Science Reader Question: Life on the Edge

Throughout this ongoing series on evolution, inspired by some reader questions, we’ve looked at a lot of the challenges an evolutionary natural history presents for traditional Christian theology. Accounting for the modern biological understanding of life’s origin and diversity is usually framed as a series of conundrums requiring either substantial effort to resolve, or an ultimate rejection of either science or scripture. If evolutionary natural history is so problematic, why bother? If there’s any uncertainty, why give the benefit of the doubt to science? Do we even want to believe in a God who creates via evolution; wouldn’t we prefer a God who can do better?

As it happens, an essay on Medium about gender imbalances in the way that so many products are designed unknowingly highlights one of the benefits of an evolutionary perspective. What grabbed me first were the statistics on car crashes; I’m frankly a little embarrassed to admit I had no idea cars were significantly less safe for female drivers. The piece alleges that automakers optimized safety testing for an average man instead of covering a range of sizes from both genders. It’s one of many examples cited of how designing for the middle fails those on the margins, not just women but minorities, people with disabilities and anyone else who doesn’t fit “the norm.” A case is made for “designing for the extremes” both because it’s inclusive of more potential users and because it creates better designs for everyone.

Last week I talked about the fuzzy boundaries of species. Our intuition might lead us to imagine some kind of Platonic ideal cat or dog somewhere near the “average” of all cats or dogs. Our approach to design implies that we think of humans that way. Yet an Irish wolfhound or a chihuahua isn’t any more or less a dog than a Labrador, just as a toddler or 7’2″ Margo Dydek of the WNBA aren’t any more or less human than me, 5’10” white dude. Species are best understood by their entire range, not just their middles. An evolutionary understanding of biology helps to cultivate this frame of mind. It encourages looking at the edges and the limits of where one group ends and another begins, even and especially when those edges and limits are fuzzy.

Even more helpfully, evolutionary biology reveals the way to find those edges. When you want to understand what defines a group, see how it adapts to a new context. Over time, recontextualizing will reveal the important characteristics that define the group and which features were just happenstance of a particular environment. Take birds for example. It’s natural to think of flight as a defining trait of birds. Then maybe you meet a turkey or a chicken, birds that can fly but neither far nor well. And then there are the penguins and the emus, birds that don’t fly at all. Penguins are especially interesting, since they challenge not only our notion of birds but also flight. Many of the features that help other birds soar through the air make penguins excellent swimmers. Water is also a fluid, like air; maybe flight is about propelling yourself through a fluid rather than just a gas.

Of course, you don’t have to accept an evolutionary natural history to appreciate the challenge of classifying penguins or platypuses. But trying to account for all of life’s diversity through common descent provides greater incentive to consistently explain all the quirks. If anything can be an exception, a special case, then that’s the end of the conversation. When you have to integrate all of those edge cases and unique exceptions into a consistent framework, you have to look harder to see what they all have in common.

An inclusive perspective on diversity encouraged by evolutionary biology isn’t challenging to reconcile with the Bible; if anything, it connects to a central theme of its overarching narrative. We start with a model of common descent for all humans; there’s no “us vs them,” no notion of our tribe being made separately by God to be special or superior to whomever we might believe to be our opposition. And from the beginning, humans are encouraged to multiply, which can only lead to greater diversity. In the end, every tongue, tribe and nation is gathered to worship the same God. The diversity of the human race is not averaged out or homogenized since each group is still distinctly recognizable.

In between the admonition to multiply and an assembly of the resulting diverse humans, we have a series of stories in which someone has to ask “Is the kingdom of God for them too?” Invariably the answer is ‘yes.’ Right away, Adam meets a human who superficially might seem quite far removed from himself, but yes, the kingdom of God is for her. Abraham, whom God specially and singularly selected to father his chosen people, meets Melchizedek and discovers that the kingdom of God is bigger than he realized. The Israelite spies and Rahab, Naomi and Boaz and Ruth, Jonah and the Ninevites — in each case, the kingdom of God is revealed to be more inclusive than originally expected. Ultimately, the entirety of the Gentile world is invited to be a part of that kingdom.

One of the challenges of this expansive and inclusive pictures of God’s kingdom is that the same Word can be realized in different ways for different people. Paul in particular anticipates this, addressing questions of whether all Christians need to be circumcised or how some can eat certain foods in good conscience while others can’t. His metaphor of the body of Christ in which some are the feet, some are the hands, and yet all share an equal claim to being part of the body provides a sort of theoretical framework for understanding those specific scenarios. Interestingly, Paul’s biological metaphor only becomes more apt the more we learn. Each cell in a body is following the same word (i.e. its genome) and yet each cell expresses it differently. More recently, evolutionary biologists have come to appreciate that different bodies can also express the same genome differently, expanding the possibilities for variation and adaption beyond what is strictly associated with mutations.

Finally, if we take this metaphor of the genome-as-word one step farther, we might ask what story it tells. If we accept the notion of common descent, then the genome tells the story of how life has developed over time, the different environments it encountered and the different adaptations employed in those environments. And if God is the creator of life and of those environments, then the genome is a record of God’s work on Earth since life first emerged. Taken together with the cosmic background radiation and the light from stars and galaxies near and far which tell of God’s work since the visible universe began, and the Bible which tells of God’s work throughout recorded human history, and we’ve pretty much got a complete record of everything God has done to get us to this point. For me, the thought that every one of my cells tells a little part of that story in its DNA makes the theological challenges of reconciling evolutionary biology and natural history worth the effort.