Sentences with phrase «lactose tolerance»
"Lactose tolerance" refers to the ability of a person's body to digest lactose, which is a natural sugar found in milk and dairy products. People who are lactose tolerant have an enzyme called lactase in their bodies, which helps break down lactose and allows them to consume these products without experiencing digestive issues. On the other hand, those who are lactose intolerant may lack enough lactase and may experience symptoms like bloating, gas, and diarrhea when consuming dairy products. Full definition
All mammals have milk, apparently only cow milk allows for lactose tolerance in humans?
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In the case of lactose tolerance, early research had estimated that it arose 7,000 or more years ago, when people in the region began making cheese.
To determine your dog's level of lactose tolerance, occasionally feed him small amounts of cheese as treats and monitor his response.
Based on this result, he believes that the mutation for lactose tolerance spontaneously arose in Europe within the past 7000 years and quickly became prevalent through natural selection.
It was thought the gene first arose in Scandinavia, where lactose tolerance is most prevalent, because it is a way of getting vitamin D in places with little sunshine, says Mark Thomas of University College London.
Surprisingly, says Thomas, none of the early Europeans had the gene mutation associated with lactose tolerance in modern - day Europeans.
To determine when this special lactose tolerance evolved in Europe, Thomas's team analysed the DNA from 55 bone samples belonging to eight Neolithic Europeans.
Lactose tolerance appears to have been a useful survival trait as, today, most adults of Western European and Middle - Eastern ancestry can digest milk.
Stanford graduate students Natalie Telis and Evan Boyle and postdoc Ziyue Gao found relatively few singletons near alleles that confer lactose tolerance — a trait that enables adults to digest milk — and that code for particular immune system receptors.
The alleles for lactose intolerance and lactose tolerance represent time - tested genes of the human race, just the opposite of the alleles of the Finnish Disease Heritage, which are native born and recent.
Pardis Sabeti unravels recent human genetic changes like lactose tolerance, changes in skin tone, and responses to deadly Lassa fever.
The results suggest that lactose tolerance first appeared in populations living between the Ural mountains and the Volga River, such as Udmurts and Mokshas.
Now, Peltonen's team has tried to trace the origins of lactose tolerance by looking at these variants in 1611 DNA samples from 37 populations on four continents.
Lactose tolerance tends to vary from critter to critter, but most hamsters have at least some difficulty digesting dairy.
Although nearly all wolves are lactose intolerant, dogs have lived alongside milking cows as long as humans have, and were under similar selective pressure to retain lactose tolerance beyond infancy.
It was thought this gene first arose in Scandinavia, where lactose tolerance is most common, because it is a way of getting vitamin D in places with little sunshine, says Mark Thomas of University College London.
Two years ago, a team led by Leena Peltonen of the University of Helsinki, Finland, and the University of California, Los Angeles, tracked down gene mutations associated with lactose tolerance, which likely play a role in regulating the lactase gene.
«The precise genetic basis for countless adaptations has been documented in detail, ranging from antibiotic resistance in bacteria to camouflage coloration in deer mice, to lactose tolerance in humans,» they wrote.
More than 100 mutations representing such adaptations as the evolution of lactose tolerance and changes in skin pigmentation.
The researchers also identified genetic adaptations for living at altitude, and a lack of genes for lactose tolerance — all genetic traits shared by the current populations of the Ethiopian highlands.
He covers the evolution of unique human traits — red hair, lactose tolerance — and delves into the genetics of historical celebrities — Richard III and Jack the Ripper, to name two.
But Larsen adds that larger studies of fossils are needed to confirm the absence of the lactose tolerance gene in Neolithic Europeans.
For example, the widespread but not universal ability to digest the milk sugar lactose in adulthood (lactose tolerance) has recently been shown to arise from any of several different mutations in and near the lactase gene.
Moreover, the study reveals that lactose tolerance was more widespread than previously believed.
One of the most cited examples is the mutation involved in lactose tolerance, which is also caused by regulation from outside the gene.
The lactose tolerance mutation «probably emerged by chance» and then remained because it was beneficial in the dairy - consuming Ural peoples, who later spread the gene to Europe and the Middle East, says Peltonen.
In the lactose tolerance test, you will be given some lactose, and then your breath will be tested for hydrogen gas.
One example of how our genetics changed is lactose tolerance.
Like when domesticated animals gave milk, we quickly evolved lactose tolerance, and we changed our jaws and teeth when we invented cooking.