A groundbreaking study examines the genetic underpinnings of human skin color, finding that gene variations behind light skin in Europeans originate in Africa. DEAGOSTINI/PHILLIP LEE HARVEY/NIGEL PAVITT/ROD WADDINGTON/TOBY ADAMSON/GETTY IMAGES
For ages, humans have divided our species into groups based upon skin color. The shade of one's complexion has been a powerful influence upon human culture, affecting everything from where we live and how much money we make to how much political power we have. And throughout history, racial divisions based upon skin color have led to violence and war.
That's all persisted because people cling to the belief that people of different skin colors are inherently different from one another, even though scientists have been telling us for years that race is a distinction that we invent in our minds, and that there isn't much actual difference in the genetic makeup of humans of various hues.
Now, an international team of researchers has published a groundbreaking study in the journal Science that may demolish the concept of race as a biological concept once and for all. Finding genetic variations for lighter skin color neither exist solely nor originate in European populations, challenging the idea of using skin color as a racial classification and showing that skin color may only be skin deep.
The San people of South Africa have lighter skin than many others on the continent.
MICHAELA URBAN/CHICAGO TRIBUNE/TNS/GETTY IMAGES
The scientists examined the genetic origins of skin color in Africans — who vary widely in shade from the dark skin of the Dinka people in South Sudan to the light-complexions of the San of South Africa. As an accompanying news story in the journal Science explains, the team used a light meter to measure the degree to which more than 2,000 individuals' skin reflected light. They also gathered blood samples for genetic studies.
The focus upon Africans was significant because most studies of the genetic underpinnings of race have been based upon European subjects — a choice that's provided an incomplete and perhaps misleading picture.
"This is part of a general bias that exists in human genetic studies which focus primarily on European populations," corresponding author Sarah Tishkoff, a genetics and biology professor at the University of Pennsylvania, says via email. "This results in a bias in our knowledge about genetic factors influencing both normal variable traits, like skin color, as well as disease risk. Specifically, studies that focused only on Europeans missed many of the genetic variants which we identified as associated with skin color. This is because there is less genetic and phenotypic (i.e. skin color) variation in that population compared to Africans. Also, many of the variants identified in Europeans are of recent origin."
Senior research scientist Alessia Ranciaro measures the skin reflectance of a man from a Nilo-Saharan ethnic group, a population whose members tend to have very dark skin pigmentation.
COURTESY OF TISHKOFF LAB
"Prior to our study," says Tishkoff, "it wasn't recognized that variants associated with both light and dark skin are common in Africa and many are very old. Also, our study shows that both light and dark skin has been evolving in humans (prior to our study the emphasis has been on why light skin is adaptive in Europeans). Our study changes our understanding of the evolutionary history of variation in skin color."
The scientists identified eight genetic variations in four regions of the human genome that influenced skin shade. Using genetic information from nearly 1,600 people, they examined more than 4 million single nucleotide polymorphisms — places where the familiar DNA code made up of proteins represented by the letters G, A, T and C may differ by one "letter." Those genes turn out to be ones that have spread all over the planet — showing that many of the gene variations that cause light skin color in Europeans actually originated in Africa. (To be specific, the regions with the strongest associations were in and around the genes SLC24A5 and MFSD12.)
The ubiquitous nature of the skin-color genes, and their persistence over thousands of years, makes racial divisions seem pretty much meaningless from a biological viewpoint. Tishkoff told the New York Times that the study "dispels a biological concept of race." In her email to HowStuffWorks, she elaborates upon the larger potential impacts.
People of the Dinka ethnic group live in and near South Sudan, and tend to have particularly dark skin pigmentation.
FIGULA PHOTOGRAPHY/GETTY IMAGES
"I think that work strengthens what so many geneticists and sociologists already know — that race cannot be defined based on genetic criteria," she says. "There have been many abuses committed in the past, and in the present, based on that assumption so hopefully this and other studies will help dispel the notion of genetically defined racial groups."
Due to genetic variants shared among populations around the world, the new data also shines a light on human evolution, supporting the notion of a "proposed early migration event of modern humans out of Africa along the southern coast of Asia and into Australo-Melanesia and a secondary migration event into other regions."
Tishkoff hopes to build upon the study and explore other questions that remain about the genetics of skin color.
"We want to better understand how the biological mechanisms by which these variants are impacting skin pigmentation," she says. "Our study has implications for better understanding skin pigmentation disorders and melanoma risk. We are also looking at the genetic basis of other adaptive traits, as well as genetic and environmental factors influencing disease risk in ethnically diverse African populations."
For further information log on website : https://science.howstuffworks.com/life/genetic/genetic-origin-human-skin-color-pigmentation-study.htm
You might be wondering, what on earth is a GMO? Don’t worry, you’re not alone. Although conversations abound GMOs have increased significantly in the media, in the news and even the world of cinema through documentaries within the past decade, many people are still uncertain about what a GMO is and the ubiquitous role GMOs play in our world. And unless you live in one of the 60-plus countries around the world, (such as Japan, Australia, and all countries in the European Union) which have restrictions or outright bans on the production and sale of GMOs, you’ve probably eaten them.
What is a GMO?
GMO stands for “Genetically Modified Organism,” and the phrase refers to plants or animals that have been genetically engineered to produce a specific set of characteristics. This is not to be confused with traditional breeding practices, where different breeds of the same species are combined to produce favorable traits. With GMOs, DNA is taken from a completely different species (like a virus or fish) and inserted into a crop (like a carrot) to transfer genetic traits. These experimental combinations of genes do not occur in nature.
The majority of GMOs are engineered in a way that makes them tolerant to large applications of pesticides and herbicides, like Roundup, a chemical fertilizer created by the corporation Monsanto. Monsanto controls 80 percent of the genetically modified corn market and 93 percent of the genetically modified soy market. Roundup’s main ingredient is glyphosate, which was found by the World Health Organization to be a “probable human carcinogen” in May 2015. Where normal weeds would die when exposed to these harsh chemicals, GM corn is designed to survive when sprayed. GMO crops are also responsible for the emergence of “super weeds” and “super bugs” which can only be killed with ever more toxic poisons like 2,4-D (a major ingredient in Agent Orange). The farmers affected by resistant pests who must revert to older and more toxic chemicals must also garner more labor or more intensive tillage, which overshadow the promised benefits of GMO technology.
The Impact of GMOs on People and the Environment
In contrast to how the majority of people think, GMOs have actually caused the use of herbicides and pesticides to increase significantly, leaving more chemical residue on crops for consumers to ingest. The research around GMOs is conflicting; however, there is a growing body of evidence connecting GMOs with environmental damage, health issues, and even violations of consumers’ and farmers’ rights. Autism, gluten intolerance, birth defects, and many more startling health issues are all linked back to Monsanto’s Round Up. To view a comprehensive list of health issues related to glyphosate (Round Up) explained, follow thislink.
While many farmers say they are pleased with GMO varieties, many others are disappointed, finding mixed results or facing new problems in the extremely concentrated and corporate-dominated seed sector.
These problematic trends affect all farmers, whether they plant GMO seeds or not.
Even if a farmer does not use GMO crops, the risk of cross-contamination with GMO seeds is common. According to the International Journal of Food Contamination, almost 400 cases of GMO contamination occurred between 1997 and 2013 in 63 countries. For farmers, the consequences have been severe. Contamination can be a catalyst for dramatic economic losses for farmers who face rejection from export markets that ban GMOs. Organic farmers suffering contamination can lose their organic certification and the premium they earn for their organic crop. As consumer demand for non-GMO products expands, farmers are looking for opportunities to diversify into non-GMO markets that pay higher prices. However, the inability of companies to properly separate GMOs from conventional varieties continues to threaten these options for farmers.
The long-term health effects of GMOs on both the planet and people are unknown. In addition, nearly all studies that claim to be safe are funded by the verybiotechnology corporations that profit from GMO sales.
The biotech industry views GM crops as a benefit to our world because they allow farmers to generate higher crop yields with fewer inputs. Monsanto and its peers have thereby flooded the seed markets with genetically modified soybean, corn, and cotton seeds with two major traits: pesticide expression and herbicide resistance. So what does this mean? Basically, plants now have the ability to survive with harmful bug killers and herbicides with the toxic trait of Bacillus thuringiensis, or Bt. Bt is related to a species of bacteria that causes food poisoning and also the bacterium that causes anthrax. Bt kills only very specific species of insects. Many organic farmers have used Bt for over 50 years as a pesticide to control insects. Now, genes from Bt are used to modify plants so that the plants produce the Bt toxins and kill insects that try to eat them without the use of external spraying.
Researcher Charles Benbrook at Washington State University demonstrated that the increase of GMOs in the United States has led to an increase in the use of toxic chemical inputs. Benbrook discovered that while the Bt trait has allowed farmers to spray dramatically lower levels of insecticides, that effect has been more than outweighed by the influx of herbicides released by Monsanto’s Roundup Ready technology, as weeds have quickly adapted resistance to frequent doses of Monsanto’s Roundup herbicide.
Do They Yield More Food?
So now the big question, do GMOs yield more food? A recently released paper by University of Wisconsin researchers and funded by the U.S. Department of Agriculture has negated the argument that GMO farming yields more food. The researchers looked at data from the University of Wisconsin’s test plots that compared crop yields from various varieties of hybrid corn, some genetically modified and some not, between 1990 and 2010. Even though some genetically modified varieties yielded small gains, others did not. Many even showed lower yields than non-genetically modified counterparts. The report concluded that it was surprising not to find strongly positive transgenic yield effects. Both the Bt trait for corn rootworm and glyphosate-tolerant (also known as Roundup Ready) caused yields to drop.
In addition, the report uncovers evidence of what is known as “yield drag” — the idea that manipulating the genome of a plant variety causes unintended changes in the way it grows, causing it to be less productive.
More encouragingly, the authors found that crop yields for GMO varieties are more stable year-to-year, and the yield fluctuation rate is less than those of conventional varieties. As a result of this stabilizing effect, the authors conclude that transgenic technology can improve farmers’ ability to deal with a risky environment, especially considering current concerns about the effects of climate change on production uncertainty in agriculture. They claim that by simply planting Bt or Roundup Ready crops, farmers face less risk from yield fluctuations.
However true this may be, it is far from generating higher crop yields with fewer inputs. It is also not clear if GMO seeds have advantages over conventional seeds when it comes to risk mitigation surpass the benefits offered by organic agriculture in this area. Therefore, deep research is needed to explore the new ingredients of organic manure for increasing the yield and other nutritional requirements of the food grains. In recent years there is a lot of debate on whether to go for organic farming or conventional farming or adopt genetically modified crops for higher yield. Human health and environmental safety are the major concerns of the GM technology, and in the absence of assurance by the proponents, many have deemed organic farming superior for its higher yields as compared to conventional farming.
There is another issue with consistent crop yields — monocultures. Monocultures ultimately deplete the soil and create the need for more fertilizers and chemicals to stabilize crops. If farmers used old farming methods – like crop rotation and permaculture that fostered a more healthy and sustainable environment for crops, there would be less need for all these chemicals.
Tips on a GMO-Free Diet
Despite the ever-presence of GMOs in our food system, there are steps you can take to transform your world into a GMO-free one.
Seek out organic veggies and fruit
Remember the 2 Ss (sugar from sugar beets and soy) and 3 Cs (canola, cottonseed, and corn). These crops are the most common genetically modified crops.
To learn more tips on how to avoid GMOs, click here. Keep in mind that you deserve the right to know what is in your food. Until we live in a world where all countries – not just 60-plus countries – have restrictions or bans on the production and sale of GMOs, you can vote with your dollar by simply not supporting the industry.
The continuous sprawl of urban and suburban areas is forcing wild animals into increasingly smaller habitats. Grasslands and wooded areas are demolished and turned into commercial, agricultural, and residential development, and in the U.S. alone, roadways have fragmented an estimated one-fifth of natural habitats to accommodate our travel needs. Animals attempt to cross these roadways in search of food, mates, and as part of their natural migration pattern, which often results in dangerous collisions with vehicles that can seriously injure or kill both animals and humans.
According to Defenders of Wildlife, it’s estimated that up to 1.5 million wildlife-vehicle collisions happen in the U.S. each year, and in Canada, there are eight large animal collisions every hour. Millions of animals die as a result of these collisions and around five percent also result in human injury or death. In Brazil, it’s estimated that five million animals are killed in wildlife-vehicle collisions every year. Species ranging from turtles and birds to moose and bears are affected by vehicle collisions, and each loss of life has an impact not only on animal populations but on an area’s ecology as well.
Fencing is often used to help keep wildlife off the roads, but even that can have a negative impact on wildlife by affecting their migration patterns and ability to find food. Signage is also used to warn motorists of areas where wild animals frequently cross, but in high traffic areas or where people are driving at fast speeds, the signs aren’t always effective.
As a solution, cities and states across the world have looked to special overpasses and underpasses made specifically for wildlife, helping them to safely migrate and putting drivers’ minds at ease as well. The concept isn’t new, with Europe and Canada having used these crossings for decades, but they’re becoming more popular in the U.S. and other parts of the world. The concept of a wildlife crossing might sound crazy, but studies across the board show that the structures are not only being used by animals on a regular basis but are making a significant difference in the frequency of wildlife-vehicle collisions.
The Netherlands has an impressive 600 wildlife crossings – known in the area as “ecoducts” – that help wildlife like deer, wild boars, and European badgers safely cross over roadways and railways. Hilversum, a city in the province of North Holland, is home to an ecoduct that spans nearly half a mile, making it the longest in the world. The structure has been in place since 2006 and is wide enough to include a bike path and riding trail, making it a safe crossing option for both animals and humans.
Banff National Park in Alberta, Canada utilizes wildlife fencing and a combination of 44 underpasses and overpasses to help wildlife travel without having to cross the busy road. The wildlife crossings, which were built between 1996 and 2014, work to connect vital habitats throughout the park. The fencing alone has reduced wildlife collisions by as much as 96 percent and the crossings have been regularly used by bears, cougars, moose, sheep, elk, lynx and other wildlife.
In the U.S., wildlife collisions along Highway 9 in Colorado have decreased by a staggering 90 percent since the addition of five wildlife underpasses and two overpasses, along with additional wildlife fencing, between the cities of Kremmling and Silverthorne. Remote cameras show that the unique underpasses are being used by wildlife ranging from small animals like raccoons to herds of mule deer. Overall, the Colorado Department of Transportation has installed 30 similar passages throughout the state, creating a safer way for wildlife to migrate and preventing dangerous collisions.
Washington State’s Department of Transportation is in the process of building a wildlife overpass over the Snoqualmie Pass, a portion of Interstate I-90 that runs through a range of mountains known as the Cascade Range. The 150-foot long overpass is expected to be completed in early 2019 and will serve as a passage for elk, foxes, bears and other animals.
These unique bridges and underpasses are saving wild animals and keeping humans safe on the road, but they can also cost millions of dollars to construct. A group of conservationists and advocates led by the National Wildlife Federation is working to raise $60 million to fund wildlife crossings in Southern California. The crossings would help mountain lions, which have been struggling with issues caused by a lack of genetic diversity.
In the Brazilian state of São Paulo, a group of researchers is working on a prototype for an electronic roadside animal detection system to help prevent collisions. It works by using invisible infrared beams of light that would transmit a signal when the beam is interrupted by an animal. The signal would then trigger a message panel or beacon light that serves as a warning for drivers to slow down and pay attention to animals in the area. The system would be installed in areas with heavy amounts of domestic animal and wildlife traffic and animal-vehicle collisions.
Innovative technology and special wildlife bridges and underpasses can help prevent wildlife-vehicle collisions, but the best thing you can do is use caution while driving, especially in areas heavily populated by wild animals. Always slow down when passing yellow animal crossing signs and use extra caution at dawn, dusk, and night, when many animals are more active. Pay attention to the shoulder of the road and slow down if you see an animal, especially since many larger animals travel in groups.
Biological diversity, shortened to biodiversity, refers to the variety of things that we have on earth. “Things” can refer to different DNA, different bacteria, different plants and animals, and even the variety of all of these things within a region or ecosystem. Biodiversity is generally acknowledged as important, even essential to survival, but it is endangered by human activities on earth. It’s not just endangered and extinct species that this effects though, through the interconnectedness of planet Earth, many humans are feeling this every day. Increasingly, it is our interactions with our food and food production that are endangering biodiversity.
Most of what North Americans eat is now the product of industrial agriculture. At the beginning of the 20th century, machinery began changing the global agricultural landscape, replacing the biological power of humans and animals for a variety of tasks. The thirties saw the advent of new, high-yield crop varieties, and throughout the second half of the twentieth century until today, the use of synthetic fertilizers and industrial agriculture techniques have continued to grow. This type of food production has been hugely successful; more food is produced than ever before on earth. Success, though, has come at the cost of dependency on fossil fuels, chemical fertilizers, and biodiversity. In short, the environment.
Why is all of this important?
Biodiversity is essential to all systems on earth, and a third of plant diversity is expected to disappear by 2050. Today, there are 80,000 edible plants on earth, but only 15o are cultivated. Climate regulation and crop pollination are big examples of natural global systems that rely on biodiversity. Monocultures and cultivation of only high yield crops has led to a decrease in biodiversity and uniform ecosystems, as well as soil degradation and biodiversity loss. There are lots of reading available on the internet about the importance of diversity to agricultural systems. This will continue to be an issue of vital importance in the future because some plants will be more susceptible to climate change than others, so variety of crops will be needed to navigate changing climates in order to make our food resilient. Loss of honeybee populations has been a major wake-up call for many people to species loss. Thankfully, awareness and action provides opportunity to engage and help species endangered by human activity.
The loss agricultural biodiversity is one thing in terms of natural systems; but all around the world, large crops are replacing the locally produced foods from different diets. As people all adopt similar diets, not only do we become increasingly dependent on a small number of foods, but we lose the cuisine and the culture that come along with varied diets.
Interesting foods that are part of a diverse, healthy world
Learning about different foods is fun; it opens windows to different cultures and lifestyles. Not to mention trying new foods, which is also a worthwhile experience. Read up on some of these foods that you might never have heard of, and the next time you come across a fruit or veggie you’ve never heard of, give it a try, you might be supporting an ecosystem’s diversity. You never know, your quest to support biodiversity might lead you to discover a new favourite food or something really neat!
Argan: This African crop is probably best known today for its oils benefits, especially as a skin product. The nut is grown in trees, mostly in Morocco, where women run the argan industry, and it’s a staple food. Argan oil has a ton of health benefits and is used in a variety of different ways.
Ermelo Orange: From Europe, this fruit is grown in the town carrying the same name in Portugal. The region is characterized by a microclimate, ideal for orange growing, where the use of pesticides and chemical fertilizers is forbidden. This variety of orange is known for its thin, pail peel, and sweet, not very fibrous interior.
Bitter Melon: This Asian gourd has a funny appearance, but if you’re up to it, it’s full of a variety of really interesting health benefits. Originally from the Indian subcontinent, this bitter crop is enjoyed in several Asian countries today.
Bunya nut: Australia’s indigenous people ate bunya nut, food from large Bunya pine trees, as a staple food before the arrival of Europeans. Still a common food, its consumption is on the decline. Similar in taste and appearance to chestnuts, this indigenous food has an interesting history.
Papalo: Grown in Mexico, where it has been used to flavour dishes, this plant has a strong smell, and adds a lot to different cuisine. Papalo is an ancient plant, which is only now growing in popularity as some American chefs are bringing it into their dishes as garnish and flavour. In addition to its unique taste, it has also been used as a natural remedy.
These list is inspired by this article on indigenous foods being replaced by the Western diet, written by the White Crow Farm Project. If this topic is of interest to you, click here to watch an interesting video on the importance of plant diversity.
Why do we care about nature, and can we actually quantify what the benefits are? This is what the UN's The Economics of Ecosystems and Biodiversity (Teeb) project is all about, and the answer is remarkable. The natural world – biodiversity – provides us with food, materials and energy. We eat animals and plants; insects pollinate many of the foods we consume; microbes in the soil provide the nutrients the plants to grow; vegetation and soil biodiversity reduce flooding and release clean drinking water; vegetation soaks up a substantial proportion of the climate warming carbon dioxide gasses that we emit. The list goes on and on. Urban and rural citizens alike rely on these natural products and benefits.
The real cost of damaging nature, it turns out, is at least 10 times greater than the cost of maintaining the ecosystem as it is so that we can reap the associated benefits. To take an example close to the University of York where I work, the costs of flood defence construction and flood-related insurance claims in the Vale of York hugely outweigh the agricultural benefits of drainage ditches and overgrazing in the River Ouse catchment. Rather than treating nature as a pleasant luxury, Teeb argues that we should integrate the real costs and benefits within our decision-making. It should not be the preserve solely of environment and conservation ministries, but it should be at the core of the activities of finance departments.
Teeb argues that we should get rid of subsidies that are environmentally damaging and reward beneficial activities that maintain natural ecosystems. This might be by including the costs of damage within the purchase price of products to encourage us to buy the least damaging items, and potentially by paying land owners and countries directly to maintain natural ecosystems. Farmers in the Ouse catchment have recently received payments for blocking their drainage ditches; and the perverse subsidies that rewarded farmers by the animal – resulting in over-grazing, trampling and erosion – have been removed. It can be done. Achieving this at a global scale is far more difficult.
If you keep microscopic predators and prey in a small bottle, the predator usually becomes too common, eats most or all of the prey, and then dies out itself. In Pilanesberg Game Reserve, a fenced 572 km2 game reserve in South Africa, predator numbers had to be reduced to stop antelope numbers from collapsing. A larger bottle.
The planet is our bottle: 7 billion people and counting, 2 billion more by the middle of this century, with the level of consumption per person increasing just as fast. Greening the world's economies and social systems is essential is we are to avoid a similar collapse. Let us hope that the Teeb conclusions and reports take us a step in that direction.
Chris Thomas is professor of Conservation Biology, Department of Biology, University of York.
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