Bipedal Apes in Sedentary Times
By Emma McDonell
(sorry the formatting is wierd...e.g. random underlines)
Professor Adrienne Zihlman relaxes into the desk
chair, her mouth curves into a wistful smile and her eyes
light up as she recalls the day her first “fantasy silverback gorilla” died
from a freak heart attack. It’s not that she was happy per se that San
Francisco Zoo’s prized gorilla, “Bwana,” had
met an early end, but a young male gorilla specimen was just what she had been
waiting for to begin a project on comparative ape anatomy. It was Labor Day
weekend of 1984 when Zihlman was alerted that Bwana was dying. She immediately
started making phone calls and a few hours later was on her way to “save”
Bwana’s invaluable flesh from the hazardous-waste
dumpster. She arrived just in time to negotiate with a California Academy of
Sciences representative who was after the bones: “I’ll give you the skeleton
after I’ve taken all the flesh off,” bargained Zihlman[M1] .
Zihlman had been waiting to dissect a silverback for a long time. When the UC Santa Cruz anthropology building was eligible for an upgrade in the early 1980’s, lab-less Zihlman joined the building committee. “I wanted a walk-in freezer and an elevator big enough to fit a full-size male gorilla,” she explained matter-of-factly as we sat at a round table in her anatomy lab. She moved into her dream lab in spring of 1984, a mere six months before getting the call about her dream silverback[M2] .
Zihlman had been waiting to dissect a silverback for a long time. When the UC Santa Cruz anthropology building was eligible for an upgrade in the early 1980’s, lab-less Zihlman joined the building committee. “I wanted a walk-in freezer and an elevator big enough to fit a full-size male gorilla,” she explained matter-of-factly as we sat at a round table in her anatomy lab. She moved into her dream lab in spring of 1984, a mere six months before getting the call about her dream silverback[M2] .
Zihlman’s
lab is a peculiar space. It’s a big fluorescently lit room, centered around a
tall table covered with colored markers and large white sheets of drawing
paper. Lab coats drape on the chair backs. A
poster of “el Copito
de Nieve”, the only known albino gorilla to ever exist, hangs beside a floor-to-ceiling
glass shelving fixture displaying enough skulls for a great haunted house,
ranging in size from the size of a kiwi to a small watermelon. Plastic baboon,
gorilla and elephant masks dangle from a hook adjacent to a life-size
watercolor painting of a gibbon skeleton. A couple dozen stuffed animal apes
look down on the room from the top of tall filing cabinets - some chimps, some
gorillas, some dressed in safari gear. Apparently, stuffed primates
are a go-to birthday gift for Zihlman.
Dressed
in khakis, a turquoise blazer, and matching earrings, she looks “put together”
as my grandmother would say. Though her crisp outfit and straight
posture make Zihlman intimidating at first glance, she warms
immediately once we’re one the
subject of primates.
Zihlman
has been moving and shaking the field of physical anthropology since she began
her grad school work in the 1960’s under the renowned
physical anthropologist Sherwood Washburn at UC Berkeley. Since her days
dissecting chimps in the Cal labs, she has been on the cover of both Time and Discover magazines and has served as Vice President of the California
Academy of Sciences for a number of years. Zihlman is
best known for her daring work examining female roles in human evolution and for
her groundbreaking research on bipedalism. Her
current venture, a two-decade comparative ape anatomy project is equally
radical in its own right[M3] .
Zihlman’s
current endeavor is to compare the anatomy of orangutans,
gorillas, gibbons, chimps and humans through dissection, looking at what
exactly each species’ anatomy is meant to do. While Zihlman is
working on the bodies of other apes to understand our entire ape family, in
making sense of our family, we can better make sense of ourselves. In our
modern urban lives, far from the jungles our ancestors inhabited, we often forget
our animal-ness, and often to our own detriment. It is not that humans evolved
from apes, Zihlman points out. We are apes.
Humans
are part of the primate order, a group of mammals comprising 16
families and about 200 individual species, who all originated from small
rodent-like, tree-dwelling vegetarians creatures in the Cenozoic era, about 65
million years ago[M4] . The primate family today includes a diverse cast
of characters. There are the nocturnal slow lorises, who render their bite
venomous by licking an arm gland and mixing the secretion with saliva. There’s
the mandrill, a baboon who lives in complex social groups
consisting of up to 800 individuals and whose males physiologically respond to
changes in their rank in dominance hierarchies through an enlargement
or shrinking of their testicles and reddening or fading of
facial [M5] skin[M6] . And there are the wanton bonobos, close relatives
of chimpanzees who are now famous for their liberal sex habits. Bonobos
are known to get it on with just about anyone in the family: males on male,
female on male, adult and child, in positions that seem even too
wacky for the Kama Sutra.[M7]
Other than a common ancestor, what primates have in common is hard to pin down. Carolus Linneaus described four key traits in 1758 that delineated primates as creatures with hands, breasts, a collar bone, and set of flat front teeth for cutting[M8] . Since Linneaus, researchers have continued to tinker with the qualifications for primatehood. They are grappling with the question to this day, mostly because unlike other animal groups, there is no single defining feature. Today, there twelve primate characteristics mostly agreed upon, but each has exceptions. To Linneaus’s list, we’ve added flattened fingernails, extremely sensitive fleshy hands, fingerprints, a poor sense of smell relative to our impressive visual acuity, lengthy pregnancies and infant-rearing periods, a sizable brain compared to body size, a herbivorous diet, and of course locomotion. It’s thanks to our family history, and of course natural selection, that you can read this small type, feel the smoothness of this page of paper, and cannot smell the remnants of the dog poop you stepped in yesterday on the bottom of your shoe.
Other than a common ancestor, what primates have in common is hard to pin down. Carolus Linneaus described four key traits in 1758 that delineated primates as creatures with hands, breasts, a collar bone, and set of flat front teeth for cutting[M8] . Since Linneaus, researchers have continued to tinker with the qualifications for primatehood. They are grappling with the question to this day, mostly because unlike other animal groups, there is no single defining feature. Today, there twelve primate characteristics mostly agreed upon, but each has exceptions. To Linneaus’s list, we’ve added flattened fingernails, extremely sensitive fleshy hands, fingerprints, a poor sense of smell relative to our impressive visual acuity, lengthy pregnancies and infant-rearing periods, a sizable brain compared to body size, a herbivorous diet, and of course locomotion. It’s thanks to our family history, and of course natural selection, that you can read this small type, feel the smoothness of this page of paper, and cannot smell the remnants of the dog poop you stepped in yesterday on the bottom of your shoe.
Zihlman studies a specific
sub-group within the Primate order, a super-family
in Linnean terms, called the hominoids. The
hominoids are a group of tail-less primates with relatively big
brains and arms that are shaped differently from
legs who diverged from the rest of the monkeys 30 million years ago
(mya[M9] ).
The hominoids split apart into two families, the
gibbons, known
as hylobatidaes,
and the hominidae, composed today of
orangutans, gorillas, chimps and the humans.
The orangutans broke off from this group a while
back, about 14mya, leaving a sub-family
of related individuals called the homininae. Not
long after the gorillas diverted, leaving
the human lineage and chimps together
under the banner hominini. Finally,
around 10mya, in
a move that would have drastic consequences for all
species across the planet, the
chimps and the homo lineage split
apart, sending each
species off to adapt to different
environmental niches, and become
completely different animals.
The terminology of
the hominoids is confusing, but that’s the point. All of these
creatures are very closely related. Chimps and humans could be compared to
siblings, while gorillas could be considered a sort
of cousin. Gibbons are that group of people at a
family reunion who you’ve never actually
met, but have distinctly similar facial features and ways of talking to your
own. Zihlman is working to understand both the
similarities amongst all the hominoids, and what sets each species apart.
Evolutionism’s two main vanguards, Charles Darwin
and Thomas Huxley, were the earliest proponents of
comparative anatomy, making extensive use of skeletal comparisons in constructing the concepts
of evolution and species relatedness described in Darwin’s An Origin of Species.
It was Huxley who constructed the famous diagram “Evidence to a Man’s Place in
Nature” in 1863 - depicting the human skeleton
adjacent to chimp, gorilla, orangutan, gibbon skeleton - to show the
biological intimacy between apes and humans, a heretic notion in his day. But
for all Darwin and Huxley’s genius, they completely overlooked the guts of the
matter.
It may seem intuitive to study both flesh and bone
to understand anatomy, but Zihlman’s emphasis on the whole body and dissection
makes her an iconoclast in the field. Physical anthropology has myopically
focused on hominid bones and brains since the field’s beginning, overlooking
the other 60-70% of body mass. While fossils recurrently make the cover of Time, and ape intelligence studies
abound – recall
the household names Leakey and Goodall – relatively little is known about the
muscles and ligaments - the meat, shall we say -
of our hominid relatives. In throwing out the flesh and ignoring the habitat
context in which apes evolved, researchers are literally left with a skeleton
of the available data, perhaps missing valuable insights into still-debated
questions about human evolution.
“It’s hard work finding ape specimens, especially
the males,” explains Zihlman who has now dissected an unprecedented five silverback
gorillas, four “orangs”, innumerable chimps, and many gibbons. Most of the time
zoos dump the flesh and ship off the bones to be made into
skeletons, spending their afterlives on museum shelves. A self-proclaimed
“ambulance chaser”, Zihlman expends lots of energy
networking with zoos and conservation organizations across the nation,
but the hassle is well worth it for the insights into the hominoid
family that she can’t get from any other technique[M10] .
Today, we have fancy DNA technologies to
cross-examine pre-existing evidence of human evolution and numerically define
species linkages by comparing genomes. But there are limitations of these increasingly
exact, increasingly narrow ways of knowing. Consider the oft-touted
statistic, that we share 95% of our genes with chimps. It seems remarkable
until we learn that humans also share 90% with lab mice and 85% [M11] with
a zebrafish[M12] . Zihlman’s project pushes against
“quantitative, pseudo-science”
skeletal analyses of anatomy to see each creature as a whole being, adapted for
a certain niche in a certain environment.
Zihlman’s project focuses on locomotion strategies,
because as she puts it, “locomotion underpins everything.” It’s the arms and legs that propel an animal toward
food, to find mates, to avoid predators. You name it, the locomotor system
enables it. “Anatomy
underlies behavior,” she explains.
Much as only
a mechanic really knows cars, you
can’t know a species without a
thorough understanding of how the creature’s mechanics work. “It’s
essential to understand the underlying infrastructure to understand the
species,” explains Zihlman. “It’s not just about seeing that they’re running
through the trees, it’s understanding the equipment they have to run through
the trees,” she says, pointing to a poster of what looks like a human skeleton
with its arms stretched to the ground.
“We all come from the same basic plan,” says
Zihlman: “It’s
understanding the precise adaptations that’s important.” It’s the small tweaks
in the locomotor systems that make huge differences in how we live our lives[M13] .
Zihlman opens a thick binder full of laminated
pages, which I soon learn is the beginnings of her new book. She flips to a
page depicting a skeleton with salmon-colored
muscles lightly painted over the bones and percentages of the individual mass
inscribed adjacent each muscle. As I look closer, I see the skeleton is split
down the center; it’s half silverback gorilla, half male orang. At first, the
two halves look fairly similar to me, two big-bodied
primates. But after ten minutes of Zihlman explaining the differences, I can’t
even see the similarities.
“They’re about the same total mass, but the mass is
in totally different places,” Zihlman begins. “To put it shortly, the orang’s
all arms and the gorilla is just the reverse[M14] .”
The orangutan, or “man of the forest” in Malay, is
an acrobat, equipped for life high in the fruit-laden forest canopies of
Sumatra and Borneo. He’s got muscular arms stretching twice the
length of his legs, enormous hands and feet, and bendy joints all
over.
“The ‘orangs’ have such a high center of gravity,”
Zihlman explains, lifting her arms above her head and slowly tilting her torso
to demo. “When they cross gaps in the trees they just kind of leeeean over,”
she continues, dragging out each syllable to emphasize the leisurely pace of
orangutan movement[M15] .
“And
his fingers are as long as his tibia!” Zihlman exclaims, springing up from her
chair to rifle through a filing cabinet. She returns holding what looks like a
human hand, except the fingers are each about a foot long and the phalanges are
as thick as a wine cork.
“Oh, and their feet: they
are not meant for walking,” she says, retrieving an orangutan foot from the
same drawer and placing it sideways on the table. It looks almost identical to
the orangutan hand, with long, thick phalanges and an opposable thumb or in this
case, toe. The feet are like extra hands, adept at grasping branches. “They
walk putting pressure on the outside of the foot.” Try this and you’ll see why
they rarely come down from the trees.
The orang’s gymnast body is specialized to satisfy
his mostly frugivorous diet of jackfruit, durian, and any of the
400 other types of food orangs are known to eat[M16] .
The gorilla on the other hand is king of the forest
floor. There are two species of gorilla, Eastern and Western, each with two
subspecies, and they’re all “built for propulsion”. Gorillas have “bulky” quads
and shoulders, allowing them to run quadrupedally across uneven forest floor at
speeds reaching 25mph[M17] [M18] .
Gorillas have broad, flat hind feet like doublewide
human feet and thick knucklebones meant to be pounded into the ground
at a
full run. Gorillas do climb trees, but they climb slowly
and carefully, taking precautions as they ascend, staying close to
the trunk and far from risky branches[M19] .
Like orangs, gorillas are casual vegetarians, focusing
on plant material foods, but occasionally indulging in an ant-covered stick.
Gorillas are experts on the mostly fibrous foliage available on the forest
floor, consuming up to 60 lbs of mostly plant materials each day[M20] , due not in small part to their agile frame. They eat bamboo, barks,
leaves, ants and berries, over a hundred plant species and are very particular
about which part of the plant is edible.
Each species has its staple foods, but what sets
ape diets apart from other animals is our lack of focus. Apes are
“generalists,” says Zihlman[M21] . Like mobile compost bins, we can digest just about anything, which is
really quite impressive considering that most mammals are strict carnivores or
herbivores. Adaptible and unrestricted, we’re
“oportunivores”.
Similarly, apes stand out for our
locomotor flexibility. Orangs can walk bipedally for short distances, and
gorillas can brachiate cautiously, and humans can climb. We’re made to make do.
So what sets humans apart from our ape brethren? “We’re long distance walkers, we’re bipeds,” declares Zihlman without a second thought. Chances are you don’t reflect daily upon how lucky you are to have the locomotor system you have, but try thinking of what you would do without it. No legs, no wheelchair. 24 hours. Go. Could you make breakfast? Did you make it to work? Answer the phone? How long did it take? Locomotion is no trivial matter; it’s the framework that allows animals to live the way they live. And for humans, it’s our gait that defines us.
The
last common ancestor we had with apes was the forefather of chimps and humans.
This creature, neither fully chimp nor fully human, lived about 7-8 million
years ago, at the tail end of the balmy Miocene epoch. Much of Africa was
blanketed in tropical forest at the time, and the primate order was multiplying,
consisting of many more species than are alive today[M22] .
A
small group of these African apes descended from the forest canopy to split
their time between the trees and the forest floor, and started walking upright.
The reason(s) for this transition are hotly
debated, but all the theories point to food sources as a factor. “Chances are
it was multi-factoral; one theory is not right and the
others wrong… that’s just too simple,” says
Zihlman. Plus, chances are we’ll never know. The tropical environments these
creatures inhabited had extremely acidic soils, dissolving any
bones long before they could even begin to fossilize. But this transition was consequential in magnitudes
difficult to fathom, as their shift onto two legs was what set in motion the
divergence of the Homo,
or human lineage, from the [M23] chimpanzees.
Fossil
evidence of the earliest potential candidates our first
distinctly bipedal ancestor around 7 million years ago is meager,
but we can tell from fossil fragments that these apes had bipedal locomotion or
upright posture, that their brain size was comparable to that of a modern-day
chimp, and that there
was not a single bipedal ape but many, each adapted to a slightly different
environmental niche. There was Sahelanthropus
tchadensis from 7 mya, Orrorin
tugenensis from 6 mya, and Ardipithecus
kadabba from 5.5 mya[M24] .
Over
the next few million years, armed with legs for walking and a flexible diet,
the Homos migrated
out of the forest and into the grasslands. Luckily
for scientists, this new habitat’s soil preserved crisp
fossils.
The
earliest clearly proto-human fossils come from the East African Rift Valley, an
area stretching from Turkey all the way to Mozambique where tectonic forces are
literally ripping the continent apart, exposing millions of years of rock, and
millions of years of human history. This area was also where the first Homos lived. In fact, there are areas
where you can literally see back in time as you look down the canyon at multimillion
year old rock layers[M25] .
The
fossil record becomes very rich when the Australopithecine show up around 4 mya.
Best known by the “Lucy” skeleton found in the 1970’s, the five known species
of Australopithecine all lived in the savannahs and grasslands of East Africa
around the same time.
Based on their
pelvis shape, the Australopithecine were clearly bipedal.
“There is only one group that has an ilium like ours and that’s the really
early hominids. Everybody else: the apes, monkeys, ungulates, insectivores, everything
has a different shaped-pelvis,” explains Zihlman. A slight broadening
of the ilium, the bone forming the
upper part of the pelvis, was the first domino to fall,
propelling the Homos to
separate from their kin in the trees[M26] .
But
the transition from arboreal life to upright walking did not occur in a single
step. The Australopithecine anatomy was hybrid ape-human, making their
stride not nearly as graceful as us seasoned bipeds. “For one thing, they
didn’t have trunk rotation,” explains Zihlman, who did biomechanical analyses
of Australopithecine pelvises and chimp pelvises to determine how the Australopithecine
walked. The Australopithecine were
stout creatures averaging 4 feet in height and 80 lbs, and some evidence
suggests that while principally bipedal, they periodically spent time in the
trees. Australopithecine could walk, but they
were no eggheads. In fact, based on their puny brains, a protruding brow bones,
minuscule neck and nonexistent waist, early hominids probably looked more like
an upright chimp than a modern human[M27] .
The anatomical tweaks that propelled bipedalism
seem minute: a slight broadening of the ilium, a knee that can fully extend, a
curved lower spine --- but it was these changes that
made Homo Homo.
“Bipedalism changed everything,” says
Zihlman. It’s thanks to our upright stance that we have manual dexterity, unhampered
by bulky knuckle-walker hands.
Bipedalism was the original key to the success of our forefathers,
allowing them to carry long distances, to throw, to run, to do things with
their hands while running, to gather the extra food sources that supported an
increase in brain size, and to eventually spread all over the
planet[M28] .
A
second trait that allowed us to spread and thrive in new places was that we are
not picky eaters. “The dietary diversity of the hunter-gatherers is quite
impressive,” says bioarchaeologist Dianne Gifford-Gonzalez, who studies animal
bones for evidence of past human diets in the same UC
Santa Cruz anthropology department as Zihlman. “Compare human
diets to just about any other mammal and there’s just no comparison.” We made do.
In Arctic regions, diets consist mostly of blubber and no plant foods with an
average of 95% fat while the natives of California ate a multitude of
species including shell fish, seeds, nuts, berries and game, depending on the
season[M29] .
The
combination of legs for long distance walking and an adaptable diet were
essential in making humans one of the most successful invasive species on the
planet. “How do you think humans spread across the planet? We didn’t get there
by boat, airplane, train car. We walked!” exclaims Zihlman. “In just a few
thousand years, the Homos
colonized Asia, Australia, Europe.” The fact that our species is characterized
by its ability to move long distances and eat anything seems quite odd
considering our stationary carbohydrate-loaded modern lives. In
many ways, human life is incredibly
comfortable and leisurely compared
to the lives of our hunting and gathering ancestors. However, the
human body was not constructed for life on the sofa or daily
drive-thru meals, and
the impacts of modern lifestyles are evident
in the mushrooming of the diet-related
diseases, many of which were non-existent in past societies[M30] .
We
are living in an “alien ecology” says anthropologist Richard Deacon. “It’s as
though we’ve been taken out of the context we evolved in and stuck into a very
strange environment,” he explains in his acclaimed Human Evolution course at UC
Berkeley. For the vast majority of our evolutionary history, we were hunting
and gathering, subsisting on diverse diets and walking everyday.
Today, we’re doing neither.
The
advent of agriculture some 10,000 years ago is the main cause for our dietary
simplification. Whereas hunter-gatherers collected many types of food based on
availability, farmers grew just a few crops and accumulated stores so they
could eat these same foods after harvest season was over. Now 10,000 years may
seem like a long time n relation to our lifetime, but it’s a mere blink in
evolutionary time. We spent 99% of our history
living as
hunter-gatherers meaning we
also spent 99% of our history adapting genes to digest
hunting and gathering diets. So if hunting and
gathering can be seen as our “state of nature,”
the question is, has 10,000 years been enough time for our bodies to adapt?
“Essentially,
the whole bottom part of the food pyramid was nonexistent before agriculture,”
says Gifford-Gonzalez. Agriculture introduced starch as mainstay in the human
diet. Rice, wheat, corn, potatoes, cassava, and sorghum, were all
domesticated by early farmers from wild strains[M31] .
Soon,
the breadth of human diets plummeted. It was not unusual for hunter-gatherer
groups to utilize over a hundred different species for food, much like our
gorilla and orang relatives. The world has over 50,000 edible plants yet, three of them -
rice, corn and wheat - provide 60% of the world's food
energy intake[M32] .
It
seems
that all of our favorite foods - potato chips,
cake, cookies, bread, french fries, pasta - are bad for us.
High fat, high sugar foods in hunter-gatherer societies were fruits and nuts,
foods chock-full
of nutrition. We have inherited taste buds with
proclivities for the sweet and fatty; hence the delicious smell of baking
cookies and the satisfying crunch of Doritos. Unfortunately for us, these foods
aren’t rare finds on day-long food collection journeys; rather, they
crowd our fridges, pantries, supermarket aisles and convenience store shelves,
leaving us in a constant battle between what we crave and what’s good for us.
If
a complete reorganization of the human diet wasn’t enough of a shocker to our
system, we hit it with a second blow over the course of the last century. We
stopped moving. Well, kind of.
For
a number of reasons, humans are moving much less. Long gone are the long days
of hunting and gathering for meals. Now we just pull up to the drive-thru
and hand over a twenty.
A
second locomotor transition around the turn of the 20th century was
a big part of this. After spending millions of years fine-tuning our bipedal
gait, we
traded our legs in for autos.
In 1920, one in every 14 Americans owned automobiles, and today the average
American household owns 2.28 cars[M33] [M34] . Just as
our bipedal locomotor system underpinned the way we lived our lives in the
past, our modern transportation systems enables our lives today. We drive more and more each year; to
the store, to the bank, to work. And we’re training our offsring to do the
same. 42% of school children walked to school in 1969 today that number is less
than half that about, a mere 16%.
In
addition, our daily lives used to involve rigorous physical labor, but today
movement is called “exercise,” this extra thing some people do in their spare
time. In the US, sedentary jobs have increased 83% since 1950,
and the amount of time spent sitting increased 8% in just 20 years between 1980
and 2000. Our bodies are built to move, and we’re not moving[M35] .
“What we’re seeing now is people
making the transition from doing a lot of physical labor, either working in
their own fields or working for other people, working on the railroad, working
in factories where they’re really using their bodies to not using their bodies
very much, but eating the same food because that’s what they’re used to,”
explains Gifford-Gonzalez[M36] .
The
ramifications of the mismatch between our biology and the environments we
inhabit are easy to see. Sixty five percent
of American adults are obese. The three leading causes of death in the US —
heart disease, cancer, and strokes — are
all linked to diet and exercise. The clash of our biology and our culture is
killing us[M37] .
But not everyone is rotting away on
la-z-boys, stuffing their faces with processed carbs. Millions of people are
fighting their sedentary fate with gym memberships, cardio-kickboxing, Zumba,
Tae Kwan Do, Bikram Yoga; anything that might make movement fun. Similarly a
new diet plan seems to mesmerize Americans each year, only to slowly fizzle out
as people give up on stringent off-limits lists and point systems. Americans
fork out 35 billion dollars per year on diet products desperately searching for
the one magic diet[M38] .
Within all the exercise and diet
mumbo-jumbo, one growing trend stands out as a potential cure
in its credo of addressing health
from a human evolution standpoint. Crossfit is a “lifestyle” plan
based loosely on the idea of aligning diet and exercise with our evolutionary
adaptations. “We do stuff your body’s meant to do,” explains Austin Einhorn, an
exuberant member of a Crossfit
gym in Santa Cruz, CA, where the whole movement started
back in 1995. “It’s like a cult, and it all started in Santa
Cruz,” he explains. Einhorn’s an ideal representative of Crossfit.
At 6’5”, with pecs popping out of his t-shirt and globular shoulders, his
towering presence is a paragon of human fitness, with the exception of the
unexplained pain he has in his “right shoulder or bicep.” He’s been doing
Crossfit for two years and doesn’t plan on stopping anytime soon.
A self-proclaimed “functionalist,”
Einhorn lives by the mantra: “constantly varied, high-
intensity, functional movement.” Crossfit uses free
weights, calisthenics, pull-ups and kettle bells, and is based on
the Crossfit mantra, “constantly
varied, high- intensity, functional movement,”
essentially doing “what we would do in he wild[M39] .”
Crossfit
workouts, which are often named after women, may seem like punishments to the
rest of us. The Mary involves five handstand pushups, ten one-legged squats, and
fifteen pullups continuously for 20 minutes. The Sarah might be even more grueling, involving heaving a
20lbs ball against a wall, “sumo squats” with 75lbs dumb bells, jumping onto
20” tall boxes, bench pressing 75lbs and finishing off with a 500m sprint. “Half way
through, you wonder why in the world you ever choose to
do this,” says Einhorn. “But
once it’s over, there’s no better feeling on Earth.”
According to
Einhorn, these caveman feats are what we should be doing. “Our body wasn’t
designed to do the same repetitive motions over and over. “Cross-fit
prepares you for the real world.” A “real world,” involving
spear hunting and nomadic latitude-changing
migrations, that we no longer
live in. About 80% of people who try Crossfit never return, but
the 20% who do can’t seem to get enough.
Today, there
are over 450 Crossfit gyms worldwide, and its following is growing rapidly thanks
to the interactive website with daily YouTube video posts of workouts of the
day, or ‘wods’ as Crossfitters say, people can do in living rooms and garages. Videos
often bring in over 200 comments ranging from affirmations, to detailed
descriptions of “sore quads” to stopwatch times.
The Crossfit
lifestyle combines militant exercise with equally vigorous dieting. “We’re
actually
in the middle of the ‘Paleo
Challenge’ right now. Everyone’s
tested before and after and we take before and after pictures, so
we all go through it together,”
says Einhorn[M40] .
“Everyone’s on either Zone or Paleo,” says Einhorn,
later estimating 40%. “You can’t go to a Crossfit gym and not talk
about diet, everyone’s comparing recipes and tips.” Crossfit advocates two
diets: Zone and Paleo. In Zone, you can eat as much as you want in the correct
proportions, 40:30:30 carbs:proteins:fats. This means measuring you eat down to
the gram and charting it on a Zone grid. The Zone diet chart Einhorn showed me
took me back to high school algebra and my eyes glazed over. Each person has a
different “block” requirement. Blocks are either 7 grams of protein, 9 grams of
carbs or 1.5 grams of fat. So if I allow myself two blocks for breakfast I can
either have 14 grams of protein or 1.5 grams of fat and 9 grams of carbs. In
Zone, diet becomes an algebra equation and a science experiment[M41] .
The other
Crossfit diet, Paleo, is based on a quasi-back-to-the-land
ethic requiring canine-like meat consumption. “We weren’t meant to eat all
these processed carbs. We’re essentially putting our insulin levels on a daily
rollercoaster,” says Einhorn.
The Paleo diet is based on the idea that the human body should only foods
available in the Paleolithic era, meaning pre-agriculture. No grains, legumes,
dairy, refined sugars, salt or processed oils. What’s left is mostly fruit,
nuts, and a whole lot of meat. “It’s what our ancestors did,” says Einhorn.
Unfortunately, this diet may exclude more than it includes: “It’s almost
impossible to go out to eat,” says Einhorn, “something’s bound to have
gluten.”
Yet the
popularity of Paleo is mushrooming. Einhorn and his Crossfit buddies have a
monthly “Paleo potluck” where they bring dishes and share recipes and diet
tips. Paleo-dieters now can choose from whole market of Paleo products on the
web including reheatable Paleo dinners, Paleo beefsticks, and even
grain-less, sugar-less, processed oil-less cookies.
“I went from
Paleo to Zone to Zone-Paleo to Paleo with portion control to take off some
weight. Now I’m back on straight Paleo to bulk up my muscle.” Einhorn’s
discipline is impressive. He’s been Crossfitting six days a week, sometimes
twice a day, and bouncing in between Zone and Paleo for two years now. And he’s
not unusual amongst Crossfitters. The Crossfit lifestyle isn’t a
yo-yo diet or a quick fix to “shed a few pounds for swimsuit season,” says
Einhorn, “a whole lifestyle improvement is what we’re going for.”
But the Crossfit/Paleo lifestyle may reflect a
caveman fantasy and a broader societal obsession with diet regimens than
anything. The hunter gathers didn’t eat one specific diet; they
ate whatever they could find.
“The
challenge is to think about what we can take from that ancient history, and
it’s really nothing specific,” says Professor Zihlman. As primates, we’re
generalists by nature, known for versatile and diverse diets. We don’t really
know the exact nutritional magic in fruit and vegetables, we just know they’re
good for us. “Eat your colors, eat low on the food chain, and eat a variety,”
says Zihlman. There was no single hunter-gatherer diet and no single primate
diet, it’s the flexibility that makes us special.
“We
can eat just about anything,” says Gifford[M42] -Gonzalez,
“but once the variety goes down and the starches up, we see the ‘diseases of
civilization’.” Gifford-Gonzalez’s advice for our gathering in the supermarket
aisles: “If you can’t picture it growing, don’t put it in your mouth.” Gifford
complicates her recommendations by adding that certain ancestries are better
adapted for different diets. For instance, Arctic peoples who lived for
thousands of years on high-fat diets start eating typical modern diets and
acquire diabetes almost instantly. “Their
bodies haven’t had as much time to adapt to heavy starch available at the
market.” But it’s the inextricable linkage of diet and exercise that are both
the problem and solution.
It’s
not a surprise that exercise is good for us, but the more we study it, the more
we see it may be the ultimate preventative medicine. Heart disease, blood
pressure, cancers, diabetes, osteoporosis, back pain, arthritis, depression,
colon cancer, breast tumors, weakened immune system, all of these ailments can
be avoided by moving more.
New
research is even linking mental faculties to exercise. Most recently, a study
on Alzheimer’s Disease, an incurable devastating ailment in which people lose
memory and a sense of self, found that the disease can be avoided by routine
exercise. However, the study participants who walked or jogged daily reaped the
benefits, while those who did exercise but less regularly did not[M43] .
The conclusions of this study aren’t a surprise for Zihlman, “Our brains need the oxygen!” the daily walker cries. The benefits of exercise are not linked to any single activity, it’s just getting out and moving that’s important.
The conclusions of this study aren’t a surprise for Zihlman, “Our brains need the oxygen!” the daily walker cries. The benefits of exercise are not linked to any single activity, it’s just getting out and moving that’s important.
Zihlman
warns against the exercise zealotry of Crossfit, which she says
does not even remotely mimic the lives of hunter-gatherers.
“It’s really just about getting out and moving,” she
explains. “There is no single exercise regimen, walking, running,
swimming, getting your heart rate up and limbs working is what matters.”
We
evolved to be distance-walkers, and spent millions of years evolving bodies
fine-tuned for moving, and yet today we have stopped doing what it is that
makes us human. We’ve used our mental abilities to think our way out of
exercise with online shopping, automobiles and grocery stores, and cubicle
jobs, but our couch lives are killing us.
After all this talk about
primates, I decide to visit our family members at the San Francisco Zoo.
— another group of primates in a 21st-century
alien ecology.
Strolling
the winding paths, passing cages filled with beings
of all shapes, sizes, colors, and locomotor systems can feel like walking on
atop an enormous Linnean taxonomy diagram. A haphazard amalgamation of
the best, brightest and cutest Anamalia
has to offer are loosely categorized by orders, families, or at least
geographical region. Humans, the species that built
the arc in the Bible, always
stand on the outside of the pens, looking in at “Cat Kingdom”, “Bear Country”,
and the “Primate Discovery Center”.
As I wind through the concrete paths of the Primate Discovery Center, the primate family tree diagram found in the beginning pages of every physical anthropology textbook comes to mind. If you aren’t familiar with this diagram, just picture a family tree that began 65 million years ago with the common ancestor we all share as the trunk from which the rest of the tree owes its existence. Like an oak tree, a few thick arms that split relatively close to the ground, representing the two primate suborders, Prosimii and Anthropoidea that broke about 40 mya. The Prosimii branch went off to make a family of saucer-eyed, nocturnal, leaf-eaters like lorises and lemurs. The Anthropoidea branch split into two families about 30 mya that each radiated out into genera, and finally those genera sprouted the leaves, or individual primate species. The last three twigs on the hominoidea superfamily divide gibbons, great apes and humans, siblings on this primate family tree[M44] .
As I wind through the concrete paths of the Primate Discovery Center, the primate family tree diagram found in the beginning pages of every physical anthropology textbook comes to mind. If you aren’t familiar with this diagram, just picture a family tree that began 65 million years ago with the common ancestor we all share as the trunk from which the rest of the tree owes its existence. Like an oak tree, a few thick arms that split relatively close to the ground, representing the two primate suborders, Prosimii and Anthropoidea that broke about 40 mya. The Prosimii branch went off to make a family of saucer-eyed, nocturnal, leaf-eaters like lorises and lemurs. The Anthropoidea branch split into two families about 30 mya that each radiated out into genera, and finally those genera sprouted the leaves, or individual primate species. The last three twigs on the hominoidea superfamily divide gibbons, great apes and humans, siblings on this primate family tree[M44] .
I
enter a hallway of wire mesh enclosures where our obnoxious and adorable
twice-removed distant second cousins New World monkeys are yieeking and
howling. The New World monkeys or the Platyrrhines
(pronounced plat-a-rynes if you have
to say it out loud), split off from
the rest of the primates when they rafted to America about 30 million of years
ago and evolved their own unique characteristics in the jungles of South America.
Chirping squirrel monkeys swing by their prehensile tails across rope bridges
onto wooden pedestals with dizzying ease. A pair of emperor tamarinds cuddle
upon a platform, their handle-bar mustached faces intent as one appears to pull
bugs from the other’s head and their baby scampers down a metal pole. Something
about the Amazon and South American sun seem to produce good looks
in monkeys and people alike. Platyrrhines all have cute flat noses and a
“prehensile” tail which serves as a fifth limb to swing through the forest
canopy. I take one last look at a jet-black
spider monkey staring straight at me, hooting with his mouth wide open like
he’s astonished at something I’ve done, and proceed towards my intelligent and
not quite as cuddly kin, the Old World monkeys[M45] .
Immediately,
I start to see the family resemblance as I enter the area where the Old World
monkeys live. A baboon distinctly resembles an ex-next door neighbor. The
furrowed brow, the nervous pacing — with
the exception of his apple-red booty he’s a dead on doppelganger. The patas
monkeys are a team of angry elves; their pointed ears, stern countenance and
mini human faces are eerie in their familiarity.
The
path steers off into a bamboo-walled passageway leading me to my blood
relatives (literally gorilla blood transfusions use human blood). Gorillas to
the left, chimps to the right, hominids everywhere; it’s a family reunion.
Children line up with their hands against
the glass wall and parents snap iPhone pictures of one of the zoo celebrities,
Oscar the silverback Western Lowland Gorilla. He sits just feet from the glass,
still and dignified. His broad shoulders are back, fists to the ground as his
steady gaze keeps watch over the troop. Even if he didn’t have the distinct
glistening silver fur, there is no question who’s in charge here.
A
playful baby gorilla scampers down the hill to visit mom, tumbling and
somersaulting between knuckle-walk skips on his way down. Mom seems tired,
but pulls him into her long arms for an affectionate hug. The
toddler sits with her for a few moments, then squirms free
and frolics back up the hill, looking for better entertainment.
The
divide between humans and animals is literally manifested before my eyes at the
zoo. The Homos stand
on the concrete paths, licking ice cream cones and reading maps pointing and
laughing at the tumbling baby gorilla. The glass wall separating us from our
quadruped relatives does much more than just protect the humans from the
“wild,” it constructs these
categories, categories that may only exist in our minds.
We
tend to forget that we too have a slot on Linnean diagrams, nestled tightly
beside chimps, gorillas and orangutans. It’s unsettling that
all of the characteristics
considered distinctly human such
as our big brain, language abilities and so on,
arose from a change in the shape of our ilium. We’ve
grown up in a world dominated by humans, and
so it’s natural that we
consider ourselves as separate from the
rest of the planet. We
do have this giant brain that allows us to reason and speak complex languages;
I am not saying humans are not different. But understanding that we are more
similar than different is important for a
number of reasons.
In exploring the deep history of the human species
and how we came to be, what
stands out is not our specialness, but the
luck, chance and role of environmental conditions that made us into
the species we are.
Eroding the edifice of human
exceptionalism and taking a step back to
see our species’ trajectory
gives us insight into the health problems we face today by
pointing to the inextricable linkage between our biology and environment.
We
seem to have completely forgotten our animal-ness, neglecting our biological
needs for movement and varied diets in favor of lives that are comfortable, but
overall bad for longevity. This mismatch between biology and our modern ecology
is harming us. Humans may have the ability to reason
and create complex systems where we don’t need to do the physical labor our
ancestors did, but we cannot reason our way out of our biological injunctions.
As long as orangutans live in jungles, they will live
their lives swinging through the trees eating fruit, and as long as we live in
habitats of supermarkets and freeways, we will drive cars
and eat processed industrialized food. Changing these habits, then, is not a
simple matter of a diet plan or an exercise regimen. Austin Einhorn is right,
“what we’re going for is a lifestyle change.” Habit and behavior changes are
extremely difficult, because as we are animals, we are also
products of our environment.
Examination of our evolutionary
history reminds us that we are part of
the primate family, a group known for our
versatility and adaptability. Evolution
does not show us a single “natural” or “right”
way to be human, but shows us that being human
means we have options.
“Movement is absolutely fundamental,” says Zihlman.
“All the studies show that you can increase your longevity, mental capacity,
avoid cancer if you move more. That’s what we’re about: motion, motion, motion.”
Her
dietary advice is similarly broad. “The
main thing is to eat as broadly as possible,” says Zihlman. “The health
literature is always saying to ‘eat your colors’ because they don’t really know
what’s in fruits and vegetables. There are so many different kinds of chemicals
working together. And we don’t really know what’s in fish, but it seems to be
important. There’s a lot that we just don’t know.” It seems we might be best
off giving up restrictive “diets” altogether and trying to expand what we eat
rather than limit it. “We know that diet is connected to health, but in a way
that’s an extreme because we can survive doing an awful lot of things.”
While acknowledging of
our animal-ness teaches us about
ourselves, it also pushes us to reconsider our
species’ narcissism.
While human health and longevity is important, we must also be aware that the
environment does not only influence us, we influence it.
In
recent years, our impact on natural systems has greatly intensified. As we
spread to new, unconquered territories with our technologies and avarice for
resources, we push out other species
and completely reorganize entire
ecosystems.
The
success of the homo sapiens is at
odds with the survival of our kin. Our last remaining relatives are all dying off
due to our gluttony. While
the homo
sapien population edges towards 7
billion, great ape populations fall to triple digits. Seven
hundred Eastern Mountain
gorillas are left and
just 3,000 Sumatran
orangutans. The impending extinctions of many
of our closest relatives bring up moral questions about our role as a species.
And given our acclaimed reasoning abilities, I think it’s only right we ask
them. How do we proceed knowing that the way we live our lives is killing off
our greater family? Does our biologic similarity to apes obligate us to take
care of their habitats more than other species?
They
say that blood is thicker than water, but endangered ape populations indicate
otherwise. We are losing our ape brothers and sisters, and in some ways, we are
losing ourselves.
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