A longtime acquaintance asked if my position on the origins of homo sapiens was based on faith, belief, a combination of these, or neither. 

It is not based on faith, which is a necessarily religious concept. I define faith as holding onto a position regardless of the evidence. All of my positions are based on evidence and observation, which means they change if warranted by the science. If research reveals a spontaneous generation of a complex life form in the fossil record, that would shoot holes in evolution, and I would adjust my thinking accordingly.

By contrast, Youth Earth Creationists insist the universe is 6,000 years old even though we can see the light from stars millions of light years away. They argue that humans and dinosaurs lived at the same time, an idea refuted by the geologic column and radiometric dating. Their positions are unmoved by science and proof, making it the definition of faith.

Continuing with what my position is based on, belief would be a better word than faith,  but it’s still inadequate. Belief is defined as “an opinion, conviction, or confidence,” or “a feeling of being sure that someone or something exists or that something is true.” Feelings or opinions have no place here, so evolution is not a matter of belief. It’s a matter of being able to understand its mechanism and process. By way of comparison, I don’t believe 5 x 5 = 25, I understand how elementary mathematics work.

The question from my longtime acquaintance was accompanied by a video of Abdul Rashid asking biology students a question, then asserting that their unsatisfactory responses disproved evolutionary science. It was further implied that this was proof of creationism, an assertion critical thinkers recognize at the negative evidence fallacy. Close to 100 percent of the products I’ve seen from Evolution is a Lie, the Creation Research Institute, Answers in Genesis, et al, are manifestations of this fallacy. They relate no science showing evidence of creationism. They instead highlight alleged deficiencies of evolution and wrongly think this is a point for their position.

All this came into play when my 8-year-old son asked me where humans came from. Not where baby humans come from, that was another conversation. Rather, he wanted to know how humans got here on Earth. Since what we know about evolution is based on verifiable, testable, falsifiable, and observable research, I was able to tell my son that humans evolved from an ape-like ancestor, through the process of natural selection, whereby beneficial mutations enable populations to adapt to their surroundings. Because of his age, I didn’t say that in so many words, and it was picture heavy, but the key point is that I can know it to be true because I understand what drives the process, how it works, and the evidence supporting it.

If evolution is true, stratas of the geologic column should reveal a succession of hominid creatures with features that are progressively less apelike and more human-like. And that’s what the fossil record shows, including the appearance of hominids capable of a bipedal gait about 100,000 years ago. As my son grows older, he’ll get more of an understanding and we can go into more detail. When that happens, here are some negative evidence arguments he may encounter from creationists. 

The silliest and simplest, and hence likely the first one he will encounter, is “Were you there?” Seriously, this is passed off as a point by Ken Ham and his ilk. And no, neither my son, Lewis Leakey, nor Stephen Jay Gould were there, nor do they need to have been. Science goes where the evidence leads, which is why DNA testing and fingerprints are better evidence than an eyewitness during a home burglary trial. Likewise, the fossil record, comparative anatomy, and so on are windows to evolution.

Subatomic physicists don’t see electrons, astronomers don’t see dark matter, and archaeologists didn’t see Greeks developing farm implements. These scientists make discoveries based on inferences and employment of the Scientific Method, and biologists work the same way.

While not ridiculous like “Were you there,” a similar ploy is to construct a deliberately narrow definition of science meant to necessarily exclude evolution from being so described. The crucial claim is that it must be observed, and the Rashid video centers on the interviewer trying to get biology students to admit this has never happened with evolution. In truth, evolution has been observed; more on that later.

But first, a definition. Science is a set of methods for empirical hypothesis testing. Done properly, it is able to support or refute some testable idea.

As Dr. Steven Novella noted in his response to the Rashid video, creationists prefer an inaccurately rigid definition of science that stipulates it must be observed at the precise moment it is happening (although that leaves them unable to meet their own criteria when arguing that God created man in his current form 5,000 years ago).

And evolution has been observed, most prominently in Richard Lenski’s ongoing e. coli experiment at Michigan State University. It has also been observed on three Florida islands. In 1995 researchers introduced brown anole lizards onto these islands, and when the researchers returned in 2010, they learned that to evade the invasive brown anoles, native green anoles had moved to higher perches. Consequently, the green anoles had developed larger toepads with more fringes in order to  provide increased surface area. This improved the lizards’ ability to cling to narrow, unstable branches. In short, they had adapted due to random mutation and natural selection, the driving forces of evolution. 

In addition to these direct observations, scientists base their conclusions about evolution on fossils, genes, population distributions, comparative anatomy, and developmental biology. These observations include learning that there are species that live exclusively in isolated locales, which is consistent with the idea of evolution. Examples include glowworms found only on New Zealand, giraffe weevils found only on Madagascar, and scaly-toed geckos found only on Vanuatu.

Also like other scientists, evolutionary biologists check the physical evidence to see whether it leads to verifiable predictions. That’s why anthropologists were looking for evidence of a hominid ancestor in the horn of Africa when they came across one of the field’s most significant finds, Lucy. It’s also why biologists suspected they might find a creature with features of both fish and land dwellers near Ellesmere Island, which led to the Tiktaalik fossil.

Just a few months ago, I had to explain to a successful 47-year-old man that evolution does not teach that humans descended from monkeys. He also wanted to know why there would still be monkeys if this were the case. A common response to such questions is to criticize science education, but I cannot put the blame on our public school system. There would be rare exceptions, such as parts of Louisiana and Mississippi where creationism is snuck into biology class, and where a student may be leading an insular existence where these notions are reinforced at church and home.

Otherwise, persons are without excuse. The information is easily accessible to anyone that wants it. A cursory Google search will reveal that evolution teaches that monkeys and other primates share a common ancestor with humans. The same search will show that we know this because of the geologic column, our sharing of 98 percent of our DNA with chimpanzees, and other anatomy inferences. The website will further reveal that when an evolving species becomes isolated from the main family it split from, it will eventually acquire characteristics that make it distinct. The parent species may survive or go extinct.

Creationists will sometimes say that evolution cannot explain the origins of life, and this assertion is perhaps the only common ground they and evolutionists occupy. Abiogenesis studies how life may have arisen from non-living matter and includes a combination of laboratory experiments and an examination of genetic information from today’s organisms. Evolution is a separate field centering on the study of inherited characteristics in biological populations over time. Trying to count being unable to explain how the first living organism got here as a strike against evolution is as nonsensical as dismissing the entire physics field because botany has yet to produce a blue rose.

My position is, quite literally, an evolved one. I was once a 15-year-old Young Earth Creationist asking my erudite biology teacher where each preceding life form came from. We kept going at least as far back as her positing that a lighting strike into a body of water may have produced Earth’s first life form. Which caused me to ask where the lightning came from, and what happened before that, and before that, and eventually her answer was, “I don’t know.” I took this as a weakness in her line of reasoning, whereas today I realizing that admitting one doesn’t have all the answers, but is still looking for them, is something commendable. And it never occurred to me that I was just as unable to explain where God came from. I was still several years away from understanding the fallacies of negative evidence and special pleading.

Some creationists say how awful it must be to think one came from an apelike creature or something resembling a salamander creeping though the slime. This is the appeal to consequence fallacy and, as such, has no bearing on whether these descriptions of human origins are true.

Another common creationist objection is that it’s inconceivable that anything as complex as a protein, much less the humans that house them, could result from chance. First, their inability to comprehend is irrelevant to whether it’s happening. That is merely the personal incredulity fallacy. Second, this argument misstates the role chance plays in evolution. Chance does determine random mutations, but natural selection is the opposite of chance. Natural selection preserves advantageous traits, enabling biological populations to adapt to their environment. Because of this, a single-cell organism that lived in water 3.5 billion years ago is the deep ancestor of an 8-year-old who is having the process explained to him.