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Kids love dinosaurs. I know I certainly did.

So much so that when I was in kindergarten and still hadn’t learned to read, I kept pestering my brother (5 years my elder) to keep bringing home books about them from the school library just so I could look at the pictures. He finally asked our mother to intervene and explain to me that they simply wouldn’t let him renew the same books every week.

And once kids—or adults, in the case of frequenters of the Creation Museum—get past taking The Flintstones as gospel, they want to know, “What killed the dinosaurs?” and “Why did those big dangerous dinos all die when so many other creatures survived?”

When I was growing up in the 1950s, the usual answer was that while they sure were big, as the late, great Muhammad Ali would say of his opponents, they “didn’t have a chaaaance” because they were just “too slow, too dumb,” and yes, “too ugly!” Smaller, but much smarter, nice furry mammals showed up on the evolutionary time scale and gobbled up the dinosaur’s eggs. After all, those newly arrived mammals were obviously superior in all but size—they had insulating hair rather than conductive scales, carried their young rather than laying eggs exposed to predation, and being warm-blooded, they were active and fast, while those dinos were coldblooded, slow, and so, opposite to Count Dracula, only active while the sun shined. And dino brains were kinda small—especially compared to their huge body size. But those mammals had much bigger brains relative to their much smaller body size! A Darwinian drama where the smart, little guys win, ready-made for an animated Disney drama (cue in Stravinsky’s Rite of Spring) or a classroom film—Triumph of the Nerdy Mammalians.

There have been other explanations for Dino-geddon, before and since. We now know that the dinosaurs did not go extinct because:

• They just got too big. Why not? Because the biggest dinosaurs lived in the Jurassic Period (201.4 to 145 million years ago), which was millions of years before the geologically sudden mass extinction at the end of the Cretaceous, approximately 66 million years ago.
• The arrival of those smart little egg-eating mammals caused their extinction. Why not? Because mammals had actually coexisted with dinosaurs for 150 million years before Dino-geddon.
• They were thick-headed, but thin-shelled. Why not? Some of their eggs had thin shells, some thick. And living birds (whom we now know are their direct lineal descendants) and reptiles (collateral cousins) have survived quite well laying their own thin-shelled eggs.
• Climate change made the earth get hotter or colder—so all the dinosaurs hatched as males. (Sex is determined by outside temperature among living gators and crocs; too hot or too cold yields females, while males need the “just right” temperatures). Why not? It’s somewhat hard to test whether dinosaurs even had temperature-dependent sex determination (TSD), but why did the direct ancestors of today’s TSD gators and crocs survive?
• The dinosaurs really were just too dumb! Why not? As best we can guess, the intelligence of various dinosaur species varied. But they all went extinct, not just the dumber ones. (Well, kind of. Their bird-brained relatives not only survived but thrived). And whatever their intelligence, they were certainly brighter than many other animal groups that did survive. And it wasn’t just dinosaurs—around half of the species living at that time went extinct.

As for the aforementioned, foreordained, straight-ahead Darwinian drama often shown in the schoolbooks of my time that started with a mindless amoeba at the bottom of the Scala Natura and progressed up ascending rungs of increasing intelligence and consciousness until modern man— usually, White and kinda Nordic—emerged at the top? Alas, as with most such stories, it just ain’t so.

We now know what actually did happen. In 1980, geologist Walter Alvarez and his father, Nobel Prize winning physicist Luis, proposed that an asteroid collision wiped out the dinosaurs. Since then, evidence for their hypothesis has accumulated, as has evidence against the aforementioned alternatives.2

So it wasn’t bad brains that got the big, dumb, ugly dinos. It was bad luck!

But what if that asteroid had hit some other piece of space junk and altered course just enough to miss hitting the Earth? Skeptic icon Stephen Jay Gould famously opined in Wonderful Life (1989), “Replay the tape [of life] a million times … and I doubt that anything like Homo sapiens would ever evolve again.”

Paleontologist Dale Russell with his Dinosauroid—a hypothetical, human-shaped theropod, invented during the early 1980s and sculpted by Ron Séguin (Photo credit: Canadian Museum of Nature)

Right? Well, maybe half right—but then, maybe not. Seven years before Gould declared that evolution (indeed, history) operated more on the basis of contingency than on necessity, paleontologist Dale Russell, Curator of Fossil Vertebrates at the Canadian Museum of Nature, had proposed, as a thought experiment, the possibility that some relatively brainier dinosaur lineage might have eventually evolved into a really big-brained dinosauroid that would have had forward-looking eyes, an erect stance, grasping hands, and big brains had that asteroid only missed Planet Earth. Why? Because of convergent evolution, that is, when two organisms look and/or behave in a very similar way, even though they’re only distantly related. And that means they’ve evolved those similarities independently rather than inheriting them from a common ancestor. Convergence in evolution happens regularly—as does non-convergence.

Here are a few examples:

• Sharks, dolphins, and the extinct ichthyosaurs each developed a streamlined body to swim far faster than any Olympian.
• Camera-type eyes evolved separately in mammals, and earlier in cephalopods (octopuses and squids).
• Some sort of opposable “digit” evolved separately in primates, opossums, koalas, giant pandas, and chameleons that allows for grasping—though the primates may have first evolved theirs to move through the trees. The giant panda hijacked a wrist bone so it could be used for grasping leaves. And only millennia later did humans hit upon using their opposable thumbs to type text messages.
• Flight—a major accomplishment in transformation of locomotion—evolved separately among insects, in the extinct pterosaurs, and in mammals (bats) and birds, only to be lost later when there was an advantage in doing so to assist in running (ostriches) or swimming (penguins).
• Echolocation is a pretty demanding feat of bioengineering. Yet it evolved separately among cetaceans (whales and dolphins) and bats.
• A form of bio-antifreeze evolved separately in Arctic fish and in Antarctic fish, which are only very distantly related.
• There are many more examples, including really unpleasant ones like stinging and blood sucking.

Ankylosaurus (top) and Glyptodon (bottom)

My personal favorite example of convergent evolution is Ankylosaurus (top) and Glyptodon (bottom). I had an Ankylosaurus in my childhood set of dinosaur models and was surprised to find out those two tank-like herbivores weren’t even distantly related when I first encountered Glyptodon in a textbook years later.

Ankylosaurus was indeed a dinosaur that lived from 160–65 million years ago; Glyptodonts, however, were mammals that lived only 38 million to 10 thousand years ago, of which Glyptodon is the best known species. Each had an armor-like carapace (like a Galápagos tortoise), large body size, stiff back, and club-like tail that the fossil record shows evolved to become stiff before the tip of the tail expanded into a dangerous weapon. Each evolved similar traits to take advantage of a particular ecological niche because despite the difference in time, there can only be a few good solutions to similar selective pressures.

So, play the tape only few times, and some of those times something very similar happens (though not always). The real questions then are not if convergent evolution can happen, but when, why, and how much it happens.

Not Necessarily the Same, but Similar

So if the asteroid had veered off just a little along the way, maybe some dinosaurs could have evolved higher intelligence and, starting with Troodon, evolved into something like Russell’s hypothetical forward looking, erect (which Troodon already was) and big-brained dinosauroid, with grasping hands that could have inherited the Earth. Even before Russell, another Skeptic icon, Carl Sagan, musing on extraterrestrial intelligence in The Dragons of Eden, speculated that, had they not gone extinct, one group of dinosaurs might have achieved the brain size and intelligence sufficient even to develop an octal numbering system, given their number of digits.

The point here is that Russell’s argument was a thought experiment to prompt us to consider what evolution is and how it works.

The Meaningful Measurement of Minds

Defining intelligence for humans is hard enough, and trying to measure it has been open to debate and criticism. But since neither extinct species nor ETs can take IQ tests how can anyone even speculate as to their intelligence?

Well, in the case of extinct species, but not ETs until and unless some UFOlogist produces the real remains of one, we often have their fossilized skeletons. Particularly instructive is the brain case—the cranial bones that once enclosed their brain. And from the brain case we can get an endocast—an internal cast of the brain once so enclosed. Sometimes we have to make an internal cast by inserting some rubbery material. But sometimes we get lucky and nature has already made an endocast through fossilization. The advantage here is that we not only have the overall size and shape of the brain, we also can determine the proportions occupied by the different brain areas (lobes) and in some cases even something about the extent of folding. And folding is important because it allows more brain matter to fit within a skull of given size.

So much for brain size, what about intelligence? Over the long haul of evolutionary time and the wide range of animal species we can observe a strong relation between neural size and neural complexity on the one hand and general behavioral complexity and adaptability on the other. And this is more so within a particular evolutionary lineage than when comparing across lineages. Of course, there will be exceptions for specialized abilities and the strength of the relation becomes harder to tease out if we try to compare individuals or groups within a given species.

Brain size, then, gives us one metric by which to estimate the intelligence of both living and extinct animals. But we know from observing living animals that brain size varies a lot just based on sheer body size. Given that neurons have a relatively uniform size across species, a more meaningful measure of neural complexity is brain size relative to body size. And that’s why for so long dinos have been considered so dumb. Despite their massive body sizes (as estimated from their fossilized skeletons) they had really minuscule brains (as approximated by endocasts). Well, at least most did.

Neuroscientist Harry Jerison developed an even more sophisticated and accurate measure termed the Encephalization Quotient (EQ). And from EQs it’s then possible to estimate the number of Extra Neurons. The Encephalization Quotient for a species is the ratio between its observed brain size (whether measured directly at autopsy/ necropsy or from an endocast) and the predicted brain mass for that species given its size and taxon. More technically, it’s predicted from a nonlinear regression across a range of related reference species. By comparing the measured EQ of a given species to the predicted EQ for an animal in its taxonomic group having its average measured body size, we can get a measure of its Extra Neurons. And Extra Neurons are like extra RAM in your computer or smart phone—the more of them you have, the more information you can process and the faster you can do so.

As the figures in the table show, across a range of living species, the Ratios of Brain Size to Body Size and especially the Encephalization Quotients correspond pretty well with both our armchair estimations of the intelligence of living animals and with their behavioral complexity and learning capacity as determined by controlled experiments.

What about those dumb dinos? Well, the four-legged herbivores such as the well-known Brontosaurus, Stegosaurus, and Triceratops, all fall below living gators and crocs (at about 1.0). But bipedal carnivores, a group that includes T. rex, have higher EQs. Some scientists have even claimed these carnivorous dinosaurs achieved EQs comparable to those of a baboon! More recent estimates have scaled those back to the crocodilian range. Troodon’s EQ ends up being possibly five times higher than that of your average dino. So, if the asteroid had missed, could dinosauroids have inherited the Earth?

The big problem for Russell’s thinking exercise is that dinosaurs likely had brains similar to birds. Assuming that their brains had the same avian nuclear type of pallial organization, rather than the mammalian-type cortical organization, no dinosaur could have achieved the brain complexity required for higher mammalian-type behavioral complexity. Or so it was assumed.

Mammalian cortical brains have a laminar architecture— they are arranged in layers, one atop the other. (Think plywood or chocolate seven-layer cake). Avian brains have a pallial or nuclear architecture—clusters of similar nerves separated by a mass of different type cells. (Think knots in a sheet of pine or meatballs in a large tray of spaghetti). The cortical organization of mammalian brains allows more layers to be packed in one on top of the other (like stuffing as many clothes in your suitcase as possible). With the brain cells close to one another, transmission is short, simple, and fast. And the layers can be folded, like squishing up a towel, so that you can fit even more in a given space. Avian-type brains, on the other hand, simply could not achieve the volume or the neural transmission speed required to support higher intelligence. At least that was the theory. However, as Albert Einstein is said to have said, “In theory there is no difference between theory and practice—in practice there is.”

When inferring behavior, brain size, or even structure, let alone from the endocasts of extinct species, we only see through a glass darkly. Looking more closely at the actual behavior of living birds has now demonstrated that while most birds can fly, their minds are anything but flighty. Pigeons can distinguish cubist style paintings from impressionistic styles, crows not only make useful tools but pass on those skills to others, and parrots can learn words and use them to communicate with us. Pigeons can even be trained to communicate their differing internal experience upon receiving uppers, downers, or placebos—to another pigeon! Bird brains have now racked up so many cognitive accomplishments that some neuroanatomists have argued that the cortex-like cognitive functions of the avian pallium demand a new neuroanatomical terminology that better reflects not their differences but rather the homologies (similarities in function) between avian and mammalian brains.

So bird brains—and by implication smart dinosaur brains—are sufficiently high enough on the evolutionary scale and complex enough to allow for complex cognitive behaviors. And just how much neural complexity is required for complex cognition? Well, we now know that honeybees, who are insects with a vastly simpler nervous system, are able to discriminate Monet paintings from Picasso’s after extracting and learning the characteristic visual information inherent in each painting style.

Still, only humans can solve the mirror self-recognition test. OK, only humans and the great apes. Wait, only humans and primates—no, humans, primates—and elephants—and dolphins and killer whales. Actually, given the proper training, magpies can too. And so can those pigeons! And that’s for a test that uses visual stimuli. As with public opinion polls, the answer you get in an experiment may all lie in how you ask the question. Vision is a dominant sense for humans—and for those birds as well. Yet, as dog owners know, for canines—unlike humans or birds—olfaction is the dominant sense over vision. Before we can truly evaluate the intelligence of other species, we need to at least make an attempt at understanding the world as they experience it. And that’s just what one German biologist did.

Umwelts and the Enneadic Brain of the Octopus

Baron Professor Jakob Johann von Uexküll (1864–1944) was a German biologist whose research ranged from physiology to animal behavior. His most important contribution was introducing the concept of Umwelt and developing its importance for biology, specifically for the understanding of animal behavior. Literally translated as the “around world,” von Uexküll defined the Umwelt as the surrounding environment as perceived by a particular animal species given its specific sensory system. That concept has since influenced fields ranging from sensory and cognitive biology to environmental design engineering, cybernetics, semiotics, and even existential philosophy.

To better understand just what von Uexküll meant by the term Umwelt, consider some very relevant differences between dogs and people. First, dogs have only two-way (dichromatic) color vision, not three-way (trichromatic) vision like humans. Our eyes have three types of color receptors, termed cones, that allow us to recognize and identify a palette consisting of reds, blues, greens, and their combinations. Dogs, on the other hand, possess only two types of cones—blue and yellow. A dog’s Umwelt does not include the range of colors from red to green (along with blue) that we see but rather just shades of yellow, blue, and grey. Grass, for example, only appears yellowish or brown to dogs.

But dogs can smell so much more than we can. It has been estimated that dogs can smell anywhere from 1,000 to 10,000 times better than humans. They have 40 times more smell-sensitive receptors, and their nasal cavities are far more complex thus amplifying their advantage in mere number of receptor cells. Some breeds, such as bloodhounds, that have been specifically bred for scent tracking are more sensitive sniffers than others. Those such as whippets and greyhounds, bred for visual tracking of fast-running prey, have sacrificed some olfactory for enhanced visual acuity, though even their sense of smell far exceeds ours.

And whereas vision is, well, line-of-sight, and transitory (out of sight, out of mind), smell is multidirectional (though affected by wind) and lasting. Even among us olfactorily-challenged humans, sensations of smell evoke some of our strongest and most enduring emotional reactions, from the sensual scent of a loved one’s perfume or cologne lingering on the pillow case to the stench of rotting garbage left uncollected on the big city street below. A mind that has evolved to handle predominantly olfactory input will construct a far different Umwelt than one built around overwhelmingly visual stimuli. And then there are the cetaceans, especially porpoises and dolphins, who construct their mental world based on auditory stimuli and whose motor responses have evolved to function in a different medium (water). While the canine olfactory Umwelt and the cetacean auditory Umwelt “map” to our human visual Umwelt, and vice versa, each “misses” a lot of the other two’s moment-by-moment experience.

Now suppose that not only are the sensory and motor systems of different species different, what if the unit that processes those inputs and generates their outputs to create their respective Umwelts is vastly different? Consider then the octopus, smartest of the invertebrates. They’re quite good at learning to get through mazes and they employ tools in constructing their well-known “gardens.”

The octopus has the highest brain size to body size ratio among those without a backbone and about as many total neurons as a dog. Instead of one brain, it has nine! Well, one generalized, central hub in the head and a smaller specialized processor in each of its eight arms, each with its own set of neurons. And if an arm is removed, the octopus can regenerate it! What might be their mental map of the world?

If the octopus could evolve human-level intelligence, would it think in terms of dichotomies of good versus bad or political liberal versus conservative the way we do? Or would the octopus have a much more nuanced enneadic view of things given its nine brains? Could distributed brains ever evolve the level of intelligence achieved by centralized brains?

Truly accurate and meaningful measurement and comparison of the intelligence of various species, living or extinct, would therefore have to take into account their entire Umwelt: their sensory inputs, motor responses, and the structure of the intellect that processes them. Until then, we’re left to deal with approximations. The more closely related the subjects we’re comparing, the more accurate the comparison.

Intelligence Costs, So Stupidity Sometimes Pays

If there is such an advantage to increases in intelligence over the course of evolutionary history, why are there any “dumb” animals left? The most basic and perhaps only law of economics is “there’s no such thing as a free lunch.” Since you can’t get something for nothing, getting one thing means giving up something else. And animal intelligence, like artificial intelligence, is very expensive, and the brain is the most energy-expensive organ in the body. Brain tissue uses 20 times the metabolic energy as an equivalent mass of muscle. Therefore, increases in intelligence must bring a significant selective advantage or they won’t take place and would not have taken place over the course of evolutionary history in so many lineages. But sometimes they don’t.

There indeed can be evolutionary advantages in being stupid. If an organism can get by with its existing intelligence, increases may actually decrease survivability. Perhaps that’s why about half of the domesticated species decreased their brain size compared to their wild ancestors. So domestication, as often as not, results in “dumbestication.” And what of the seemingly “smarter”—to our minds—domesticated ones? Are dogs such as Border Collies that humans can train to herd sheep and obey over 500 commands, using both words and hand signals, really smarter than wolves that successfully navigate much harsher environments, often outsmarting both people and dogs?

Consider that the average human brain size has decreased over the last 10,000 years, with our transition from hunter-gatherers to agriculturalists. Being a hunter-gatherer calls for brains as well as brawn, and you’re regularly facing many life-determining novel situations compared to all those regular, repetitive days on the farm. Have we, as a byproduct of our great success as a species, dumbesticated ourselves, and, if so, is that still going on today? Does the relaxed selection pressure resulting from the benefits of modern technological society foster similar changes as our transition to agriculture? Clearly, evolving increased intelligence is not the sure and only path to survival and success, nor is such success guaranteed.

A Tale Told by an Intellect, Filled With Chance and Necessity

Nonetheless, over the course of evolution, there has been an increasing, self-perpetuating, competitive advantage to be derived from increases in neural complexity (which can be approximately, variously, though somewhat fuzzily estimated by brain size) and behavioral complexity (gauged in like manner through various tests of intelligence, reaction time, and cognition). Our best tests of intelligence involve the process of decontextualization—removing a stimulus from its immediate sensory meaning.

A prime example is when a set of arbitrary marks are used to represent sounds, and then some of those marks are used in a completely different context to represent concepts unrelated to those sounds. The equation E=mc2 is about as decontextualized as you can get. There’s nothing in those sounds or marks that directly represents energy, mass, and the speed of light, or the process of multiplying a quantity by itself, which can be represented geometrically by a shape called the square. Yet, that equation has certainly increased the power in humanity’s hand—enough to power or annihilate whole cities. Across human history, we see how our increased intelligence has been put to work to harness increasing amounts of that energy and turn that into increased levels of societal complexity.

And with that increase in intelligence, one hopes, there has been a similar competitive advantage in ever-increasing awareness of the environment, including and especially the minds of other individuals of our own group and of our own species, and with that in developing consciousness, and even conscience.

This article appeared in Skeptic magazine 29.3
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Alas, the race of life is not to get ahead—it’s to get ahead of somebody else. Another species, whether predatory or competing, another group, or an individual in the same group competing for food, range, or mates, rival relatives or siblings, even for resources in the womb in the case of twins and other multiple births. Differential outcomes depend on group and individual differences. And without individual differences, the very concept of intelligence itself would be meaningless—group differences being merely the aggregated individual differences.

Things didn’t have to happen exactly as they did, but given enough chances, either in various evolutionary lineages over the course of geological time—or even other places in the cosmos over the course of astronomical time—the odds are in favor of something very much, though by no means exactly, like that eventually happening somewhere sometime. Will Homo sapiens’ particular instantiation of “higher minds”—those with not only intelligence, emotion, consciousness, but possibly even conscience—ever encounter lesser, equal, or superior others before our evolutionary run runs out, whether through chance external encounter or necessitated by self-indulgent failure to use our intelligence?

The answer to that question lies less with scientists than with philosophers, to wit—

“Everything existing in the Universe is the fruit of chance and necessity.” —DEMOCRITUS

“… or vice versa!” —YOGI BERRA