2 - Endings
What is the long-range future of our species? We can look at the evolutionary past, the other species on our branch of the evolutionary tree: how long did they last? Old bones can be assigned to different extinct species based on their morphology, and they can be assigned approximate dates by means of physical and chemical methods. Where there is enough fossil material, the earliest and latest dates for a species provide an age-range for its duration.
We have fossils of about 28 different species on our evolutionary branch since its separation, six or seven million years ago, from the branch that led to modern chimpanzees, our closest living evolutionary relatives. For nine of them, there are a sufficient number of fossils to allow estimates of species-duration:
Approx. duration of
Species species existence
(thousands of years)
Australopithecus afarensis 1000
Australopithecus africanus 1000
Paranthropus boisei 1100
Paranthropus robustus 800
Homo habilis 900
Homo erectus 1500
Homo ergaster 500
Homo heidelbergensis 300
Homo neanderthalensis 400
Homo sapiens 300 (so far)
Average (excluding H. sapiens) 833
(If more fossils of any of these species are found that are either younger or older than the ones already known, then of course the duration of that species' existence will have to be revised upward. But for now, these are the best estimates.)
Paranthropus boisei is an interesting case. It existed for a little over a million years. As nearly as we can tell, climate change likely made its world in east Africa uninhabitable. It went extinct about a million years ago.
As species on our branch go, we Homo sapiens are a relatively young species. If we turn out to be average, we’ve lived maybe about a third of our species’ projected existence, and have several hundred thousand more years to go.
But we’re not average. Our survival and reproductive abilities and our advanced technology have put us way over the top in comparison with other mammalian species. The question is, will our technology doom us to an early end, or will it extend our species’ existence beyond even that of Homo erectus?
Our technology may bring us to an early end. It is responsible for human overpopulation, environmental pollution, degradation of water and agricultural land, and the depletion of other life-sustaining resources. It is answerable, in part, for war’s devastations and the great inequality of resources and length of life across the populations of the globe.
On the other hand, our future is in our own hands: it could be controlled and planned for by conscious, rational decisions. We could, theoretically, on a world-wide scale, find ways to limit population growth, curtail manufacturing, stop using fossil fuels, conserve water, develop alternative food sources, re-use and recycle, and change our ideology from growth to maintenance. Running counter to these goals is human short-sightedness, greed, aggressive tribalism, and the persistent view of ourselves as having dominion over the Earth rather than being part of it.
I’m not optimistic about the long-term future of Homo sapiens. Will our species survive even a thousand more years? Isaac Bashevis Singer, looking back from an imagined future time, wrote, “God had granted the sons of Adam an abundance of self-love, the precarious gift of reason, as well as the illusions of time and space, but no sense of purpose or justice. Man would manage somehow to crawl upon the surface of the earth, forward and backward, until God’s covenant with him ended and man’s name in the book of life was erased forever.”
Meanwhile we can forestall the looming bleak future. We can strive to live in better harmony with nature. We can try to make the life of future generations—several dozen of them at least, surely—more sustainable, and better, in the time left our species.