What Is "Real Scientific Understanding"?Jeffrey Israel at BigThink.com on May 4, 2012, 2:05 PM
If I were asked, "do you believe that human beings evolved millions of years ago from ancestors shared in common with gorillas and chimpanzees?" I would answer emphatically and unequivocally: yes. But I know very little about evolutionary biology.
Why am I so emphatic and unequivocal if I am so ignorant?
Before addressing this question directly, let me first note that I am not entirely ignorant in this area. I think I’ve watched two or three NOVA episodes dealing with evolution, I’ve been to the Hall of Human Origins at the Museum of Natural History in New York probably five times, and I’ve even read some books about the political history of the theory of evolution. The 1960 movie version of Inherit the Wind has been a favorite of mine since I first watched it in one of my high school science classes.
But I don’t have anything like the real scientific understanding of human evolution that an evolutionary biologist presumably enjoys.
What is "real scientific understanding"?
Someone with real scientific understanding of human evolution will walk into the Hall of Human Origins and be able to make a variety of sophisticated judgments about what is presented and how it is presented. She will be able to surmise the choices made by the curators. She will be able to imagine what such an exhibit might have looked like 30 years ago. She might say about one part of the exhibit, "there is some recent research that complicates this account." Or, "they’ve left out something crucial!"
Each bit of information will trigger a network of associations that include the names of the scientists who contributed to the research behind it, the nature of their research, what critical reviewers have said about it, and unanswered questions that it has stimulated, which require more research. In general, each bit of information is a hyperlink connecting to a web in her mind of concepts, hypotheses, academic journals, books, scientists, institutions, and so on – all anchored in a vivid mental picture of specimens, excavations, computer modeling programs, museum archives, and so forth.
This, anyway, is how I imagine the experience of a person with real scientific understanding.
And if this is what it is like to have real scientific understanding, then I can say with certainty that I don’t have any. I walk through the Hall of Human Origins and the cartoon bubble above my head reads: "wow!" "fascinating!" "awesome!" "wait, …huh?" That’s right, my reaction is not unlike that of a chimp in the produce section of a grocery store.
I merely consume what I take to be the juicy back-story of human history. To be sure, this particular exhibit presents a lot of information about how evolutionary biologists have come to their conclusions, but I usually skip that part and go right to the life-size dioramas. My favorite is the model of two Australopithecines walking side-by-side. I find it romantic.
What, then, accounts for my assumption that the statement, "human beings evolved millions of years ago from ancestors shared in common with gorillas and chimpanzees," is true? And why should I be so emphatic and unequivocal about it?
Here are a few thoughts:
Upbringing. When I was growing up no one ever used non-naturalistic reasons to explain anything. No one ever said casually, "this is God’s plan" or "it was a miracle."
No one ever suggested that if I wanted to achieve something I should "pray about it" or take serious precautions to avoid any encounters with a black cat. It’s not that we didn’t go to synagogue from time to time and formally enunciate all manner of praise to the God of Abraham, Isaac, and Jacob – but no one would ever imagine that these performances had anything to do with nature. On the other hand, I don’t remember anyone specifically espousing the theory of evolution in my direction. It was simply an unspoken assumption when I was growing up that nature follows its own laws and the experts on nature are called scientists. Naturally, when I learned that scientists explain the origin of human beings with the theory of evolution I believed it.
It’s Easier. I probably continued to take the scientific account of human origins for granted because nothing ever seemed to contradict it. Or, rather, no one that I took to be an expert on nature ever indicated that an alternative explanation might be plausible. It has always just seemed obvious to me and entertaining an alternative would require too much work and self-doubt to seem worth the effort.
Meaningfulness. Knowing that my biological ancestors have been eking-out evolutionary progress for millions of years has a quality of transcendence: it includes a humbling sense that there are arcs of connected action that transcend truly vast expanses of time and space, making my own everyday actions seem far less consequential than they appear. This knowledge also amplifies my self-understanding with narrative coherence on the grandest scale: I am a participant in the American story and in the Jewish story, but also in the hominid story!
Moral Insight. We should never make the mistake of thinking that our duty is merely to "follow our natural instincts." But if we are a kind of animal then it is important for us to recognize that, like every other animal, we have a set of capabilities that require opportunities for exercise if we are going to have flourishing lives. If it is bad for a cheetah to spend his life locked in a small cage with no opportunities to run, there must be some state of affairs that is similarly bad for human beings – we should decide what we think it is and make sure that no human being is forced to endure it.
A good indication that the truth of human evolution is very important to me is that I am constantly reminding my niece and nephew, and my son, all of whom are under ten, "remember, we are related to monkeys!" I feel deeply compelled to pass on to them the story of their ancestors.
Sometimes I wonder if there is something reactionary – a kind of "orthodoxy" or "fundamentalism" – in my need to propagate intentionally what I learned as unspoken truth.
Jeffrey Israel has taught religion and political philosophy at Northwestern University and Rutgers University. He currently teaches Jewish history at Eugene Lang College of The New School in New York City. He has a Ph.D. in religious ethics from the University of Chicago.
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Note from the Blog Author
To me this is a terrible, dweeby, babbling article on behalf of evolution. It seems to state that evolution is true because it is groovy and hypnotic. Cool, fascinating dioramas can be constructed, so it is true.
Evolution is the product of the scientific method – the successful stating and testing of a hypothesis. As such, it is an example of a "hard" method of logical argumentation, along with the double-blind medical and pharmaceutical tests (through which we can state absolutely that something is efficacious even if we don’t know how it works) and mathematical proofs. All three of these techniques are stronger than strong inferences, which are stronger than weak inferences.
Evolution was "just" a theory until 1952. For generations, the strongest argument against evolution was the criticism that there was no known mechanism for replicating and storing the information that conveyed the structure of a species from one generation to the next.
And then came the understanding of the self-replicating power of DNA in 1952 by Crick and Watson. And that made the theory of evolution into a fact. This is so even through we still don’t know all the details about punctuated equilibrium or the potentially profound impact of inter-species DNA transfers.
See also my June 26, 2011 Quiddity Blog entry on evolution. In that entry, Jonathan Dudley is quoted from a June 18, 2011, editorial in the Huffington Post on the failure of creationism:
It has failed to explain why birds still carry genes to make teeth, whales to make legs, and humans to make tails.
It has failed to explain why the fossil record proposed by modern scientists can be used to make precise and accurate predictions about the location of transition fossils.
It has failed to explain why the fossil record demonstrates a precise order, with simple organisms in the deepest rocks and more complex ones toward the surface.
It has failed to explain why today's animals live in the same geographical area as fossils of similar species.
It has failed to explain why, if carnivorous dinosaurs lived at the same time as modern animals, we don't find the fossils of modern animals in the stomachs of fossilized dinosaurs.
It has failed to explain the broken genes that litter the DNA of humans and apes but are functional in lower vertebrates.
It has failed to explain how the genetic diversity we observe among humans could have arisen in a few thousand years from two biological ancestors.
Casting evolution as fact and theory occurs regularly in the public and scientific discourse on the fundamental nature of the scientific philosophy within evolutionary biology. This topic appears frequently in publications that aim to clarify misconceptions about the science of evolution and the nature of these terms, often in response to creationist claims that "evolution is only a theory", "it is not a fact", or that intelligent design offers a credible counter "theory". In ensuing debates, evolution is identified as either fact or theory and occasionally both or neither. Semantic differences between the usage of these terms (fact and theory) in science versus the meanings they convey in common vernacular have led to confusion in public discourse. In the context of creationists claims, theory is used in its vernacular meaning as an imperfect fact or an unsubstantiated speculation. The purported intent is to discredit or reject the scientific credibility of evolution. However, this claim cannot be substantiated.
Evolutionary theory unifies observations from fossils, DNA sequences, systematics, biogeography, and laboratory experiments into a testable explanatory scheme. In this sense, the scientific (as opposed to the vernacular) definition of theory refers to an overarching framework that makes sense of otherwise disconnected observations; this includes, for example, the theory of gravity. Theodosius Dobzhansky, a key contributor to the modern evolutionary synthesis, articulated the unifying power of evolutionary theory in a famous paper entitled: "Nothing in biology makes sense except in the light of evolution".
The scientific theory of evolution explains the causes of evolution, as distinct from the more straightforward factual claim that the process of evolution occurs. Natural selection and the neutral theory are examples of theories of evolution. These and many other causal evolutionary theories can be expressed in the mathematical framework of population genetics. Since Darwin, the theory of evolution by means of natural selection has not only been expressed mathematically, but has also been rigorously tested and corroborated empirically by scientific evidence from countless studies. Evolutionary theories continue to generate new testable hypotheses within paleontology, genetics, ecology, and developmental biology.
A fact is not a statement of certainty, but through repeated confirmation the things or processes they refer to are generally accepted as true according to the reliability of inference (inductive, deductive, and abductive). Facts refer to "events that occur" or "the state of being of things" that can be publicly verified, proven through experiment, or witnessed by direct observation. That all forms of life on Earth are related by common descent with modification is one of the most reliable and empirically tested theories in science that continues to explain vast numbers of facts in biology.
(1) Gould, Stephen Jay (1981-05-01). "Evolution as Fact and Theory". Discover 2 (5): 34–37. http://www.stephenjaygould.org/library/gould_fact-and-theory.html.
(2) National Academy of Science Institute of Medicine (2008). Science, Evolution, and Creationism. National Academy Press. ISBN 0309105862. http://www.nap.edu/catalog.php?record_id=11876.
(3) Fitzhugh, K. (2007). "Fact, theory, test and evolution". Zoological Scripta 37 (1): 109–113. doi:10.1111/j.1463-6409.2007.00308.x. http://www.mobot.org/plantscience/ResBot/EvSy/PDF/Fitzhugh%202007%20-%20Zoologica%20Scripta.pdf.
(4) Dobzhansky, T. (1973). "Nothing in biology makes sense except in the light of evolution". The American Biology Teacher 35 (3): 125–129. http://img.signaly.cz/upload/1/0/9a462eb6be1ed7828f57a184cde3c0/Dobzhansky.pdf.
(5) Evolution vs. Creatinism: An Introduction. Berkeley and Los Angeles, California: University of California Press. 2004. pp. 298. ISBN 0-520-24650-0. http://books.google.com/?id=03b_a0monNYC&pg=PR9#v=onepage&q&f=false.