Archive for May, 2012

CARTOONS FROM THE REV

Sunday, May 27th, 2012

Build a tourist photo-op, and dinosaurs will come. At least that's been my experience.

SERMON: “It’s a Small World” by the not-so-reverend bob

Sunday, May 27th, 2012

The East Coast of the United States as seen from space. NASA photo.

I heard a commentator on Christian radio proclaim that the way in which God had “hung the stars” in so “perfect” a manner was a clear sign that behind our vast universe resides an intelligent designer.

She did not explain by what measure the stars were perfect in their arrangement, or how, precisely, said perfect arrangement necessarily required an intelligent star-hanger.  She did, however, use the ancient imagery of someone hanging stars in the heavens in the way that someone might hang ornaments upon a Christmas tree.  And in so doing I think she gave me a glimpse into the mind that finds evidence for God in the apparent organization of nature.

For doesn’t the idea of “hanging” the stars give you an immediate image of someone working on an relate-ably  human scale, only on a somewhat enlarged basis?  What do I mean:  We imagine God in a gigantic (yet) human form, with face, beard, arms and hands that are able to reach out across the night sky, literally hanging stars against the black fabric of the night (which itself implies an ancient conception of there being a sort of dome stretching out across the (flat?) earth).

Which brings me to this: the only way that the idea of God as ruler of all, creator of all, knower of all — and yet intimately involved with our individual lives down to the number of hairs on our head —  works at all is because we humans naturally think small.  It makes sense.  We have to think small, for underneath everything else about us, we remain earth-bound animals that must see to our own survival.  There is no reason for our brains to be conversant in the stretches of time or distances necessary to properly grasp the age and expanse of the universe we live in.  Of what use is any sense of time or distance beyond the span of our own life times?  Why not simply invoke “God”, “eternity”, and “infinity” to paper over this yawing conceptual void in our cognitive, imaginative abilities?  This approach — this coping mechanism — has served our species well, to be quite honest, and has only, really, been challenged in the last 150 years by the discoveries of modern science.

I am firmly convinced that the average believer in God (or the average human, as far as that goes), carries a rapidly diminishing hierarchy of other beings and concepts in their mind at any one time (I’ve checked this in myself).  We are the center of our universe (that goes without saying) so we start with a conception of ourselves in physical space and time and then move out to our immediate family, friends, those we know in our community, our collection of famous personages (that we are familiar with), a modest collection of small bands of African tribesmen (and/or Europeans or Asians), some penguins or elephants, an anthill (topped with some ants), a couple of bees, a forest, a picture of something living in the sea, the moon, some stars sparkling in the night sky and at least one image from a space probe.  Oh, and dinosaurs.  We all know about dinosaurs.

But it is the way in which we picture these things that matters here.  We almost always see them in ones, twos, threes, or small groups.  In the same way that we do not picture billions of humans living in the narrow temperate zone of an actual-sized earth, we don’t picture thousands of varieties of dinosaurs, but perhaps imagine one Tyrannosaurus chomping down on one plant-eater, not millions of them evolving, reproducing, adapting, and then going extinct of a period of 165 million years.  We see them in the numbers that almost the entire history of  our evolution has accustomed us to: small family and tribal groupings.

And we imagine the stars (if we’re honest with ourselves) as all being equidistant from where we stand as we look at them — convinced, on some level, that we could almost reach out and touch them.

And why shouldn’t we be able to touch them?  After all, we are enormous, and they are merely pinpoints of light!  We can blot them out with a fingertip held in front of our eyes!  This fact is not insignificant (and I’d love to hear about any research into how our visual perception of the world colors our cognitive organization of it).

Try this experiment:  We know that our binocular vision is only effective for a short distance, and beyond that we use inference to interpret the size of more distant objects.  What I have found is that I can disengage that part of my brain that tells me that those distant, tiny objects aren’t really tiny at all, but merely appear small because they are far away from me.  When I do that, I can actually feel like a giant — surrounded by mountains that are only a few steps away, and which I could stride over with one step.  Cars on the freeway ahead of me are suddenly the size of matchbox toys which I could pick up between two fingers (try it — it’s fun!).  It’s kind of a trip, and as disconcerting as it is entertaining, for it offers a glimpse into just how much we rely on perceptions that are not as immutable as we might like to think.

The religious criticize the non-religious for being motivated most by a desire to avoid responsibility to God.  The underlying assumption is that the non-believer is fighting against nature (the same nature that so clearly proclaims His presence) by refusing to obey God.  On one level, this is true.  For if there is one thing very clear about humans, it is that we are natural believers.  Therefore, those that move beyond belief are, in essence, fighting against their nature.  But what does that say about the believers, then?  Could it be they who are the ones most locked into their natural, animal nature?  That would be truly ironic: if it turned out that they are not the enlightened ones, but instead are the deniers of reality that they imagine all those nonbeleivers to be!  The believers, then, turn out to represent the primitive in humankind, and not the enlightened after all.

I don’t blame them.  I’ve been a believer and so I get it.  And I don’t expect their numbers to drop dramatically in my lifetime (if ever).  I just want it to be known that they are, ironically, the very thing they criticize in the non-believer: they are the ones maintaining a reality almost completely dependent upon belief.

(I need to be clear here that irrational belief is not the sole domain of those that believe in God.  A human is just as capable of attaching irrational belief to non-theistic sources, be they aliens, computers or any number of conspiracy theories.  I am equally opposed to all irrational belief).

So, to get back to where we started:  Did an actual God reach out millions of light years away from us, and hang every single star (as well as every grain of cosmic dust that floats in any number of the galaxies we will never be able to see from earth)?  Did he create those long-dead stars that coalesced and collapsed upon themselves in titanic explosions, creating the elements that he then used to form the individual cells with which each of our bodies (and every other living thing on earth) are formed?  In light of what we actually know about the universe, could this idea be any more absurd?  And it is the non-believers who are the deniers of reality?

We humans struggle so hard with who and what we really are.  It’s really a difficult thing for us to imagine with any sort of consistent clarity.  But, then, evolution did no better job preparing our brains for a realistic self-conception that it did setting us up for grasping the distance between the stars.

One thing is for sure, however: the distance between us and the stars we see at night is not just greater than our human brains can comfortably imagine: it is greater than any God we humans can imagine could possibly reach.

t.n.s.r. bob

CARTOONS FROM THE REV

Sunday, May 20th, 2012

The "rev" waits for a train to the Philadelphia airport.

REVIEWS FROM THE REV: “Scientists Confront Intelligent Design and Creationism” Edited by Andrew J. Petto and Laurie R. Godfrey.

Sunday, May 20th, 2012

This book is a collection of essays from scientists, each speaking to his or her field of study and thereby confronting the challenges to science mounted by the proponents of Intelligent Design and Creationism.

Intelligent Design is the current brand name of religious creationism, which holds that life was created by a divine being (generally said to be God).  In the essays in this book, we learn about the different schools of thought in the creationist movement and the divisions between, say, “Young Earth Creationists” (that hold to a literal interpretation of the story of creation as told in the book of Genesis), and the “Intelligent Design” folks, who, while granting some aspects of evolution and geology, still hold that God is behind it all.

There is a nice overlap between the essays in this book so that no gaps are left in the discussion of the range of scientific understandings under assault by the religiously motivated.  So we have essays on genetics, the ways in which we’ve learned to determine the age of rocks, physics, the scientific method, the definition of just what a scientific “theory” is, and the process (and evidence for) evolution.

Included are detailed critiques of the shabby pseudo-science of the leading minds of the “Creation Science” movement, as well as a thorough history of this social and religious phenomenon.

The essays are all rather formally written (and heavily referenced), though clearly meant to be read by a popular audience.  This is a book put together by serious scientists who have set aside their research to uncharacteristically confront an alarming social movement that threatens to weaken the very foundations of science and science education.  The fact that this book needed to be written is disturbing enough.  Reading the thing will only add to that alarm.

The good news is that “Scientific Creationism” in any and all of its forms is shown to be nothing but good old fashioned pseudo science.  The bad news is that it remains a very real threat to our future as informed citizens.

It’s worth a read.

t.n.s.r. bob

The Rev gives is 3.5 out of 4!

SERMON: “The Brain: A User’s Guide — Abridged” by the not-so-reverend bob

Sunday, May 20th, 2012

WHAT OUR BRAINS ARE GOOD AT:

Keeping us from stepping on a rattlesnake.

Getting us to throw up when we see someone else do it.

Thinking about sex.

These are survival responses: fight or flight; mirror neurons that pay detailed attention to what those close to us are feeling, experiencing, or seeing, and; reproducing to ensure the continuation of the species.

What our brains are not good at:

Critically examining things we hear from others.

Perceiving reality without a thick filter of magical belief.

Not being fearful.

Our brains are physical machines that have evolved with us over millions of years.  They exist because they are good at keeping us alive and fruitful.  We exist because they work as well as they do.

When we started using tools to aid our survival (around 6 million years ago), we were on our way toward becoming the dominant life form on the planet that we are today.  Our advancement, however, was slow.  But over time our cleverness led us to things like fire and cooked food (which fed our growing brains while reducing the need for our huge ape-like chewing muscles, which then allowed our brain cases to expand to the limits finally imposed on them by natural selection — namely the width of the human female’s pelvis).

We are the tool-making ape, and because of the protections we have built for ourselves from the forces of nature (extreme heat, cold and disease), and our ability to alter the environments we live in (as well as the plants and animals we live with), we have spread out and flourished.  In just the last 15,000 years we went from a small bunch migrating out of Africa to the global population of modern humans we are now.

This is no small success.  But we are mistaken to lean as much as we do on the idea that our brains are more than our most advanced sensory organ — that our minds are something that transcends the physical world.  They don’t.

As I sat on a park bench today, watching a pair of grackles chase a squirrel from the lawn beneath “their” tree, and then return to their mix of mating and feeding behavior, I was reminded that, if you get right down to it, the “purpose” of life is to continue to live.  Life, by any definition, is a complex process that exists only by dint of its ability to feed itself and reproduce.  Even the most mindless of life is propelled by this innate impulse.  And we humans are no different.

But, of course, we are very different when it comes to cognition. All animals have brains, some small, some large.  And some of those animals are eerily similar to us in having a social sense and an emotional interior life.  Some even make simple tools.  But none have the self-awareness that we humans do, and I think that gives us a very singular set of existential problems to deal with.

We humans have huge brains. Okay, maybe not quite THIS huge!

In particular is the question of “why us?”  Our attempts to answer that existential question have created thousands of gods, thousands of religions to go with those gods, and creation myths aplenty — all of them stories with us at the center, revealing some satisfying aspect of our “true” purpose here on Earth.

Of course one of the problems with that approach is that we are not divine in origin (at least as far as we can tell), nor are we “intelligently designed”.  What we are is  “naturally selected” (a process that can bring about results that easily mimic what we might consider “design”).  And what we generally end up with, then, is a lofty narrative of our special creation draped over the pulsing drive of the survival-insuring primitive animal brain.  This is a recipe for conflict and cognitive dissonance on a fairly grand scale!

The fact that we are living in an age of technology and science lends support to our already-elevated view of our brain’s “designed” perfection.  Therefore we consistently overestimate the power of the human brain — to the point that many believe that with the right amount of practice, we can project ourselves across the universe, read other minds or predict the future.  At the same time we under-estimate some of the real powers of the brain: such as our natural animal wariness that can create debilitating fears, irrational thoughts and faulty perception.  Both are problematic.

The predicament that we are in is this: we are alive, we are conscious, and the only organ we have for navigating that rather stunning state of existence is a multi-layered, quirky sensory organ that retains its most primitive life-preserving functions even as it serves as the source of our most lofty, artistic and humane expressions.  Darwin wasn’t just whistling “Dixie” when he said that “…man with all his noble qualities …still bears in his bodily frame the indelible stamp of his lowly origin. ”  We do.  Oh, indeed, we do.

The truth is that we humans can seem to be rational only as a sort of last resort.  As I observe the battle lines of ideological debate in our current Presidential campaign, I am mostly struck by how many people are willing to take, at face value, almost any falsehood as long as it promises to support their belief-dependent view of reality.  If I could put one idea into the brains of all of my fellow citizens, it would be to embrace the true challenge that ownership of an evolved conscious mind entails, and learn to use our brains as effectively as possible (which has to include an awareness of the many quirks, biases and sensory mistakes that it is subject to).

It is a paradoxical challenge, this: using one part of our brain to figure out where the other parts of that same brain might be leading us astray.  But this is our reality: everything about our consciousness is playing out within the confines of our physical bodies.  (Though little wonder — since it can feel at times like there’s more than one person inside our head — so many of us are willing to imagine the different parts of our own consciousness as external beings, be they demons, spirits or angels).

Our brains may not be perfect, but they are certainly remarkable.  We just have to remember that they can rule us (fear) as much as we rule them (reason).  The best we can do is come to an understanding — an alliance, if you will — with the several aspects of our brain, and recognize the reality of what is happening inside our skulls.

t.n.s.r. bob

[CORRECTION/CLARIFICATION: My statement “In just the last 15,000 years we went from a small bunch migrating out of Africa to the global population of modern humans we are now.” is incorrect in that modern humans had already occupied regions of the Middle East and Central Europe before this time, but our global expansion has occurred within the last 15,000 years.  — t.n.s.r. bob

CARTOONS FROM THE REV

Sunday, May 13th, 2012

The "rev" Bob near Independence Hall...with a Federalist T-Rex.

SERMON: “Witnessing for Darwin” by the not-so-reverend bob

Sunday, May 13th, 2012

I wondered whether it would be prudent to keep my little brass “bob bless” pin on the lapel of my sport coat as I worked my way through security at the airport.  Would that quarter-inch of pin welded on the back be seen as a potentially deadly weapon?  Apparently, I need not have been concerned (though two screeners did get a chuckle after close inspection of my solid-bronze Dimetrodon skull belt buckle).

As the jet powered up and began rolling down the runway, I was like a kid again, thinking “Whee!  I’m on a jet!”.  The pilot in me noted how long it took for the jet to rotate up into the air, and felt the dramatic clunk of the wheels coming up.  I watched the ground drop further and further below me, until I could see the random “pattern” of the distinctive clumps of mesquite bushes on the desert floor.  I wondered if someone else would look for a pattern of divine design in the obvious spacing between the plants.  What I assumed I was observing were the natural limits on proximity dictated by the features of those particular plants in that particular environment.  I made a mental note to read up on how desert plant spacing is determined.

When cloud cover obscured the ground, I returned to reading an essay on early human evolution.  And as I read about the evidence for when our hominid ancestors first began using tools (about 6 million years ago), I couldn’t help but see myself at the leading end of that ancient process that, at a certain point, really began to speed up (in this case, up to about 600 miles per hour!).

My "bob bless" pin.

It’s difficult to imagine that we were once not much better at using tools than modern chimpanzees are today (they use rocks to crack nuts, stripped twigs and spit to draw termites out of logs).  But that’s how we were.  For us humans, however, the use of tools turned out to be the beginning of a major shift in our evolutionary direction.  For at this point in our history, we began our dependence on technology that continues to this day.  The morphological implications were huge — for our reliance on tools seems to have had a great deal to do with our bipedalism.  And one thing led to another until we no longer needed the natural defense systems of apes (for instance, we lost our protruding canines as we relied more and more on defensive weapons of our own design, and as the need for massive chewing muscles went out with our increased consumption of meat and the added calories available from cooked food, our brain cases could increase in size).

Over millions of years we continued to evolve as tool-using primates until there came a point (some 300,000 years ago) when we hominids were all cooking our food over fires and hafting flaked stone points to wooden spears.  This is the point in history where our brains stopped increasing in size (having likely reached the limit of size that would still allow human mothers to deliver their big-brained babies)  and we were likely talking to each other in some form of language.  After this point, our technological and social progress took a series of dramatic turns that led to our more recent “Neolithic revolution” and then the modern industrial/technical age we now find ourselves in.

I stood in the aisle of the jet as we flew on into the night, heading further east, and pondered the physics that allowed me to be standing with relative ease on an assemblage of human-designed and manufactured parts, all of which (along with dozens of my fellow humans) were rocketing along some 30,000 feet above the earth.  I looked at my fellow hominids, and noted how all were focused on some task or conversation or asleep.  And I couldn’t help but think how we take all of our progress for granted, as if we have always been so insulated from the challenges of life in a natural world.

Back in Dallas, the greeter at the cafe I ate in had asked me about my “bob bless” lapel pin.  I told him about the church of bob, and he said he wasn’t very religious himself, but his girlfriend had a job at a Christian camp, and that if she were to reveal to them that she accepted anything Darwinian, she’d lose her job.  “And she really likes her job” he said.  “But how can they ignore it [the science]?”, he asked.  I gave him some encouraging words about science, and the name of the church of bob’s website, and felt like any other evangelist on the road.

Despite the similar sensations of that exchange, however, science is not — as I’ve said before — religion.  I may be an atheist, but science is not atheistic.  The religious say science is atheistic only because science will not support their system of non-evidential beliefs.  Science is attacked not because science attacks God (it is, in fact, neutral), but because it does not actively support Him.  There is a huge difference.

Creationists use examples such as a jet liner to show how such a machine infers a designer.  This is correct, of course.  But to take that idea of “design inference” and apply it to nature is another thing altogether, and it simply does not work.  All attempts to prove this sort of “intelligent design” are pure pseudo-science, and absolutely no different than astrology, reading tea leaves or alchemy.  Creationism is always an argument from ignorance, in that it takes refuge in the notion that because a phenomenon is not yet scientifically explained, it must, therefore, be divine in origin.  The key word in that sentence is “not yet scientifically explained”.

There may well be things that we will never be able to explain through science.  However, it is wise to note the many times in our recent history when it was proclaimed that we were at the end of what the sciences could reveal.  Each time, science has found a way.  (And, I would note, each time that science finds a way, at least one existing religious explanation has fallen into obscurity — hence the antipathy of religion to science as general debunker of false claims).

It’s as hard, perhaps, to accept that I’m flying at 600 miles per hour, 30,000 feet over the ground as that I am evolved up from a fish-like ancestor that couldn’t even dream of having hands that would grasp a stone-tipped spear (much less write on a laptop computer in an airport terminal, as I am right now).  But, then, how could our ancestors have imagined any of this?  I can accept that I am really in a jet because I’m actually flying on one.  In the same way I have to accept that I am an evolved species because I really do exist, and the evidence for my origins is now known to me.

The challenge for us living humans, then — at least when it comes to accepting our natural origins — is not imagining the here and now so much as trying to imagine ourselves back then.

t.n.s.r. bob

CARTOONS FROM THE REV

Sunday, May 6th, 2012

I just hope that fence is electrified. A roadside dino near El Paso, Texas.

REVIEWS FROM THE REV: “Lone Survivors: How We Came to Be the Only Humans on Earth” by Chris Stringer

Sunday, May 6th, 2012

It’s a good question: “Why us?”  And it’s a question that’s bound to come up at a certain point in the contemplation of our natural origins.  After all, we bandy about truths such as “99% of all species that have ever lived on earth are extinct” without getting that chill up our spine that reminds us that we could very easily have been just one more extinct species.  And the unsettling truth is that there were many others of our species — or, at the least, closely related human species — that did, in fact, go extinct.

But the fact that we are still standing protects us from any sense of our true vulnerability and damn good luck in the game of evolution.  “Lone Survivors” tells us our story as we understand it today.  And today’s understanding is very different from what we knew only forty years ago.  It is a story that is continually unfolding.  But in this book we get the benefit of the first-hand experience and accumulated wisdom of Chris Stringer “one of the world’s foremost paleoanthropologists“.

This is a well written and well organized book.  I’ve read enough on the subject to sense what particular “camp” (or “school of thought”) the author is partial to, but one of the quietly wonderful parts of this book is how the author tracks the progression of his own ideas as they have been challenged by new evidence (significant parts of it from his own discoveries and research).  This is one of those uncommon (but, thankfully, not scarce) books written by the scientist actually doing the research he describes.  Add to that the detail that the scientist in question is writing from the back side of a forty-year career that seasons his conclusions and you get a fine, fine book.

The thing I notice about reading current science books is that many of them include last-minute additions, written as the books were “going to press”.  But, then, this is the inherent challenge of reporting science: authors must state what they know today, always understanding that somewhere, someone is finding out something new that will add new dimension to their current understanding of the world.  Nowhere is this more true than in the field of human evolution.  Though we had no hominid fossils at all when Darwin correctly predicted that humans had evolved in Africa, we still don’t have an exhaustive collection of our ancestry.  And so this remains an area where each new discovery has a tremendous impact on our knowledge.  But “Lone Survivors” does a tremendous job of telling our story up to now.

t.n.s.r. bob

The Rev gives is 3.5 out of 4!

SERMON: “Trimming the Family Tree” by the not-so-reverend bob

Sunday, May 6th, 2012

Although it’s easy (and correct) to critique religious views that place humanity at the logical end of a creation timeline (whether that creation occurred in the Biblical Garden of Eden or through hundreds of millions of years of evolution), it is worth taking a step back to consider that this teleological bias infests just about every human head, be they believer or scientist.

When (as a boy) I first learned about Neandertals, they were seen (along with every other early hominid) as our direct ancestors.  At that time, all different shapes and sizes of early primates and humans were just sort of crammed into a single family tree, with explanations abounding about how one evolved into the other and, eventually, to us.

Of course, it’s fair to be kind to these ideas (that are now clearly wrong), as we haven’t had all that many ancient human fossils to examine, and the technology to truly examine them scientifically has been developing rapidly over the last forty years.

As my geo-chemist friend pointed out with regards to studying the tectonic actions of Earth “We only have one data point”.  Meaning that we’ve only found one planet (so far) that has the qualities of Earth to study.  When it comes to our early human ancestors, we have a few more “data points” than that but, still, we don’t have all that many.

When a new fossil discovery hits the press, there is always a bold proclamation about how “everything we thought we knew” is thrown out the window, or an equally confident claim of where the fossil fits in our family tree.

But it is a testament to the steady work of science that all such announcements are eventually put through the wringer, and out the other end comes a more sober evaluation of what the new discovery can reliably tell us.

And so the sequencing of Neandertal DNA (quite a story of technology and tenacity in itself) has opened up new swaths of data from bones that we thought had already told us all that they could.

The story of the story we tell of the Neandertals is enlightening.  At first thought to be our classic “caveman” ancestor, brutish and dumb, they have had a sort of re-birth as noble, red-haired, cultured savages who may have been our equals (in their time).  Both of those descriptions are turning out to be a bit overdrawn, and it seems like we are settling down to an understanding that — though necessarily based on frustratingly few pieces of evidence — seems much more likely to be accurate.

In my short monologue "Forbidden Love of the Pleistocene" I tell the story of a doomed love affair between a Cro-Magnon man and a Neandertal Babe. Hey -- it could have happened!

For the Neanderthals now appear to be cousin to our Ice-Age “modern” human ancestors.  It also appears that (though highly evolved in their own right) they may have lacked a handful of key social and cognitive traits that many think made the difference when it came down to a question of “them or us”.

More importantly, it seems to me, we are coming to appreciate them for who and what they were, without the need to either demean or ennoble them out of our own emotional needs to feel guilt or superiority (after all, there is a chance that we played an active role in killing them off about 40,000 years ago).

So what about this “cousin” relationship?  Darwin predicted that it was Africa that was the nursery for modern humans, and he guessed this without a single ancient human fossil to go by.  Subsequent fossil finds (and modern DNA sequencing) have so far proven him right.  There are still some who hold a view that many populations of humans evolved in multiple regions on the planet, but the mainstream view now is one that we did, in fact, evolve in Africa before spreading out into the rest of the Earth.

But here’s where things have gotten interesting.  As always seems to be the case, when scientists first decided that we had, in fact, all “come out of Africa”, they looked for a single migration event that led directly to us.  It seems we can’t help but think that way.  But the science now supports a more nuanced view that, frankly, fits much better with how nature actually works.

Our current view, then, is that there have been lots of lines of humans through the millennium, most of them evolving in Africa, and occasionally migrating out of there where some groups found long-term success (the Neanderthals in the Middle East and Europe, Homo Erectus in China before we “modern” humans arrived).  There are signs in our DNA of a lot of cross-pollination between ancient humans in Africa, which makes sense when we look at other animal populations.  (The fact is that we can’t tell from fossils alone whether our ancestors had spectated to a point where they could no longer exchange genes.  It looks like they hadn’t, despite some surely dramatic morphological and cultural differences.  And, knowing humans as we do, there can’t be much doubt that we would find a way to have sex with just about anything that looked remotely like us).

The DNA evidence also seems to confirm that there was mixing of genes between the Neanderthals and the modern humans that first migrated into their areas (there is no sign of this mixing in modern African populations, nor of modern human DNA in Neanderthals), as well as some mixing going on between modern humans and Homo Erectus in Asia.

What we begin to see is the natural ebb and flow of reproduction among related species in a way that fits with what we observe in other animals.  And here is the key: it has taken us a while to really see ourselves as being “just like” the other animals.  (Even in science, we held on to an idea of our specialness, even when it kept us from properly interpreting the data of our origins).

But having at long last made that intellectual leap, we can now begin to appreciate what we think we know about our evolution.  The picture is complex and rather sobering.  For it turns out that there have, indeed, been countless groups of human varieties since we split off from our last common ancestor with modern apes (but even then, there was much cross-breeding for a very long time!).  If this is true, what happened to all of the other groups of “humans” that did not lead directly to us?  The answer is that they went extinct, in groups large and small.

But not too large, for it appears that the most critical factor in the evolutionary leap that we refer to as the Neolithic Revolution may have had almost everything to do with population size.

Modern studies of hunter-gatherer populations give us a picture of what happens to groups of humans when their numbers drop below a certain threshold: we revert to more primitive means, losing the gains in culture and technology that we achieve when we have more of our fellow humans to exchange ideas (and genes) with.  This, combined with our extended period of childhood (compared to other primates and, it is assumed, other early humans) may be what gave us the advantage over all of the other groups of our “cousins” that managed to hang on to their basic, set ways, for thousands of years but, in the end, could not adapt well (or rapidly) enough to avoid oblivion.

The nice (if we can call it that) thing about this conclusion is that it does make us feel a bit special for being, well, the ones that “won”.  On the other hand, there rests beneath this understanding the uneasy realization that we were incredibly lucky.  For the evidence also suggests that our lineage was down to just a few thousand individuals at times in our history (for more on this look up our “Mitochondrial Eve”).  It also tells us that perhaps Homo Erectus or even the Neanderthal’s might have done equally well had they ever had the right “breaks” that allowed their numbers to expand.

The other stunning part of our story is how we went from being a fairly dispersed species of low population density for pretty much all of our history to numbering in the many billions in an astonishingly short time.  That, somehow, once we got a foothold on our “modern” state of mind (and had developed the social structures and technology to support our increasing numbers) we went from one more smallish troop of naked apes to the dominant life form on the planet.

The “true” story of we modern humans is one of heartbreaking drama, and deeply humbling knowledge.  Entire species of our fellow humans went extinct at different times (the Neanderthals as recently as 38,000 years ago, Homo Florensis — the “Hobbit” — perhaps only 8,000!).  We lost our cousins (or drove them to the brink of extinction) the same as any other modern animal that stands as one of the survivors.

But we couldn’t even come to this picture of the many branches of our human family until we let go of the idea of a single-file, heroic march through time.  Only then could we see the evidence for what it could actually tell us.

This capacity: the courage to see ourselves as we really are, is a huge achievement for us as a species, and perhaps we must give most of the credit to the objectivity of science, and the scientists themselves who have had to fight the same self-centered tendency that is shared by their entire species.

As time goes on, we will continue to discover more fossils.  New technologies (and new knowledge) will wrest more information from those discoveries.  It may well be (it must be, in fact, highly likely) that there will be even more dramatic twists and turns to our human story.  But at least we are now, it seems, ready to hear the truth.

t.n.s.r. bob