History of lactose tolerance
What do such genetic changes tell us regarding the evolutionary history of milk tolerance in human populations?
Expert
As per studies, the genes regulating lactose intolerance was quite rapid in evolutionary terms. The ultimate source of variation is mutations in the genes responsible for lactose persistence and carried forward over the generations. About 3000- 7000 years ago, dairy products such as cow's milk, cheese and yoghurt were not in existence. Only human milk was most likely only consumed by young children. With domestication of cattle, consumption of non human milk became widely popular. As a result, natural selection gradually switched to favor lactose tolerant people which resulted in the progressive evolution of the gene pools. In 2007 by researchers from University of Mainz, Germany. They analyzed of DNA in bones from 10 Central and Eastern European human skeletons dated between 3,800 and 6,000 years ago. In spite of the fact that these populations seemingly raising milk producing farm animals for hundreds or even thousands of years, the gene that allows lactose tolerance in adults was not common in them. In 2007, Sarah Tishkoff, University of Maryland, reported that the mutations among East Africans that keep the lactase gene permanently turned on, are different from those of Europeans who also share this trait. According to her studies, among 43 East African ethnic groups, 3 different mutations leading in lactose tolerance in Africa developed between 2,700 and 6,800 years ago. Her research findings narrates genetic diversity among Africans. She analyzed DNA samples of one ethnic group, the Yoruba of West Africa. Traditionally the the Yoruba group was not involved in cattle herding. There was no mutation for lactase persistence reported in them. Although, a sector of population of West Africans, who were traditionally involved in cattle herding have reported mutation for lactase persistence Above research findings revealed that nature is getting hold on the environmental challenge with with different successful genetic solutions.
Give some illustrations of arthropods? Answer: Ants, cockroaches, flies, shrimps, spiders, crabs, and scorpions are some illustrations of arthropods.
Describe the structural formula of glycerol? To which organic function do such molecules belong?
Why is cytoplasm of sperm cells much decreased?
Client-Server Architecture: It is network architecture in which each and every computer or process on the network is either a client or a server. The Servers are powerful computers or processes devoted to managing disk drives (that is, file servers),
Vendor Partnerships: In quality control, extended relationship among buyers and sellers based on confidence, credibility, and joint benefit. The buyer, on its part, gives long-term contracts and assurance of merely a small number of c
Which hormones are secreted by the adenohypophysis? What are their respective functions?
I. It is the quickest means of transmitting messages. II. E-mail does not thrust itself upon the receiver. You can check your mailbox and receive your messages at your leisure. III. E-mail saves you from telephone tags.
What is the antagonism between sympathetic and parasympathetic neural actions?
Specify the Haversian canals and the Volkmann’s canals of bones? Whether, osseous tissue is vascularised or not?
Most of an individual's specific needs are dormant much of the time. The arousal of any particular set of needs at a specific point in time may be caused by internal stimuli found in the individual's physiological condition, emotional or cognitive processes, or by stimuli in the outside environme
18,76,764
1936064 Asked
3,689
Active Tutors
1451317
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!