Dawkins: Not One of Our Ancestors Was a Failure

Richard Dawkins’s theme is upbeat:

All organisms that have ever lived—every animal and plant, all bacteria and all fungi, every creeping thing, and all readers of this book—can look back at their ancestors and make the following proud claim: Not a single one of our ancestors died in infancy. They all reached adulthood, and every single one [allowing for the inclusion of such outliers as in vitro fertilization] was capable of finding at least one heterosexual partner and of successful copulation. Not a single one of our ancestors was felled by an enemy, or by a virus, or by a misjudged footstep on a cliff edge, before bringing at least one child into the world. Thousands of our ancestors’ contemporaries fail in all these respects, but not a single solitary one of our ancestors failed in any of them.…Since all organisms inherit all their genes from their ancestors, rather than from their ancestors’ unsuccessful contemporaries, all organisms tend to possess successful genes. They have what it takes to become ancestors—and that means to survive and reproduce…That is why birds are so good at flying, fish so good at swimming, monkeys so good at climbing, viruses so good at spreading. That is why we love life and love sex and love children. It is because we all, without a single exception, inherit all our genes from an unbroken line of successful ancestors. (River Out of Eden)

Many readers love this passage. Its any-organism’s view backwards along the unbroken line of forebears celebrates the successes and joys of being alive. And it explains this success not as the result of human uniqueness or a generous deity but as nature’ own selection process. The same pride and pleasure we take in hearing about a great-grandmother who struggled, travelled, settled, and raised a family, Dawkins extends to all ancestors of all species, without exception. Any reader who may have earlier viewed evolution as alien and godless might feel a little less resistance now.

But other readers may take exception to the passage for other reasons. Some of that inheritance from our successful ancestors, we wish we would be spared. Down Syndrome, Cystic Fibrosis, some cancers, and other diseases are inherited to a degree. So are mental illness and violent tendencies. For those suffering from such inheritances today, the genetic filter has not been effective enough.

And then there’s bad luck. Many organisms that were as well-endowed genetically as “successful” ancestors might also have left offspring had it not been for factors beyond their control. The twin of that pioneer grandmother may have died in battle, gone down with the ship, succumbed to an earthquake, or starved in a drought—childless.

Last but not least, many people today are able to have children but choose not to. They may remain, though, no less “successful” in every other sense of the word.

In the end, I think these exceptions, instead of weakening Dawkins’ point, strengthen it—as if each living organism could say with conviction, see, so many different pieces, not only the genes but the circumstances too, had to fall into place for me to be here. And they did.

 

 

 

Who Were Homo Sapiens’ Parents?

Let’s imagine for a moment that you don’t know who your parents were. No records of them have been found yet. And because you don’t know your parents, you also don’t know for sure who your grandparents, great-grandparents or other direct ancestors were. But by some fluke you do know about some of your great-aunts and great-uncles, though none are alive now.

So you know about your general ancestry, where you came from, how your ancestors lived. But the family tree is complicated and you can’t be sure who your direct relatives were. You may be the offshoot of one of these aunts or uncle for all you know, you may be the result of a one-night fling or other scandalous pairing, or maybe your parents and grandparents just haven’t shown up in the records…yet.

Such a situation is where we stand with our species as a whole. We were “born” as a species when our bodies reached their present proportions about 195,000 years ago. Here’s a basic  version of the family tree around us and just preceding us, with some species omitted. There isn’t complete agreement on it, and it keeps changing as new bones and DNA samples come in.

  • Homo habilis (“handy man”) might be viewed as our great-great-grandfather (the masculine here will stand for both genders). He was good with tools and lived in Africa from 2.5 million years ago to 1.4 mya.
  • His descendant or cousin, Homo ergaster (“working man,” even better with tools) lived at about the same time,  1.9 to 1.4 mya.
  • homo_heidelbergensis-wikipedia-com

    Homo heidelbergensis (wikipedia)

    One of H. ergaster’s descendants was our grand uncle, Homo erectus, the first to stand tall and erect. Overlapping with our origins and a dominant presence in our past. H. erectus lived a long life not only in Africa but in Asia as well until 70,000 years ago. He used fire and he cooked. He lived in small, organized bands of families. He was thought to be our parent for a while but today the connection looks shaky.

  • The strong contender for our immediate ancestor at present is Homo heidelbergensis, an offshoot of the handy man H. habilis. H. heidelbergensis lived about the same time that we appeared.
  • Some H. heidelbergensis migrated into Europe where they evolved into the Neanderthals, our genealogical brothers or cousins. When we H. sapiens later migrated out of Africa, some of us lived near H. neanderthalensis, interbred with them (today almost all of us have a little Neanderthal in our genes), and survived them.

It’s a stunning story, all the more so because where we connect to it is still uncertain. The traits that we recognize as us—the abilities to walk and run, the skillful eye-hand coordination, the smarts to keep track of who to trust and who not to, our abilities both to exchange gossip and to discuss philosophy—all appeared step by step through such interesting early versions of us. And imagine being Homo erectus, with curiosity about how to chip a slightly sharper edge on your cutting stone or the skill to try out slightly different sounds as you talk to others. Or hearing the rumor that a group of men that look a little different than you, men who seem more organized and who carry longer spears, were appearing in the next valley.

 

Journey from Small to Smaller: Spirituality and Size

Try out the moveable “lens” on a great graphic from the Genetic Science Learning Center at the University of Utah. Slide the button to the right and zoom in from a grain of rice down past human cells to chromosomes and bacteria on down to viruses, glucose molecules, and finally a carbon atom.

Cell Size and Scale

(2008 Genetic Science Learning Center, University of Utah)

The zoom takes you down into the roots of life. But the graphic is also a time machine, taking us back billions of years, from complex single-celled creatures and building blocks towards the not-quite-alive viruses that perhaps predate full reproductive life, back to the atom that makes it all possible. Small came first—and life stayed small for a long time.

Then it got bigger. Today humans are not only complex but also relatively large. There are elephants and whales and trees larger than we are but also hundreds of species—from cows to dogs—in our size range. Up to a point and with exceptions, a bigger body is better at surviving.

Perhaps this trend underlies our perceptions of authority and even spirituality. The entities that we “worship” in any sense of that word are bigger than we are—not only gods but powerful people who seem “larger than life,” or the universe itself, or nature, or the breadth of evolution. They are the something-larger than we are often seeking. We grant even big trees and elephants a majesty that we don’t attribute to bushes and mice. Large things, if they seem to be the friendly kind, offer protection and inclusion.

Sunset worship

What we worship is larger than we are. (experiencinghope.net)

But we don’t extend such sentiments to tiny things. That’s partly because we can’t see them. I wonder what it would be like if we were able to see individual bacteria, skin cells, the cells in a piece of fruit in the same way that we can easily see individual blades of grass. Imagine seeing the single-celled creatures floating in the air and the water and on our skin, on other skins, in our food, in our rooms. Would we feel enveloped by life in the way we do when walking in a forest or watching flocks of birds? If we could see all those individual cells pumping, crawling, swimming, dividing, would we find our something-larger in that something-smaller?