Dartmouth College physicist Marcelo Gleiser, writing at Big Think, asks, “Does life on Earth have a purpose?” Obviously, this is more than just a scientific question. It’s a very personal one for each of us. Given the venue, Gleiser’s answer of course is going to be no. He notes the geologically sudden eruption of complex life in the Cambrian Explosion, 530 million years ago. Life came onto dry land and diversified, leading to the appearance of man.
No wonder so many people believe that life as a collective has a plan, that of increasing its complexity. It follows that if life has a plan to become ever more complex, there must be a planner behind the whole thing. Of course, under this view, the apex of the process would be us — intelligent, technology-savvy humans. Theologians call this teleology.
Regarding teleology, he issues a flat denial.
This conclusion is false. There is no plan to make life more complex so that it can finally generate intelligent beings. (Eminent biologist Ernst Mayr makes a powerful argument against teleology here.)
The Cretaceous–Tertiary Extinction
Citing a famous biologist in a hyperlink is not an argument. Gleiser’s own case rests on the part played by chance in life’s history. For example, the asteroid that wiped out the dinosaurs:
If we changed one or more of the dramatic events in Earth’s history — say, the cataclysmic impact of the asteroid that helped eliminate the dinosaurs 66 million years ago — life’s history on Earth would also change. We probably would not be here asking about life’s purpose. The lesson from life is simple: In Nature, creation and destruction dance together. But there is no choreographer.
His argument: The Cretaceous–Tertiary extinction cleared the field for mammals, allowing ultimately for the rise of “intelligent, technology-savvy humans.” No asteroid –> no humans. The asteroid was a chance, unchoreographed event. Therefore, says Dr. Gleiser, no “choreographer” intended our existence.
The Role of Providence
This is a remarkably shallow conclusion. As luck would have it (if you want to put it that way), I’ve been thinking about the role of providence, as I see it, in my own path of life. Any of us can point to certain pivotal events in our past — a seemingly chance meeting, a piece of advice received, an idea that came to us unbidden — that need not have occurred, but did. And because they did, we found the path to our current place (marriage, relationships, friendships, work, the whole thing) laid out before us.
Gleiser’s argument about the history of life is just a separate application of the depressing view that denies anything in our life paths could have been intended for us. That the view is depressing doesn’t mean that it is mistaken. That it can be asserted doesn’t mean that it is correct.
To decide about providence in the rise of complex life, you would have to look at a much wider suite of evidences than the fact that an asteroid doomed the dinosaurs. Scientific proponents of intelligent design have done this, noting vast evidence of extraordinarily careful tuning in physics, chemistry, and biology, from the Big Bang itself, to the origin of life, to the series of biological “big bangs” through which bursts of purposeful information infused the biosphere.
The most recent treatments of this theme include biologist Michael Denton’s The Miracle of Man and philosopher of science Stephen Meyer’s Return of the God Hypothesis. Meyer’s book points to three scientific discoveries that demand a conclusion of purpose behind the cosmos (that the universe has a beginning, that it was fine-tuned for life from the start, that life is a form of information-processing technology). On the radical discontinuities in evolution that bespeak purpose and creativity, see Meyer and paleontologist Günter Bechly’s chapter (“The Fossil Record and Universal Common Ancestry”) in the volume Theistic Evolution.
“The Wheel Has Turned”
From a different perspective, Denton explains this beautifully and profoundly. What Gleiser terms “intelligent, technology-savvy humans” are exactly what almost countless coincidences in nature have been set just so in order to permit. As Dr. Denton has written here about this “prior fitness” for human beings, creatures capable of manipulating fire, and therefore of engaging in technological invention:
Even though many mysteries remain, we can now, in these first decades of the 21st century, at last answer with confidence Thomas Huxley’s question of questions as to “the place which mankind occupies in nature and of his relations to the universe of things.” As matters stand, the evidence increasingly points to a natural order uniquely fit for life on Earth and for beings of a biology close to that of humans, a view which does not prove but is entirely consistent with the traditional Judeo-Christian framework….
The wheel has turned…. [S]cientific advances beginning with the flowering of chemistry in the 19th century and continuing at an ever-increasing pace through the 20th century and now into the 21st have vindicated the ancient covenant and revealed humanity to be as the medieval scholars believed, reflective in the depths of his natural being of all facets of the greater macrocosm of which he is an integral part.
“Mysteries remain,” as Denton acknowledges. Yet, “The wheel has turned.” Modern science calls us to recognize the role of providence in the history of the cosmos, of our planet, and of life. If that is true in cosmology and biology, it’s a hint that it might be true, too, on the far smaller scale of our individual biographies.