How old is old, part II: 3465...and counting!

Early life
How old is old?  We asked this question on Monday when it came to relate to human evolution and our species' age and history as revealed by genetic data, in light of new estimates of the genetic mutation rate.  Here, we're talking about differences of around 1 million or so years since we evolved from chimps, or much less since modern humans diverged from our barbarous colleagues like Neandertals.

We see some modest changes in less than 10 million years, and debate whether it was 10 million or 'only' 7.  But let's put that in perspective.

The really early life
A former college classmate of mine, Bill Schopf, at UCLA, has been one of the discoverers of the earliest of early life, the first fossils of life that are found on earth.  These are bacterial colony constructs.  Some are organized in compacted layers, known as stromatolites.  The structures resemble modern stromatolites, and they and other structures of fossil bacteria bear remarkable resemblance to today's bacteria and their biofilms, modern day versions of fossil stromatolites.  How old are they?  A mere 3465 Million, that is 3.465 billion years!

A recent report by Schopf and Anatoliy Kudryatsev, in the journal Gondwana Research (Gondwana is the name for the earliest continent), reports on modern tests to show definitively that these fossils are real, as this as been the subject of some debate.  Here are images of these fossils and of their bacterial structures found from that report. After many years of various types of highly technical tests, the internal details as well as external shape and cellular structures now seem convincing that these are not natural mineral formations, but really are evidence of life.

The earth itself is estimated to be 4.54 Bya.  This means that from the first fireball, to life's first primordial 'soup' essentially to modern bacteria took only 1 Billion years.  If bacteria and their aggregations were very primitive, or just barely making it as living organisms, then one might say that's about what we'd expect: a billion years to make the first staggering living things.  But these are, in a reasonable sense of the word, already modern.

One has to assume that their genomes would be very different from bacterial genomes today.  If you look at genetic divergence among bacteria and other comparably primitive forms of life, you see that they are as different as you'd expect for such an old beginning....that is, they have diverged by an amount consistent with the 3+ billion year common ancestry. There is a touch of circularity in species split-time estimates because they are calibrated by fossil and other geological dating.  But the picture is consistent.

What this means is that the morphology, to a great extent, has been conserved for aeons of time, a rather remarkable fact, given that other descendants have diverged hugely, leading to plants, and us!  How we can explain this  level of conservation of structure, given the divergence of genomes, is a major but largely unrecognized challenge for evolutionary genetics.

These findings make it seem trivial to ask how a few hundred million year old arthropods, like horseshoe crabs, or ancient but much more recent fossil insects or fish, can appear to be so highly conserved, if evolution is a relentless rat-race to adapt to a competitive and changing environment.

The environments on earth are always changing, even if gradually and with some long-term stability.  One can imagine that once adapted to an environment, it may be risky for a mutant organism to survive, if most mutations, occurring randomly with respect to function, are more likely to cause harm than to be beneficial.  But since so much life is no longer bacterial and since there are so many  kinds of bacteria, do we have a serious question to ask how any recognizable morphology of this nearly earliest of life could have persisted so long--when their descendant genomes as a whole, even among bacteria, have diverged in a reasonably molecular clock-like way?

One would expect drift to occur in many, if not all traits: small, gradual changes that didn't harm fitness but that accumulated over billions of years to make the founding forms basically unrecognizable. Apparently this is not the case.  Thinking about how to explain that is interesting--at least as interesting as accounting for Neandertal vs modern human variation and evolution.

Encounters with Evolution....or....the Ark-etype of Ignorance

So the governor of Kentucky is supporting job creation by building an ark.  No, not just 'an' ark, the Ark!  As the New York Times reports:

The state has promised generous tax incentives to a group of entrepreneurs who plan to construct a full-size replica of Noah’s ark, load it with animals and actors, and make it the centerpiece of a Bible-based tourist attraction called Ark Encounter.

This theme park is being designed by the same people who designed Kentucky's Creation Museum, a tourist destination that, according to the NYT, has drawn 1.2 million visitors in its first 3 years of operation.  Yes, Cashing in on Christ, something surely Jesus himself would have gone to (but he'd only have gone there after chasing money-changers out of the temple).  The good Governor is surely correct that these same people would happily drop more money in his state at the proposed Ark Encounter.  Build it and they will come -- two by two.  Or was it in sevens (take a look at Genesis)?  And was it really only one male and one female of each type -- or did Noah have a don't ask-don't tell policy?. 

Some benighted citizens are wrestling with the question of whether it's constitutional to give governmental funding to a religious endeavor -- the governor says that's not an issue, it's just a jobs issue (or did he mean to say Job's).... but we'll let him battle that one out.

We would like to propose an alternative to the Ark Encounter along the lines of the replica of Lescaux, the early human cave complex in southwest France, with the 17,000 year old paintings of animals that grace the walls.  Lescaux II, the reproduction of two halls of the cave, and paintings, has drawn millions of visitors since it was opened in 1983 -- many of them even Americans.  Lescaux II is a replica because the tromping and defacing caused by huge numbers of tourists on a human ancestry pilgrimage there was destroying the very site they came to see.

We want to take a tip from Lescaux, however, and suggest that a theme park with replicas of sites around the world that have been of major importance to the understanding the real creation story, how life really got here and evolved, could create as many jobs and draw as many visitors as the Governor's Ark.  Maybe not the same visitors, granted.

But imagine it:


Exhibit A could be a replica of the stromatolites found in western Australia, as in the photo to the left, fossilized evidence of the earliest organisms yet found on Earth, from something like 3.8 billion years ago.  The foyer might be quickly passed by because it's just a  rocky remnant of what looks like layered mud.

But Exhibit B could reproduce much of the Burgess Shale Formation, in the Canadian Rockies, an extraordinary deposit of tens of thousands of fossilized organisms that represent a diversity of life from 500 million years ago, during the Cambrian explosion, that is no longer seen today.  It could be hands-on, too, with prickly trilobites for kids to play with, or video Find the Fossil games.

Next perhaps, there'd be the requisite dinosaur exhibit, beloved of kids, and a great draw.  T. rex and all that, of course.  But no halo'ed humans walking amongst them giving blessings in our exhibit, however.

And then, of course, we'd expect a Hall of Early Hominids -- replica fossil footprints would be fun, such as from Laetoli.  And a hulking, growling Neandertal or two.  Or a diarama of them sitting around a fire gnawing half-cooked moose meat or hide (to make clothing), or hammering out projectile stones or big Alley Oop clubs.  And, of course, the lazy one back in the cave daubing it with graffiti.

And of course, the pièce de résistance, a replica of the HMS Beagle, the ship that Charles Darwin spent 5 years on ship's naturalist, collecting the evidence that eventually convinced him that all life on Earth shares a common origin, and that the diversity of life he saw around him was due to descent from that common origin, with modification. Kids would love exploring the Beagle absolutely as much as they'd love climbing around on an ark. There should be a lifelike statue of Darwin  himself, with net in hand, setting out on a bug-collecting expedition.  This could be made by a contract to Madame Tussaud's.   Here, should one be generous and compromise by allowing a halo to be placed over his head?

This theme park, lets call it Encounters with Evolution, would be educational, that is, about real facts, there would be no controversy over using government funds to build it, and as for jobs, it would employ many people in its construction, and it would surely attract many visitors, as the Governor's Ark.

Of course this is just a quick imagining of such a site.  There are many many more exhibits that could be included...surely you could suggest some.  Maybe a contest for ideas could be held.

Ah, well.  A pipe dream.  The sad fact that it's an Ark and not our dream that's being proposed by the Governor of Kentucky (yes, elected by a majority of the state's population!) goes a long way toward explaining why American students score so poorly in science when compared to much of the rest of the world (such as Shanghai).  Science education is failing us.  (Note to the governor: Google and Intel are looking at graduates from legitimate colleges, not setting up recruiting desks outside revival-meeting tents.)

In the foreseeable future, it'll be us Americans who are sitting around a meagre campfire gnawing raw meat (probably rat-meat, or maybe just McBurgers), while people in other countries, who value real education, will be dining on caviar.....and smiling patronizingly at our plight.