Doctor Doolittle attainable?

 kw: book reviews, nonfiction, zoology, sociology, communication

How do animals communicate? Why do they do so? What do they have to talk about? What are they saying? Can we eavesdrop? Can we horn in?

The first question has numerous answers, and has motivated a great lot of literature. The answers to the third and successive questions are still elusive at best, and impossible (to date) to answer. But the second question, now: Ah, that's a good one. Why, indeed, do animals communicate? To narrow the focus quite a bit: Why do animals talk?

Why Animals Talk: The New Science of Animal Communication by Arik Kershenbaum takes up precisely that question. Were I the editor I would suggest adding a word to the title: Vocally. Dr. Kershenbaum states in the Introduction that this book focuses only on auditory communication, to keep the book's size manageable. And while I am making suggestions, may I offer that the cover picture, of a frog nose-to-nose with a snail, is way off the point? Frogs eat snails, and snails are remarkably mute. There's a pair with nothing, but nothing, to talk about!

In the context of biological evolution, vocalizing, in common with all kinds of communication, must serve the needs of the creature in its environment. Take up the question for yourself: what needs to you have? Shelter, food, a mate, and enjoyment. Each of these needs is different in detail from the similar needs of any animal in its own environment. Also, for most animals larger than a limpet, a fifth need would be a sense of purpose, even though that may be largely wrapped up in both providing and securing the first four needs.

The author illustrates the range of animal talk by discussing seven animals: Wolf, Dolphin, Parrot, Hyrax, Gibbon, Chimpanzee, and Human. In each chapter the animal's unique vocalizations are examined with this question in view: Is it Language? And a corollary: Is it a stepping stone towards language?

At first it seem to me that the order is a bit odd: Hyraxes weigh a pound or two, with a correspondingly small brain; dolphins are the heaviest on the list and, after humans, have the largest brain in relation to body size. I finally recognized a specific order, that of successive degrees of verbal complexity. I wondered why Dolphins were brought in so early. Most of us think of them has being closest to having a language. However, their whistles are variable, not repeatable, and nobody has yet been able to discern a vocabulary of "dolphinese". The author stresses in this chapter and others that language does not necessarily require discrete words. I am strongly skeptical about that. I personally tend to put "wordlessness" as distinctive on non-language, but I am willing to withhold judgment for now.

Can wolf howling be considered linguistic in any way? It must be pre-linguistic, as it is a kind of singing. Howling wolves are clearly enjoying the experience; howling is emotional. Considering that, in humans, the brain structures that support song are larger and more deeply established than those that support speaking and speech hearing, it is evident to me that song came long before speech, and perhaps by a million years or more…or perhaps by several millions of years.

The first animal treated that seems to have word-like utterances is the hyrax, a little marmot-sized relative of elephants—they even have little tusks! It may seem a stretch to call their chippy, chittery vocalizations as songs, but the author thinks they are. They are not random strings of the five distinct sounds a hyrax makes; they seem to have a syntax. That is, certain sounds never occur one after the other, while others are usually found in succession. Just as we have words that contain several syllables, it may be that, if hyraxes actually have "words", many are of several syllables. (In human speech, contrast monosyllabic Chinese with polysyllabic Japanese.)

Putting gibbons next in order, we find certain similarities in their "songs" to hyrax "songs" except that gibbons have 27 (or 28, the text says both at different points) distinct utterances, with a much more complex syntax than that of hyrax "songs".

Parrots are a really mixed bunch. While most parrots, and several other birds such as Mynah birds and ravens, can mimic human speech sounds (and doorbells, gunshots and sirens), they don't use these sounds in meaningful ways, with an exception or two. A bird named Alex, an African Grey Parrot, became famous for his ability to hold a simple but meaningful conversation with a human. Getting Alex to this point took a lot of training, of a special type described in the Parrots chapter. Alex has died, and another African Grey Parrot is being trained; stay tuned.

Was Alex an exceptional genius among birds? For one thing, his verbal abilities indicate that the arrangement of a bird's brain might be quite a bit more efficient and economical than that of a mammal's brain. His brain was the size of a shelled walnut and weighed less than a quarter ounce. A typical house cat has a one-ounce brain, and only a very exceptional cat can learn to recognize more than their name and the sound of a can opener. Regardless of Alex's skills, it is evident that parrots in the wild don't use language in any humanlike, or even Alex-like, way.

So, gibbons sing. Chimpanzees don't. What some (stress: some) chimps can do is learn either rudimentary ASL (American Sign Language) or other physical means of indicating a small number of words. Sentences longer than "give banana" seem to be beyond them. The gorilla Koko learned more ASL and was a better conversationalist. But neither chimps nor gorillas have a vocal apparatus that can produce uttered language, and it is pretty clear that they don't have the flexibility of mentation to support humanlike language at the level of a two-year-old human. Somehow, Alex the parrot could hold his own with a six-year-old human.

The author stresses again and again that animals communicate according to the needs imposed by their environments. The complexity of their utterances—and again, he is reporting only on audible communication—generally reflects the complexity of their social environment. It appears that only humans can maintain relationships with potentially thousands of other humans (The number of names in the Picasa face-name directory for my photos comes to about 1,200. There are a few hundred other people I know by name and face and converse with more frequently than yearly, whom I have not photographed). The largest chimpanzee "village" is less than 100. Similarly for dolphins, orcas, and their kin.

How and where and when did humans make a breakthrough that allows an actual infinite range of expression? We may not make many more unique sounds than the sound-repertory of a gibbon (English phoneme lists range from 44 to 46, and Mandarin Chinese requires 88 phonemes, but Hawaiian gets by with 24). We combine them endlessly, and we can distinguish them. Thus, most English speakers can speak and recognize about 10,000 one-syllable words, 30,000-35,000 2-syllable words, and a total of 60,000-100,000 total words, plus all the case inflections and conjugations needed to make grammar work. The author stresses this point: No other animal has grammar, or at least nothing like a grammar that we can recognize.

What conclusions can we draw from all this? Firstly, that a great deal of research lies ahead, for us to begin to understand what any particular species of animal "means" by its utterances. Secondly, whether "words" really are necessary for the kind of flexible communication we call "human communication," which is what we usually mean when we use the term "language."

What Dr. Kershenbaum has given us is not the answer to "Why animals talk," but a few foundation stones, of a set of unknown size, the groundwork for learning why they do talk, and eventually, what they are saying (which we may find out is not anything we'd enjoy hearing!).

More Octo-fun

 kw: book reviews, nonfiction, zoology, cephalopods, octopus, octopuses

Almost a year ago I reviewed Soul of an Octopus by Sy Montgomery. She has followed up with a delightful, small book Secrets of the Octopus. Even more than the prior book, this one is replete with amazing pictures of these astounding creatures. The core of Soul is the relationship Dr. Montgomery had with four Giant Pacific Octopus individuals, during the short time (just a few years) that each resided in the aquarium at Monterey Bay. In Secrets we find a number of newer discoveries about octopuses.

At present we know of about 300 species of octopus. The largest is the Giant Pacific Octopus, Enteroctopus dofleini, which can reach twice the size of a man and weigh between 100-250 pounds. The first octopus I saw was one of these, at Marineland of the Pacific, when it was still open. I was about ten years old. The large female was plastered to the glass, and I had to look in from the side to see her mantle (which many people mistake for the head; it is behind the head).

I remember at the time being told that red color for an octopus meant anger, but that is wrong. It means interest or excitement. An angry octopus will instead blacken, particularly when it rises up to intimidate an opponent. The animal in this photo is excited from interacting with the diver. Many species of octopus quickly learn to enjoy human company.

Octopuses are cephalopods, the "brainy" order of mollusks, which also includes squids, cuttlefish, argonauts (which produce lovely, featherweight shells), nautiluses (with coiled, heavier shells), and sepiolids (often called "dumbo octopuses"). All cephalopods have arms, which most people call "tentacles", but to a biologist, the tentacles are the two long, extensible members that shoot out to capture prey, and only have suckers at their ends, the part often called a club. Arms typically have suckers all long their length. Also, all cephalopods have color-shifting skin, and many have skin that can dramatically change shape. Almost any octopus can mimic a rock or patch of seaweed in both color and shape.

The smallest octopus is the Hairy Octopus, which was discovered only a couple of years ago. It is so new a scientific binomial name hasn't been chosen yet. These lovely little critters, only 5 cm long (2 inches, or the size of a large paper clip), exhibit the shape-shifting skill almost all the time, looking mostly like drifting bits of seaweed. Depending on the screen you are using, this picture is probably twice as large as the actual animal.

It was once thought that octopuses are strictly solitary, only meeting to mate or fight or eat one another. This is also out of date. A lot depends on the density or scarcity of food. In abundant circumstances, some (perhaps many) species can be quite social, as seen with a few "octo-cities" such as Octopolis near Australia. While no large settlements of Giant Pacific Octopuses are known, their apparent enjoyment of human association indicates that they also can be quite sociable.

Some octopuses use tools. The Coconut Octopus, Amphioctopus marginatus, is just the right size to fit into a coconut shell. When an individual finds either a coconut shell portion (or two), or a similarly-sized shell of a clam or scallop, it will typically begin to carry it around to use as an impromptu shelter. This is a good strategy for an orange-sized, tasty morsel in an ocean full of predators.

This species is also one that "walks". Holding a shell with up to six arms, it uses two to stride along the ocean floor like a bellhop with a heavy suitcase. This image is two clips from a video of an octopus that wraps six arms around its body while walking on the other two. Starting about 10 seconds into this video, we see another species "stand up and walk away" from the photographer.

This is the video link, in case the one above doesn't work right: https://www.youtube.com/watch?v=kHwUW1inDCs.

These are just a few of the recent learnings about various species of octopus. The last part of the book, "Octoprofiles" by Warren K. Carlyle IV, presents brief descriptions of sixteen cephalopod species to give us a taste of their variety. Reading this book and gazing at the terrific pictures is pure enjoyment.

Babies outnumber all

 kw: book reviews, nonfiction, biology, zoology, population, embryology

I couldn't think of a better illustration of the book's theme than the cover art. It shows the larval or infant form of several dozen animals, from tadpoles to veligers to baby monkeys and birds. 

"Veligers?", you ask? A veliger (soft "g": "vell-uh-jer") is the larval form of most kinds of mollusk, like this tiny snail shown at 50x.

The book is Nursery Earth: The Wondrous Lives of Baby Animals and the Extraordinary Ways They Shape Our World, by Danna Staaf. The author's enthusiasm for these small-to-tiny-to-invisible animals will soon become your own as you read.

We seldom pay much attention to baby animals of any kinds besides kittens and puppies, because they are small and mostly unseen. However, in numbers they dominate the biosphere! Think about it: we usually relate everything to our human milieu and to the most familiar animals, which are mostly domestic. These familiar animals live a long time as adults (if not slaughtered for food), compared to their lives as infants and juveniles. 

When we think "animal", what comes to mind is mainly mammals and possibly birds…and maybe lizards and fish. Mammals and birds, in particular, care for their offspring, and we were all told in a beginning science class that "other animals" such as fish and turtles and "everything else" simply leave newborns to fend for themselves. Maybe we've seen documentaries of newly-hatched, nickel-sized sea turtles struggling down the beach to reach the water. Now, step back a moment: How many of those little sea turtles will survive to adulthood and produce more baby turtles? A few out of hundreds, or of thousands? It is easy to conclude that, by numbers, the vast majority of sea turtles alive at any one time are the babies, even as they are being gobbled up by predatory fish or dying of diseases. This is true for nearly every living animals species. Most animals alive now are babies, but most are hidden.

Even for backyard birds, the nestlings may number four or five or six, like these little robins (there are four, but one had just closed its beak) in a nest outside our kitchen window. But on average, only two grow up and have their own families, from a lifetime of nesting, not just from one nest. A pair of robins may produce five or six clutches of eggs in their lifetime; only two nestlings will survive to reproduce. Birds care for their young with great diligence, but they still need to lay many eggs to ensure a stable population. It's a similar case with most mammals. Infant and juvenile mortality is very high, so they must have many cubs or kits or joeys or puggles so that the next generation will not be less numerous than the present one. 

Now, what of fishes? There are a few notable species of fish that care for their young, but only a few. Salmon may represent the opposite end of the spectrum: they struggle upstream to their birthplace and lay millions of eggs, and then die. The fry (newborns) have been bequeathed a yolk sac, which nourishes them until they learn to catch their food. They look like fish, but not much like they will appear when grown. This is because of a theme of the book, that the environment of a newborn animal is quite different from the adults' environment, so they need a different kind of body to thrive in it. This is more evident among animals that develop through stages, with partial or full metamorphosis. The conversion of a caterpillar into a moth or butterfly, or of a grub or mealworm into a beetle, are familiar examples. Even baby grasshoppers, that have "partial metamorphosis", and thus look a lot like adults, don't grow wings until they reach full size.

Most people have seen caterpillars, or inchworms, or lawn grubs. Particularly for insects, the larval stage (or stages) of life can last much longer than the adult period. A mayfly nymph grows underwater for several months, then surfaces and metamorphoses into the adult, flying form, which lives just a few days, mates, and dies. Periodical cicada larvae live underground for 13 or 17 years. When they emerge, the adults "serenade" us (really, each other) for a month or so, and die before winter arrives. Therefore, at any one time, there are trillions of cicada babies hidden away underground, and then for a short time, this year's crop emerges to amuse and irritate us while they hurry to reproduce. Crops of other years remain hidden until their time comes.

Many details about many of these baby animals fill this very enjoyable book. The author, who has children of her own, circles back to the human condition. We don't think of mammals, or humans in particular, as experiencing metamorphosis. While a human baby doesn't pupate and melt away, to be radically reorganized to a new form, we do change a lot between birth as a seemingly helpless wiggle-wormy, squirmy baby, and the competent (we hope!!) grownup we become after 15-25 years. Baby humans are actually very well adapted to the environment into which they are born. And at birth they have already undergone the greatest period of growth of their lives: from a single cell to around 3 kg, complete with all major organs, the motivation to find a nipple and suckle at it, and a brain about 1/3 adult size; everything is primed to go through the decades-long metamorphosis we call "growing up." As adults, we may not remember that much of going through puberty. It is a huge metamorphic change in both body and mind. (For neurotics, many of the outdated defense mechanisms that plague us were formed during adolescence.)

Here's the takeaway: The vast majority, in number, of animals alive at any time are babies.

Is one percent of a mind still a mind?

kw: book reviews, nonfiction, psychology, zoology, animals, experience

The title and cover art (a Leafy Dragon, a kind of seahorse) of MetaZoa: Animal Life and the Birth of the Mind, by Peter Godfrey-Smith promise good thing inside, and that promise is abundantly kept. Thinking about thinking is the highest human art, and while Sturgeon's Dictum ("90% of everything is junk") holds especially true in this field, when the right ideas come together, the synergy is wonderful.

Dr. Godfrey-Smith has a prior book particularly on the mind of the octopus, Other Minds, and the work there is a springboard to his thinking about the full range of cognition, from the first evolution of neurons onward. MetaZoa begins with the eukaryotic cell—it could have begun with prokaryotes, but that would have added little and taken much more space—, a cell that senses and reacts to the environment, and is complex in its own right. However, there seems to be nothing we can do (so far) to determine whether amoebas, or critters like Euglena and Paramecium, have "experiences" or a "sense of being" in any way comparable to ours. Thus, the discussion proper begins with the simplest metazoans, those without nervous systems (so far as we know): sponges and placozoans.

A sponge is a metazoan—a multicellular creature—at its most basic: a collection of cells of three (some say four) types of cells, that produce spicules composed of either calcite or silica to stiffen a roughly vase-shaped "body". There seems to be a very simple system of cell-to-cell communication that allows the animal to react, quite slowly, to certain stimuli, perhaps including light. We still don't know much about sponges. Working with them is very difficult. 

A placozoan is one of nature's great secrets: an animal typically smaller than one millimeter in diameter and 1/10 millimeter thick, that creeps among sand and silt grains using cilia for locomotion. This also implies some kind of cell-to-cell communication to coordinate the cilia. There are no cells with long projections that could serve as nerves for longer-range communication across the body. They eat by creeping atop a bit of algae and excreting enzymes to digest it outside the body, absorbing the products of digestion directly. These are even harder to work with than sponges.

The book doesn't discuss that favorite of experimenters, the nematode Caenorhabditis elegans (usually C. elegans), which is less than 1/10th the mass of a placozoan but is much better organized. About a third of its 959 cells constitute its nervous system, including a 56-cell brain. The author chose instead to move right along to coral polyps and to cnidarians in general, which have a minimal nervous system (in terms of percent of body mass), a neural net (no brain) that coordinates swimming motions in swimming polyps and grasping motions in sessile polyps, and also feeding behaviors.

A point the author makes repeatedly in the first several chapters: we shouldn't think of sponges, placozoans, corals or jellyfish (or any other animals) as "primitive". They have four billion years of evolution in their history, the same as we do. They are successful in their environments, or they'd have been eliminated.

With these simple animals, their similarities and contrasts, we begin a journey around (not necessarily "up"!) the tree (or network) of life. The author wished to puzzle out the origin of experience. Looking from "our" end of things, we, and a number of other animals (maybe a very large number), have something we call "consciousness", sometimes described as a "here I am" feeling. Are there animals that don't have this feeling? The smaller an animal is, the less we think it is "like us", and therefore capable of consciousness. Is this so?

Our pet calico cat is rather touchy, even peevish: it doesn't take much of a transgression on my part for her to give me a hurt look and stalk off. Another cat I had long ago would run across a carpeted room onto the linoleum in the hallway, and find himself skidding past the turn into the bedroom. Once he came to a stop, he would stroll, the picture of dignity, in the direction of the skid, as though he'd intended to go there all along. Unflappable aplomb! These animals have a definite sense of being "who they are". I call it consciousness, even if it is simpler than a human's.

Now, let us jump almost to the other extreme. A honeybee has much more brain than a nematode, about a million neurons. Even though the bee brain is tinier than a pinhead, it is well organized. This drawing, from an article in ResearchGate by Eleni Vasilaki and others, has this title: 

"Basic anatomy of the honey bee brain showing the major pathways involved in odor classification and olfactory learning."

Think about that: olfactory learning. It sounds like a lot can go on in the brain of a honeybee. But does the bee have a sense of "here I am" or "this is me"? While it cannot have such a sense at a human level, or even a mammal level, perhaps it does.

An aspect that Dr. Godfrey-Smith turns to in the last two chapters is gradualism. My statement above, "…even if it is simpler…" is along this line. Much is made of the phrase, "the lights are on". Some claim consciousness is like pregnancy: "Can you be a little bit pregnant?" I think to take such a purist attitude is misguided. 

There may be a threshold effect. Is the neural net of a coral polyp (there is no brain) enough to generate a sense of presence, of "I am here"? Are the 56 neurons of a C. elegans brain enough? The million neurons of a honeybee's brain? Right in the middle of such a spectrum is the octopus, which has half a billion neurons.

The octopus's brain is quite different from a vertebrate brain. A ring of nerve tissue surrounding the gullet contains about 140 million neurons. A ganglion near the big end of each arm has about 45 million; those 360 million (45x8) plus those in the ring brain add up to 500 million. There is a lot of text in MetaZoa about whether this is a 1+1 situation, or 1+8, because the eight arms seem to act semi-independently. As I read, I remembered that 75% or more of human brain neurons are in the cerebellum, which runs the body, the "autonomic system". Our vaunted reasoning abilities, plus systems for vision, speech, sound, and the interpretation of our senses use 20% or so (16-18 billion neurons), and our emotions primarily reside in the limbic system, which has around a billion neurons. That in itself indicates that, if our feelings are entirely in the neurons, and primarily those of the limbic system (this is by no means certain), we use two whole octopus nervous systems to run our emotional being. So of course, octopus emotions (and they definitely have some!), belong to a much smaller set of neurons. But the octopus does behave as we'd expect of an animal that has a sense of self. Does a fish, or a bee? We can't say "Definitely not." Not yet, anyway.

Here I lean a lot on a concept I developed over many years. It is not anthropomorphism to attribute feelings and thoughts to animals. I look at it from the other end. The reason humans have feelings, thoughts, a sense of presence, and so forth is because our genetic ancestors had them, as do the other descendants of those ancestors. Have we developed all these things further than the rest? Some of them, at least, but perhaps not all!

This sense of being we have, which I consider belongs also to many animals, how far back does it go? When did an animal first experience it? We get a hint from electrical activity in brains themselves. When any neuron-containing animal is idle, a kind of synchronized cycling occurs throughout the nervous system. In humans, when we close our eyes we soon enter a state called "alpha", characterized by an overall brain rhythm around 10 Hz (it ranges from 8-13). Open the eyes, and the frequency roughly doubles to the "beta" rhythm. Pay attention to something, or get into problem-solving mode, and it doubles again, or more; the "delta" rhythm ranges from 30-140 Hz, usually centering around 40Hz. Do these patterns have meaning?

I immediately thought of regeneration and superregeneration in radio receivers (I am a radio amateur). Regeneration occurs when a tuned system oscillates in the absence of a signal. That is bad for radio reception, though it is what we want to happen in the signal generator of a radio transmitter. Regeneration also happens if a weak signal arrives in a system tuned to nearly self-oscillate; it is quickly triggered to oscillate. The stronger the incoming signal is, the more rapidly the oscillation begins. A superregenerative radio receiver is set to just barely self-oscillate, but the power supply is interrupted frequently (in old CB radios, this "squelch" occurred 30,000 times per second). During each short period, the oscillation's strength depends on the strength of the weak signal the receiver is tuned to detect. The resulting series of little peaks is filtered to remove the high frequencies (usually, above 5,000 or 10,000 Hz), and what comes through the filter is the audio that was carried on the incoming signal. This may sound complicated, but it is a cheap way to make a very sensitive receiver. It is an example of the use of a "keep alive" signal to enhance the system's performance. I suspect the various brain rhythms are akin to this, the beta rhythm being the main "detector". It is well known that our basic reception is limited to noticing fewer than 20 things per second, and the beta rhythm may be why.

I want to comment on one other matter. Vertebrate brains in particular are divided, at least in their upper sections, the cortex in mammals for example (the limbic system is only partly divided). When the connections between the cerebral hemispheres are cut, as is sometimes done to treat epilepsy, a split-brain person sometimes behaves as if there are two minds in one body. Certainly, if the brain of any smaller animal has sufficient "heft" to support a mind, there is room in half a human brain for a distinct mind. In an endnote to the chapter on the octopus, the author mentions a neuroscientist, Semir Zeki, who defends the view that we have several, or even many, distinct consciousnesses. Whether that is so, it does open the door to considering what happens in dissociation, in which a person develops "extra personae" as a response to extreme abuse. This used to be called multiple-personality disorder, but is now called dissociative disorder. The notion of true multiple personalities is mostly pooh-poohed, but it does seem to exist in some cases.

This and all notions that one brain can host multiple consciousnesses lend weight to gradualism. If there is a threshold below which a brain cannot support consciousness, it must be less than one-third of the 16-18 billion neurons of the typical human cortex, based on The Three Faces of Eve by Thigpen and Cleckley. I wouldn't have a clue where to place such a threshold, and Dr. Godfrey-Smith also declines to do so. He points out that, if lab rats and other smaller animals have a sense of self, we need to develop a better set of ethical standards for how we treat them. We have come a long, long way from the day René Descartes kicked a dog at a lecture and claimed that its cries of distress were "automatic" and did not signal pain or suffering.

It is worth considering that a smaller brain may actually be capable of thoughts that we would consider very high level, but they just take a lot longer to occur, given the smaller amount of "machinery" involved. However, time and time again our author expresses that more is going on than raw computation, and he explicitly denies strong AI, and equally denies that "uploading" the contents of a brain to a supercomputer will allow someone's consciousness to continue to run, unimpeded by having been removed from the body. Maybe we must have the computer also simulate all the rest of the body (endocrine systems at least!) for uploading to work, but I don't think so even then. That is a philosophical end of things that gets beyond how the mind came to be. It'll take another book (I hope he will) to delve into the future of the mind.

Is anthropomor-fear finally behind us?

kw: book reviews, nonfiction, zoology, animal studies, cognition

By one common definition, Anthropomorphism is the attribution of human traits, emotions, or intentions to non-human entities. Among zoologists, it has been considered a serious fallacy to use "anthropomorphic language" when speaking about animal behavior and the possible "internal state" of an animal. The fear of making animals "too human" has actually held back the valid study of animal thought and behavior, purposes, and feelings for more than a century.

The recent book Are We Smart Enough to Know How Smart Animals Are? by Franz de Waal, is a kind of manifesto that explores and validates studies of the ability of many species of animal to plan, use tools, make tools and even toolkits, deceive one another (and experimenters), and think in all sorts of ways that we, in our hubris, have long denied they can do.

Consider the opening story, of a female chimpanzee who takes straw bedding outside her sleeping enclosure, where we must surmise she expects to encounter chilly conditions. Dr. de Waal expresses the surprise he felt when she first did this. It was entirely unexpected. Later in the book we find that creatures as small as some spiders can also anticipate future conditions and make plans to deal with them. They are not just acting by "instinct," a term for which I have not encountered a satisfactory definition or explanation.

As a college student taking the occasional course in biology (I was a chemistry major at first, later a geology major), I heard the typical series of canards, that "animals will never do" something or other. When Jane Goodall reported tool creation and use by chimpanzees, Louis Leakey wrote, "…scientists are faced with three choices: They must accept chimpanzees as man, they must redefine man, or they must redefine tool." That was in 1967. Have we learned anything in the past half-century? Some have, but I fear most haven't. The author writes, "We routinely deny [animals] capacities that we take for granted in ourselves." (p. 7) He calls this attitude anthropodenial. (p. 30)

Some may be willing to "move the goalposts" a little, saying that chimps and perhaps other apes might do these things, but zoologists and naturalists continue to report more and more species that make and use tools, including crows, elephants, sea otters, and octopuses. Would Louis Leakey advocate accepting octopuses as humans? The brain of an octopus is only partly localized; most of it is spread through the body, such that a severed arm can move about on its own for quite a while. How can a human and an octopus "get into each other's heads", when those heads are so different? But scientists are trying.

Rather than belabor examples, let me come to his most useful conclusion: "There is no single form of cognition, and there is no point in ranking cognitions from simple to complex. A species's cognition is generally as good as what it needs for its survival." So, whether the cognition of a snail, for example, is "simpler" than ours, all we can say for certain is that it is different. Snails aren't as social as we are, for example, but they do prefer the company of their kind, unlike most felines, which prefer solitude and only meet to mate or fight. Whatever amount of brains they need, however, snails are certainly a successful group of species: by the latest count there are about 70,000 species of them, and half of those are terrestrial, the land snails and tree snails. There is only one species of human.

I wonder how our best athletes would fare in a track meet proctored by cheetahs or antelopes, both of which can run faster than 50 mph? How about a rock-climbing meet, competing with bighorn sheep? Could we compete in color discrimination with snapping shrimp, which have ten kinds of color receptors in their eyes, whereas we have four (one works in low light, the other three by daylight)? We have a hard time seeing in murky water. Bullfrogs can see infrared light, which cuts through the murk better. Many creatures also see ultraviolet light that we can't see. Different senses (there are many more!) mean that animals sense a world we don't sense, and so to cope with it they must think thoughts we don't think, and cannot think.

What about feelings? Ask any pet owner. We all know dogs are very loving. Cats? usually not so much, but some are and some aren't (kind of like many people). And take a look at these three animals, rescues, who turn to one another for companionship and comfort.

When we lived in Oklahoma, one of the farmers that lived a few miles north of town plowed with draft horses. He said, "Their feed costs less than gasoline for a tractor, they start right up on a cold morning, and they greet me enthusiastically every day." I've seen his horses rubbing against him with great affection. There's no other way to describe it. I've also seen a very resentful look on our cat's face when we must delay giving her a meal or a treat, if the delay goes on too long. Yes, I know cats don't have so mobile a face as humans, but they can show feelings, and we soon learn to "read" them. Dr. de Waals reports lab studies that also show now emotional animals are.

This points up a contention I have long had, which the book notes in its own way, that it is quite logical to attribute thinking and feeling to animals that is similar to ours, because we came from them. Our feelings didn't arise by magic when our brains grew to a size of 3 pounds. Great apes, with their one-pound brains have the same feelings, and probably with nearly equal intensity. But they also can show remarkable self-restraint. When we say someone is "behaving like an animal", we are condemning lack of self-control. Actually, many animals are better at that than most people!

I also understand why so many people are unwilling to allow that any animals have a self-concept, or thinking ability. Some still claim they don't feel pain the way we do. Why is this? It is so our conscience won't feel bad when we abuse them. That explains nearly everything about poor treatment of animals. Maybe this book and others sure to follow will begin to break the logjam of scientific opinion and, even more, the thick-headed attitude that we can treat other thinking and feeling creatures just any way we like.

To survive, dig in

kw: book reviews, nonfiction, science, paleontology, zoology, burrowing, mass extinctions

Shortly after we moved to our house 22 years ago we bought some flat stepping stones for high-traffic areas in our yard, such as the path through a "gate" in a hedge. I dug these in to be an inch or so above ground level, a little lower than the mower blade at its lowest setting. Now, nearly all of them have sunk to ground level or below. Two examples are shown here. Is this just soil compaction from the stones being walked on? Not entirely. Wherever I dig in my yard, I encounter several earthworms in every shovelful.

Charles Darwin spent about 20 years studying earthworms, and using "worm stones" plus an ingenious measuring device attached to bedrock beneath, determined that bioturbation (the modern term) of the subsoil by earthworms caused the stones to sink by an average of 2.2 mm/year. Darwin's earthworms must have been very energetic. The "sink rate" for my stepping stones is closer to 1.0-1.5 mm/year.

One of Darwin's worm stones is pictured in The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet by Anthony J. Martin. Dr. Martin's thesis is simple: burrowing and other means of living below ground at least part of the time is so beneficial that many animals are burrowers. I don't know if you could say "most animals", but that might be true (he doesn't say). Also, burrowers provide homes for other species that share their spaces. The author makes a good case, with numerous examples, that living at least part time underground enabled many animal species to survive the various nastinesses we call "mass extinctions".

The "big five" mass extinctions had such profound effects on both biology and geology that they mark geological boundaries (the abbreviation "mya" means "million years ago"):

• Ordovician-Silurian boundary, 429 mya. About half of species vanished, and about 85% of all animals died.
• Late Devonian, 364 mya. About 75% of species became extinct.
• Permian-Triassic boundary, 251 mya. The baddest of the bad, this one drove 96% of species extinct. All living things today are descended from the remaining 4%.
• Triassic-Jurassic series, between 214 and 199 mya. By the end of this 15-million-year period, more than half of species had been eliminated.
• End-Cretaceous, 65 mya. This is the best known, because it centers on an asteroid impact and led to the demise of the dinosaurs…or, at least, the non-avian dinosaurs. It is now known that birds are dinosaurs, or, if you prefer, birds are descended from theropod dinosaurs. 76% of species went extinct.

Many cases show that animals that were underground during the big smash, or whatever happened, were the most likely to survive in numbers sufficient to restore their populations afterward and become the ancestors of modern life. But before the first of the mass extinctions, there were big changes as animal life arose and developed, including the development of the first burrowing creatures. An odd group of animal species called the Ediacara Fauna did just a little burrowing, but were followed by the "Small Shelly Fauna" that burrowed more and deeper, and then the proliferation of hard shells that marks the beginning of the Cambrian period also marks the beginning of rather thorough bioturbation of ocean floor sediments.

The author shows the history of animal life from the perspective of an Ichnologist, a scientist who studies trace fossils. This picture, a 6"x8" section of a rock about 15" square, shows trace fossils on a rock I picked up from a sandstone bed near the base of the Morrison Formation in South Dakota, so it is about 150 million years old. This is a bottom cast; we are "looking up" at sediment that settled into tracks and shallow burrows in the late Jurassic sea bed.

Somewhat visible are ripples crossing from top right towards bottom left, showing that this was in rather shallow water. At least three kinds of tracks are visible, though I don't know what animal made any of them. Other dug-in structures are seen, or rather, their casts. Dr. Martin and his colleagues are experts in discerning the meaning of such traces.

Before digging into his subject, however, the author discusses "A brief history of humans underground." If you've heard of Cappadocia, you may know of the underground homes dug into the soft sandstone. That has been going on for several thousand years! Long before that, humans utilized natural caves, not only for shelter and burials but even for their art (think of the amazing art in the caves at Altamira and Lascaux).

While we tend to denigrate "cave men", thinking only Neanderthals lived in caves, the "art gallery" caves were painted by our species. When there were only a few humans worldwide, it makes sense to consider that many or most of them used caves and sometimes stayed in them for extended periods, not just during bad weather or extreme seasons. A cave is easier to defend from predators. And just as the burrows of gopher tortoises permit them to thrive in areas with tough winters, so caves shield those who dwell in them from climatic extremes. Indian Echo Caverns, in Pennsylvania about two hours from where I live, was the home of William Wilson from 1802-1821. The "Pennsylvania Hermit" stayed pretty well wrapped up most of the time, because the cave stays a nice, chilly 54°F (12°C) all the time.

There just aren't enough caves to go around, so now we build artificial caves we call "houses". One of the professors at South Dakota Tech had an "underground house" when I was there in the 1980's. It was technically a house built into a tight place between two rock outcrops. An underground house is nearly free to heat or cool, if it is in the "temperate band" across the world where average temperatures are between about 60°F and 75°F (16°C-24°C). The below-ground temperature near Rapid City, SD is closer to 47°F (8°C), so my professor had to insulate the excavation, pour concrete for the dwelling, and insulate more. South of Oklahoma in the U.S.A. an underground house would not need heating or cooling (just moisture control, perhaps!); in Europe, think Spain, Italy, Greece and Turkey, including Cappadocia.

This may become more pertinent in another generation, if the climate continues to warm. I will be even more pertinent when the "Holocene warming" that began about 12,000 years ago comes to an end and another 100,000-year Ice Age begins! Today's "global warming" caused by "carbon pollution" (an oxymoron; we are made of carbon and its oxy- and hydro-derivatives!) may actually delay an ice age by a century or so.

The most ubiquitous burrowers and tunnelers, humans aside, are invertebrates. Earthworms don't leave open tunnels; their burrows fill in behind them with the excreted feces from which they've digested key organic materials. But ants and termites produce long-lasting tunnels. Some of these have been studied by pouring in plaster or even molten aluminum. This cast of an ant nest is from leaf-cutter ants of Central America.

There is a surprising array of vertebrate burrowers, however. We are familiar with gophers and voles, perhaps, but certain birds burrow, such as kiwis, bee-eaters, and some penguins. The gopher tortoise, as its name suggests, is quite a digger, and its burrows shelter at least 400 species that are enabled to live in otherwise inhospitable places because of a tortoise's "hospitality".

The author also discusses the most amazing tunneler of all prehistory, the giant ground sloth. You might not think of an animal the size of a 4-door sedan as a burrower, but in southernmost Brazil there are hundreds, perhaps thousands, of burrows you could literally drive a truck through! The tunnels are 4-4.5 m wide (13-15 ft) and 2-2.5 m high (6.5-8 ft).

The last Brazilian ground sloths died (probably eaten by early Brazilians) about 12,000 years ago. They had used their strong claws to dig though soft, semi-cemented sandstone. The various species of giant sloth lived through numerous ice ages, having evolved about 23 million years ago, or perhaps earlier. Great bulk is itself helpful for surviving great cold, but burrowing confers an added advantage.

Biologists and paleontologists in general pay most of their attention to animals that lived above ground. True, finding and recognizing the fossil of an animal that died underground is more difficult. But there is so much going on beneath our feet, and so much of prehistory that took place underground, that we must realize that the livability of our environment is largely a result of these hidden lives. Scientists of all stripes would do well to take note.

Are we the cause of a great extinction being called, by some, the Anthropocene? If we are, it is mainly affecting the critters above ground. If we should extinct ourselves at some point, the "rulers of the underworld" will remain, and may hardly notice much difference. They will continue their ecosystem services as before, keeping a significant percentage of the subsurface a nice place to make a home.