Tuesday, August 31, 2010

Protosphyraena perniciosa in Stereo

It’s a kind of magic.

One shaft of light
That shows the way.

~ lyrics from Kind of Magic, a song written by
 Roger Taylor and performed by Queen

Gentle Warning:  If you thought that the Magic Eye books of the mid-1990s were the work of the devil, you may have a problem with this posting.

During the Late Cretaceous, the Western Interior Sea occupied a broad swath of the interior of North America, stretching the entire length of the continent.  The map below, created by Ron Blakey, professor emeritus of geology at Northern Arizona University, shows North America and its inland sea about 75 million years ago.  (A rich array of paleogeographic maps is available on Blakey’s website.)

Many fossils from the predators and prey that lived in this marine environment are preserved in the Smoky Hill Chalk of northwestern Kansas, a chalky limestone deposited about 82 to 87 million years ago.  The local landscape in that part of Kansas is startling (to this Easterner), to say the least, offering a western John Ford-like landscape.  Mike Everhart’s Oceans of Kansas website offers a collection of pictures of the Smoky Hill Chalk which capture their badlands flavor.

Among the fierce predators of these waters was Protosphyraena perniciosa, a fish with a mouthful of forward-thrusting dagger-like teeth, a long pointed beak, and dangerous front fins.  Think swordfish starring in a nightmare.  Everhart’s informative overview of the Protosphyraena perniciosa on his website includes a painting recreating this disturbing monster.  The 3 cm. long tooth from a Protosphyraena perniciosa pictured below was collected (not by me) from the Smoky Hill Chalk in Gove County, Kansas.

The technique I’m using here to depict this tooth is appropriate, I think, for this especially horrific fish.  The two images in this picture are of the same tooth but, despite appearances to the contrary, are not identical.  Previously on this blog, I’ve pondered how to capture images of fossils.  Being open to the unbidden means that inspiration can come from anywhere.  So it was that earlier this summer I happened to catch Terry Gross’ interview with Brian May on her NPR show Fresh Air (August 3, 2010).  May was lead guitarist and a composer (e.g., We Will Rock You) with the storied rock group Queen.  But, lest one think he’s a burned out rocker drifting through life living on his royalties, know also that he is an astrophysicist, having earned his Ph.D. in astrophysics from Imperial College, London, in 2007.  Terry Gross’ primary interest in this interview was in May’s role in Queen and how songs were composed and played by the group.  A worthy topic since May brought intellect and science to it.  Almost tangential in this interview (but what I suspect he really wanted to spend much more time discussing) was one of his consuming interests (besides astrophysics) – stereoscopic photographs or stereoviews – which is the subject of a book he recently co-authored with Elena Vidal, entitled A Village Lost and Found:  A complete annotated collection of the original 1850s stereoscopic photograph series – Scenes in Our Village by T.R. William (2009).  This is an amazing work, as fascinating for its exploration of the quiet, small village of Hinton Waldrist in mid-19th Century England, as for its glimpses of the broader world of stereoviews.  What little I know about stereoviews (and share below) I learned from this wonderful book.  It comes with a stereoscope (see picture below).

Stereoviews came into being in the early days of photography at the beginning of the 19th Century.  It was dissatisfying to some that photographs captured only two dimensions, offering a flat representation of reality, so they looked for ways to bring depth, the third dimension, into the images.  They built on the techniques already being used for “stereo” drawings and created stereoscopic pictures which, when properly viewed, offered a view with depth, a view in stereo.

To do this, they took advantage of the fact that we humans have two eyes set a bit apart from each other, giving us binocular vision.  As a consequence, stereoviews hold two pictures of the same scene; these right and left images are shot from slightly different positions, the camera having moved horizontally between each exposure (unless it’s a camera designed specifically to take these dual pictures).  Viewed through a stereoscope or by free-viewing (more on that in a moment), these dual photographs are processed by the brain as a three-dimensional image.

[This ability of the brain] is no accident.  Through the long, leisurely process of our evolution as a species, having two slightly different views of the same scene gave humans (any many other species) a great advantage . . . . [T]his binocular vision gave us the ability to perceive depth, enabling us to instantly recognise how far away each object in our sight was, a vital factor in assessing how close to us a potential danger might be.
                            A Village Lost and Found, p.12

The two images above of the Protosphyraena perniciosa tooth are sequential stereo photographs which, if viewed through a stereoscope (such as the one shown below), depicts the tooth in three dimensions.

But, that’s not the only way to see the stereoscopic image.  There’s free-viewing, a technique that many of us used in the mid 1990s when the various Magic Eye books were populating the New York Times best seller lists.  (As with nearly everything else in life, Magic Eye also made an appearance on Seinfeld.)  Free-viewing works not only on printed images but on images displayed on a computer screen.

May and Vidal offer this guidance for free-viewing stereoscopic pictures:

All we need to do is line our head up squarely with the page, and imagine we are looking through the page to infinity.  Usually what happens is that the two images in front of us both become double, and four images swim about sideways, as we try to make sense of what we are seeing.  If we persevere, though, and keep the eyes relaxed, eventually we will see two of the four images coalesce into one.  This become the central, solid picture, and is flanked by two other pictures, which both appear partly transparent.  All we need to do now is forget about the outside pictures, and concentrate gently on the centre one.  With a little patience, it is possible to keep the convergence of our eyes constant, so the central picture keeps its integrity, but relax the focus of the eyes to make this picture sharp.  At this point, the magic happens, we are suddenly aware that the central picture is no longer flat, but completely three-dimensional . . . the window is open . . . we are free-viewing in stereo.
                        A Village Lost and Found, p. 15

Well, I suspect the process is a bit different with everyone, and, I know, impossible for some.  With the images of the tooth above, the process for me seems to be a bit simpler, perhaps because there’s less information in the photographs for my brain to deal with than there is with the stereoviews of the village of Hinton Waldrist.

Here’s how it works with me on the tooth images.  As I bring my face close, centering my nose between the two pictures, I try to look beyond the pictures.  Up close to the pictures, I see a central, blurry image.  Then, as I slowly move back from the pictures, I keep focused on the convergence image.  Two other images appear on the left and right.  I ignore them and stay focused on the central image.  Not too far removed from the page, the central image comes into focus in three dimensions.

May and Vidal have other good advice – it may not happen the first time or the second . . . .  

As I noted, these techniques work on images on a computer screen.  But, if the dual image of the tooth is printed for stereographic viewing, I find that it works wells for me if the composite picture is about 3 3/8th inches high and some 4 ¼ inches wide.  Clearly a range of sizes will work, so there’s not anything particularly magical about these dimensions.

And to be honest, in many stereoviews, objects all at the same range often seem to have retained a two-dimensional quality.

Each of the images in the Scenes in Our Village series was accompanied by a verse, presumably written by the photographer T. R. Williams.  May and Vidal liken their spirit to that of haikus.  I loved the one in which the poet extols the virtue of stereoscopic viewing as a way of giving the untrained eye a glimpse of deeper beauty.

Lane Leading To The Farm

Seen with the artist’s eye, how many a spot
On nature’s face that seems a simple blot,
Teems with rich images and beauties rare!
Taught to appreciate, the traveller there
Marvels that he so often hath before
Unknowing, unadmiring, passed it o’er:
Thus, what is cultivation to the eye
Of the taught artist – stereoscopes supply.

[Note: I later edited this post by adding in various places the term "stereoview" which is the more common label applied to this two-picture arrangement.]

Thursday, August 19, 2010

The Equation of the White-tailed Kite

Seems like everywhere I go,
The more I see,
The less I know.
        ~ from the song Say Hey (I Love You) by Michael Franti

Late one recent night, accompanied by the white noise of a window AC that was barely beating back the summer’s heat and humidity, I listened to a recording of a talk delivered several weeks ago to a fossil club of which I’m a member.  Topic – one member’s adventure in Montana collecting the associated bones of a Triceratops that included a complete left back foot, apparently a very rare element from such a dinosaur.  Listening to his account was the closest I’d come to fossiling this summer since so much of it has been spent on Long Island (a lament about the absence of fossils here can be found in a prior posting).  This talk was a vicarious thrill.

Yet, as I listened to the end of the talk, I groaned.  In response to a question, the speaker said that some of the ranchers on whose property he’d hunted received cash for access, and agreements were struck with others, such as the one whose land had yielded the Triceratops, that they would receive 30 percent of what was realized from the subsequent sale of the fossils.  The speaker added that he hoped the Triceratops would bring big bucks.  So, in the end, it became about commerce and ownership.

A couple of weeks ago, in a summer ritual, I dropped in on a local gem and mineral show and scouted out the fossil vendors.  It was a curiously dissatisfying experience.  Examining fossils in this surrounding seemed like buying puppies from a pet store.  They deserve a good home yet the transaction only serves to encourage the practice.  Curious reaction since I’ve bought fossils before without compunction.

Fossil collecting involves acquiring individual specimens.  The equation here is fairly obvious since the resources are finite.  If it enters my collection, it cannot enter yours, and vice versa.  A zero sum game.  I think many of us enjoy that kind of game.  For some, it’s a competition and there are winners . . . and losers.  (Add a financial side to the fossil hunt equation and things can get completely out of whack.)  Still, collecting doesn’t always end up that way.  In particular, I am very fond of museums and the role they play in breaking apart this equation.  The collected specimens are shared, available to others to see, to study.

At one stage this summer (seeking to fill the fossil void), I turned my attention to the wild flowers growing along nearby roads and began recording what was in bloom, amazed at the diversity of species.  It’s hard not to be inspired when you think you spot the Evening Lychnis or White Campion (Silene latifolia) and read in the Peterson First Guide to Wildflowers of Northeastern and North-central North America (1986):

This introduction from Europe blooms at night, when its white flowers attract moths to perform the mystic rites of pollination.

Lovely language.  It is interesting that the full version of the Peterson guide to wildflowers has no such sentence in it.

But, another evening stroll to the same area, this time equipped with a camera, suggests things among these flora are not what they originally seemed. 

In all respects save one the flower pictured here appears to be a White Campion.  It’s the color of the petals that throws me.  My initial thought was that these petals have a purplish tinge.  If it’s truly purple, then I have no clear candidate for this flower’s identity.  If, instead, these petals can be considered pinkish, it could still be a White Campion.  The Ohio Agricultural Research and Development Center (Ohio State University) notes that the White Campion may “rarely” have pink flowers.  Alternatively (sticking with pink as the color), this may be a hybrid between the White Campion and the Red Campion (S. dioica).  (The flower is roughly 3/4th inch across.)

Curiously, many of the websites that put me on to the possibility that this flower is a hybrid were describing wildflowers in Britain.  The one I enjoyed the most was English Wildflowers:  A Seasonal Guide, created by Keith and Violetta Jones.  In their discussion of Campion species, they describe a Pink Campion as a hybrid between S. latifolia and S. dioica, noting that the calyx (the inflated sac below the petals) is green as it is with the White Campion (the Red’s is red).  One of their pictures of a Pink Campion is similar in color to this one.  Among the real pleasures of this wonderfully organized and written website is the authors’ description of themselves:

Dr. Keith Jones has recently retired after 40 years as a microbiologist at Lancaster University and has returned to his first scientific love, plants, showing that it is never too late to use your first degree (botany, Nottingham University, 1963). He is responsible for the pictures, identifications and the descriptions on the site.  Violetta, his wife, has given enthusiastic encouragement to the setting up of the web site and proof-reads every page. She was the first to realise the potential of the digital camera and it was she who made the suggestion that Keith would need a hobby on retirement and not get under her feet.

This collecting of wildflower sightings has a communal aspect to it.  It’s the sighting that enters my collection (assuming I get it right), not the object itself.  What’s spotted can be shared with someone else, a person accompanying me down these same road, some stranger who comes by on his own.  Nothing exclusive about it.  The math of this effort is great – the sighting can be divided infinitely.  Of course, there are those who would wreck that calculation and collect the rare plants, not just the sightings of same.  I’ve posted on this before, regarding Canby’s Bog Orchid.  Zero sum game again.

A few days ago I attended a birthday party at an Audubon center on the Connecticut shore of Long Island Sound.  It’s a heavenly place for anyone interested in nature.

A salt marsh stretches out before it, replete with osprey, heron, the usual denizens of this area, and, these days, somewhere in the vicinity, a White-tailed Kite (Elanus leucurus).  Had not most of those attending the party been birders, I would have had no clue that the sighting of a White-tailed Kite on the Connecticut shore was such a rarity that it would be the stuff of tales to tell future grandchildren.  This beautiful raptor appears in the eastern U.S. only along the southern tip of Florida.  As friends gathered, invariably the question was, “Have you seen the Kite?”  The answer seemed always to be “Yes.”  And probably with good reason.  This bird being found in this area was a rare event and apparently birders share information electronically with abandon.  Corey Finger, on the blog 10,000 Birds, which he co-authors, provides a great description of his pursuit of this out-of-place White-tailed Kite.  Sharing information is the watchword.  He also took superb pictures of the bird which he posted; I’ve reproduced one below with his permission.  (These birds are roughly 16 inches in length with a wingspan of some 3 feet.)

For non-birders, like me, I should note that Corey uses the word “twitch” in his account.  Sean Dooley, in his book Big Twitch: One Man, One Continent, a Race Against Time – A True Story about Birdwatching (2005) defines “twitch” as:  “The act of chasing after a rare bird.”  He notes that it can be used as either a noun or a verb.  My sense is that it also involves the willingness to join in that chase of a wayward bird regardless of the distance one might need to travel.

There is something to be said for this collecting of sighting or pictures.  The community bonds over the pursuit and it does not become the province of a single individual, the one first on the scene.  I wonder what that would be like.  Still, at the moment that is perhaps too civilized for me, part of the thrill of the hunt is the prospect of adding something special to my collection.

In thinking about the equations of these various collecting efforts, I realize that, at another level, there’s a decidedly unbalanced accounting possible here.  If, in this kind of pursuit, I am open to new ideas and challenges to my “facts,” the knowledge side of my mental ledger will probably build.  That’s good.  But, at the same time, my acknowledged ignorance will grow still faster.  And that’s good, too.

Reminds me of a Calvin and Hobbes exchange.  (Come back, Bill Watterson).  In it, as they watch a snake, they bubble with questions about it.

Hobbes:  Do snakes have eyelids?  Do they sleep with their eyes open?

Calvin:  Don’t snakes eat mice?  How could a snake swallow something bigger than its own head?

Calvin:  Hobbes, we don’t know ANYTHING about snakes.

Hobbes:  Maybe your mom would get us a book.

* * *

Calvin:  Hey, wait a minute!  It’s summer!  I’m on vacation!  I don’t want to LEARN anything!

Hobbes:  If nobody makes you do it, it counts as fun.

Wednesday, August 11, 2010

Shells At Hand

Every observer brings to his or her own science a unique perspective,
and I am no exception.
~ Geerat Vermeij, Privileged Hands: A Scientific Life (1997)

My little experiment in perception is inspired by Geerat Vermeij and takes place on a hot midsummer’s morning on the shore of Flanders Bay. Flanders Bay is at the beginning of a series of bays separating the North and South forks of the eastern end of Long Island, NY, these waters ultimately connect to Block Island Sound and the Atlantic Ocean (see map).

View Larger Map

It’s a shallow bay, and along with its big sisters, the Great Peconic and Little Peconic Bays was once rich in scallops, clams, and oysters. Recreation is its claim to fame now. The bay this day is its usual meek self, waves little more than ripples lapping at the sand. The receding tide has left a motley array of shells and other marine debris in a rough line extending along the beach.

At the water’s edge, I select three shells. Each is a very common shell here – in the picture below, the shell at the top is the top valve of the bivalve known as a Jingle Shell (Anomia simplex) (to provide a frame of reference, this shell is roughly 1 inch from edge to edge), the smaller shell immediately below it is, I am convinced, a little example of a valve of the bivalve Bay Scallop (Argopecten irradians), and the third is a Common Slipper Shell (Crepidula fornicata) from a gastropod (snail).

I then sit on dry sand, and try to answer the question,

What can I learn about these shells by touch alone?

Since I am by myself on this morning, I select the shells by sight. And, so, not unexpectedly, my experiment begins on a false note. Still, despite that, the experience of exploring each shell with my fingers is revealing. Even this brief effort suggests what I might miss relying almost solely on sight.

The differences between sight and touch emerge quickly.

Textures. The feel of the shell surfaces serve as the introduction for the exploring fingers. The exterior of the Slipper (or Boat) Shell has somewhat erratic ripples that work their way across the shell, they are relatively smooth. The apex is smoother and devoid of ripples. The interior is smooth though somewhat chalky once it has dried. The platform on the Slipper Shell’s underside (see picture below) is almost pearly to the touch with a subtle ridge that emerges from the underside of the apex and runs in an arc along that edge of the shell.  I wonder why the platform's surface should be different from the actual interior?  I assume a purpose for this difference though I don't know what it is.

The Scallop Shell is surprising because the interior and exterior surfaces are remarkably similar in feel but only primarily along the outer portion. The crenulated edges reflect the radiating ribs.  Why ribs?  What's gained by that, is it defensive architecture?  Though the ribs can be felt clearly on the interior along the outer edge, their definition fades as my fingers travel toward the underside of the apex.  The inner surface becomes coarse. Even with this very small shell, it’s relatively easy to feel that the each rib on the exterior is bumpy as is each of the grooves that separate the ribs. Once again, the apex is relatively smooth.

The Jingle Shell’s interior and exterior surfaces are, to the touch, a study in contrasts (despite how similar they appear to the eye). The exterior is bumpy and uneven, feeling as though it is made by a hand that paid little attention to symmetry, the grooves that surround the apex are only roughly concentric. The interior, on the other hand, is a fingertip’s delight – glassy in its texture with one ridge that runs parallel to the far edge.  Why should the interior be so smooth, so different from the exterior surface?

Edges and Thickness. Of course, I feel edges on all of these shells and quickly register whether the edge is thick, thin, strong, fragile. The Slipper Shell’s edges are ragged, sharp, and broken. The platform on the underside has lost a lot. The edges of this shell are relatively thick, suggesting that it takes some significant force to break it. Though the edges of the Scallop Shell are mostly complete, they are sharp to the touch and relatively thin, seemingly very breakable. The Jingle Shell’s edges are relatively smooth, though they do reveal some breakage. Curiously, the outer edge feels as though it has a lip that curls back under the shell.  To what end?  Protection for the much flatter bottom valve that is only infrequently found on the beach?

Weight. Though none of these shells weighs much, weight, as an attribute of each specimen, is registered almost immediately by my fingers and my palm.

Simultaneity. This is the most striking difference to me between examining by sight and examining by touch. By using my thumb and index finger I can simultaneously examine the inner and outer surfaces of each of these shells. This immediate sensation of contrasting textures highlights how very different or similar these surfaces can be. Is this of some value in trying to learn about and understand the creatures that made these shells? I don’t know, but it’s a lasting impression from this experiment.

Questions. Finally, I wonder if there isn’t some aspect of this exploring by touch that sparks questions. Perhaps it has to do with the inability to take in the totality of the object as one does with sight. The fingers identify pieces that need to be assembled into the whole, triggering questions of how does this fit with the other pieces I’ve felt, and, perhaps, why is this shaped, textured, sculptured in this particular way.

Obviously, there are attributes of these shells that touch alone cannot identify. Color, for example, is denied the fingers, not only the presence of color but the location and any changes in color. Also, the overall structure of the specimen is more quickly apparent using sight, though educated hands might do as well.

I began this posting with a quotation from evolutionary biologist Geerat Vermeij’s autobiography Privileged Hands. From early childhood, Vermeij has been blind. Though that attribute is one frequently used in identifying him, it is not the one that defines him.

Vermeij, professor of marine ecology and paleoecology at the University of California, Davis, and an expert on molluscs, has written extensively on the evolutionary consequences of the ancient and continuing arms race between molluscs and their predators, and among those predators. He has identified what he calls the Mesozoic marine revolution when some 200 million years ago marked innovations occurred in predation and in shell architecture resisting that predation, a revolution as “shallow-water marine communities underwent a profound general reorganization.” (Privileged Hands, p. 200).

There is a great deal out there by and about Vermeij.  An interesting profile of the scientist ran in 1995 in the New York Times. (Though the article suggests that he and I might not see eye to eye politically, so be it.) Among his myriad articles is a wonderful piece he wrote for Natural History (February, 2002) The title suggests its appeal – Why Are There No Lobsters on Lands or Bats at Sea?

It is apparent that, because Vermeij examines shells, from extant and extinct creatures, with his fingers, he gains a different and strikingly useful perspective. The quotation that began the posting comes from this paragraph which suggests some of what Vermeij derives from his fingers:

I cannot claim to observe shells better than others do, nor would I pretend to discriminate more easily among species on the basis of shell features than other malacologists do. Every observer brings to his or her own science a unique perspective, and I am no exception. Inspection of an object with fingertips, fingernails, and thin needles reveals not only the broad outlines but also the small-scale details – the number, relative size, and orientation of elements of sculpture; the placement of teeth and folds surrounding snail-shell apertures; the pattern and asymmetry of clam-valve serrations; and the like – that a casual observer is apt to overlook. (p. 265)

Privileged hands, indeed. His research has included an examination of the evidence of predator attacks on mollusc fossils from millions of years ago, an exploration where the sensitivity of his fingertips to the healed over scars left by failed assaults is crucial.

A moment in the 4th grade set him on his life’s course. His teacher brought in some shells gathered in Florida. When Vermeij held them and ran his fingers over them, he was struck by the differences between these shells and the cold-water ones he had collected previously in his native Netherlands. An apparently endless sequence of questions was engendered by this tactile encounter. He continues to grapple with versions of the question he asked as a 4th grader, concluding his autobiography with several, beginning with that first one:

Why are northern shells chalky and tropical ones so beautifully crafted and so finely textured? Why do some predatory snails have lip spines while others do not? Why did acorn barnacles replace other kinds of shore animals when they appeared some fifty million years ago? I do not know, but I shall ask. Nature will surprise us if we let her. (p. 272)

Monday, August 2, 2010

Thoughts About A Missing Cousin

My original intention with this posting was to write a review of Clive Finlayson’s book entitled The Humans Who Went Extinct: Why Neanderthals Died Out and We Survived (2009), but it turned out to be too slim reed, as I will make clear at the end. So, this is something else, a mélange of thoughts about Neanderthals with a little piece of a review appended.

As I sketched out this piece, I realized that I’ve had a steady reading diet of things Neanderthal, frequently dipping into the flow of recent articles and books featuring or starring our close cousin from the human family tree. For many of us, Neanderthals (Homo neanderthalensis) hold a particular fascination which arises, I think, because they are such a powerful reminder that much of what we have considered quintessentially human is not unique to modern humans (Homo sapiens) (and quite possibly the very separation of these two human populations into separate species is misguided). Perhaps even more important, the emerging picture of the world of the Neanderthal tells us that the presence of modern humans in the here and how is largely a matter of chance. Given, say, a different roll of the climate dice, we would be among the missing human cousins. It’s a healthy counterweight to the belief that we are the culmination of the implementation of some plan.

Neanderthals exhibited behaviors we previously thought distinguished our species from others. The Smithsonian Institution’s Hall of Human Origins displays a Neanderthal youth’s skull showing clear evidence that, at a very young age, he experienced a severe blow to the head, damaging the left eye socket and area of the brain behind it. Movement on his right side would have been seriously compromised. But this didn’t condemn him to an immediate death. His people nurtured and cared for him over several years as evidenced by the withered right humerus (the right side of his body would have been controlled by the damaged portion of left brain hemisphere). I am struck by the implications of this. Sharing had to undergird the relationship he had with his group. Certainly, food and other resources were given to this possibly unproductive member of the group. Someone may have been spared to provide care, particularly when the child was first injured. It’s a wonderful fillip for seeing the Neanderthals in a different light.

We know Neanderthals buried their dead, testament to their cognitive and social attributes because burial rituals signal a belief in something more than the brutish present. Shinadar Cave in Iraq is a Neanderthal burial site dated at roughly 65,000 years ago. In What Does It Mean To Be Human? (2010), Richard Potts (director of the Smithsonian’s Human Origins Program) and Christopher Sloan describe one such burial:

. . . an adult male Neanderthal was carefully placed on his side in a shallow grave in a fetal position. There is good evidence that colorful flowers and evergreen boughs were intentionally placed in the burial with him. (p. 49)

The authors consider the import of this action, arguing that burial rituals

. . . reinforce social bonds and may have helped earlier human groups cope with life’s difficulties by allowing grieving. [Also], burials show that humans were able to conceive of something other than the immediacy and harsh realities of their daily lives.

Among those researchers most strongly staking out the position that Neanderthals’ capabilities and often their behavior differed little from ours is João Zilhão of the University of Bristol. As I understand it, in his eyes, the discovery of purported body ornaments (painted shells) at two Neanderthal sites puts a lie to the notion that modern behavior depends upon modern anatomy. Regardless of anatomical differences between Neanderthals and early moderns, the behavior of individuals in both populations was the same. (See, Symbolic use of marine shells and mineral pigments by Iberian Neandertals, PNAS, January 19, 2010.)  In a recent interview under the title “Did Neandertals Think Like Us?”, Zilhão asserted that the body ornaments show that, indeed, they did think like us. (Scientific American, June 2010). He explained the implications of his position:

There are several possible conclusions one could draw from this observation. Either modern cognition and modern behavior emerged independently in two different lineages, or they existed in the common ancestor of Neandertals and anatomically modern humans; or the groups we call Neandertals and modern humans were not different species and therefore we should not be surprised that despite the anatomical differences there are no cognitive differences, which is the conclusion I favor.

As for the role of chance, I’ll turn to Finlayson’s slim volume.  The Oxford-trained Finlayson certainly has the expertise to write on this subject. He is Director of the Gibraltar Museum and Director of Heritage for this British Territory, and has researched and written extensively on Neanderthals, particularly the last remnants of the Neanderthals who lived on Gibraltar between 28,000 and 24,000 years ago.

Though a handful of themes run prominently through the book, such as:  populations living on the environmental margins are the source of biological and cultural innovation, and modern humans are not intrinsically “better” than other ancient humans including Neanderthals, one theme trumps them all:  the presence today of modern humans, and the absence of Neanderthals (and other ancients) are the product of chance, driven largely by climate.

Consider just a few of the chapter headings in the book: Being in the Right Place at the Right Time; If Only . . . ; and Children of Chance (title of the epilogue). Finlayson places that the big uncontrollable – climate – in a starring role, creating the chances for Homo sapiens to arise, survive, and ultimately expand. Swings in climate are crucial for his explanation of the extinction of the Neanderthals. In one of his strongest statements, he asserts:

. . . human history has been an affair between contingency and luck, conspiring with the erratic whims of climate and geology to produce the improbable character that is Homo sapiens. (p. 105)

I devoted some time to reading this book because it held out such great promise, but, ultimately, it disappointed me. I can live with some repetition of central arguments, though I think Finlayson went too far. I suppose he was successful in that the reader comes away with an appreciation of the role of chance in human evolution, but this repeated note hurts the coherence of the book. There are other questionable choices about how he organized his material, but they aren’t the critical failure for me.

The most substantial problem with the book is that, despite its subtitle, it offers no detailed and nuanced portrait of Neanderthals. It fails to place them front and center, and so leaves the reader without a firm grasp of the where, when, and how of their emergence, endurance, and extinction. Oh, the information is there, spread throughout, but one struggles to accumulate it, given how fragmented it is. I think the problem lies in Finlayson’s decision to tell a broader story, the sweeping story of the rise and fall of innumerable proto-Ancestors and Ancestors (the terms he uses to identify those humans who ultimately yielded modern humans). Yes, that is the reality, the Neanderthals were just one among many failed human experiments, but that is not the story I thought he set out to tell and not the one I wanted to read. The expected main actor seems unfortunately marginal in this account.
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