Search results for "Lactase"
showing 3 items of 13 documents
Adult Lactose Tolerance Is Not an Advantageous Evolutionary Trait
2004
To the Editor. I read with great interest the recent article from Fomon1 in which he refers to the well-known hypothesis that views the variable frequencies of lactase persistence in different human populations and, consequently, the possibility for some adults to feed on milk (lactose tolerance) as an advantageous evolutionary trait that has been genetically determined and brought about through centuries of natural selection. This notion stands as a common statement in current medical literature, and most authors have accepted its validity since the 1970s.2,3 Because adult mammals are lactose-intolerant, this hypothesis is, moreover, based on the low percentage of lactose malabsorption and…
Genomic Data from an Ancient European Battlefield Indicates On-Going Strong Selection on a Genomic Region Associated with Lactase Persistence Over th…
2020
Lactase persistence (LP), the continued expression of lactase into adulthood, is the most strongly selected single gene trait over the last 10,000 years in multiple human populations. It has been posited that the primary allele causing LP among Eurasians, rs4988235*T (Enattah et al. 2008), only rose to appreciable frequencies during the Bronze and Iron Ages (Mathieson et al 2015; Olalde et al. 2018), long after humans started consuming milk from domesticated animals. This rapid rise has been attributed to an influx of peoples from the Pontic-Caspian steppe that began around 5,000 years ago (Allentoft et al. 2015; Furholt et al. 2016). We investigate the spatiotemporal spread of LP through a…
Absence of the lactase-persistence-associated allele in early Neolithic Europeans.
2007
Lactase persistence (LP), the dominant Mendelian trait conferring the ability to digest the milk sugar lactose in adults, has risen to high frequency in central and northern Europeans in the last 20,000 years. This trait is likely to have conferred a selective advantage in individuals who consume appreciable amounts of unfermented milk. Some have argued for the “culture-historical hypothesis,” whereby LP alleles were rare until the advent of dairying early in the Neolithic but then rose rapidly in frequency under natural selection. Others favor the “reverse cause hypothesis,” whereby dairying was adopted in populations with preadaptive high LP allele frequencies. Analysis based on the cons…