Robert Veale has posted a comment to one of Marcelo's blogs on climate change that raises several points related to religion and biological evolution.
If we did arise accidentally from blue-green algae then we are no more important than either algae or parasites. Evolutionary theory provides no foundation for any urgency to solve global warming. What is the imperative that we survive? If, however, we were created purposefully and given the task to be stewards of this earth, only then is there a basis for our prudent care of this earth. Think about it.
If the concept that we were created purposefully and not accidentally serves to encourage prudent earthly stewardship, then that's terrific. Increasing numbers of faith organizations are moving in that direction, where the Forum on Religion and Ecology at Yale provides abundant information along these lines.
But thousands of Christian clergy "believe in evolution," and evolutionary understandings also provide robust foundations for climate-change evangelism.
The notion that "we arose accidentally from blue-green algae" contains two common misunderstandings of evolutionary theory.
First, we didn't arise from blue-green algae. Modern algae, modern parasites and modern humans all share common ancestry, where the common ancestor to us all was a highly complex single-celled organism, estimated to have lived on the planet some 3 billion years ago. From that ancestor, all life radiated forward to the present time.
Second, "accidental" misses the point. To be sure, the mutations that have generated biological diversity have arisen by accident — the best way to generate diversity in any context is to subject existing systems to random variation and then selection. But the outcomes haven't been accidental at all because the selection part is exquisitely choosy. Each outcome — parasite, human, alga — is the consequence of a long series of fine-tuned and highly purposeful adaptations to local ecosystems. Each new idea builds on a genome's-worth of previous ideas, and novel lifestyles keep emerging, again and again.
So, all of us creatures were created purposefully via evolution, and each local ecosystem that we inhabit is nested in the global ecosystem. Take away the marine algae, whose lifestyles depend on present-day ocean conditions that are threatened by both climate change and human impact, and you take away 80% of the atmospheric oxygen. Sounds pretty urgent to me.
No, I haven't forgotten the core question: If this is how we arose, then what is the imperative that we survive? There are many answers, including those that lift up the sweet innocence of human children who don't deserve the horrors of a mass-scale catapult into non-survival.
But I'd say, in this context, that the imperative arises from those 3 billion years of incessant endeavor that generated our wondrous present. Yes, climates have changed countless times in the absence of human agency. Yes, extinction has been the long-term rule. But massive sudden extinctions of the kind we now face have only occurred a few times during those 3 billion years, and never before via the intentional, and avoidable, actions of a single species.
In religious language, those creatures who came before us can be said to have died for us; those creatures with whom we now share the global ecosystem are literally our brethren. The notion that my species might thrust all this intent and beauty into chaos fills me with the deepest possible shame.