06/14/2012 04:54 pm ET Updated Aug 14, 2012


Science needs an overhaul. No, wait, that's not quite what I mean. Science is doing just fine. What needs work is how we talk about science, how we teach it, learn it, write about it. I still remember my first college biology course, in which I was required to memorize all the different digestive enzymes, where they were produced and what they did. Those were the days when the smart science students went into physics or maybe chemistry, while the ones with good memories "did" biology.

I loved biology but hated those damned enzymes! Even now, decades later, I still can't stomach them. I also loved science in general, and still do. And although most of the basic "material" of my own field, evolutionary biology, is fascinating in itself, I want to argue that what's especially fascinating -- and important -- isn't what science (any science) already knows, but what it doesn't.

Most of us teach science incorrectly for this simple reason: we focus on the obvious, on what we know. And sadly, this gives the uninitiated a very misleading impression; namely, that science is a recitation of things we know to be true... whereas, in fact, there is immensely more that we do not know! (One of these days, I'm going to develop a college-level course in "What We Don't Know About Biology," and hope that my colleagues in physics, chemistry, geology, psychology, even mathematics, get inspired and join in the fun.)

My point is that we are surrounded by mysteries. Mysteries "R" Us. And by "mysteries," I'm not referring to some sort of mystical nonsense beyond the reach of human comprehension. I simply mean that the world in general, and the living world in particular, abounds in stuff we don't yet understand. But someday will. And this is where science gets downright exciting, as well as fun. Moreover, and little known even to members of the educated public (who don't have to be persuaded about the reality of evolution), many of these mysteries concern us, members of the species Homo sapiens, and our own evolutionary reality.

Although some people have suggested that we're approaching "the end of science," the reality is otherwise: We are just beginning to glimpse the most basic truths, many of them revolving around our own species. And the most crucial -- and exciting -- of these truths is the extent to which our current knowledge is incomplete.

In closing, here is an admittedly incomplete list of some of those questions that a full evolutionary understanding of our own species ought to answer, and -- I am confident -- someday will:

- Why does homosexuality persist? Given that, on balance, gay people of either sex produce fewer children than straight people, this is a first-class evolutionary mystery.

- Why do women menstruate? Some female mammals bleed a little bit in mid-cycle, but not as conspicuously as Homo sapiens.

- Why do women have prominent nonlactating breasts? We are the only species of mammals thus endowed.

- Why do women experience orgasm? Non-orgasmic women are no less successful than their orgasmic counterparts, so what is its fitness payoff?

- Why do men consistently have shorter lives than women? Similarly, why are they more hairy on most of their body, yet less so on the top of their heads?

- Why is it close to a "cross-cultural universal" for women to adorn their bodies more than men? Among most animals, it's the other way round.

- Why do women undergo menopause? It is exceedingly rare in other animals for females to stop ovulating when they still have much of their lives ahead of them.

- What is the purpose of all that "junk DNA" that encumbers our genome?

- Why is religion found in all human societies? In short, what are the presumed compensations that make up for the personal costs associated with practicing nearly all religions.

- Are there any truly neutral traits, or does every consistent biological component of Homo sapiens have an identifiable "adaptive significance"?

- To what extent has our evolution proceeded gradually ("phyletic gradualism") or via small, discrete jumps ("punctuated equilibrium")?

- Why do people make art (including music, poetry, stories, visual art, sculpture, dance, and so forth)? Alfred Russel Wallace thought this necessitated divine intervention; Darwin disagreed.

- Why are human beings conscious? After all, it is possible to imagine a world of intelligent robots or zombies, going about their fitness-enhancing business without the slightest self-awareness of what they are doing.

- Why did we evolve such big brains? Was it in the service of communication, tool use, social competition, warlike competition, sexual attraction, etc.?

- Did the human species evolve in many different geographic regions and then coalesce, or did we evolve in one place (probably Africa), and subsequently spread out?

- Why did we become bipedal? And similarly, why did we become so (relatively) hairless compared to other mammals?

- Why do we laugh, cry, blush, sleep, dream?

- What are the biological sources -- if any -- of human ethical judgments and rules?

- Why do we "possess" an unconscious?

- Is there an evolutionary reason ("adaptive significance") associated with our numerous mental illnesses? Our physical ones?

- To what extent are human races biological realities, or social constructs?

Despite the world's impressive store of accumulated scientific knowledge, final answers just aren't yet available, although in each case there are numerous plausible hypotheses, waiting to be evaluated. That's where the real work of science lies, and also most of the fun.

David P. Barash is an evolutionary biologist and professor of psychology at the University of Washington; his most recent book is 'Homo Mysterious: evolutionary mysteries of human nature (Oxford).