolution and development (also known as evo-devo).

In the area of phylogenetics, David Baum has contributed a pair of articles on "tree-thinking"; the first describes how to read a phylogenetic tree, while the second discusses the implications of such trees with regard to relatedness and the myth of evolutionary advancement.

Next, to introduce molecular population genetics, Laurence Loewe discusses mutation in the context of molecular evolution, and Laurent Duret elaborates on that topic in his article on neutral mutations. Natural selection is then introduced in a pair of articles. Here, Laurence Loewe explains negative selection (i.e., selection against harmful mutations), while Stephen Schaffner and Pardis Sabeti explain positive selection (i.e., selection for beneficial mutations). Sabeti also contributes an article on the impact of positive selection in humans. To round out this portion of the room, Sally Otto discusses the evolutionary advantage of sex, while Simon Ho explores the concept of the molecular clock.

The room then turns toward the subject of speciation. Norman Johnson begins by discussing genic models of speciation, specifically the role of epistasis in the Dobzhansky-Muller model. Johnson also describes researchers' current understanding of Haldane's rule, which states that sterility and inviability tend to be associated with the heterogametic sex in species hybrids. Laurie Stevison next examines the relevance of gene flow between incipient or recently diverged species.

Finally, with respect to genome evolution, Chitra Chandrasekaran and Esther Betrán close out the topic room with their discussion of the possible fates of duplicated genes, including the formation of pseudogenes.


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All Articles Within Evolutionary Genetics (19)

Genome Evolution (1)

  • Origins of New Genes and Pseudogenes
    The formation of new genes is a primary driving force of evolution in all organisms. How exactly do these new genes crop up in an organism’s genome and what must occur in order for them to be passed on?

Macroevolution (1)

Microevolution (7)

  • Sexual Reproduction and the Evolution of Sex
    Birds do it, and bees do it. Indeed, researchers estimate that over 99.9% of eukaryotes reproduce sexually. What, then, are the true costs and benefits of sex?
  • Neutral Theory: The Null Hypothesis of Molecular Evolution
    In the decades since its introduction, the neutral theory of evolution has become central to the study of evolution at the molecular level, in part because it provides a way to make strong predictions that can be tested against actual data. The neutral theory holds that most variation at the molecular level does not affect fitness and, therefore, the evolutionary fate of genetic variation is best explained by stochastic processes. This theory also presents a framework for ongoing exploration of two areas of research: biased gene conversion, and the impact of effective population size on the effective neutrality of genetic variants.
  • Negative Selection
    How are humans contributing to negative selection? It’s a part of evolution that can also drive some species to extinction; models of negative selection help us understand biodiversity.
  • Evolutionary Adaptation in the Human Lineage
    Are you lactose intolerant? Many people are. In fact, the ability to digest lactose may be an example of adaptive evolution in the human lineage.
  • Natural Selection: Uncovering Mechanisms of Evolutionary Adaptation to Infectious Disease
    The evolutionary link between sickle-cell trait and malaria resistance showed that humans can and do adapt. But are the “bugs” that make us sick evolving as well?
  • Negative Selection
    How are humans contributing to negative selection? It’s a part of evolution that can also drive some species to extinction; models of negative selection help us understand biodiversity.
  • Genetic Mutation
    Is it possible to have “too many” mutations? What about “too few”? While mutations are necessary for evolution, they can damage existing adaptations as well.

Phylogeny (2)

Speciation (5)

  • Hybrid Incompatibility and Speciation
    Often, hybrids between closely related species are often inviable or sterile. How does this sterility and inviability happen? Genetics helps provide insight into answering this question.
  • Haldane's Rule: the Heterogametic Sex
    Why are there deformities in male hybrid flour beetles while female hybrids are spared? Haldane’s rule: the male beetles have the heteromorphic sex chromosomes.
  • Hybridization and Gene Flow
    What are ways species exchange genes with each other? Hybridization and gene flow are shortcuts to biodiversity that don’t always involve differentiation.
  • Why Should We Care about Species?
    The questions "What are species?” and “How do we identify species?” are difficult to answer, and have led to debate and disagreement among biologists. See how consensus on answers to these questions can steer global, political, and financial pressures that affect conservation efforts.
  • Genetic Mutation
    Is it possible to have “too many” mutations? What about “too few”? While mutations are necessary for evolution, they can damage existing adaptations as well.
 
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