The interaction of lactase persistence and skin depigmentation in connection with the calcium assimilation hypothesis
| Autor: | Grendelová, Gréta |
|---|---|
| Přispěvatelé: | Černý, Viktor, Brůžek, Jaroslav |
| Jazyk: | slovenština |
| Rok vydání: | 2016 |
| Předmět: |
the calcium assimilation hypothesis
lactase kalciová asimilačná hypotéza Neolithic Revolution vitamín D laktáza laktázová perzistencia skin depigmentation depigmentácia pokožky neolitická revolúcia melanín natural and sexual selection prírodný a pohlavný výber positive selection vitamin D melanin lactase persistence pozitívna selekcia |
| Popis: | The most recent genetic studies have proven that skin colour of our European ancestors was originally very dark. Skin depigmentation has begun after "out of Africa" time as a result of low levels of the ultraviolet radiation in changed regions at the higher latitudes. Lightly pigmented skin allows sunlight to penetrate human skin more deeply and vitamin D, which is essential for optimal functions of human body, is synthesised by biochemical interaction of ultraviolet radiation and epidermis. A deficit of vitamin D and calcium may be associated with the rickets in children and osteomalacia in adults. Following the correlation of rising depigmentation at the higher latitudes we may notice an increasing number of people with specific metabolic ability known as lactase persistence. Lactase persistence allows the digestion of milk sugar, lactose, in fresh milk in adulthood. It has likely evolved as a substitute in order to compensate for lower amounts of vitamin D in human body. The origin and spread of lactase persistence began around 7,000 years ago after the start of milk production. The oldest evidence of milk production was found in the Middle East. Lately, it has also been supported by the recent genetic analyses. Depigmentation and lactase persistence both began as an adaptation due to changed... |
| Databáze: | OpenAIRE |
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