The study of recent natural selection in human populations has important applications to human history and medicine. Positive natural selection drives the increase in beneficial alleles and plays a role in explaining diversity across human populations. By discovering traits subject to positive selection, we can better understand the population level response to environmental pressures including...

Nucleotide substitution models used in molecular phylogenetics do not account for nucleotide sequences evolving under selection, yet selection is rarely tested for. If non-neutral markers violate these models (i.e. non-independence of sites), it is expected that their reconstructed topologies be incongruent with those inferred from neutral ones and conclusions made from those phylogenies should...

background spirulina is one of the most profitable known microalgae in the world, which is used as food and superfood. in the other hand, spirulina is a useful source of healthy components. it seems that the spirulina is transformable so that the introduction of a selectable marker is needed. objectives the purpose of this study was to determine a suitable selection marker for spirulina platens...

BACKGROUND It has been speculated that the polymorphisms in the non-coding portion of the human genome underlie much of the phenotypic variability among humans and between humans and other primates. If so, these genomic regions may be undergoing rapid evolutionary change, due in part to natural selection. However, the non-coding region is a heterogeneous mix of functional and non-functional reg...

Genetic adaptation to different environmental conditions is expected to lead to large differences between populations at selected loci, thus providing a signature of positive selection. Whereas balancing selection can maintain polymorphisms over long evolutionary periods and even geographic scale, thus leads to low levels of divergence between populations at selected loci. However, little is kn...

The population of thymus-derlved (T) lymphocytes reactive to strong histocompatibility (H) 1 alloantigens (HARC) is peculiar in two respects in comparison to lymphocytes~responsive to other antigens: first, the T cells reactive to any given strong H antigen outnumber by two to three orders of magnitude the T cells responsive to more conventional antigens (1-3); and secondly, the frequency of HA...

The traditional way of identifying targets of adaptive evolution has been to study a few loci that one hypothesizes a priori to have been under selection. This approach is complicated because of the confounding effects that population demographic history and selection have on patterns of DNA sequence variation. In principle, multilocus analyses can facilitate robust inferences of selection at i...