[Government]
"A fifth gene, 'SLC24A5', has recently been shown to impact skin pigmentation and to have a derived selected allele near fixation in Europeans (Lamason et al., 2005; Voight et al, 2006; Soejima and Koda, 2006). Genetic studies show that the high frequencies of this variant allele in European populations may be associated with a substantial reduction in regional heterozygosity (Lamason et al., 2005; Soejima et al, 2006). This tends to tie in with other molecular genetic research that has shown Europeans to have among the world's lowest levels of genetic variation which results in lower heterozygosity levels (Weber et al, 2002; Watkins et al 2003). Heterozygosity is thought to enhance resistance of hosts to infectious diseases, offers a greater degree of fitness for one or the other allele, and improves overall health (Gangestad & Buss 1993, Thornhill & Gangestad 1993). Reduced levels of genetic variation and heterozygosity have also been linked to lower reproductive and evolutionary fitness (Lacy 1987; Reed and Frankham, 2003)."