Researchers examine how evolution relates to health

February 12 marks the birth of the 19th century naturalist Charles Darwin, who launched the scientific study of evolution. While Darwin's theory laid the groundwork, ongoing studies have deepened our understanding of evolution, including how it relates to health. Research funded by the National Institutes of Health has helped answer many questions about evolution, health and medicine. Here's a sampling.

How is evolution relevant to health?

Considered by scientists as the central unifying concept of biology, evolution is a set of complex processes by which populations of organisms change over time. Evolution results in genetic adaptations that allow organisms to survive, be healthy and thrive. For example, humans have evolved digestive enzymes that break food into nutrients, immune systems that can both eliminate harmful microbes and co-exist with helpful ones, hormones that enable the "fight or flight" response, and traits that allow populations to live at high altitudes.

Can evolution help us understand why we get sick?

Yes. There are many reasons why we get sick, including being exposed to environmental hazards or having certain combinations of genetic variations that predispose us. But a key reason is that we're surrounded by other living—and evolving—creatures. For example, some strains of bacteria have genes that enable them to evade the antibiotics designed to kill them, allowing infections to continue. The flu virus also evolves, changing rapidly from year to year and helping to explain why new vaccines must be developed. Scientists carefully monitor this evolution to help ensure that each year's vaccines are effective against the most dominant strains in circulation.

Why do disease-causing mutations persist?

There are several reasons. Some mutations can have both beneficial and harmful effects, depending on the circumstances. Other mutations persist because they don't impair our ability to survive and reproduce. And finally, because evolution is an ongoing process, typically in response to environmental conditions, some mutations simply haven't yet been weeded out of our genomes.

How does knowing our evolutionary history advance biomedical research?

Because we and other organisms share common ancestors, our basic biology is similar. This means that researchers can learn about our biology by studying mice, fruit flies and even single-celled creatures that share part of our evolutionary history. Findings made in these and other so-called model organisms have taught us a tremendous amount about cell division, gene expression, embryonic development, metabolism and other fundamental processes that contribute to our health.

Can understanding evolution improve our health?

Studying evolution not only helps us understand why we're healthy, it can help us stay that way by guiding the development of approaches to prevent and treat many different types of diseases. For example, knowledge of bacterial evolution has led to the creation of a technique for tracking down the source of a foodborne illness outbreak. Learning how bacteria and viruses evolve can point to potential weaknesses that can be targeted in designing new drugs and vaccines. By understanding how our gut microorganisms adjust to the foods we eat and the medicines we take, we can explore new ways to promote the microbes' beneficial roles and reduce any harmful ones. Finally, studying the evolution of certain adaptations can help us understand how chronic conditions like diabetes and cardiovascular disease arise and persist, as well as identify ways to overcome them.


National Institutes of Health


  1. Charlie Hare Charlie Hare United States says:

    I think Mother Nature is trying to tell us something, but I don't know if we're listening very well.  Our overall health and welfare greatly depends upon how we deal with our natural surroundings, as we already know all too well, I think.  We are, in essence, products of our planet; and if our planet is unhealthy, it stands to reason that we, too, will likely be unhealthy.    

    We already know that many of our modern-day inventions have contributed to certain health issues (especially some of the chemicals we've created that confuse Mother Nature in big ways).  Yet we continue to use them and even introduce newer, more questionable things like genetically modified organisms (GMOs). Some GMOs are created by introducing genes from completely dissimilar organisms, like using genes from bacteria to modify plants.  

    Somehow, I don't know if Mother Nature would do that, but we think we're wiser, I guess.  Such practices will, undoubtedly, result in changes to our health, in one way or another.  

    We're seeing today what is happening to many people who are "celiac" or have other kinds of gluten intolerance issues.  Some sources say the recent uptick in this kind of health issue may be directly related to genetically modified wheat and other grains, which was experimented with and implemented mostly during the last half of the 20th century (post-1950s)
    See also:

    Will we learn?  Not likely, because there's too much at stake, I think.  Money, power, fame and fortune still command top-billing in many of these issues, and, until humanity learns how to "always do the right things", I suspect we'll see more of this same kind of "pseudo-ignorance" (because I believe we KNOW more than we're ADMITTING we know, y'know?).  

    I'm just sayin'...

  2. Babu Ranganathan Babu Ranganathan United States says:

    NATURAL LIMITS TO EVOLUTION: Only micro-evolution, or evolution within biological "kinds," is genetically possible (such as the varieties of dogs, cats, horses, cows, etc.), but not macro-evolution, or evolution across biological "kinds," (such as from sea sponge to human). All real evolution in nature is simply the expression, over time, of already existing genes or variations of already existing genes. For example, we have breeds of dogs today that we didn’t have a few hundred years ago. The genes for these breeds had always existed in the dog population but never had opportunity before to be expressed. Only limited evolution or adaptation, variations of already existing genes and traits, is possible.

    The genes (chemical instructions or code) must first exist or otherwise the evolution cannot occur. Genes instruct the body to build our tissues and organs.  Nature is mindless and has no ability to design and program entirely new genes for entirely new traits. Nature can only work with the genetic ability already existing in species. Nature cannot perform the genetic engineering necessary to increase that genetic ability.

    Many people have wrong ideas of how evolution is supposed to work. Physical traits and characteristics are determined and passed on by genes - not by what happens to our body parts. For example, if a woman were to lose her finger this wouldn't affect how many fingers her baby will have. Changing the color and texture of your hair will not affect the color and texture of your children's hair. So, even if through physical exercise an ape's muscles and bones changed so that it could walk upright it still would not be able to pass on this trait to its offspring. Only changes or mutations for traits that occur in the genetic code of reproductive cells (i.e. sperm and egg) can be passed on to offspring. Read the author's popular Internet article, HOW DID MY DNA MAKE ME? Apes, by the way, are quite comfortable in how they walk, just as humans are quite comfortable in how they walk. Even a slight change in the position of a muscle or bone, for either, would be excruciatingly painful and would not be an advantage for survival.

    The new science of epigenetics shows that certain acquired traits from the environment that affect how genes are expressed may be passed on (i.e. whether a gene is turned on or off), but these certain acquired traits do not change or alter the fundamental structure or function of the genes themselves.

    Modern evolutionists believe and hope that over, supposedly, millions of years random genetic mutations in the genes of reproductive cells caused by environmental radiation will generate entirely new genes. This is total blind and irrational faith on the part of evolutionists. It's much like believing that randomly changing the sequence of letters in a romance novel, over millions of years, will turn it into a book on astronomy! That's the kind of blind faith macro-evolutionists have.

    When evolutionary scientists teach that random genetic mutations in species over, supposedly, millions of years caused by random environmental agents such as radiation, produced entirely new genes (i.e. genetic code or genetic information) leading to entirely new forms of life, they are not teaching science but simply a faith, a belief!

    What about natural selection? Natural selection doesn't produce biological traits or variations. It can only "select" from biological variations that are possible and which have survival value. The term "natural selection" is a figure of speech. Nature doesn't do any conscious selecting. If a variation occurs in a species (i.e. change in skin color) that helps the species survive then that survival is called being “selected." That's all it is. Natural selection is a passive process in nature, not a creative process.

    How could species have survived if their vital tissues, organs, reproductive systems, etc. were still evolving? A partially evolved trait or organ that is not complete and fully functioning from the start would be a liability to a species, not a survival asset. Plants and animals in the process of macro-evolution would be unfit for survival. For example, “if a leg of a reptile were to evolve (over supposedly millions of years) into a wing of a bird, it would become a bad leg long before it became a good wing” (Dr. Walt Brown, scientist and creationist). Survival of the fittest actually would have prevented evolution across biological kinds! Read my Internet article: WAR AMONG EVOLUTIONISTS! (2nd Edition).

    All species of plants and animals in the fossil record are found complete, fully-formed, and fully functional. This is powerful evidence that species did not come into existence gradually by any macro-evolutionary process but, rather, came into existence as complete and ready-to-go from the very beginning, which is possible only by special creation.

    All the fossils that have been used to support human evolution have been found to be either hoaxes, non-human, or human, but not non-human and human (i.e. Neanderthal Man was discovered later to be fully human). Textbooks and museums still continue to display examples and illustrations supporting human evolution which most evolutionists have rejected and no longer support. Many diagrams of ape-man creatures over the years were reconstructed according to evolutionary interpretations from disputable bones that have now been discredited but still being taught in school textbooks.

    What about genetic and biological similarities between species? Genetic information, like other forms of information, cannot happen by chance, so it is more logical to believe that genetic and biological similarities between all forms of life are due to a common Designer who designed similar functions for similar purposes. It doesn't mean all forms of life are biologically related! Only within a true species can similarities be used as evidence for relationship because only within a true species can individuals be capable of mating and producing offspring.

    Also, so-called "Junk DNA" isn't junk. Although these "non-coding" segments of DNA don't code for proteins, they have recently been found to be vital in regulating gene expression (i.e. when, where, and how genes are expressed, so they're not "junk"). Read my popular Internet article: HOW FORENSIC SCIENCE REFUTES ATHEISM

    The real issue is what biological variations are possible, not natural selection.

    Visit my latest Internet site: THE SCIENCE SUPPORTING CREATION .

    I discuss: Punctuated Equilibria, "Junk DNA," genetics, mutations, natural selection, fossils, dinosaur “feathers,” the genetic and biological similarities between various species, etc., etc.

    Babu G. Ranganathan*
    (B.A. theology/biology)


    *I have had the privilege of being recognized in the 24th edition of Marquis "Who's Who In The East" for my writings on religion and science. I have given successful lectures (with question and answer period afterward) before evolutionist science faculty and students at various colleges/universities.

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News-Medical.Net.
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