Lactose Intolerance and Lactase Persistence Can You Drink Milk

A total of 65% of the human population today has lactose intolerance (LI): drinking animal milk makes them ill, with symptoms including cramps and bloating. That is the typical pattern for most mammals: they stop being able to digest animal milk once they have moved on to solid foods. The other 35% of the human population can safely consume animal milk after weaning, that is to say they have lactase persistence (LP), and archaeologists believe that is a genetic trait that developed between 7,000–9,000 years ago among several dairying communities in places like northern Europe, eastern Africa, and northern India. Evidence and Background Lactase persistence, the ability to drink milk as an adult and the opposite of lactose intolerance, is a trait that arose in humans as a direct result of our domestication of other mammals. Lactose is the main carbohydrate (disaccharide sugar) in animal milk, including humans, cows, sheep, camels, horses, and dogs. In fact, if a being is a mammal, the mothers give milk, and mothers milk is the major energy source for human infants and all very young mammals. Mammals cannot normally process lactose in its ordinary state, and so a natural enzyme called lactase (or lactase-phlorizin-hydrolase, LPH) is present in all mammals at birth. Lactase breaks down the lactose carbohydrate into usable parts (glucose and galactose). As the mammal matures and moves beyond mothers milk to other food types (is weaned), the production of lactase decreases: eventually, most adult mammals become lactose intolerant. However, in about 35% of the human population, that enzyme continues to work past the point of weaning: people who have that working enzyme as adults can consume animal milk safely: the lactase persistence (LP) trait. The other 65% of the human population is lactose intolerant and cannot drink milk without ill effects: the undigested lactose sits in the small intestine and causes the differing severity of diarrhea, cramps, bloating, and chronic flatulence. Frequency of LP Trait in Human Populations While it is true that 35% of the worlds population has the lactase persistence trait, the likelihood that you have it  depends largely on geography, on where you and your ancestors lived. These are estimates, based on fairly small sample sizes. Eastern and Southern Europe: 15–54% have LP enzymeCentral and Western Europe: 62–86%British Isles and Scandinavia: 89–96%Northern India: 63%Southern India: 23%East Asia, Native Americans: rareAfrica: patchy, with highest percentages associated with cattle pastoralistsMiddle East: patchy, with highest percentages associated with camel pastoralists The reason for the geographic variation in lactase persistence has to do with its origins. LP is believed to have arisen because of the domestication of mammals, and the subsequent introduction of dairying. Dairying and Lactase Persistence Dairying--raising cattle, sheep, goats, and camels for their milk and milk products--began with goats, about 10,000 years ago in what is today Turkey. Cheese, a reduced lactose dairy product, was first invented about 8,000 years ago, in that same neighborhood in western Asia--making cheese removes the lactose-rich whey from the curds. The table above shows that the highest percentage of people who can consume milk safely are from the British Isles and Scandinavia, not in western Asia where dairying was invented. Scholars believe that is because the ability to safely consume milk was a genetically selected advantage in response to milk consumption, developed over 2,000–3,000 years. Genetic studies conducted by Yuval Itan and colleagues suggest that the European lactase persistence gene (named -13,910*T for its location on the lactase gene in Europeans) appears to have arisen about 9,000 years ago, consequent with the spread of dairying into Europe. -13.910:T is found in populations all over Europe and Asia, but not every lactase persistent person has the -13,910*T gene--in African pastoralists the lactase persistence gene is called -14,010*C. Other recently identified LP genes include -22.018:GA in Finland; and -13.907:G and -14.009 in East Africa and so on: there are no doubt other as-yet unidentified gene variants. They all, however, likely arose as a result of a reliance on milk consumption by adults. Calcium Assimilation Hypothesis The calcium assimilation hypothesis suggests that lactase persistence might have gotten a boost in Scandinavia because in high-latitude regions reduced sunlight doesnt allow sufficient synthesis of vitamin D through the skin, and getting it from animal milk would have been a useful substitute for recent immigrants to the region. On the other hand, studies of DNA sequences of African cattle pastoralists indicate that the mutation of -14,010*C occurred about 7,000 years ago, in a place where a lack of vitamin D was certainly not a problem. TRB and PWC The lactase/lactose set of theories test the larger debate over the arrival of agriculture in Scandinavia, a debate over two groups of people named by their ceramic styles, the Funnel Beaker culture (abbreviated TRB from its German name, Tricherrandbecher) and the Pitted Ware culture (PWC). By and large, scholars believe the PWC were hunter-gatherers who lived in Scandinavia about 5,500 years ago when the TRB agriculturalists from the Mediterranean region migrated into the north. The debate centers around whether the two cultures merged or the TRB replaced the PWC. DNA studies (including the presence of the LP gene) on PWC burials in Sweden indicate that the PWC culture had a different genetic background from those of modern Scandinavian populations: modern Scandinavians have far higher percentages of the T allele (74 percent) compared to PWC (5 percent), supporting the TRB replacement hypothesis. Khoisan Herders and Hunter-Gatherers Two 2014 studies (Breton et al. and Macholdt et al.) investigated lactase persistence alleles among southern African Khoisan hunter-gatherer and pastoralist groups, part of a recent reassessment of the traditional concepts of the Khoisan and the broadening of applications for the appearance of LP. Khoisan is a collective term for people who speak non-Bantu languages with click consonants and includes both Khoe, known to have been cattle herders from about 2,000 years ago, and San often described as the prototypical (maybe even stereotypical) hunter-gatherers. Both groups are often assumed to have remained largely isolated throughout prehistory. But the presence of LP alleles, along with other recently identified evidence such as shared elements of Bantu languages among Khoisan people and recent archaeological discoveries of sheep pastoralism at Leopard Cave in Namibia, has suggested to scholars that African Khoisan were not isolated, but instead were descended from multiple migrations of people from other parts of Africa. The work included a comprehensive study of LP alleles in modern southern African populations, descendants of hunter-gatherers, cattle and sheep  pastoralists and agropastoralists; they found that Khoe (herding groups) carried the East African version of the LP allele (-14010*C ) in medium frequencies, indicating they are likely partly descended from pastoralists from Kenya and Tanzania. The LP allele is absent, or in very low frequencies, among Bantu-speakers in Angola and South Africa and among San hunter-gatherers. The studies conclude that at least 2000 years ago, pastoralism was brought by a small group of eastern African migrants to southern Africa, where they were assimilated and their practices adopted by local Khoe groups. Why Lactase Persistence? The genetic variants that allow (some) people to consume mammal milk safely arose about 10,000 years ago as the domestic process was being undertaken. Those variations allowed populations with the gene to broaden their dietary repertoire, and incorporate more milk into their diet. That selection is among the strongest in the human genome, with a strong influence on human reproduction and survival. However, under that hypothesis, it would seem logical that populations with higher levels of milk dependence (such as nomadic herders) should have higher LP frequencies: but that is not always true. Long-term herders in Asia have quite low frequencies (Mongols 12 percent; Kazakhs 14–30 percent). Sami reindeer hunters have a lower LP frequency than the rest of the Swedish population (40-75 percent versus 91 percent). That might be because different mammals have different concentrations of lactose, or there may be some as-yet-undetected health adaptation to milk. In addition, some researchers have suggested that the gene arose only in times of ecological stress, when milk had to be a larger part of the diet, and it might have been more difficult for individuals to survive milks ill effects under those circumstances. Sources: Breton, Gwenna, et al. Lactase Persistence Alleles Reveal Partial East African Ancestry of Southern African Khoe Pastoralists. Current Biology 24.8 (2014): 852-8. Print.Burger, J., et al. Absence of the Lactase-Persistence-Associated Allele in Early Neolithic Europeans. Proceedings of the National Academy of Sciences 104.10 (2007): 3736-41. Print.Dunne, Julie, et al. First Dairying in Green Saharan Africa in the Fifth Millennium BC. Nature 486.7403 (2012): 390-94. Print.Gerbault, Pascale, et al. Evolution of Lactase Persistence: An Example of Human Niche Construction. Philosophical Transactions of the Royal Society B: Biological Sciences 366.1566 (2011): 863-77. Print.Itan, Yuval, et al. The Origins of Lactase Persistence in Europe. PLOS Computational Biology 5.8 (2009): e1000491. Print.Jones, Bryony Leigh, et al. Diversity of Lactase Persistence in African Milk Drinkers. Human Genetics 134.8 (2015): 917-25. Print.Leonardi, Michela, et al. The Evolution of Lactase Persistence in Euro pe. A Synthesis of Archaeological and Genetic Evidence. International Dairy Journal 22.2 (2012): 88-97. Print.Liebert, Anke, et al. World-Wide Distributions of Lactase Persistence Alleles and the Complex Effects of Recombination and Selection. Human Genetics 136.11 (2017): 1445-53. Print.Malmstrà ¶m, Helena, et al. High Frequency of Lactose Intolerance in a Prehistoric Hunter–Gatherer Population in Northern Europe. BMC Evolutionary Biology 10.89 (2010). Print.Ranciaro, Alessia, et al. Genetic Origins of Lactase Persistence and the Spread of Pastoralism in Africa. The American Journal of Human Genetics 94.4 (2014): 496–510. Print.Salque, Mà ©lanie, et al. Earliest Evidence for Cheese Making in the Sixth Millennium BC in Northern Europe. Nature 493.7433 (2013): 522–25. Print.Sà ©gurel, Laure, and Cà ©line Bon. On the Evolution of Lactase Persistence in Humans. Annual Review of Genomics and Human Genetics 18.1 (2017): 297–319. Print.

What You Must Know About Global Essay Topics

What You Must Know About Global Essay Topics The author of an essay identifies with the topic and has to take total responsibility for her or his statements. It's also advisable to constantly work to enhance your writing style and create your essay attractive to read and simple to navigate. Don't forget, if you cannot finish the essay, be sure to contact Paper per Hour for assistance. At any time you catch yourself feeling captivated by somebody's essay or article, take a good look at it. Since there's a word limit for the essay answers it's important to make sure the content isn't repeated. A properly structured essay is quite appealing. A prudent student doesn't have to cover a sample paper. To compose an outstanding essay, it's critical to use specific academic language. Ok, I Think I Understand Global Essay Topics, Now Tell Me About Global Essay Topics! If you have just a few activities you'd like to describe, don't hesitate to go into more detail and compose a compelling story so the admission officer can understand your passion for said activities. You may want to include an extra essay if you think the college application forms do not offer sufficient chance to convey important information regarding yourself or your accomplishments. Students that are too lazy or uninterested in doing any true learning are likely to lose out in the international economy. It's desirable to discover a native-speaker teacher specializing in IELTS. Today, people are beginning to turn into active participants in the struggle against global issues and as a consequence, progress is being made. Everyone says they can handle change but the truth isn't many folks do well with change. The world is waiting to hear what you need to say. The area of work is changing, and if we want to keep up, we have to concentrate on learning new skills. Last, search the internet for educational and present event resources, stay interest in news since it will help you remain updated and allow you to explore several aspects of a situation or topic. The aim of the project is to harness the ability of a worldwide community of interest to go over and debate a succession of issues concerning the museum sector's responses to digital technologies, and the possible implications. Communication technology essay topics may include a variety of ideas. It is very important to remember, that technology is a wide subject, and therefore, it is necessary to narr ow down the particular technology area or invention you want to go over. The 30-Second Trick for Global Essay Topics When you've gathered all the info you can about your subject, you should pick your side and produce a valid opinion. Most issues can have essays on all the aforementioned questions. Attempt to locate a deeper issue in the subject you would like to do. Make changes wherever it's possible. Structural Elements An introduction should specify a context and offer a concise summary of why the topic was chosen. It covers the main problem or question that an essay addresses. For instance, the introduction and the conclusion is going to be offered to you. Think beyond the box as you answer the subsequent questions. The collection of the topic may also relate to the historical questions so that it is crucial to read history books as a way to find out the type of project you should work on. The list might seem lengthy but it can help save you a good deal of time. Nevertheless, stay away from grammatical mistakes and go for a Grammarly check once you are finished with your answers. Make sure that the whole worldwide warming essay you write must stick to a particular pattern and structure. The term terrorism has come to be the the heart of fear and loss over the previous several decades. Disasters like floods and hurricanes will become increasingly more frequent. The origin of the crime isn't the human being born into hyper-segregation, it's the hyper-segregation, which is that which we should be focused on for preventive measures.

Sexual Ethics Essay Free Essays

1. There are a number of dilemmas in sexual ethics such as homosexuality, marriage and divorce and pornography. For instance homosexuality is a major problem within sexual ethics because homosexual sex cannot lead to reproduction. We will write a custom essay sample on Sexual Ethics Essay or any similar topic only for you Order Now However sexual ethic it differs between denominations compared to government law. Therefore these issues are a concern to religious belief; different faiths have different view on homosexuality or marriage and divorce. Many religious beliefs do not encourage homosexuality in fact it is severely discouraged for example in the Islamic faith they do not allow this because there is no doubt that in Islam homosexuality is considered ‘sinful’. Homosexuality as far as Islam is concerned is a profound mistake (as are all sins if they are not intending to do wrong). For instance a quote from the Qur’an says â€Å"What! Of all creatures do ye come unto the males, and leave the wives your Lord created for you? Nay, but ye are forward folk. † Qur’an 26:165. The references relate to gay sexual activities; lesbian practices are not mentioned in the Qur’an, neither is it mentioned in the bible. Christians are divided over the issue of homosexuality. Due to natural law homosexual sex cannot lead to reproduction therefore the marriage would be considered invalid, however then a marriage between an older couple or couples who infertile would also be invalid, therefore all homosexual acts and relationships are sinful so many believe homosexuality is contrary to God’s will. However the Roman Catholic Church teaches that homosexual should be treated with respect, compassion and sensitivity and no discrimination, they believe the feeling aren’t wrong but the actions are sinful because they contrary to the will of God. The scriptures of the bible suggest that the only sexual relationship that God approves of is one between married heterosexual partners. The creation narrative describe woman as being created especially for man: â€Å"a helpful suitable for him† (genesis 2:18). The Old Testament said â€Å"If a man lies with a man as one does with a woman, both of them have done what is detestable. They must be put to death† (Leviticus 20:13) however there is still no mention on lesbian practices. Marriage is an important part of the Christian life a the purpose of Christian marriage is faithfulness to one another, many Christians teach than within marriage there is a natural hierarchy that reflects the relationship of Christ and the church. The Roman Catholic Church says â€Å"wives, in the same way be submissive to your husband†¦ Husband, in the same way be considerate as you live with your wives, and treat them with respect† (1 peter 3:1, 7). Whereas the Church of England argues that the relationship is based upon Christ’s headship over the church and is about love and sacrifice, not domination and power. This argument originally started as the bible said â€Å"a man will leave his father and mother and be united to his wife and they will become one flesh† (genesis 2:24). On the other hand, in the Islamic faith marriage is only a way to make sex and having children legal and lawful, the belief also states in the eyes of Allah both members of the relationship are treated equally even though they have separate duties. Whereas the Christian views on divorce are that marriage is for life. People take vows for better or worse so if they meant that then there should be no divorce. For instance the Roman Catholic Church believe there shouldn’t be any divorce unless the marriage has not been consummated or they are willing to get a divorce with the permission from the pope. Whereas the Church of England except divorce but some more traditional vicars don’t allowed divorces to remarry in church, the bible believes divorce is not favoured by God: â€Å"Therefore what God has joined together, let man not separate (Matthew 19:6) which means God joins them so the law cannot separate them. Even Jesus forbids divorce: â€Å"Anyone who divorces his wife and marries another woman commits adultery. And if she divorces her husband and marries another man, she commits adultery† (Mark 10:11-12) However in Matthews gospel it say â€Å"anyone who divorces his wife, except for marital unfaithfulness, and marries another woman commits adultery† (Matthew 19:9). Alternatively divorce in Islam is only when the male partner says Talaq 3 times can divorce the couple, however this banned in some countries which results in going to arbitration council and judicial intervention before the divorce is granted. . Due to the loss of faith in many denomination and cultures today, we as people no longer look to religion to guide our sexual ethics as we once did. It is no longer relevant because many people believe that anymore should be able to marry anyone they want, for example same-sex partners. The debate is still being waged between the church and government to offer this un ion. Many people believe if two people are happy together and want to join themselves in holy matrimony, then they should be allowed. Marriage has also undergone many changes as people are less likely to have a â€Å"traditional† wedding instead they are more likely to enjoy extended co-habitation. Also the concept of marriage has change because it is more of a legal act rather than a declaration of love to God. Whereas divorce is seen by the eyes of most people is all about the law rather than church. Church seems to have very little authority when a marriage has got to the divorce stage. A minority of people do still take guidance from the church and believe the once they have entered into holy matrimony then it is for life just as God ordained. In conclusion, like most of the civilised world I believe that the religious beliefs about sexual ethics are no longer relevant because civilisation has changed so much and people are willing to accept all that was once considered taboo by the church and are willing to open their mind about the change in religious beliefs and sexual ethics. How to cite Sexual Ethics Essay, Essay examples