Why Did Darker and Lighter Human Skin Colors Evolve?

By Bridget Alex | January 28, 2019 4:00 pm
evolution of human skin color human migration people walking

Members of the Hamer Tribe walk at sunset in Ethiopia’s Omo River valley. Studies show that new skin colors evolved as humans moved north and south from equatorial Africa toward higher latitudes. (Credit: Kimberly Petts/shutterstock)

Human skin color reflects an evolutionary balancing act tens of thousands of years in the making. There’s a convincing explanation for why human skin tone varies as a global gradient, with the darkest populations around the equator and the lightest ones near the poles. Put simply, dark complexion is advantageous in sunnier places, whereas fair skin fairs better in regions with less sun.

That may seem obvious, considering the suffering that ensues when pale folks visit the beach. But actually, humanity’s color gradient probably has little to do with sunburn, or even skin cancer. Instead, complexion has been shaped by conflicting demands from two essential vitamins: folate and vitamin D. Folate is destroyed by the sun’s ultraviolent (UV) radiation. Whereas the skin kickstarts production of vitamin D after being exposed to those same rays.

Hence, the balancing act: People must protect folate and produce vitamin D. So humans need a happy medium dosage of sun that satisfies both. While the intensity of UV rays is dictated by geography, the amount actually penetrating your skin depends on your degree of pigmentation, or skin color.

That’s the basic explanation, proposed in 2000 and fleshed out since by anthropologist Nina Jablonski and geographer George Chaplin. But for the full story of skin color, we’ve got to go way back to hairier days.

Shielding Naked Skin

Several million years ago, our ancestors’ skin tone would not have been obvious. That’s because early hominins were almost certainly cloaked in dark fur. But beneath the body hair, they probably had pale skin based on the fact that our evolutionary cousins, chimpanzees and gorillas, have light skin under dark fur today.

Our ancestors eventually lost this fur and gained pigment in their skin. Although the exact timing and causes are debated, many researchers agree that when humans lost their fur, it helped us stay cool while foraging as upright-walking bipeds in the sunny, open habitats of equatorial Africa. The tradeoff, however, was bare skin that was exposed to intense, year-round UV rays. In this context — roughly 1 to 2 million years ago — darker skin was likely better to protect folate stores.

Why is folate so important? The nutrient plays a role in DNA activities, but its major impact is on evolutionary fitness — one’s ability to survive and reproduce — through fetal development. When pregnant women don’t have enough folate, it can lead to neural tube disorders like spina bifida, a condition where the vertebrae do not fuse completely around the spinal cord. Most neural tube disorders are debilitating or fatal.

Experiments have shown that sunlight breaks down folate, as an isolated molecule, in blood plasma and in skin biopsies. It’s thought that dark skin impedes this because it contains higher amounts of melanin, a dark-brown pigment that absorbs UV rays and chemically disarms their harmful by-products.

skin color map around world

Human skin color found in indigenous peoples varies with latitude. (Credit: Emmanuelle Bournay, UNEP/GRID-Arendal)

Leaving the Tropics

But the human lineage did not remain exclusively in equatorial Africa. At different times, people ventured both north and south, to higher latitudes with less sunlight.

That’s when vitamin D became a problem. Like folate, this vitamin is important for evolutionary fitness. It facilitates absorption of calcium, necessary for healthy bones and immunity. Vitamin D can be made in the skin, but only when the process is initiated by certain wavelengths of UV rays.

Away from the tropics, for most of the year, there is just not enough UV of the right wavelength for skin cells to form vitamin D. One study in the 1980s showed this using fresh foreskin collected from Caucasian babies circumcised in Boston. The researchers divided each sample in half. Then, they exposed one part of the foreskin sample to three hours of midday sun and kept the other in the dark. In the spring through fall months, the sun-exposed skin still produced the precursor for vitamin D, as would happen in a living human. However, no measurable precursor was synthesized during winter, up until March 17.

So, to get sufficient vitamin D year-round in high latitude places like Boston, people have to rely on body-stores built up during the summer months or acquire the nutrient through foods, like fatty fish. But the darker your skin, the harder it is to maintain adequate vitamin D. In studies comparing dark and light-skinned residents of northern cities, paler people had higher vitamin D levels throughout the year. Their less pigmented skin let in more rays.

From Light to Dark to Varied

A range of skin colors evolved at different times, in different populations, as human spread across the globe. In addition to these genetic biological changes, groups have also developed cultural adaptations to deal with variable sunlight. For instance, we can consume diets rich in folate and vitamin D. We can also build shelters, wear clothing and slather sunscreen to block UV rays.

Skin color is one of the most obvious and (literally) superficial ways humans differ. But the evolutionary story behind this variation is shared: Over the course of human evolution, complexion evolved from light to dark to a continuous gradient, mediated by geography, genes and cultural practices.

CATEGORIZED UNDER: Living World, Top Posts
MORE ABOUT: anthropology, evolution
  • peterjohn936

    What to the eye may look like a big difference is genetically insignificant.


    Again another misuse of the word ‘evolution’. This was, and is, simply the process of adaptation. Science has now settled the question and adaptation is the result of pre-programmed (not evolved) abilities in the species. Its in the DNA. Natural selection encourages the characteristic in a population so it becomes common. Adaptaion can only produce micro-changes such as skin color, or fur color, shape of nose etc. but cannot change the species on anthing other than a superficial level. So it is not ‘evolutionary’, it is simply adaptive. I am sick of psuedo-scientists misusing terms. What up with that? None the less, once understood correctly, interesting article.

    • http://www.RNA-mediated.com jvkohl

      It’s not just the pseudoscientists. On 1/2/19 552pm Henry Morris IV wrote:

      “There is no such thing as “natural selection.” Nature does not “select” anything — it just is. Rather, from the very beginning, our Creator built into creatures the ability to adjust to changing environments so they could survive and thrive and “fill the earth” as He commanded.”

      The theologians have added to the confusion and the forthcoming issue of Acts & Facts tries to change Darwin’s claims about natural selection for “conditions of life” to claims about “immanent selection.”

      • okiejoe

        God preserve us from religion.

        • https://www.facebook.com/app_scoped_user_id/YXNpZADpBWEVNU2tBQW5qQy1zc1FPX211N3ZAFT0JwcFZAJMFZAvUW83a2lnb09HU25XVUtpNzJqNzgzYm5hUGdpTkdSVy1sa1VIdmFmdDh5cURDRGhRUlU2aldmVmEwTVpSMWVncHhOcDRI/ Roger Sinden


        • vcragain

          The concept of whether or not there is some higher ‘authority’ that ‘created’ us or the first ‘live’ organism, is not a right of those professing ‘religion’. They like to pray hoping ‘it’ is listening, the problem is there is no evidence of that ! It does not mean there is no high-level ‘it’ there, it simply means we cannot determine that at the moment. Logically speaking in human terms we need a ‘beginning’ to all this & a reason for our existence, but since we have no clue what ‘this’ is, we are left in limbo. So – never condemn another human making themselves feel better by deciding to ‘just believe’ in a particular construct, and if you DO decide that yourself – do NOT condemn others who make the opposite decision – NOBODY KNOWS what is real !

    • Tony Boswell

      I have to disagree. An individual within a group doesn’t “decide” to have darker skin because it would be better. Over generations the more successful individuals pass on their genetics to their offspring, That’s evolution. Also, I would reserve the term psuedo-scientists for the true culprits like those who advocate homeopathy, chiropractic, acupuncture etc.

      • Jim

        You have to try acupuncture before you say these things…

        • Tony Boswell

          Or I could just look at the overwhelming mountain of data that it’s a scam that has no medicinal value.

      • ITBWTW

        Tony, that is not evolution, that is classic adaptation. And who says they didn’t want to be black? Who says they weren’t created black in the first place? But what the author describes is not evolutionary for the species, at best it is micro evolving of the characteristics of the individual, and completely superficial. It is simply the bodies response to stimuli. If it has advantages then it will be selected for multiplication (natural selection) over other choices. Its certainly not a method of morphing into something else.

        • Tony Boswell

          I can’t quite tell if you’re a creationist or if we’re arguing over semantics. An organism doesn’t “choose” to have darker or lighter skin any more than a giraffe chooses to have a longer neck. Within any species there is variation. In this case, more or less melanin. If a particular variation has benefit, that organism will pass on it’s genotype to successive generations more so than it’s cohort. The successive generations will express that in their phenotype. That’s evolution.

      • Capt Doug Nemo

        Chiropractory works wonders, sometimes. some practitioners are “naturals” other simply trained and not as effective. It is NOT pseudoscience. In my book adaptabion over many generations, involving genetics, IS evolution.

        • Tony Boswell

          Well at least we agree on one thing, Captain. As far as chiropractic I encourage you to look with an open mind at some of the evidence of real harm caused by it.

      • vcragain

        In your wholesale condemnation of the “pseudo-sciences” you are forgetting that at the bottom level of all things, we are electrical organisms within electrical fields, made of electrical particles – all is merely a huge “pea soup” of electrical charge with defined ‘order’ that keeps us ‘solid’ & with mostly prescribed definitions. BUT that same underlying structure of all ‘earthly’ things allows for the results we sometimes find strangely ‘real’ and inexplicable within our everyday worldly ‘system’. We in fact DO have an ‘aura’ – our ‘edges’ are not so defined as we appear to be. We do not understand anything outside of what we can see, feel, hear, smell etc….it is all hidden to our senses, so to just assume that is all there is, is very ignorant. All that the so-called ‘pseudo-sciences’ are trying to do is to try to bring the study of ‘stuff’ outside our perceived limits, into our field of research & give them serious consideration, no more ridiculous than the speculation of astrophysicists on what is ‘out there’ – including the concept of other dimensions in space-time !

        • tony

          So prove it. These scams use sciency sounding words and phrases mostly for the express purpuse of seperating people from their money. You and they have the option to use double blind, peer reviewed studies to prove their is something to it and then guess what it becomes instead of psuedo science? Science.

    • Fernando Dosa

      Wrong. The small changes you mention is evolution. Keep changing the nose. Arms legs. fur. over a long time you get the difference between human and chimp.

      • ITBWTW

        Sorry Fernando, its not evolution. It is adaptation, which an inherent response to outside stimuli, or selective breeding. Take dogs for example. We have selectively bred them for over 10,000 years, millions of times, and yet everyone of them remained a dog. They did not evolve, they just change shape and color. Nothing has ever evolved into something greater or different than the original subject. At least nothing science can point to without adding a great amount of imagination. And once selective breading is stopped, within a very few generations, they look just like the original dogs they were to begin with. That’s the science of it all.

        • Fernando Dosa

          What do you have against evolution if it’s true?.
          It seems you are trying so hard against it as if your life depended on it . what would you need to change if our ancestors are great ape.

          • ITBWTW

            Not at all, I am so disappointed at the complete lack of hard evidence in the scientific record of evolution. Your study of biology is a good thing, but you have not seen a single piece of evidence for one species morphing into a completely different species. In fact, you should know this, with the discoveries of DNA we are seeing that the Evolutionary processes cannot possibly account for trans-speciation. The composition of DNA is could never evolve as so many pieces to exist require other pieces to be present that can’t be present unless the original piece is present and then some how brought together at the same time. Cellular Biology has practically destroyed every part of the theory of Evolution. So now the best hope to salvage Evolutionary Theory is the hopes random Mutations will explain trans-speciation, in FACT its the last best hope. And yet, we know definitively, and since you studied Biology I presume you know this, they have never found a mutation that is beneficial in any long term sense, and the vast majority of mutations are harmful, most deadly. They have zapped fruit flies Millions of times over the last 120 years, and have never produced a beneficial mutation or change in the species. Despite the hype of a few mutation, it was later discover the mutation had sterilized the subject and although one feature was enhanced it was at the expense of other characteristics and ultimately destructive. So Science today knows less than it did 100 years go about trans-speciation. Don’t get me wrong there have been tremendous discoveries and great products from all this. Just no coherent explanations, yet.

            So if I have any objections, its the misuse of the word ‘evolution’. The precise mechanism is ‘Adaptation’. And the most recent research findings are that Adaption is an characteristic already present in the species through DNA. In other words every species has the ability to adapt on superficial levels.The ability to get a sun tan is a present capacity of your body based on DNA. If you do not have the DNA for suntans, then you cover up and or figure out how to prevent sunburn. Even that process is an adaptation. It does not evolve. So when I hear or read the misuse of the word Evolution, I know I’m dealing with a pseudo-scientist. A real scientist bases his conclusion on science not propaganda, or if he is discussing a Theory, he will speak in theoretical terms. In this article the term ‘evolution’ is not only misused, but presumed to exist. That is contrary to scientific evidence.

          • ITBWTW

            First let me say I have Bachelors of Science. I was a devoted Evolutionist in under-grad. I was taught that it was true and I accepted it without much thought. I received my Juris Doctorate at a prestigious Law school and after practicing litigation law for 2 decades, became a Judge. I am trained to analyze facts and make conclusions on facts, regardless of my personal feelings, and have been doing that for 17 years. After becoming a Judge I had time to re-engage my love for science. As a Judge I was presented with many precedent cases by lawyers that pre-supposed they were right on the law. I would have to go to the source and read the case law myself, only to discover that those case did not support the lawyers positions at all, and many time stood fro just the opposite of what was proposed. So with time on my hands, I applied the same exercise to science and evolutionary theory. I simply decided to look behind the narrative to study the facts that support the narrative Evolution as the cause of the Origin of Species. Although there is mountains of proof on adaptation and natural selection, there seems very little evidence of evolution as an explanation for the origins of species. When one brings up evolution we must always ask “evolving to what?”. As a lawyer I am a word smith and words have meaning. Words in my view must be used correctly to accurately convey thought, especially in Law and Science. So when this author misidentifies the process of adaptation, and calls it evolution, I must object. To do otherwise is to continue to to mis-lead people.

          • Fernando Dosa

            Return your degrees .
            You don’t sound educated and you certainly don’t have an understanding of evolutionary biology at all.

          • ITBWTW

            Fernando,Why are you vehemently nasty about what I have pointed out? Your defensiveness suggests insecurity. And I can see why you would be so insecure. Not a single legitimate scientist would say “Evolution is a Fact”. It is a theory. So that eliminates you from the legitimate scientist category. As science investigates more and more, there is less and less evidence to support it as a cause of “origins”. But small changes within the species is observed. So if you want to call a brunette turning blonde “evolution”, so be it. They have branded that “micro-evolution”. Changes within a species that does not change the species, but minor attributes. I do not call that “evolution”. It is natural selection and adaptation, or maybe just Clairol.

            “Natural selection”, even according to the most devout evolutionists, does not have the power to generate anything “new.” Evolution, now sometimes called “Macro- Evolution”, is the evolving from one species into another, or from a lower to higher. That is the old Darwinian Evolutionary theory. When no evidence was found to support Darwinian Theory, the Evolutionist created a new theory called “Modern Synthesis” attributing genetic and random Mutation with the ability to evolve. It too has failed because, so far, there has been no discovery of any net beneficial mutations. All the radiation of Fruit flies for over 120 years has produced millions of mutations, and billions of strands of damaged DNA, but not one single evolved Fruit fly. That is the science of it as of today.

            So now we are entering the 3rd edition of Evolutionary Theory, the “Integral Theory” of evolution, which hopes to find the causes of life and its variations through studies of DNA, random mutations, Mobile DNA, errors and DNA damage to explain genetic variation. They hope to find evidence that damaged DNA accounts for changes and speciation. They stand confounded on how DNA exists in the first place.

            Fernando, Please learn, and refrain from showing your ignorance on the subject. BTW, Sir Francis Bacon,who is credited for creating the scientific method was a lawyer. He taught to use inductive reasoning and careful observation of events in nature.

          • ITBWTW

            Oh, lastly there is absolutely no evidence that micro evolution has created Macro evolution! That too remains a theory. The commonly taught mechanisms of “Phylic Gradualism” (Classic Darwinian theory) and “Punctuated Equilibrium” (Catastrophic event survived with sudden appearance of new attributes) simply have no evidence in Fossil record. It just a theory without any proof, yet.

          • Fernando Dosa

            Micro evolution happens on a small scale (within a single population), while macroevolution happens on a scale that transcends the boundaries of a single species. Despite their differences, evolution at both of these levels relies on
            the same, established mechanisms of evolutionary change:
            Question. How old is the earth?

          • ITBWTW

            Ignorant statement. Just because micro evolution is observed and is true, that mechanism to create a Macro-evolution has never been observed! That, despite 150 years of major experiments. Take breeders for instance, have bred 100,000s differently looking dogs over millenniums (micro evolution). They have never produced a Bear, a cat, a squirrel, or any thing remotely close to a trans species. You are living on blind faith. Again All scientists of repute agree that adaptation cannot create anything new.

          • Fernando Dosa

            Question 1.What is a theory?
            Question 2. Is evolution by natural selection a theory?
            Question 3. what is a fact?

          • Fernando Dosa

            Why don’t you publish your scientific work on evolution and have it peer reviewed.
            Oh wait you’re not a biologist what am I thinking.

          • ITBWTW

            I never said Evolution is is not True, Its a theory! Its being tested. I said its unsupported by evidence. The theory is still useful to attempt a better understanding or nature. BUT I GAVE YOU A SHORT HISTORY OF THE MORPHING OF EVOLUTIONARY THEORY TO TRY TO EXPLAIN THE LACK OF SCIENTIFIC EVIDENCE FOR THEIR THEORY. But there are air -heads out there that think evolution is a “Fact”, like yourself. People who do not think deeply. You are exhibit “A” to my original objection that the misuse of the term “Evolution” when if fact the science they are describing is “Adaptation”. (Skin color is evidence of “Adaptation”, not “evolution”!) misleads people. The author, wittingly or not, baits gullible folks like yourself into believing something there is little or no evidence of, by supplanting something that there is overwhelming evidence of. So calling “Adaption” “evolution” is scientific dishonesty- a form of “propaganda ” not Science. And, I admit I had blind faith like you do, before I really studied the subject. That’s why your sophomoric insults are not worth addressing. I hope this sends you on a journey of truth seeking. And I continue to study. In the mean time I will challenge pseudo-scientists who misuse words to propagate, rather than enlighten.

          • Fernando Dosa

            You are not educated in science and it shows by your casual use of the word theory when used in scientific terms, here’s science 101.
            scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results. Where possible, theories are tested under controlled conditions in an experiment.[1][2] In circumstances not amenable to experimental testing, theories are evaluated through principles of abductive reasoning. Established scientific theories have withstood rigorous scrutiny and embody scientific knowledge.[3]

            The meaning of the term scientific theory (often contracted to theory for brevity) as used in the disciplines of science is significantly different from the common vernacular usage of theory.[4][Note 1] In everyday speech, theory can imply an explanation that represents an unsubstantiated and speculative guess,[4] whereas in science it describes an explanation that has been tested and widely accepted as valid. These different usages are comparable to the opposing usages of prediction in science versus common speech, where it denotes a mere hope.

            The strength of a scientific theory is related to the diversity of phenomena it can explain and its simplicity. As additional scientific evidence is gathered, a scientific theory may be modified and ultimately rejected if it cannot be made to fit the new findings; in such circumstances, a more accurate theory is then required. That doesn’t mean that all theories can be fundamentally changed (for example, well established foundational scientific theories such as evolution, heliocentric theory, cell theory, theory of plate tectonics etc). In certain cases, the less-accurate unmodified scientific theory can still be treated as a theory if it is useful (due to its sheer simplicity) as an approximation under specific conditions. A case in point is Newton’s laws of motion, which can serve as an approximation to special relativity at velocities that are small relative to the speed of light.

            Scientific theories are testable and make falsifiable predictions.[5] They describe the causes of a particular natural phenomenon and are used to explain and predict aspects of the physical universe or specific areas of inquiry (for example, electricity, chemistry, and astronomy). Scientists use theories to further scientific knowledge, as well as to facilitate advances in technology or medicine.

            As with other forms of scientific knowledge, scientific theories are both deductive and inductive,[6] aiming for predictive and explanatory power.

          • ITBWTW

            Boy Fernando, with all due respect, you really are ignorant (meaning uninformed, clueless through no fault of your own I hope), both of Science and literacy. But you accidentally, I’m sure, affirmed what I have said. “scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results” (your words). I agree. So where are they, Fernando? Where are those repeatable proofs that support evolution. Where is the verification that one species over time changed into another? (Macro evolution) I’m really open to hear what you think those repeatable proofs are.

    • David

      Everyone in this comment is wrong. Skin color is both an adaptive trait and an evolutionary one. When the skin color changes within one lifetime in the same organism, that is adaptation. If the color of skin affects the fitness of the species, natural selection takes over. Natural selection is a process of “picking out” the unfit organisms from the species. Over time, the more fit organisms will reproduce to higher numbers than the less fit ones, leading to the trait being more common under the same circumstances. If colored skin is more suitable in the tropics region, meaning the survivability in the organism is higher, that is Evolutionary. Instead of spreading knowledge simply to prove someone wrong, take into consideration that facts are facts and changing them to fit your own opinion makes them OPINIONS. Some people here ought to learn how to do research before debating something. The first thing someone is taught in a debate class is to do your research! This article mentions folate and vitamin D folate being in a balance with vitamin D. If higher Vitamin D means less folate and vitamin D folate, or vise versa, one may infer that people with dark skin require more sunlight than those with pale skin. If the skin wasn’t dark in areas like Africa, folate levels would become extremely low, while vitamin D would be high. Putting natural selection into the equation will result in different pigmentations being more or less fit in different areas. Over time, meaning evolution is occurring, the more fit trait for the area will be the dominant trait. Adaptation and evolution work in conjunction and that is where people are confused. Evolution is adaptation over time and many generations.

      • ITBWTW

        Thank you David for your thoughtful reply. But my issue is that I think using the term “evolution”, in place of “adaptation” is scientific dishonesty. Especially when science agrees that adaptation produces nothing that is “new”. In other words a Black dog, a spotted dog, a large dog and a small dog have a basic unchangeable characteristic, they are all dogs and remain dogs. All of the dogs have DNA programing that allows them to adapt, select and multiply with new minor characteristics. The program is inherent in the species. Natural selection causes the characteristic to spread and become dominant, but other than adapting to the environment, nothing new has been added to the subject. And experiments have consistently shown that acquired adaptive characteristics when left to their own devices without controlled breeding, they return to being just a basic dog. If the Human race today interbred without barriers we’d all be brownish. But nothing new would be added to the human race. No evolution.
        You said “If colored skin is more suitable in the tropics region, meaning the
        survivability in the organism is higher, that is Evolutionary”. But you have perfectly described “Adaptation”. And unfortunately popular evolutionary literature misuses this term like you have to propagate an idea rather than a reality. Evolution Theorists have abandoned Darwinian theory..there is no evidence and too many holes, it doesn’t do what it says it does. The focus now is on DNA, the program. And they are confounded as to why it (DNA) is so resistant to trans speciation. In other words they still can’t find evidence of evolution even in DNA, yet. So if this article said, ‘exposure to the sun affects vitamin processing that affects skin color, demonstrating once again the fact of ‘adaptation’, I would not have even bothered writing this, because that is scientifically true. But it adds an “assumption” of evolution, it does not show evolution. And notice, Fernando still has not gotten back to me with any evidence. I’ve looked hard, and would like someone to show me. Even the Spine was present in the Cambrian Bloom, the sudden appearance of creatures in the millions with thousands of differing types and species. How do you figure melanin did that?

  • Kamran Rowshandel

    No primate doesn’t know the color of its skin and the assortment by this organ’s color in geopolitics around the world is an arrow pointing straight to suppressed history

  • http://www.RNA-mediated.com jvkohl

    “Environmental selection during the last ice age on the mother-to-infant transmission of vitamin D and fatty acids through breast milk” linked the uniquely elevated frequency of the human-specific EDAR V370A allele to cancer prevention due to recent bout of positive selection North and East Asian and New World populations.

    No experimental evidence links the epigenetically-effected changes in morphological and behavioral phenotypes to ridiculous claims about evolution, which have retarded scientific progress. The progress made by serious scientists has since linked.the sun’s anti-entropic virucidal energy to the prevention of cancer via the conserved molecular mechanisms of biophysically constrained microRNA-mediated cell type differentiation in the context of the physiology of reproduction.

    See: A self-assembled peptide nucleic acid-microRNA nanocomplex for dual modulation of cancer-related microRNAs

  • http://www.RNA-mediated.com jvkohl

    Researchers from Israel reported they will deliver the cure for cancer within the next year. “A cure for cancer? Israeli scientists say they think they found one”

    Researchers from China confirmed that the technology is already available. “A self-assembled
    peptide nucleic acid-microRNA nanocomplex for dual modulation of cancer-related microRNAs”

    That fact links skin color from ecological adaptations to differences in cancers among different human populations.

    If God-less Communists develop the cure first, they may decide to let everyone else suffer
    unnecessarily and die prematurely. No more war. They win everything based on the ignorance of biologically uninformed atheists and pseudoscientists.

  • Anna

    St­art making extra cash weekly… This can be a valuable part-time work for anyone… The best part about it ,work from comfort of your house and make from 100 to 2000 bucks every week … Apply now and receive your first cash at the end of this week…> LALMOST.TUMBLR.COM


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


See More

Collapse bottom bar