Genomic analysis of a key innovation in an experimental Escherichia coli population

by Romain Savary in genome ecology evolution etc

In this paper Richard E. Lenski and colleague are showing an example of how efficient adaptation by natural selection is. During 20 year they have been growing twelve populations of Escherichia coli in glucose medium containing also abundant citrate, this … Continuer la lecture →... Read more »

Genome Patterns of Selection and Introgression of Haplotypes in Natural Populations of the House Mouse (Mus musculus)

by Martha Serrano in genome ecology evolution etc

  1. How genomes evolve in natural populations? is a question that, despite to be a long-standing search for geneticists, recent molecular genomic approaches may help to understand. Their evolution among natural populations may be shaped by forces derived from … Continuer la lecture →... Read more »

Flycatchers’ genomes bring new insights into the genomic basis of evolution

by Charlotte Récapet in genome ecology evolution etc

How exactly do lineages diverge to the point that they can be considered separate species, and especially reach reproductive isolation, is still an ongoing question in evolutionary biology. Classical views of speciation hypothesize the existence of speciation genes, defined as … Continuer la lecture →... Read more »

Genomic Variation in Seven Khoe-San Groups Reveals Adaptation and Complex African History.

by Romain Savary in genome ecology evolution etc

Genomic Variation in Seven Khoe-San Groups Reveals Adaptation and Complex African History. The origin of modern Human is clear with evidences coming from many different disciplines. Africa is the continent where the highest genetic diversity is found; this clue associated … Continuer la lecture →... Read more »

The Genetic Architecture of Adaptations to High Altitude in Ethiopia

by Guillaume Cossard in genome ecology evolution etc

Human populations have colonized high altitude (HA) habitats (above 2500m of altitude) multiple times and independently. HA habitats are essentially characterized by lower biodiversity and low levels of oxygen availability, also called hypoxia. Classically, organisms respond to this decreased oxygen … Continuer la lecture →... Read more »

by Nicla Loviglio in genome ecology evolution etc

Genome-wide analysis of a long-term evolution experiment with Drosophila For decades, most researchers have provided some general insights into the nature of adaptation in asexually reproducing populations with small genome, such as bacteria and yeast. They assumed that sexual species evolve the same way these populations do, i.e. their adaptation is driven by the so-called selective sweeps or newly arising beneficial genetic mutation quickly becomes "fixated" on a particular portion of DNA, w........ Read more »

Genome-wide analysis of a long-term evolution experiment with Drosophila

by Namrata Sarkar in genome ecology evolution etc

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Parallel evolution in adaptive phenotypes: the case of the threespine stickleback

by Francesco Nicola Carelli in genome ecology evolution etc

How do adaptive phenotypes evolve? This question, despite the increasing availability of genomic and other molecular data, remains still largely unanswered. Among the different aspects investigated, a major point of discussion in this topic is the extent of the contribution of coding versus non-coding variation in the evolution of new traits. Although many research groups suggested that non-coding mutations might play a pivotal role because might avoid pleiotropic effects, still few examples are........ Read more »

Ecological success of recently emerged bacterial hybrids living in the wild

by Nicla Loviglio in genome ecology evolution etc

Microbial species are one of the most ubiquitous living group on Earth's biosphere, showing incredible ability to thrive even in ambient conditions to the limit of human endurance. By virtue of their rapid growth, bacteria are ideal for unraveling the molecular mechanisms of many evolutionary processes. Their rapidity to respond to changes has been associated to the combined effect of evolutionary processes, species composition or gene expression shifts. Most of the studies have focused so far ........ Read more »

What could our genomes actually tell about disease risk?

by Charlotte Récapet in genome ecology evolution etc

Despite the recent advances in whole-genome sequencing, two recent studies let us think that we are far from uncovering the genetic basis of common diseases risk. In fact, information relevant to complex diseases might hide within rare or even private genome variations, often too scarce to be studied statistically. We might thus have to change radically our way of thinking of genes-diseases associations to make a step forward and make the DNA talk.Whereas a few, usually rare and severe “gene........ Read more »

Evolutionary consequences of sex: It's not about what you're doing, but who you're doing it with...

by Charlotte Récapet in genome ecology evolution etc

Bacteria are one of the most ubiquitous living group and exhibit finely tuned adaptations to a wide range of habitats, even the most inhospitable ones. Their ability to evolve rapidly is at the roots of many public health issues, such as the development of resistances to antibiotics or the rapid evolution of seasonal diseases, but can also be of great help to humans by creating new metabolic pathways to transform human-made pollutants and harmful substances. In the early 20th century, new bacter........ Read more »

The yak genome and adaptation to life at high altitude

by Nadja in genome ecology evolution etc

Normal 0 false false false EN-US JA X-NONE ... Read more »

The evolutionary history of polar bears

by Sacha in genome ecology evolution etc

The study of the Ursus lineage, composed of brown bear (Ursus arctos), black bear (Ursus americanus) and polar bear (Ursus maritimus), provides the ability of addressing the subject of adaptation to extreme (salty and glacial) environments in mammals. Moreover, in last few decades, polar bears won public and media attention, being one of the most charismatic species endangered by global warming and Arctic ice melting. To trace history of innovations and determine response to environmental change........ Read more »

The Molecular Diversity of Adaptive Convergence

by mrr in genome ecology evolution etc

The ArticleThe authors of this article wanted to find out how the mutational background of adaptation looks like. Specifically, they asked if identical populations adapted to a fixed environment, would adaptation occur via identical mutations or via various alternative pathways. To answer this question they experimentally evolved 115 populations of Escherichia coli to 42.2° Celsius for 2000 generations (6.64 generations of binary fission daily) and sequenced one clone each of ........ Read more »

Rapid Evolution of Enormous, Multichromosomal Genomes in Flowering Plant Mitochondria with Exceptionally High Mutation Rates

by mrr in genome ecology evolution etc

Theories Genome size and complexity variation has been a long-term debate during the last decades. In multi-cellular eukaryotes, genome expansion is a consequence of noncoding DNA proliferation [1]. Several theories have emerged to explain variation in genome size and complexity. Among them, the most generally accepted are the bulk-DNA hypothesis, followed by the selfish –DNA hypothesis [2]. However, theses hypotheses explain only partially divergent patterns observed in eukaryotes. Mut........ Read more »

An Aboriginal Australian genome reveals separate human dispersals into Asia

by mrr in genome ecology evolution etc

This blog section concerns a trendy debate in science, the human population history, which has extensions into daily life, as it can constitutes a topic of general public curiosity. Therefore, let’s see what is contribution described herein.BackgroundModern human populations seems to be derived from a single African ancestral population, under the well supported “out of Africa” hypothesis (1). Particularly, for eastern Asian colonization a “single-dispersal” model have been hypothesiz........ Read more »

Distinct signatures of diversifying selection revealed by genome analysis of respiratory tract and invasive bacterial populations (Shea et al, PNAS 2011)

by PierreMillon in genome ecology evolution etc

Diversifying selection is a form of natural selection where intermediate values of a trait become less represented within a population, in favour of extreme values; a process that may subdivide a population between specialized niches and eventually lead to speciation. For instance, it can be theorized that a pathogen colonising several sites of the human body, where it is exposed to wildly different conditions and selective pressures, would have greater chances of survival by expressing a mult........ Read more »

Mouse genomic variation and its effect on phenotypes and gene regulation (Keane, Goodstadt, and Danecek et al., Nature 2011)

by Laetitia in genome ecology evolution etc

Motivation: Documenting the genomic variation of 17 inbredstrains of mice. Describing the distribution of variants between strains andits relation to phenotypes and gene regulation. Exploring the evolutionaryorigins of the subspecies that gave rise to the laboratory mouse.-      Structure: The article is divided up in three mainparts: i) description of genomic variants, ii) examination of functionalconsequences of allele-specific variation on transcript abundance, a........ Read more »

Cryptic genetic variation promotes rapid evolutionary adaptation in an RNA enzyme (Hayden et al, Nature, 2011)

by Diego in genome ecology evolution etc

Cryptic genetic variation (CGV) is defined as “standing genetic variation that does not contribute to the normal range of phenotypes observed in a population, but that is available to modify a phenotype that arises after environmental change or the introduction of novel alleles”... Read more »