Genetic matchmaking is the idea of matching couples for romantic relationships based on their biological compatibility. The initial idea was conceptualized by Claus Wedekind through his famous "sweaty t-shirt" experiment. Males were asked to wear T-shirts for two consecutive nights, and then females were asked to smell the T-shirts and rate the body odors for attractiveness. Apr 26, · A page review of the scientific evidence, some based on state-of-the-art magnetic resonance imaging (MRI) of brain size, has concluded that /5().
Nadra Kareem Nittle has written about education, race, and cultural issues for a variety of publications including the Robert C. Maynard Institute for Journalism Education and Change. Updated June 19, Imagine a world where everyone had brown skin. Tens of thousands of years ago, progettare camera da letto online dating was the case, say betwfen at Pennsylvania State University. So, how did white people get here? The answer lies in that tricky component genetic difference between white and asian dating evolution known as a genetic mutation. They quickly evolved dark skin for protection from skin cancer and other harmful effects of UV radiation.
But in the north, where sunlight is less intense and more clothing must be worn to combat the cold, melanin's ultraviolet shielding could have been a liability. Just a Color This makes sense, but did scientists identify as well a bona fide race gene?
As the "Post" notes, the scientific community maintains that "race is a vaguely defined biological, social and political concept In fact, scientists posit that all people are roughly Skin Deep When the research was first published, scientists and sociologists feared that the identification of this skin-whitening mutation would lead people to argue that whites, blacks, and others are somehow inherently different.
Keith Cheng, the scientist who led the team of Penn State researchers, wants the public to know that's not so. He told the "Post," "I think human beings are extremely insecure and look to visual cues of sameness to feel better, and people will do bad things to people who look different.
Truth be told, people may look different, but there's virtually no difference in our genetic makeup. Skin color really is just skin deep. Continue Reading. But recent genome analyses , which include samples from a wide range of indigenous groups, suggest that the Americas might have been colonised by at least four independent waves of settlers. We are a restless species, and our genomes reveal that even the most intimidating geographical barriers have managed only to somewhat restrict human movements.
Today, international migration is increasing at 1 to 2 per cent per year, with million people in living in a country other than the one in which they were born. The biological implications of this massive experiment in interbreeding we are now witnessing will not be known for generations.
But applying what we know about genetics and evolution can help us predict our future, including whether humans will be able to continue adapting to the constantly changing conditions on Earth. Biological adaptation is a result of natural selection, and natural selection requires diversity.
Only the genes from those individuals that are well suited to their environment at that time will reproduce, passing their genes through the sieve to the next generation. The more variation there is in the population, the better the chances that some genes present in a generation will be able to pass through the sieve and be inherited by future generations. Unfortunately for us, humans are not very diverse.
We Homo sapiens have less genetic diversity than do many species of chimpanzees, gorillas and orangutans — our closest living relatives — despite the fact that each of these are so few in number that they are considered either endangered or critically endangered. Our low diversity is due to the fact that we have only recently become so numerous whereas the opposite is true for our primate cousins.
There are now roughly 7. Our population has exploded in the recent past, and is continuing to grow , with some million babies born each year.
Each baby carries on average 60 new mutations in its genes. With these new gene variants comes the potential for future evolutionary change. People today are more likely to live in an environment for which they are not biologically well-suited Our ability to continue to adapt to the changing conditions on Earth improves as new genetic variation is introduced to our gene pool through mutations.
But the entire human gene pool is made of many smaller gene pools, each corresponding to a particular population. The movement of people around the Earth is mixing these populations, allowing genes to flow back and forth between gene pools, with several important implications for our ongoing evolution. Like all species, human groups became adapted to local environments as we spread around the world. Yet the rapid movement of people between regions and the mixing of people with distinct characteristics means that people today are more likely to live in an environment for which they are not biologically well-suited.
Consider natural resistance to infectious diseases, which evolved in places where such diseases were common. Such geographical associations are being eroded by global migration. The prevalence of malaria, which continues to cause some , deaths each year and is especially deadly to children, has resulted in the evolution of physiological protections from infection. Examples include sickle cell disease and thalassaemia — blood conditions that can create health problems of their own but that nevertheless afford protection from the deadly disease and were therefore favoured by natural selection in regions where malaria was common.
Today, sickle cell and thalassaemia exist in places without malaria as a result both of migration and of the local eradication of malaria. Likewise, many people live in regions where their skin pigmentation is not ideal for the local sunlight intensity.
The colour of human skin is determined by the amount of the pigment eumelanin, which acts as a natural sunscreen. Having a lot of eumelanin is an advantage for those who live in a place where sunlight is intense and, since our species originated in tropical Africa, the first humans were probably dark-skinned. Lighter skin evolved later in populations that migrated out of the tropics, into regions where sunlight hits the Earth more obliquely.
Not only is eumelanin needed less in such regions, it is actually problematic because our bodies require sunlight to penetrate the skin in order to produce vitamin D.
With too much eumelanin, dark-skinned people living at high latitudes risk developing nutritional disorders such as rickets, which causes the skeleton to become deformed.
This trade-off — having either too much or too little sunlight penetrating the skin — caused human populations to evolve eumelanin levels that are appropriate for their region. As people move around the world, mismatches between eumelanin and local sunlight intensity result in skin cancer and vitamin D deficiencies, both of which are considered epidemics in some regions.
As populations blend, medium skin tones will become more common. Such blending is expected for complex traits encoded by multiple genes, such as skin pigmentation or height.
But some characteristics, such as having dry earwax or thick hair, are controlled by just a single gene. Blending is not possible for these traits, which a person either has or does not have, based on the genes inherited from the parents.
What population-mixing might cause, however, is combinations of traits that were previously rare, such as dark skin and blue eyes. Just such a combination can already be found in the Cape Verde islands, whose modern population is descended from Portuguese and West Africans.
In many parts of the world, blending is well underway. In highly diverse urban centres such as Singapore, inter-ethnic marriages are rising quickly — from just 7. In the United States, interracial marriages have doubled since Not surprisingly, the number of multiracial US children climbed fold over roughly the same time span, up from just 1 per cent of all births in to 10 per cent in A distinct advantage of this blending is that beneficial traits present in one population can make their way into the other.
Yet if someone with the mutation moved to South America and established a family there, the mutation could save lives and hence be passed to future generations. A striking example comes from one of the highest altitude regions on Earth, the Tibetan plateau.
Low oxygen levels are especially problematic for childbirth, and complications such as preeclampsia a pregnancy disorder are more common at higher altitudes. Although people from lower altitudes who spend extended amounts of time at high altitude can partially adjust by making more red blood cells to capture oxygen, this is an imperfect solution as it can lead to a condition known as chronic mountain sickness.