Lanugo and whale legs

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.

The bacterial flagellum and the fallacy of irreducible complexity

On multiple occasions I have heard the bacterial flagellum (pictured above) used as evidence of irreducible complexity in biology, an argument often used by promoters of intelligent design. After examining this diagram it is not difficult to imagine why promoters of ID would claim it as evidence. The bacterial flagellum is a complex and rigidly organized appendage that superficially appears to be an intricately planned machine rather than an accidental biological structure. And if such an intricate thing looks too complex to be reduced or to have evolved from simpler forms, what other explanation remains except design? However, as with most arguments for intelligent design, evoking irreducible complexity is a fallacious action based on naive conceptions of biology and evolution.

Bacterial organisms have existed on Earth for the past 4 billion years, a very long time for evolutionary processes to be taking place, and have adapted to live in virtually every conceivable environment. Populations of bacteria grow exponentially, with billions of generations produced in a relatively brief period of time, allowing natural selection to have a very strong influence. Evolutionary biologists have theorized that large populations of organisms are more readily influenced by natural selection and that prokaryotes, bacteria and archaea, more readily exchange genes amongst each other. Therefore a large population of prokaryotes evolving over a vast period of time would predictably possess very intricate and complex biological structures. The bacterial flagellum is no surprise or dilemma for evolutionary biologists, in fact it is expected.

Utilization of the bacterial flagellum, or any other so-called irreducibly complex biological structure, as evidence of design is itself an evidence, evidence of a clear misunderstanding of biology and ignorance of evolutionary processes. Anyone who would challenge the modern theory of evolution with intelligent design either does not understand the widely accepted, peer reviewed science they are challenging or has been blinded by their religious convictions. After all ID is a religious view, not a scientific theory, supported almost exclusively by Christians, not scientists. Irreducible complexity is just one in a long line of fallacies promoted by the ID camp that poses no serious challenge to legitimate science.

Intelligent design and its supposed evidences are intellectually dangerous because they provide the public a falsified view of biology and evolution and the religious an erroneous vindication in denying the prevailing views of science. None of the discoveries in the fields of evolutionary biology, genetics, paleontology, etc have done anything except substantiate the accidental, impersonal, material processes of evolution as the best explanation for the origin and development of life. Irreducible complexity is a product of scientific illiteracy and religious conviction, not good science, and denying the true origins of astounding, beautifully complex biological structures like the bacterial flagellum only diminishes those astounding and beautiful qualities.

Speciesism

For thousands of years up to the present day humans have viewed animals primarily as a resource. Our evolutionary history has been marked and in many ways driven by the tools and resources we have been able to exploit. Soon after our ancestors developed rudimentary stone tools they were able to shear flesh from animal carcasses. Over a million years ago they began actively hunting and over 7,000 years ago anatomically modern humans developed agriculture. Since this time humanity’s primary interactions with animals have been through agriculture, a system in which animals are utilized and viewed as resources. Having concluded that we are intelligent and special while other animals are stupid and trivial we have proceeded to use, and often abuse, them for our own benefit.

In the past the hunting, raising, and slaughtering of animals for food and other resources was often a necessity and human beings have been apex predators throughout most of our evolutionary history. Little concern was given to the suffering and death of the prey, and later of the livestock, and both the use of animals as resources and the indifference towards their suffering continues today. But what have we learned about animal species other than ourselves that should change the way we have been exploiting them and behaving towards them for millions of years? Is there anything wrong with treating animals as resources or denying them to the right to lives free of pain and suffering?

Due to scientific advances in ethology, neuroethology, and behavioral ecology we now understand that the cognitive differences between humans and many other animal species are not as cut and dry as they once appeared. Primates such as the common chimpanzee and especially the bonobo display complex social systems, tool making, and independent language. Dolphins have been observed to use tools as well and also form social groups as complex as great apes. Many scientists now believe that great apes, dolphins, elephants and possibly other species possess self-awareness. Scientific discoveries regarding what animals are capable of feeling, thinking, and understanding have fundamentally altered the way we view the boundaries of animal cognition, human cognition, and the nature of cognition itself.

In light of this knowledge, domestic pigs and cattle, laboratory rats and primates, circus elephants, and oceanarium cetaceans and pinnipeds are among the many animals that should be regarded as individuals potentially capable of full cognition and treated as such. To deny animals the right to life free of pain and suffering is an act of speciesism, the selective discrimination of species outside of humanity. Anthropocentrism can be blamed for many of the atrocities that have been and are currently being committed against animals across the world and despite the scientific discoveries regarding animal behavior and cognition too many of us continue to view them as resources that deserve little to no rights.

Should the exploitation of animals as livestock, laboratory research subjects, or obligatory entertainers end completely? It seems obvious to me that the raising and slaughter of animals for food will not end in the foreseeable future, despite the fact that the vast majority of wanton animal cruelty takes place in modern agriculture, and outside the First World the utilization of animals as food can still be a necessity, rather than a choice. But it seems equally obvious that the way we in America treat and exploit animals for our own ends must be radically changed. We must accept our ethical responsibilities towards animals and begin the process of ending speciesism.

Arrogance and antiscience

Suppose a doctor, a family physician, informs you that you are displaying the symptoms of liver cancer and strongly recommends that you visit a liver cancer specialist to receive proper testing and diagnosis. You make the rational decision and visit the specialist who does blood work and takes a biopsy. After these tests the specialist informs you that you have Stage II liver cancer and require immediate surgery and subsequent chemotherapy. You make the rational decision and allow the cancer specialist to perform the surgery and treatment.

Why trust a family physician or liver cancer specialist? Why go through with the tests, surgery, and treatment? Because, as we can all agree, those are the rational decisions to make. We trust medical professionals because they are extensively trained and make recommendations based on empirical testing and evidences, and we allow them to take our lives in their hands because we are unqualified to treat ourselves.

Geologists inform us that the Earth is over 4 billion years old. Paleontologists inform us that eukaryotic life originated over 1.8 billion years ago. Anthropologists inform us that anatomically modern human beings evolved approximately 200,000 years ago. These scientists are professionals in their fields, are extensively trained, and base their conclusions on empirical testing and evidences. So why is it that so many Americans reject the conclusions of these scientists? Why do so many of us believe that we know better?

The United States is rife with antiscience. Based predominantly on religious beliefs, scores of Americans reject empirically verifiable scientific facts such as the age of the Earth, the origins of life, and human evolutionary history. Many of our politicians, including the majority of the candidates in the current presidential campaign, are not only scientifically illiterate but aggressively opposed to many of the important intellectual consequences of science. How else could travesties like intelligent design be seriously considered in American public education?

Arrogance is the root cause of antiscience. It is arrogance that causes fundamental religious adherents and the scientifically illiterate to deny proven scientific facts in favor of ideology. It is arrogance that causes so many Americans to distrust the scientific community and the invaluable information it provides. The medical profession that we exploit every day would not exist if not for the modern scientific method. Too many Americans, both politicians and private citizens, take the methods and products of science for granted all while they assault the most important information science provides us about our world, our universe, and ourselves.

Descent

The taxon Homo sapiens denotes a great deal of information. It denotes that we are a species, sapiens, within a genus, Homo. There were other species within our genus, such as Homo habilis, Homo erectus, Homo heidelbergensis, and Homo neanderthalensis, and the endmost of these went extinct less than 35,000 years ago. Many of these species lived contemporaneously. Homo floresienses, a diminutive hominid, lived alongside anatomically modern humans on the island of Flores up until 12,000 years ago.

Homo sapiens are the successful descendants of a long and complex evolutionary lineage and although we are currently the dominant species on Earth this was not always the case. For an estimated 20,000 years modern humans and Neanderthals coexisted. The latter were endemic to the colder continent of Eurasia and we were the invasive species migrating from Africa. The global climate had shifted and so allowed modern humans, who were not adapted to the cold like Neanderthals, to push farther north and exploit the abundance of natural resources. Eventually, despite some interbreeding and possible cultural commingling, Neanderthals were pushed to extinction. Our planet had changed and put them at a disadvantage they could not overcome.

If ecological circumstances had been different our ancestors may have been unable to compete with Neanderthals in the cooler, forested climate of Eurasia. If not for the overwhelming power of accident Homo sapiens may have been pushed back south, leaving Europe, the Middle East, and Asia to our close cousin Homo neanderthalensis. By chance this was not the case. We seized our advantage and, according to some scientists, spurred on the faltering Neanderthal’s extinction by waging genocidal war against them. Now we are the only representatives of our genus, the lone survivors of a remarkable lineage.

Our dominance of this planet is a product of accident. Over approximately 2 million years the Homo genus produced a number of successful species. Homo erectus existed across Africa, Europe, and Asia for 500,000 years, more than twice as long as Homo sapiens have so far. Evolution, that impersonal and dispassionate force, never favored us over any of our relatives, it never showed us any differential treatment. The history of human evolution should teach us how fortuitous our current position of supremacy in Nature truly is, and how swiftly it could be taken away.