Wednesday, December 21, 2011

Holiday Nature Connection

While out walking on this day, the shortest of the year, I began thinking about how grown-ups might be connecting kids with nature this time of year. To my mind, finding ways to help children make meaningful connections with (nonhuman) nature is one of the most pressing challenges of the 21st Century, rivaling global warming, habitat loss, and species extinctions. After all, how can we possibly live sustainably in a place we don’t care about? And why would we care unless we have meaningful experiences in that place, and know something of how it works and how it came to be?

Jade out having fun in Nature!

On the one hand, the holiday season would seem to offer great opportunities for making nature connections, since kids have time off school and other activities. On the other, adults are often running around working, shopping, and/or staggering from party to party. Then there are the obstacles of winter, like finding sufficient daylight and warmth. How many kids are going to be passionate about turning off the screens to face the frigid temperatures outdoors? Yet, I know that there are millions of people who will be out there connecting their kids to nature this holiday season. What I—and, my assumption is, many others—want to know is, What are they doing?

Before getting to that question, let me return for a minute to technology. Many people in the children-and-nature movement see technology as the enemy—the evil that now enslaves children for 7-10 hours a day in front at screens. But, let’s be frank. Technology isn’t going away; indeed it’s only going to accelerate, at least for the foreseeable future. So, perhaps ironically, I’m convinced that we need to come up with creative ways to use technology to aid the cause of nature connection. And that, my friends, brings me to Twitter.

I recently joined the Twitterverse, which, for me, felt like a big move. But I have to say, the decision was a great one, and I haven’t looked back. Not only have I shared ideas with many like-minded (and not so like-minded) people. I have learned about cutting edge news and events that I undoubtedly would have missed if I hadn’t been tossing out the occasional tweet.

Jade and friend Tessa camping.

So here’s what occurred to me while out walking (which, by the way, research suggests is the best time to think). Let’s find out how people are connecting kids to nature this holiday season by putting out a call on Twitter. So here goes:


It might be something you’ve done before, something you’re doing this year, or something you dream of doing (e.g., surfing off the coast of Maui on Christmas day). Stargazing, beach walking, snowball fights, snowboarding, a visit to the local natural history museum—it’s all fair game.

Tweet your answer to #HolidayNature by Wednesday, January 4th, 2012, so that others can find out what you’re up to. Please include @DrScottSampson in your tweet so that I can track all the submissions.

I will tally and blog about the results, choosing what I think are the Top 10 best answers. And if, as anticipated, the material warrants, I’ll write up an article and submit it for publication so that many other folks can benefit from your collective creativity and wisdom!

Jade on one of our birding trips

Please get the word out through the Twitterverse asap so that we can get some amazing feedback. I already have my first response, from Michael Barton (@darwinsbulldog), who wrote, “Last year we visited a local state park on Christmas day and I said we should do so every year...”

As for me, well, let me throw my hat into the ring too. Jade, my 9-year-old daughter pictured in the accompanying photos, is passionate about birds (you know, living dinosaurs), so we'll be heading into the local hills, or perhaps down to the lagoon, to do some birding.

So, what are you doing to connect your kids to nature this holiday season? Let the masses know! And please follow me on Twitter (@DrScottSampson). I promise many future tweets on nature connection!

Friday, December 2, 2011

Dinosaur Train Gets Into Nature!

When I was initially invited to get involved with PBS KIDS Dinosaur Train a few years ago, I was very skeptical about working on a TV series that might further addict children to screens. After all, my focus as a science communicator is all about getting kids outside. However, following some negotiations with the Jim Henson Company (which produces the show), it was agreed that I would add an enthusiastic tag line at the close of every episode (the final version being the brainchild of my wife Toni): “Remember, get outside, get into nature, and make your own discoveries!”

At the time I had no idea if a television program could induce kids to turn off the TV and head outdoors. However, based on the hundreds of comments I’ve received from parents, I’m now convinced. I regularly hear about boys like Tommy who are always heading outdoors to dig for fossils (makes me wonder about the holes in the backyard . . .), and girls like Mary who have become avid birdwatchers (that is, dinosaur observers!). A nationwide Dinosaur Train geocaching program was added, which has also been very successful at getting kids to explore their local areas.

By the time we began production on Season 2 of Dinosaur Train, the Henson Company and PBS KIDS were equally excited about the idea of getting kids outside. Indeed it was decided that nature connection would become one of the show’s primary themes. As a result, the animated kid characters, led by Buddy the T. rex and Tiny Pteranodon, have formed their own nature club (the “Nature Trackers”) and now spend much of their time making natural history collections and firsthand observations about their surroundings.

Some kids at the beach being filmed making nature art.

Along with cool new dinosaurs, featured topics for connecting kids to nature now include plants, insects, stars, rocks, and nature art. In the interstitial portion of each episode, which I have the pleasure of hosting, we’re encouraging kids more than ever to explore local nature. In Season 1, all of the interstitials were shot on green screen in a Hollywood studio—hardly the ideal setting for encouraging nature exploration. But for Season 2, we’re featuring shoot locations out in nature (e.g., redwood forests, beautiful beaches, and tidepools burgeoning with animals), as well as in museums, often showing real children connecting to real nature!

Check out some of the new episodes and songs here, including a very cute tune called “Get Into Nature.” The award-winning website will soon be bolstered with all kinds of activities to help parents connect their kids to the natural world. Dinosaur Train has even partnered with the Cornell Lab of Ornithology to help foster an entire generation of kid birdwatchers! Currently, the show is viewed in more than 9 million households a month, and appears to be gaining steam! So stay tuned and get onboard!

The Dinosaur Train Film Crew!
(The show's creator, Craig Bartlett, is second from the left in the back row.)

Thursday, November 10, 2011

Deep Technology

What do kingfishers, Namibian beetles, and humpback whales have in common? Do the members of this unlikely trio serve as the namesakes of professional sporting teams? Have their genes been spliced together to make a super-cucumber? Nope. All three have inspired new human technologies.

Kingfishers are expert predators who dive into the water to catch fish. A Japanese engineer was tasked with solving the problem of thunderous claps generated by the Shinkansen bullet train as it emerged from tunnels. He decided to look to nature for answers, and came across the kingfisher, which also must pass from one medium (air) to another (water) at high speed. The nosecone of the speedy train was redesigned to mimic the bird’s elongate beak, and the result was not only much quieter, but 10% faster and 15% more efficient in its electricity consumption.

A dime-sized Namibian beetle inhabits a harsh desert setting that receives less than half an inch of rain each year. Intrepid biologists found that the beetle meets its water needs with the help of a specially designed shell. Microscopic bumps on the outer surface capture moisture from fog to create water droplets, which then travel along water-repellent channels directly to the animal’s mouth. MIT engineers mimicked this design to create a new, highly efficient water harvesting material that combines a Teflon-like, water-repellent surface with water-attracting bumps.

The flippers of humpback whales are lined along the leading edge with irregular bumps, which, at first blush, would seem an odd design for a limb that must maneuver a giant animal through water. However, an enterprising engineer tried adding similar looking tubercles to blades, conducted wind tunnel tests, and found that, among other benefits, the design reduced drag by almost one third. Today, bumpy, whale-inspired blades can be found in everything from wind turbines to HVAC systems to computer fans.

I could cite literally hundreds of additional high tech examples founded on Nature’s genius. Don’t believe me? Check out the amazing database at“Biomimicry” (from bios, meaning life, and mimesis, meaning to imitate), is a nascent, vibrant and rapidly growing field that seeks innovative answers to human problems by turning to Nature. The most famous example is Velcro, inspired by burrs that stuck tenaciously to the canine companion of a Swiss engineer.

Contrary to popular belief, evolution is not a random process. It is highly creative, constantly seeking solutions through a trial-and-error process that successfully marries organisms to environments. The core idea of biomimicry is that nature has already solved most of the problems now faced by human engineers and designers. By tapping into these solutions, or “adaptations,” we’re learning to harness energy like a leaf, create color like a butterfly, grow food like a prairie, and recycle our wastes like a swamp. “We live on a wildly diverse planet surrounded by genius,” says Janine Benyus, founder and leader of the biomimicry movement [1].

Got a pressing problem to solve? Just ask nature!

The new web home of this movement is, where you’ll find business applications—people engaged in creating new, sustainable technologies inspired by nature—and a range of education programs (organized within the Biomimicry Guild and the Biomimicry Institute, respectively). Under the new umbrella organization “Biomimicry 3.8” (in reference to 3.8 billion years of life’s evolution on Earth), this entrepreneurial organization has an explicit bias toward ecologically and socially sustainable solutions, steering away from, say, military applications like weaponry and armor.

Today, when speaking of cutting edge technology, we often refer to “high technology.” I like to refer to nature’s technological solutions as “deep technology,” the result of evolutionary R&D conducted over billions of years of deep time. My strong hunch is that the future “sweet spot” of technology will be at the interface of high-tech and deep-tech. Here we will eventually learn to model not just our materials and gadgets, but entire societies after Nature’s wisdom. In such a place, buildings would behave like trees, grabbing energy from the sun and regulating temperatures without expensive heating and cooling. Such innovations are already well underway in the world of architecture. Ultimately, linked to networks of other buildings, both homes and businesses, cities could become much like ecosystems, funneling local resources where they’re needed and using the waste from one sector as the raw materials of another. This would be biomimicry scaled up to civilization proportions. A dream? Yes, but a glorious and attainable one.

A few weeks ago, I had the pleasure of attending a day-long education workshop spear-headed by the Biomimicry Institute. I was fascinated to learn how fast and how deeply this young field is making inroads into K-12 and higher education. I was also impressed by the passion of biomimicry practitioners. A number of pioneering teachers are quickly finding ways to place biomimicry at the heart of the curriculum. Today, you can even attain a masters degree in this area. No question. Biomimicry is a powerful lens through which to view science education, encouraging children and adults to new creative heights inspired by the nonhuman world around them.

Nevertheless, what excites me most about biomimicry is the revolutionary shift in perspective it leads us toward. No longer merely something to learn about, the living world is suddenly transformed into something to learn from. No longer merely a bunch of material resources, Nature becomes mentor and model. Deep technology and biomimicry are potent tools that unite the evolutionary epic with a sustainable future, helping us navigate our way back to a home fully embedded within the natural world.


1. Benyus, Janine (1997). Biomimicry: Innovation Inspired by Nature. New York, NY, USA: William Morrow & Company, Inc.

Image Credits (from top to bottom):





Wednesday, September 21, 2011

A Feathered Terror From Utah

This week, another “new” dinosaur was officially announced to the world. Like several other discoveries over the past few years, this one was unearthed from rocks of the Late Cretaceous Kaiparowits Formation in Grand Staircase-Escalante National Monument (GSENM), southern Utah. Over the past decade, the Kaiparowits Basin Project, which I have the pleasure of heading up, has yielded about a dozen new dinosaur varieties from these sediments, amongst them duck-billed hadrosaurs like Gryposaurus and horned ceratopsians like Kosmoceratops. Thanks to the work of geologists and paleobotanists, we know that these animals lived about 76 million years ago in a wet, often swampy setting about 100 km from the coast of an inland sea.

Over the past decade, tantalizing bits and pieces of a small, carnivorous “troodont” theropod have been found in the Kaiparowits Formation. Closely akin to Velociraptor, troodonts are a clan of feathered “raptors” with sickle claws tipping the second toe of each foot. They were lightly built runners with some of the largest brains for their body size of any dinosaur. Most of our GSENM troodont fossils have consisted of random teeth, augmented by a few isolated skull and limb bones. But a couple of years ago, graduate student Michael Knell from Museum of the Rockies in Bozeman, Montana—while working in GSENM with Monument Paleontologist Alan Titus—found a partial skeleton that turned out to belong to this mystery theropod.

A team of workers consisting of Lindsay Zanno (University of Wisconsin-Parkside), David Varricchio (Montana State University), Patrick O’Connor (Ohio University), Alan Titus, and Michael Knell has just published their conclusions about this ancient little beast in the online journal PLoS ONE [1].

Talos, as it was dubbed, is the first troodont to be named from North America in more than 75 years. (In Greek mythology, Talos was a winged bronze figure who protected the island of Crete by throwing large stones at invading ships.) The vast bulk of fossils attributed to this group have been found in Asia, including the famous sleeping dinosaur (Mei long), as well as many eggs and nests. With few exceptions, the remains of North American troodonts have tended to be much scrappier. In life, Talos would have been about 6 feet long, but most of that length consisted of neck and tail, so the animal would have weighed in at a paltry 80 lbs or so. Mike Knell’s key specimen consists of most of the back limb plus a few other odds and ends. Most striking of all is the virtually complete foot with the lethal-looking claws.

One of those claws shows distinct signs of injury, a visual diagnosis that was confirmed with CT scanning of the bones. Particularly since the remainder of the foot was uninjured, this finding suggests that, at least occasionally, troodonts put their sickle claws “in harm’s way,” as Zanno colorfully puts it. Although it has long been assumed that these claws were used as predatory weapons, Talos offers the first fossilized evidence of such behavior. Whatever the cause of the injury, this particular animal survived for some time after the initial trauma and infection.

Many readers of this blog will know that Late Cretaceous North America was subdivided into a pair of landmasses—Laramidia in the west and Appalachia in the east—by high sea levels that flooded the central region of the continent. For about 25 million years, Laramidian dinosaurs evolved in isolation from the rest of the world. Most remarkable is the fact that this diminutive landmass, less than one fifth the size of present day N. America, hosted at least two distinct dinosaur faunas: one in the north and another in the south. Talos provides yet another unique addition to the southern fauna, deepening the mystery of how so many dinosaur varieties managed to co-exist on such a small chunk of real estate.

Finally, I have to thank the Talos authors, who have graciously called the second half of Talos’ name “sampsoni.” I am honored to have this little predator named after me, and had to chuckle when I heard the news. Until recently, the name Troodon was known only to professional paleontologists and a few die-hard kid enthusiasts. However, millions of fans of the PBS KIDS series Dinosaur Train (for which I serve as the science advisor and host) are now well aware of Troodon, because these animals run the famous train, and frequently tell anyone who will listen, “We are the smartest dinosaurs, ya know!”

The bones of Talos will be on exhibit for the first time in the brand new Museum of Natural History of Utah in Salt Lake City (previously the Utah Museum of Natural History), which is set to open to the world on November 17th!


1. Zanno LE, Varricchio DJ, O’Connor PM, Titus AL, Knell MJ (2011) A New Troodontid Theropod, Talos sampsoni gen. et sp. nov., from the Upper Cretaceous Western Interior Basin of North America. PLoS ONE 6(9): e24487. doi:10.1371/journal.pone.0024487

Monday, August 8, 2011

The Human Journey: Part 3

Below is the third and final part of the human evolution story. Parts 1 and 2 can be found in the previous two posts.


Touching down once more in the time machine, we find ourselves surrounded by now familiar grassland expanses. The monotonous scene is punctuated only by a mud-lined waterhole, which at the moment is hosting a herd of Elephas recki, the same giant proboscideans from the second act. Standing in the shallows close by, seemingly oblivious to the elephants’ antics, a six-foot tall marabou stork fishes for whatever critters might reveal themselves. African waterholes in late afternoon attract a wide range of thirsty animals, and their predators. After a few hours spent watching the faunal procession, you guess correctly that all of the usual suspects are present—pigs, antelope, zebra, hyena, and the like.

Mesmerized by the setting sun and the building hum of insects, you’re surprised to see five hominins approaching, three individuals moving together in front and two trailing behind. As they get closer it becomes clear that these upright primates, all males, are wholly different than any seen previously. Compared to hobbit-like Ardi and Nutcracker Woman, these individuals are giants, approaching six feet in height. Much of this length is devoted to long, muscle-bound, striding legs. Gone are the elongate, gorilla-like arms, replaced by upper limbs proportioned like our own. Also absent is the profusion of body hair, exposing the naked skin beneath. Indeed, in the waning light of dusk, these figures look so familiar that for a moment you wonder if the time machine has returned you to the present day. But above the shoulders, that sense of familiarity diminishes. The skull dome looks bigger than that of an australopith, yet notably smaller than our own. A prominent nose protrudes from beneath thickened brow ridges. Among the trio in the lead, two are shouldering bulky antelope shanks still encased in mottled brown skin, while another totes some unidentifiable hunk of meat. Bringing up the rear are two younger males carrying stone tools. You elect to follow the group, who, after another a half-mile trek, join up with several females and children. The female adults, only slightly smaller than the males, are busy working with fist-sized stone tools to release nutrients from large tubers, while the four youngsters run about playing.

Welcome to Act III, the most recent of the human journey, extending from roughly 2 million years ago to the present day. We’ve arrived in the midst of the Pleistocene Epoch, about 1.5 million years ago, another landmark moment in our story. Increasing aridity has decimated the forests and driven the proliferation of grasslands. Several mammal lineages, herbivore and carnivore alike, have been traveling northward with the expanding grasslands, and some have recently broken the bonds of the African continent to venture into Asia and Europe. Accompanying these emigrants is a two-legged omnivore, Homo erectus, the very hominin you’ve been watching.

Whereas Act I hominins like Ardipithecus were devoted forest-dwellers, spending most of their time in trees; and Act II protagonists like Paranthropus and Australopithecus split their time between the trees and the ground; in the skeleton of erectus we see the first evidence of a permanent pact with terra firma. Tree-climbing adaptations were replaced by long, lean legs well suited for endurance walking. Brain sizes averaged close to 1000 cc, only about 25 percent less than our own. Regional populations, each with unique traits, developed in Europe and Asia, where they encountered new varieties of large mammals, from mammoth to cave bear. It is unclear whether erectus had made the transition from scavenger to predator by the time of its initial exodus from Africa. But it appears virtually certain that this close cousin of our’s was an effective big game hunter throughout most of its lengthy tenure. The hunting and gathering lifestyle that would eventually characterize the bulk of human history got its start in Homo erectus. The Old World had received its first taste of a carnivorous ape.

One of the perils of walking long distances over hot, arid terrain is water loss. This hazard is exacerbated by a cooling system that depends on sweat glands distributed over much of the body. Like chimps and gorillas, earlier hominins possessed a flat nose marked by a pair of forward-facing openings in the middle of the face. With erectus the bony margins of the nose openings became raised and conjoined, forming a distinctive, sloping bridge. Inside, expanded nasal cavities housed complex swirls of bone lined with spongy mucous. The newly remodeled nose offered a finely tuned water retention device, capturing moisture from the hot, humid air exhaled from the lungs. For similar reasons, although we can’t be certain, Homo erectus may have been the first hairless hominin. Body hair tends to hold onto heat, so erectus’ commitment to life on the hot savannah may well have triggered the loss of a “furry” covering. If so, we can thank Homo erectus for both our prominent noses and our nakedness.

The so-called “Acheulean” tradition of Homo erectus was dominated by a single stone implement—the hand ax. The Acheulean hand ax is the epitome of functionality, crafted by using some sort of “hammer”—often made of bone, antler, or wood—to remove flakes of rock from a “core.” Whereas Oldowan toolmakers were apparently most interested in the flakes, it’s the core that became the chief implement of erectus. By removing flakes symmetrically from both sides, the fist-sized hand ax offered a highly versatile tool that likely served for slicing, scraping, crushing, digging, and other uses. (Can’t you just imagine the late night television advertisement? “Brought to you by Erectus Industries Inc., the amazing tool that slices, dices, and juliennes!”) Homo erectus was the longest-lived hominin, thriving for over a million years. Although we see some evidence of a progressive improvement in tool technologies, the hand ax persisted throughout that impossibly lengthy duration. Confronted by the bewildering pace of technological change seen today—with computers outdated almost as soon as they reach the market—it’s inconceivable to imagine a particular tool being used for a century, let alone ten thousand centuries! What does this staggering monotony tell us of the mind of Homo erectus? On that matter there is much disagreement, but one thing’s for sure. We can safely assume that innovation was not a priority.

How are we to explain this suite of bodily and behavioral features, which pushed the hominin lineage, as one anthropologist put it, over to the human side of the “great divide?” Best we can tell, the eco-evolutionary chain of events went something like this. By 2 million years ago, the human line was devoted to a diet of high-quality, widely dispersed, and difficult-to-obtain foodstuffs, both plants and meat. The major bump in body size seen in erectus is plausibly linked to the dangers of carnivory. With pathetic footspeed and fewer trees to retreat into, hominins had no choice but to face down competing carnivores, among them lions, leopards, and sabertooths. Six-foot tall hominins would have had a great intimidation advantage over their four-foot forebears. With larger bodies came greater caloric needs, which in turn translated into more extensive home ranges (necessary to locate sufficient amounts of food). Longer legs would have been beneficial to travel the increased distances, and a larger brain would have come in handy to store mental maps of the surrounding terrain. Increased brainpower may also have been necessary to mimic Acheulean stone tool-making techniques.

The trend toward bushiness of the hominin family tree continued in Act III. In earlier scenes, Homo erectus shared the African continent with several Act II die-hards; Australopithecus sediba persevered until about 1.75 million years ago, Homo habilis until 1.4 million years ago, and Paranthropus boisei until shortly before 1 million years ago. Later in the record-breaking reign of Homo erectus, several additional species of Homo appeared, perhaps evolutionary offspring of the king himself. Examples included antecessor (Europe), heidelbergensis (Europe, Africa, and China), and neanderthalensis (Neanderthals, Europe).

Following the extinction of Homo erectus, several Homo species persisted [9]. Among the most successful were the Neanderthals, cold weather specialists that thrived in Ice Age Europe and Asia between about 200,000 and 28,000 years ago. Key adaptations of this clan, possibly our closest hominin cousins, included a brawny build and stocky stature (better for retaining heat), with males averaging about 5’ 5”. Dominating the Neanderthal face was a huge nose used for warming and humidifying cold, dry air. Other features included a long mid-face region, low forehead, and an elongate cranial vault housing a brain as large or larger than our own. Neanderthals controlled fire, lived in shelters, hunted big game, and buried their dead.

They made and wore clothing and developed a sophisticated tool kit. The highly successful Neanderthals may have displaced groups of Homo sapiens in certain regions when the climate turned extra frigid. The fate of Neanderthals remains a mystery, but recent genetic studies suggest that they interbred with humans, and that we still carry some of their genes[10].

Among several recently discovered hominins that lived late in Act III are a phantom and a hobbit. The phantom, informally dubbed the “Denisova hominin,” is known from a single fragmentary finger bone and an isolated tooth dating to 41,000 years old [11]. Recovered from Denisova Cave in Siberia, Russia, the single bone has yielded mitochondrial DNA suggesting that the finger’s owner belonged to a distinct species sharing a common ancestor with Neanderthals. Meanwhile, Homo floresiensis was a three and a half foot tall hominin that inhabited the Indonesian Island of Flores between 95,000 and 17,000 years ago [12].

Nicknamed “Hobbit,” this pint-sized, large-footed, small-brained, chinless wonder used stone tools to hunt pygmy elephants and giant Komodo dragons! Controversy still ensues about the closest relatives (and even the veracity) of this surprising member of our family tree, but the growing consensus is that Hobbit is descended from an ancient member of our Homo tribe who departed Africa about 2 million years ago.

Finally we come to our own species, Homo sapiens, a name that translates as “wise man.” Although various species of Homo had already spread over much of Asia and Europe, the first sapiens were birthed back in the womb of Africa some 200,000 years ago, perhaps evolving from erectus populations that had stayed behind. Compared to our first cousins, the Neanderthals, we possess a more lightly built skeleton, weaker jaws with smaller teeth, a flatter face, a thinner brow, a vertical forehand, and a vaulted cranium. Like erectus, neanderthalensis, and most other members of the Homo clan, the earliest sapiens gathered food and hunted animals. Indeed our ancestors were apparently ardent carnivores who took big game hunting to a new, more lethal level.

Around 60,000 years ago, Homo sapiens underwent what some refer to as the “Great Leap Forward.” The pace of cultural change suddenly accelerated. Bone artifacts such as fish hooks and needles appeared. Stone tools took on a strongly regional flavor, in some cases including sophisticated weaponry. Cave paintings, body ornaments, and sculptures appear, hinting at a fundamental shift of mind, and we see the first evidence of long-distance trade. Genetic evidence indicates that much of this revolution can be traced to a small group of sapiens that migrated out of Africa, mimicking the wave of erectus populations hundreds of thousands of years prior [13]. This time, however, the wave swelled to a tsunami that did not stop in Asia or Europe. The first tsunami wave of modern humans crossed the Red Sea into the Near East and then on to East Asia and Australia. The second moved northward into Europe, Asia and eventually the Americas. Along the way, these populations encountered and displaced other varieties of Homo, including Neanderthals, until we were the only surviving hominin species.

Homo sapiens, a late-arriving, globe-trotting bipedal ape, had somehow developed the capacity to live pretty much anywhere, from sweltering deserts to the frigid Arctic. (Among mammals, only the Norwegian rat [Rattus norvegicus] even approaches the geographic distribution of humans, occurring on every continent except Antarctica.) Beginning about 10,000 years ago, we began to give up our itinerant ways and settle down, likely in response to a shift toward more stable climates. The ability to stay put came largely from cultivating plants and animals. Over a relatively brief period, agriculture arose independently five times. With heightened food yields came much larger populations and, very quickly, civilizations. Civilizations have continued to expand ever since, swallowing all but a handful of foraging cultures and, in the last eyeblink of time, wreaking havoc with the Earth’s biosphere.

returning to the question that kicked off this discussion, why did humans, as opposed to chimpanzees, elephants, orcas, or some other creature, become such a dominant presence on Earth? The answer, it seems, invokes a unique concatenation of events within our lineage. Humanity’s runaway success required several essential elements—in particular, the physical, mental, and social capacity to develop advanced technologies. In Act 1, the most critical evolutionary acquisition was bipedalism. Walking upright freed the hands for other activities, including transport. It also enabled early hominins to expand their geographical ranges and encounter environments well beyond the experience of other apes. In Act II, manual dexterity was added to the repertoire, a capacity that transformed stones into tooth-mimicking tools. The making and transporting of stone tools opened up an entirely new niche—carnivory—sending our ancestors off down yet another evolutionary rabbit hole. Finally, in Act III (and the tail end of Act II), our newly acquired penchant for meat and nutrient-rich marrow sparked the evolution of larger, more sophisticated brains. Out on the open savannah, our ancestors quickly evolved traits that could help them tap into the large, scattered packages of plants and meat available there. The evolutionary results included new tool technologies, heightened imitative abilities, and a strong bias toward within-group cooperation.

But beware the fallacy of hindsight. Reflecting on the human journey, we must fight a powerful, largely unconscious bias to view early hominins as a succession of warm-up acts—“experiments in being human,” to use the preferred scientific phraseology—leading to our inevitable main event. Evolution has no foresight. It reacts only to present circumstances, fitting organisms to the habitats they live in. In hitting one rock against another to generate sharp-edged blades, Australopithecus garhi (or some near cousin) gained access to a new suite of foodstuffs, thereby enhancing its odds of survival. These little hairy hominins had no clue that stone tools might trigger a cascade of events that would ultimately send their distant descendants to the moon. They were concerned only with immediate circumstances, just as we are most of the time. In short, chimps don’t run the world today because the ecological circumstances encountered by their ancestors didn’t produce the necessary evolutionary steps (for example, bipedalism, manual dexterity, and bigger brains). Similarly, elephants and whales didn’t evolve key elements, such as the physical capacity to create a material culture.

Is that it then? Are we merely an evolutionary fluke, the result of a staggeringly improbable series of events? Or is there a larger arc to this narrative? What greater meaning, if any, are we to derive from the human journey? Answering these questions must be the topic of a future post.

Notes and References (continued from Part 2)

9. A key lesson emerging from the human journey is that our present day circumstance, with a single hominin species, is the exceedingly rare exception. Throughout most of the past several million years, multiple hominin species have co-occurred, with two or three frequently sharing the same habitat. Those who continue to make the claim that no evidence exists of fossil intermediates in the human family tree are either not paying attention, or (as is too often the case) purposefully twisting the data to match preconceived biases against evolution.

10. Richard E. Green et al. 2010. A Draft Sequence of the Neanderthal Genome. Science 328(5979): 710–72

11. Krause, J., Fu, Q., Good, J. M., Viola, B., Shunkov, M. V., Derevianko, A. P., and Pääbo, S. (2010). The complete mitochondrial DNA genome of an unknown hominin from southern Siberia. Nature, 464(7290):894–897

12. Brown P., Sutikna T., Morwood M., Soejono R. P., Jatmiko, Saptomo E.W. et al. 2004. A new small-bodied hominin from the late Pleistocene of Flores, Indonesia. Nature, 431:1055-61; Morwood M. et al. (2005): Further evidence for small-bodied hominins from the Late Pleistocene of Flores, Indonesia. Nature, 437:1012-1017.

13. Stringer, C. and McKie, R. 1998. African Exodus: The Origins of Modern Humanity. Holt, New York; Tattersall, I. 2009. Human origins: Out of Africa. Proc. Natl. Acad. Sci. USA, 106(38):16018-16021.

Image Sources (from top to bottom)

1. Homo erectus (

2. Homo erectus discovering fire. (

3. Neanderthal woman (Joe McNally, National Geographic)

4. Homo floresiensis (

5. Homo sapiens sapiens (Jay Matternes, National Geographic)

Wednesday, July 27, 2011

The Human Journey: Part 2

Today's post continues the human evolution story begun in my last entry:


NEXT STOP IS eastern Africa two and half million years ago—Act II of the human journey. Our arrival coincides with the dawn of the Pleistocene Epoch [5]. An initial scan of the landscape reveals another mosaic of grass and woodlands not so unlike Ardi’s homeland. The expected array of big mammals is here: monkeys, pigs, antelopes, horses, rhinos, hippos, elephants, and carnivores. Like the modern Serengeti, horned antelope are particularly plentiful and diverse. Wildebeest and impala roam the plains in great numbers. Gazelles bound in and out of woodland patches. Waterbuck frequent the thick scrub adorning lake margins. Yet slowly you realize that something is profoundly different. The proportion of grasslands has increased at the expense of forests, and many of the mammals are mega-sized. There’s Elephas recki, a giant elephant far exceeding the bulk of the present day African elephant (Loxodonta). Also present are ultra-big baboons, wildebeest, and pigs, among others. Together with extra body bulk, all of these plant-eating mammals possess beefed up jaw muscles and broad, high-crowned cheek teeth covered in thick enamel. This trio of traits—enlarged bodies, molars, and jaw musculature—represents a convergent evolutionary response to the same dietary challenge. Food in grassland settings is dominated by tough, fiber-filled, low quality offerings. Many animals here, like Elephas and wildebeest, are consumers of grass. For others, like pigs and baboons, the menu consists mostly of tough fruits, hard seeds, and underground tubers. Either way, oversized cheek teeth driven by big chewing muscles offer a first line of defense. Big bodies with enlarged guts are the second line, digesting high volumes of low-nutrition fodder.

In a nearby ravine, you spot an unfamiliar primate hunched over, intent on some task. Moving closer, you see that this is a hominin about four feet tall and less than 100 pounds—slightly bigger than Ardi, perhaps, yet smaller than an average chimp. This female is clearly digging with a stick, laboring to remove chunks of hardpan soil. Eventually, successful in her quest, the ape-like animal picks up a freshly unearthed tuber and walks upright to a nearby patch of shade. Like Ardipithecus, she possesses long arms, yet her gait appears much more like our own, with long, efficient strides. As she sits and begins to gnaw on the bulbous root, you note that her face is distinctive, with massive jaw muscles housed inside strongly flared cheek bones. The molars are oversized as well, mimicking the pattern described above. This is Paranthropus boisei, part of a group of robust hominins that lived over much of Africa between 2.7 million and just shy of 1 million years ago. Besides boisei, two other Paranthropus species are known (aethiopicus and robustus). All share the same body plan and elaborate chewing adaptations. The first discovered boisei specimen was nicknamed “Nutcracker Man” because of its giant chompers, heavy-duty jaws, and pronounced crest atop theskull for anchoring the thickened jaw-closing muscles. As with pigs and other local omnivores, this specialized eating

apparatus was well suited to a diet of coarse plants, tubers, and other hard foods. Although her appearance is strange, you can’t help but feel a certain kinship toward this bantam-sized creature.

Then, from far off in the distance, an alien sound arrives, carried by the whispering grasslands. Rising to investigate, you walk across several low hills, listening as the cacophony intensifies and spiraling vultures congregate overhead. Ascending the last rise, you find yourself on a ridgetop overlooking a stunning scene. At the center, under a large tree, is a dismembered wildebeest. Scattered around the carcass are about a dozen boisterous hominins. Other than being slightly leaner and longer-legged, this bunch closely resembles Nutcracker Woman a few hills over. These animals are also efficient bipeds, striding back and forth between the dead antelope and its various amputated body parts. The only notable physical differences occur in the face, which are considerably narrower and slightly more humanlike. Most astonishing of all is what this hominin mob is up to. Some individuals slice meat from the foul-smelling carcass with sharp stone blades. Others use larger, fist-sized stone tools to break bones and access the sweet marrow within. On the far side, three hooting, gesticulating males (about a third larger than the females) keep a large spotted hyena at bay, while a pair of jackals paces impatiently in the wings. Clearly frightened by the hyena,

several smaller hominins have retreated to the tree, using their long arms to move through the branches with great dexterity. The unfortunate wildebeest, perhaps the victim of a lion kill, has been dead for at least a day and apparently dragged to this location. The hominins are clearly excited to be feeding on meat, yet anxious to move on. In a world of lions, leopards, sabertooths, and hyenas, hit and run is the only viable strategy for a runty scavenger.

The scavenger in question is Australopithecus garhi [6]. Australopiths were a hyper-successful group of hominins that persisted throughout most of Africa for well over 2 million years. The oldest known example, from about 4 million years ago, is Australopithecus anamensis, a species that heralds the onset of Act II. Then comes afarensis (Lucy), africanus, garhi, and sediba, the last of which disappears about 1.75 million years ago. This sequence does not denote a straight line of ancestors and descendents. Several of these species overlapped in time. Some lived in southern Africa whereas others are known only from East Africa. If the pace of recent finds is any guide, additional kinds of australopiths await discovery in African sediments. The skeletons of Australopithecus and Paranthropus are closely similar in both size and shape— an arm bone or vertebra of one could easily be confused with that of the other. Their brains were similarly sized as well. But australopith skulls lack the swollen cheeks, massive molars, and large, muscled crests of Paranthropus. Early Australopithecus species such as Lucy’s tribe are thought to have consumed a mixed diet of fruit, seeds, and wild vegetables, though studies of microscopic tooth wear suggest that this diet was augmented with occasional hard foods.

Later australopiths, including our raucous toolmaker, Australopithecus garhi, appear to have developed a taste for meat. In fact, garhi is arguably the first hominin to embark on a technological adventure that would one day result in electron microscopes, 747s, and iPads. The earliest evidence of stone tools dates to about 2.6 million years ago. For a long time it was thought that these crude blades, scrapers, and hammers—referred to collectively as the “Oldowan” tradition—must have been made by early members of our own, big-brained genus: Homo. The oldest known representative, Homo habilis (“handy man”), had a respectable brain size of 600 cc, a substantial gain over the 450 cc of gray matter housed in the noggin of Australopithecus garhi. The embarrassing problem is that the habilis remains date back only as far as 2.4 million years ago, resulting in a 200,000-year hiatus between the first stone tools and the first Homo. Of course, we could simply be missing the earliest Homo fossils, but, by the same logic, we may be missing even earlier stone tools. Adding fuel to the controversy is the fact that garhi remains were found in close association with a 2.5 million-year old butchery site, in which antelope and horse bones show distinctive cut marks. Slices on a zebra jawbone demonstrate that at least one of the tool-users was going after the tongue. So perhaps big brains weren’t necessary to launch this technological revolution. My guess is that the stick- and hammer-wielding chimps in the present-day forests of West Africa wouldn't be surprised.

It’s difficult to overstate the evolutionary significance of Oldowan stone tools. Think of them as multi-use, replaceable teeth—external dentures perhaps—that gave hominins access to a range of previously inaccessible (or at least rarely acquired) foods, from hard-shelled nuts to meat and marrow. Whereas genetic evolution can require millions of years to craft a thick-crowned molar or slicing canine, our ancestors learned to modify quartz and lava into a modest array of tools. Hit one chunk of basalt against another and the slicing blade that flies off is likely to have a sharper edge than the most lethal canine. The larger rock with a piece missing can be used for crushing, chopping, grinding, or generating more blades. In effect, tooth-mimicking tools enabled hominins to escape the limits of their own dentitions and begin the process of digestion outside the body. Best of all, this newly acquired technological capacity could be passed, gene-like, from generation to generation.

Stone tools had cascading consequences. Most rocks make for lousy tools, so early Pleistocene hominins had to venture to lava outcrops or concentrations of stream cobbles to find the necessary resources. Studies of microscopic markings on the edges of Oldowan tools demonstrate that they were used for processing both plants and meat. Food plants tend to occur in predictable places from one season to the next. In contrast, the divergent distributions of meat and rock resources, heightened by the unpredictability of carcasses, raised an immediate conundrum. Since you can’t carry stone tools around all the time, and since predators aren’t always going to make their kills conveniently near your key rock sites, how do you ensure that you have a ready tool supply to take advantage of a carcass? To make matters worse, out there on the open savannah you could easily become a lion or leopard’s next meal, so scavenging requires quick action. The solution, which garhi and our early Homo ancestors apparently hit upon, is transport and storage. Collect armfuls of rocks suitable for tool making and carry them to scattered locations around the landscape. That way, as long as you can remember where the rocks are, you’ll always have a ready tool supply. When one freshly made blade dulls, others can be generated quickly. In addition to meat, tool making allowed access to a high nutrition food that had previously been the domain of hyenas--marrow. Some researchers think that marrow's

fatty acids fueled the initial brain expansion in our Homo lineage [7]. Coincidentally, it was within a few hundred thousand years of the earliest stone tools that the first major leap in brain size occurred.

Finally, stone tools conferred upon early hominins a large measure of flexibility in the face of change. Plants counter the efforts of plant-eaters through a variety of evolutionary “strategies,” from hard outer coverings to chemical toxins. When shifting African climates transformed plant communities in a given area, it would have required significant time and effort for resident hominins to determine which of the new varieties were palatable, and how their nutrients could be extracted. Yet, barring a major deterioration in ecological conditions, chances are that carcasses of large herbivores would still occur on the landscape. So as long as opportunistic scavengers had their stone toolkits handy, they could probably eke out a living.

Towards the end of Act II, evolution’s creativity generated a bevy of hominins. One of these was bigger brained Homo habilis, the aforementioned “handy man.” Arguably the first representative of our own genus, habilis was not much larger than an australopith. At present, Australopithecus garhi is a plausible candidate ancestor for Homo habilis, but any such conclusion is provisional at best [8]. Despite our continual emphasis on the importance of brain size, there’s no evidence that the initial appearance of a larger-brained hominin was an ecological “game-changer.” Homo habilis did not immediately utilize its heightened neuron-power to conquer all foes and emerge as the dominant “ape-man.” On the contrary, the waning scenes of Act II witnessed the greatest known florescence of hominins, with up to six co-existing species in Africa around 2 million years ago. Other than habilis, the hominin menagerie included two kinds of Australopithecus (sediba and africanus), two of Paranthropus (boisei and robustus), and a last minute walk-on—the thick-browed, lanky-limbed Homo erectus. As we shall see, erectus would turn out to have greater staying power than any other hominin, rising to become a major star of Act III.

Notes and References (continued from Part 1)

5. The Pleistocene Epoch is now recognized to extend from 2.6 million years ago until 12,000 years ago. Up until 2009, this time period was said to begin at 1.8 million years ago, so any sources older than this will regard the 800,000 year period from 2.6 million to 1.8 million as part of the preceding Pliocene Epoch.

6. Asfaw, B., White, T., Lovejoy, O., Latimer, B., Simpson, S., Suwa, G. 1999. Australopithecus garhi: a new species of early hominid from Ethiopia. Science, 284(5414):629–35; De Heinzelin, J., Clark, J. D. White, T., Hart, W., Renne, P., Woldegabriel, G., Beyene, Y., Vrba, E. 1999. Environment and behavior of 2.5-million-year-old Bouri hominids. Science, 284(5414): 625–9.

7. Cordain, L., Watkins, B. A., and Mann, N. J. 2001. Fatty acid composition and energy density of foods available to African hominids. Pp. 144-161 in A. P. Simopoulos, K. N. Pavlou (eds.), Nutrition and Fitness: Metabolic Studies in Health and Disease. World Review of Nutrition and Dietetics, Vol. 90. Karger, Basel.

8. Currently, Australopithecus garhi appears just prior to Homo habilis and makes a plausible ancestor to the genus Homo. However, given such a bushy hominin family tree, identifying ancestors and descendents has become a high-risk sport, with another imminent discovery likely to blow the latest hypothesis to smithereens. So paleontologists don’t put too much weight in such claims.

Images (listed from top down)

1. Australopithecus afarensis (John Gurche;

2. Paranthropus boisei (

3. Australopithecus africanus (

4. Australopithecus garhi (

5. Homo habilis (