The more I learn about the depth, magnitude, and elegance of evolutionary theory the more shocked I become that, according to polls, most Americans believe evolution is at least partially if not entirely false and that humans were created as we exist today and did not evolve from an ape-like ancestor. Now, according to another poll, when scientists were asked their opinion we find that virtually all of them, 97% in fact, believe in the validity of evolution and that humans evolved by the same processes as all other organisms. There is essentially no debate among the experts: evolution is a scientific fact that has been and is continually being supported by the evidence. But the majority of the American public is not on board with evolution and continually claim there is not enough evidence for it or that it is ‘just a theory’. So I will posit two accessible, straightforward examples in favor of evolution that I have found quite convincing, the sort of examples Americans have grown so adept at denying.
At around 22 weeks during human gestation the fetus begins to grow a coat of dark, downy hair, called lanugo, all over its body. Premature babies are most often covered in this lanugo. Whether the fetus continues to develop normally in the uterus or is born prematurely this coat of body hair is eventually lost and replaced by the shorter, finer vellus hair. Why do fetuses grow lanugo during gestation only to shed and replace it? Lanugo has no known developmental function. Since the uterus remains at normal body temperature the fetus does not need this thicker coat of hair for warmth and loses it before it comes to full term. The only reasonable explanation science can provide is that lanugo is an evolutionary relic. Primate fetuses also develop lanugo during gestation but do not lose it before birth and other animals such as elephants and cetaceans develop lanugo and shed it just as humans do. Lanugo is a vestige handed down from our hairy ancestors, a now useless characteristic that remains unexplainable outside of evolutionary theory.
If you were to go to a natural history museum and look at the mounted skeleton of a whale or dolphin you could observe a very odd thing. Beneath the vertebrae, suspended by wires, there is a small assemblage of undersized bones. These are the leg bones most cetaceans develop during gestation that are subsequently absorbed back into the body to remain unseen and utterly useless. Occasionally a whale or dolphin will be born with all four limbs visible but these are rare aberrations. Why do cetaceans grow hind limbs that they never use nor need? The only reasonable explanation science can provide is that these are an evolutionary relic. Cetaceans evolved from land-dwelling mammals, most likely artiodactyls, beginning in the Eocene and over millions of years they lost the the function of their hind limbs, which thus became the vestigial structure we see today. Whale legs are a vestige handed down from the land-dwelling ancestors of the cetaceans, a now useless structure unexplainable outside of evolutionary theory.
These are but two easily comprehensible and unambiguous examples that make arrant, logical sense only in the light of evolution. Vestigial characteristics such as lanugo and whale legs match up near perfectly with the indifferent, impartial, imperfect natural processes of evolutionary theory, in fact they are predictable. What other reasonable, empirical explanation for these examples could there be? Having transitioned from ardent evolution denier to eager evolutionist I appreciate full well both the desire and methods used to deny the overwhelming evidence in favor of evolution. For my part the evidence simply became too overwhelming for denial to continue, but for most Americans the denial remains steadfast and even accessible, straightforward examples such as lanugo and whale legs do little to convince the public of the validity of evolutionary theory. Until we begin to respect the scientific method, act in accordance with the evidence, and value the consensus view among the experts America will remain one of the world’s only developed nations in which the majority denies the fact of evolution.