Interestingly, it is also found that homozygosity for this polymorphism is associated with protection against severe malaria, where selection pressure may contribute to the higher frequency of FcγRIIB-T232 and, hence, SLE in Africans and Southeast Asians (Willcocks et al., 2010).
Several environmental selection pressures can shape birdsong characteristics.
These results indicate that there is a stronger tendency for selection pressure to preserve functional compensation to severe phenotype by duplicate genes.
Paradoxically, while increased p53 is expected to inhibit tumorigenesis, Rps27l −/− ;Trp53 +/− mice develop lymphomas at higher incidence with p53 loss-of-heterozygosity and severe genome aneuploidy, suggesting that Rps27l disruption impose a selection pressure against p53.
We conclude that the ocean as a habitat poses severe restrictions to fitness by several environmental factors e.g. nutrient limitation and pH, while the selection pressure from toxicants in the marine environment seems to be comparably small.
The strong protection against severe malaria conferred by the HbS [7], G6PD [9], [10] [10] and the alpha-thalassemia mutations [11], [12], [13] illustrate the striking selection pressure of malaria on the human genome.
"That ups the selection pressure tremendously," he said.
In this case, at least, selection pressure favoured symbiosis.
This modular assembly implies a selection pressure favoring substrate channeling.
