it is a hot sunny day in Eastern Africa
and a pack of ancient Lions is on the
prowl they all have their eyes on a herd
of elephants spotting one member that
has fallen behind the giant prey has not
detected its stalkers indeed the big
cats approach in near silence concealed
by the long grass and shadows of trees
but after zeroing in on their target all
at once the Lions tear off after the
herd leaping on to the unfortunate
straggler and plunging their teeth into
the elephant's leathery skin as the rest
of its herd Thunders off once their prey
has died the Lions waste no time tearing
into its flesh they eat quickly messily
soon vultures approach and begin
circling overhead now seated The Killers
run off and as they leave the carcass
behind the vultur swoop down settling in
for a feast one descends and perches on
the dead elephant's
Tusk but these vultures are not the only
scavengers on the
Savannah for from behind the trees a
group of small figures emerge they are
somewhat aplike but they walk on two
legs they bear an uncanny resemblance to
humans but they're not quite like
anything you or I have ever seen indeed
Standing Tall they'd only be waist or
shoulder high on most of us
these not quite human looking creatures
living in the African Savannah roughly 2
and 1 half million years ago are our
ancestors and they are ready for a
meal carrying sharp edged pieces of
stone they descend on the carcass even
Fallen the dead elephant Towers over
them they hoist themselves onto its body
which is still warm under their feet
squatting on the carcass they cut away
the exposed meat with their flaked stone
tools the meat is tough and slippery
between their teeth but they work at it
until they've broken it down enough to
swallow before working free their next
piece eventually their stone tools
strike bone but they don't stop here now
they use their stones to pound at the
bone Until It Breaks open and then take
turns slurping up its Rich fatty marrow
but what to these ancient creatures is
just a hearty meal is to us a turning
point in
history for tens of millions of years
ever since the asteroid strike that
wiped out most of the dinosaurs our
primate ancestors and relatives ate a
diet consisting mainly of fruits leaves
insects and perhaps the occasional small
animal but at this moment on the cusp of
the Stone Age our ancestors started
Scavenging and as their diets changed so
did they along with every species that
descended from them
[Music]
Lucy our 3 milliony old ancestor was
dated using argon Isotopes in the rock
layer she was found in that worked for
her but maybe wouldn't be the best way
to track down your ancestors my Heritage
how sponsored today is probably an
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it didn't take long for it to grow and
grow here's a photo I discovered of my
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Peak 19th century and this is because my
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who knows maybe we'll find out we're
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[Music]
YouTube on a chilly day in early spring
a spotted salamander lays a group of
eggs in a small pool of standing water
on a leafy forest floor the clump of
eggs is encased in a thick layer of
protective jelly but the jelly does not
keep everything out
soon algae will invade the egg capsules
where the embryos are developing they
will Nestle into the cells of the
embryos themselves and yet these
Invaders are
Lifesavers as each salamander embryo
floats in the shallow water the algae
and its cells will harness energy from
the Sun and produce a constant flow of
oxygen to the embryo in exchange the
embryo releases carbon dioxide as waste
and the algae takes it in as fuel for
photosynthesis
together with the sunlight that
permeates the jelly embryos and algae
produce a self- sustaining ecosystem
nourishing each other in this sealed off
world a rare example of an animal that
uses photosynthesis to grow and
[Music]
develop every organism whether or not it
eats in the way we think of as eating
needs nourishment and across the animal
kingdom creatures have evolved all sorts
of creative ways to get
it herbivores like deer and pandas get
nutrients from fibrous leaves grasses or
other plants carnivores like foxes and
lions hunt or scavenge meat we humans do
a bit of both making us
omnivores but not everything has a diet
of plants or meat or some combination of
the two throughout the American Tropics
leaf cutter ants in Forest canopies live
up to their name by snipping small
pieces of foliage with their jaws and
loading them onto their backs once their
cargo is in place each ant merges into a
column of hundreds headed for their
underground Nest but for all the work
they've put into this Harvest these ants
aren't your average herbivore and they
won't eat their Bounty instead they will
look after the leaf clippings until tfts
of white fungus Sprout from them and
they will dine on
this these old little farmers are
fungivores subsisting entirely on the
fungus they cultivate in their Gardens
indeed even microorganisms have to eat
and they have their own ways of
nourishing themselves sometimes in some
of Earth's most inhospitable
environments yet while a good meal means
something different to every species we
all need some form of
it carbohydrates are the quickest way to
supply energy to the human body simple
carbohydrates such as the sugars in
fruit or honey are faster than complex
carbohydrates like starches and Grains
but both are quicker than fats if a
surplus is consumed our bodies store
some of this as glycogen within our
cells and converts the rest to Fat fats
composed of fatty acids or glycerol are
the slowest source of energy but the
most energy efficient food per gram
offering more than twice the energy of
carbohydrates and proteins and it's for
this reason that the human body stores
excess energy as fat proteins ever are
complex molecules made of formations of
amino acids that are not usually used
for energy instead they are vital to
maintain and replace tissues but before
any kind of food can become fuel the
body first has to break it down or
digest it to release the energy stored
in its molecues chemical bonds enzymes
in our blood break down complex
carbohydrates into simple sugars
proteins into amino acids and fats into
fatty acids only then can this fuel even
ENT our cells but this energy doesn't
get put right to use because our bodies
depend on stores of energy that they can
tap into as needed instead the released
energy gets trapped in other molecules
like adenosine triphosphate better known
as
ATP and ATP is not just for animals like
us with bodies made of many cells when a
bacterium at the bottom of the ocean
takes in nitrogen compounds it breaks
them down to release energy and forms
atp2
but it's not just these carbohydrates
proteins and fats that our bodies depend
on they also need smaller amounts of
nutrients like ion vitamins and iodine
to regulate chemical activities like
brain activity digestion and hormone
regulation and so in spite of the wide
ranging diets of life on Earth on a
basic level our bodies all run on pretty
similar ingredients so if we living
things have fundament into these similar
needs why the different diets as
unappetizing as a dead fish or a dong
ball sounds to us for some animals these
are not just desperate choices but
rather dietary preferences or even
requirements so why does any animal eat
what it
eats ultimately all living things have
to balance a few important needs the
first order of business is to consume
enough energy to fuel out bodies blue
whales are some of the largest creatures
on Earth with some adults growing to
about the length of a basketball court
these Giants require a colossal amount
of food each day and yet their meal of
choice is an odd one they get almost
every single calorie from Krill
minuscule crustations that float in
patches in the ocean a tiny creature
averaging a couple of centimeters in
length might seem like an odd meal
choice for what may be the largest
animal to ever live on Earth but whales
eat Krill for a good reason krill are at
the bottom of the food chain and that
means they're packed with energy we
humans can afford to be a little less
efficient our broad diets come from many
different points in the food chain but
on average across the globe humans diets
are a little over two levels removed
from the
bottom and when it comes to meeting our
energy needs we are also all constrained
by our biology and the environment where
we find ourselves millions of years ago
before the invention of tools our
ancestors used their hands to get food
despite their dextrous fingers Adept at
grabbing branches and plucking fruits
their hands were of little use for
cutting into an animal or tearing flesh
given these constraints they gravitated
towards a diet of mostly fruits
vegetables and other easy to pick foods
that were easy to both find and
consume as well as this our teeth over
time have become not exactly suited to
catching and killing prey
most carnivores possess large canine
teeth some such as cougars can even use
these to penetrate between vertebrae and
sever the spinal cord of their prey but
one of the key characteristics of the
homin family our family are small
canines just as hominins are the bipedal
Apes so too are they the small Canin
Apes yet whether we can find and consume
something is only useful if our bodies
can process
it and evolution has outfitted animals
with countless different systems for
digesting food one of the most striking
ones belongs to snakes these animals
don't have teeth that can chew but that
doesn't discourage a python from gulping
up a whole deer as soon as the python
swallows its prey its digestive system
switches into high gear secreting acid
and enzymes that get to work breaking
apart the meal meanwhile some creatures
that have no teeth have evolved
resourceful techniques for mechanically
crushing their food birds and earthworms
both have an organ in their digestive
tract called a gizard as they eat small
stones collect in the gizard which
contracts to grind the stones against
each other and Crush any food that is
passing through of course we humans have
a whole Suite of tools for digesting the
wide range of foods we eat we have teeth
and chewing muscles that can tear crush
and Shear our food we we have saliva in
our mouths and acid in our stomachs that
help break down chewed food indeed
saliva contains an enzyme called amalay
that can break down starches and lingual
lipase which breaks down fats and our
stomach acid is unusually strong which
helps prevent food poisoning on top of
this we have a digestive tract full of
hundreds of species of bacteria that
help break down food and fight off
pathogens that might be in
it the size of animals bodies and
certain body parts Hearts can also lend
their own insights into their diets
insectivores for example tend to be
smaller than carnivores that eat larger
prey after all the more energy you're
getting from your food the bigger you
can be but while meat eaters bodies have
more freedom to grow their gut area
tends to be smaller than that of non-c
carnivores thanks to the efficiency of
eating meat more concentrated sources of
protein like meat and insects take less
work to digest so carnivore's digestive
machine scy can be simpler than that of
a herbivore processing fibrous
vegetation every day gorillas whose diet
mainly consists of leaves and shoots
have stomachs that can hold 4 to 20% of
their body weight whereas for humans
with our more varied diets it's barely
1% ultimately we are limited by what our
bodies can process and how they extract
energy from the things we consume and
these diets Define Us in more ways than
one we are all what we
eat not least because our digestive
system transforms some of the food we
eat into the raw materials our bodies
are actually made of like all living
things we humans are made up of lots of
carbon but not all carbon atoms are the
same the ones that come from corn and
sugar cane are ever so slightly heavier
than the ones that come from leaves and
Grains a look at your hair under the
microscope can reveal how much of each
kind of carbon you have in you which can
in turn expose ose your diet and even
hint at where you likely live more than
half the carbon in an average American
for instance comes from corn by a
cornfed
animals but the notion that we are what
we eat is also true in another perhaps
more important sense for all of
evolution there has been a give and take
between what's eaten and what is doing
the eating a species started eating new
things their bodies adjusted to those
diets so what we eat in particular what
our ancestors ate over millions of years
has literally made us what we
are and the story of our ancestors diet
is not a simple
one in 1899 a quarry worker uncovered a
bewildering fossil deep in the mountains
of
Russia at first glance it resembled
spiral-shaped shells that house the
ancestors of today's octopus and squid
hundreds of millions of years ago but
the edges were serrated like a buz and a
closer look revealed that this peculiar
fossil was the remains of teeth
belonging to an ancient relative of
sharks the fish which had roam the sea
some 270 million years ago was named
helicoprion and for over a century
paleontologists debated how these teeth
had fit into their owner's mouth and how
they
worked some hypotheses plac the spiral
teeth on the snout others on the back
others deep in the throat many models
later scientists now believe that the
world of teeth sat in the creature's
lower jaw and rotated back and forth as
the Jaws moved slicing and tearing prey
while pulling them towards the
throat the shape and mechanics of this
unusual set of teeth not only clarified
our picture of this ancient creature
they also offered some Clues into what
this odd fish ate researchers reasoned
that hard shelled prey would have
slipped off its curved teeth and that it
more likely ate soft prey that it could
easily slice into pieces like squid or
soft bodied fish and so as unusual as
helico pran's teeth are their usefulness
for reconstructing the diet of an
ancient creature is not
unique today paleontologists rely
heavily on fossilized teeth to piece
together the diets of animals that are
long gone from the earth well after most
other Clues have
disappeared the clues from teeth come in
several different forms one way that
diet manifests on a fossilized tooth is
in the way it has been worn down it
takes different kinds of chewing to
break down different kinds of food
chewing flat fibrous plant parts
involves a great deal of shearing while
rounder items like berries seeds and
insects can easily be crushed between
molers over time these repetitive
motions erode microscopic patterns into
the teeth that paleontologists can
decipher millions of years later to
figure out how an ancient animal chewed
which in turn hints at what it ate the
shapes of fossilized teeth offer similar
Clues leaf eating animals whose chewing
involved more shearing typically evolved
longer crests on their molers meanwhile
insect eating animals often had sharp
points on their MERS that allowed them
to puncture or SL into insect's bodies
beyond the individual teeth the drawer
itself holds another piece of the puzzle
paleontologists can use its structure to
infer how it once moved for example the
spot where the lower jaw attaches to the
skull can indicate its range of motion
and the strength of its
bite in general each of these methods
offers a window into an animal's dietary
habits or helps constrain what it might
have eaten but used together methods
like these can help paleontologists
construct a detailed picture of the diet
of ancient creatures including our
distant
ancestors and so with these techniques
in hand we are now equipped to ask what
did our ancient ancestors
eat all around the planet dust from a
catastrophic asteroid strike is still
floating in the atmosphere dimming the
Sun
the animals that dominated the Earth for
tens of millions of years are dying off
in droves it is 65 million years ago and
the Cretaceous has come to an
end and yet as the old webs of life on
Earth unravel it is a time of new
beginnings the surviving life is
blossoming into a wide array of new
forms small mammals that have survived
the devastation are scurrying through
forests plucking insects out of trees
for
food these are placental mammals the
first animals to give birth to fairly
developed Offspring they are our ancient
ancestors and not long after the dust
settles a relatively new lineage emerges
from among them A Primitive form of
primates these early primates don't bear
much of a family resemblance to anything
we call a primate today they are small
furry tree dwellers the oldest one found
in the fossil record is a chipmunk sized
creature known known as
purgatorius like us and most other
modern primates scientists believe
purgatorius was an omnivore able to
process a wide range of foods insects
were plentiful at this point in history
not to mention a good source of protein
and vitamins and they appear to be a
centerpiece of purgatorius diet our
distant relative also likely ate a great
deal of fruit for unlike some other
early placentals purgatories had teeth
that were adapted for crushing soft food
foods like fruit the sharp insect
piercing molers that characterize the
teeth of other insect ofor mammals had
rounded out a bit suggesting that
insects were becoming less important to
purgatorius it's not clear what exactly
drove this particular change primates
have always been flexible eaters often
able to make meals out of whatever kind
of food is available in their habitat
and as finding food in the trees became
increasingly important to early primates
like purgatorius they evolved to get
better at finding it their hands got
better at grasping branches and plucking
fruit allowing them to navigate their
Treetop habitat with ease their eyes
evolved to face forwards rather than to
either side giving them binocular vision
which enhanced their depth perception
color vision also improved enabling
these primates to move swiftly through
the forest and spot a ripe snack on the
go meanwhile their cognitive skills
improved to meet the challenge of
finding ripe fruit in a complex
environment it was becoming increasing
important to remember what was edible
and where to find it and as primates
grew sharper their brains grew
larger by the dawn of the EO scene 56
million years ago the planet was warming
and thick forests were blossoming across
the continents amid this changing World
primates thrived spreading around the
globe and evolving into new forms they
were still tiny compared to today's
primates but some were gradually getting
bigger our ancestors belonged to a group
of primates called anthropoids that
lived in Africa and parts of Asia these
would later Branch into monkeys apes and
humans but then they were still fairly
small furry tree dwellers judging by
their teeth they continued to eat a
broad diet of mostly soft foods like
ripe fruits gums and leaves along with
insects some anthropoid teeth from this
era are spotted with cavities supporting
the idea that they ate a diet full of
sugary foods like ripe fruits anoid
fossils from the eosine also have very
few chipped teeth indicating that these
primates were not eating many hard foods
like nuts or
seeds and with time their diet shifted
perhaps in response to what was easiest
to come by in their environment most
anthropoids gradually went from favoring
insects to favoring fruits and
leaves by the time the eosine was giving
way to the oliga scene amid a wave of
global cooling around 30 4 million years
ago these miniature anthropoids were
growing larger with bigger bodies to
fuel they started incorporating new
foods into their diets such as unripe
fruits nuts and leaves their jaws grew
stronger and more stable perhaps as an
adaptation to these new food sources
their bodies were changing in more
subtle ways too natural selection
fine-tuned their senses to help them
pick out edible items based on features
like texture color and
smell and so for millions of years our
ancestors ate and evolved some 23
million years ago Earth entered another
warm period as it ushered in the meia
scene Apes had emerged in Africa Asia
and Europe and by now the resemblance to
modern day Apes was definitely there for
now fruit still made up the bulk of
their diet but subtle changes in their
teeth signal that a dietary change was
underway in some of these
Apes their enamel was getting thicker
possibly giving them an advantage for
chewing harder more abrasive food like
seeds some might have begun eating
harder less ripe fruits and this mixed
diet may have reflected changes in the
environment temperatures eventually
cooled again possibly making fruit a
more seasonal offering this lack of ripe
fruits during offseason months might
have driven Apes to seek out new food
these ecological changes might also have
shifted the balance between competitors
and food sources forcing Apes to
diversify their
diets and all the while cognitive skills
like learning and memory continued to be
important as our ancestors foraged
across broad diverse habitats where the
availability of fruit varied Evolution
continued to favor these traits along
with the fine motor control it took to
forage and consume fruit by this point
many primates bore little resemblance to
the Shrew likee creatures they descended
from but their diets had not vastly
changed overall for millions of years
our ancestors subsisted on a mixed diet
of mostly fruit leaves and
insects but that was going to change
[Music]
on a lak Shore in what is now Central
Europe a thrum of insect song fills the
air the hot sun fills the sky and birds
soore over the glassy water scanning the
lake for
fish and in a small clearing a group of
hominins is squatting on the ground
using the sharp edge of a flaked Stone
to shave down slender branches they've
pulled from a spruce tree
they predate modern humans by a few
hundred thousand years but they look and
move like you or I working with intense
Focus they shave a gentle Arch into
their stick and then sharpen its two
ends to a point a pile of shavings
growing beneath them they are building
up their Arsenal for their next
hunt as they work two birds fly overhead
preoccupied with their own hunt ignoring
them for the most part they have no idea
that the natural order is Shifting soon
not even the air will be safe hominins
just like the ones now patiently shaving
down sticks will soon be hurling these
makeshift weapons at them aiming to
pluck them out of the air so they can
Feast on their Warm
[Music]
Bodies but this pivotal development in
our ancestors diets was still far off
when the first hominins emerged in
Africa some 7 million years
ago this branch of primates hominins
includes humans and all our living and
extinct relatives the earliest ones were
still relatively small brained but they
walked on two feet like us although for
the first few million years they were
still adapted for life in the trees
these archa commins emerged during yet
another time of change on our planet the
Lush African forests they've been living
in for Generations were thinning out
giving way to sparse trees and
grasslands famia food sources dwindled
as the trees receded forcing our
ancestors to seek out new forms of
sustenance some of these turn to hard
foods like nuts seeds and tough plant
roots and their Anatomy reflects this
change in diet they evolved massive jaws
and large teeth with thick enamel that
were up to the task of processing foods
that required forceful crushing or
grinding paranthropus Boise or
Nutcracker man a famous example from
about 2 million years ago though some of
their cousins retained more slender
features and seem to have stuck mostly
to softer foods such as fruit and
leaves despite these differences these
archaic hominins were all omnivores that
likely survived on whatever Foods were
available including fruits leaves
insects eggs and even small animals that
they could catch and eat with their
hands but it was at this point our
ancestors were about to arrive at a
pivotal juncture in their evolutionary
Journey they began making tools out of
stones in the vast arid Plains of
modern-day Tanzania a canyon cuts across
the land nearly 50 km long and 90 M deep
The alivi Gorge the region it cuts
through has been home to our ancestors
for millions of years it saw hominins
come down from the trees and take up
walking on two feet it saw the thin of
forests and the arrival of grazing herds
and it also witnessed one of the most
revolutionary changes among our species
and we know this all thanks to this very
Gorge slicing through the Great Rift
Valley where the African Continental
pleat is in the slow process of
splitting in two as water carved out
this Gorge over thousands of years it
exposed layers of rock dating back
millions of years now sitting on top of
each other like pages in a book since
the 1950s archaeologists and
paleontologists have been coming to this
site to explore what is in those pages
each one containing a different chapter
in human history they are rich with
fossils of our ancient ancestors and
their stone
tools and it is here that in 1981
researchers discovered fossilized animal
bones bearing some unusual
scars these were not the dull bite marks
of a predator but rather thin straight
lines these lines had been made by the
sharp edges of stone tools wielded by
some of our species early butchers some
1.8 million years ago in the 1990s
similar markings appeared in various
sites in Ethiopia dating back even
further to some 2 and 1 half million
years ago the shape and pattern of these
Butchery lines showed that our ancestors
were using stone tools to carve meat off
bones and to break bones open for
marrow and this practice May date back
much further more recently bones with
possible Butchery marks have been dated
back to over 3 million years but
researchers are still debating whether
or not these oldest marks were truly
made by
hominins and so with this timeline still
in question it's not yet clear which of
our four Bears first started butchering
large animals it might have been our
ancient relative called Australopithecus
or a m of one of the homo lineages what
is clear is that at this point there was
no going back it was the beginning of
the Stone Age these new tools let their
owners access new foods these hominins
could pound and slice fruits and
vegetables making tough plant parts
easier to digest but these weren't the
only new foods they were pursuing with
their Woodland environment now
transformed into more open land large
herds of grazing animals had begun
moving through their habitat and for the
first time in history our ancestors
would start to see these large animals
as food of course 3 million years ago
our ancestors could not yet topple a
large animal themselves indeed it would
be a long while before the first hunting
tools appeared in the fossil record but
they had learned how to get at the
precious calories in these large animals
Flesh and Bones they bashed open animals
skulls to get at the fat in their brains
hammered open leg bones to suck out the
fatty marrow and C off the muscles for
protein lacking hunting skills of their
own they became masters of Scavenging
how exactly they scavenged is still up
for debate some of these hominins may
have Lain in weight watching as hyenas
or Sab tooth cats had their fill of a
hippo or wilderbeast and then going in
for the leftovers but there is evidence
that at least some of these early
scavengers were more aggressive
[Music]
Butchery marks reveal that our ancestors
were often eating the heartiest part of
the animal suggesting that they weren't
just raiding the leftovers perhaps some
of these early scavengers hadn't waited
their turn at all but rather charged the
scene with rocks and sticks scaring
Predators away from their own kill and
staking their claim to the meal as
unpalatable as it seems to us raw meat
in itself wasn't a dramatic change for
our ancestors who'd likely been eating
small animals raw for millions of years
at least occasionally but over time
their bodies adapted to a diet that
included scavenged meat their jaws grew
more suited to biting and tearing and
their teeth shrank as they increasingly
outsourced food processing to their
crude tools meanwhile their guts shrank
in tandem as they began to depend more
on meat which gave them more energy for
much less digestive work over millions
of years our ancestors lost their
adaptations for life in the trees they
now rely made fully on food that they
could find on the ground and by half a
million years ago some of them possibly
Homo erectus took up hunting as a way to
meet that
[Music]
need the first Hunters may have taken
down their prey with thrusting Spears
carved out of tree branches it was a
dangerous method that required them to
attack their prey from up close but over
time they developed savier weapons
including throwing Spears that allowed
them to assail their prey from a safe
distance and so as they mastered hunting
they evolved from opportunistic
scavengers to ruthless Predators who
were selective about what they
killed fossil remains of hunted animals
reveal that their Hunters increasingly
sort out adult males seeking to maximize
their gains from the effort it took to
hunt exactly how important at this point
meat was to our ancestors is still
debated it's clear that they continued
to eat a wide iety of foods but their
diets morphed as they began to eat more
meat and once again so did their
bodies to begin with their guts steadily
shrank as their diets Incorporated more
meat a smaller gut meant our ancestors
could no longer process the high volumes
of tough plant material that they'd
eaten for Millennia instead they relied
on calorie rich foods that were easier
to digest large animals took great
effort to hunt but they offered great
reward for the energy expended
and all the while as hominins bodies
adapted to their shifting diets traces
of their evolutionary Journey remained
written in their genes and still remain
in ours thanks to our insectivore
ancestors we retain genes encoding
enzymes for breaking down insects we
have acidic stomachs that more closely
resemble the stomachs of scavengers than
those of our vegetarian cousins acidity
can help kill pathogens in decaying meat
suggesting that our stomach chemistry
may be a vestage of the days when our
ancestors dined on Kion today the human
digestive system resembles an old
factory stocked with Machinery that's
been retrofitted across deep time to
process new forms of
sustenance so what can all this history
tell us about what we evolved to eat or
indeed what we should eat
today the answer depends greatly on who
you ask but perhaps the greatest Insight
we can glean from our ancestors is that
our bodies did not evolve around one
specific diet they evolved to thrive on
whatever was around for all the changes
our ancestors have been through since
dinosaurs walk the earth they have
remained flexible eaters that thrive not
on one specific diet but on
variety when early primates were still
subsisting on fruit and insects they
likely still snacked on the occasional
small animal or egg even when our
ancestors began Scavenging and hunting
meat they never stopped eating
plants and so this is the Legacy we have
inherited we are omnivores as our
ancestors have been for tens of millions
of years and even among omnivores we
have a remarkably broad diet there are
very few animals on this planet that
could eat a cow or a shrimp or a peach
or a salad like all living things we
need a balance of nutrients but we can
get them from many places as our
ancestors have shown us time and time
again but this story of our Evolution
from shw sized insect eers to spear
wielding hominins is not yet
complete in the years since our hominin
ancestors began Scavenging hippo and
eating large quantities of meat our
dietary history has taken at least two
more major
turns and our bodies have done the
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same in 1989 Israel suffered a drought
this caused water levels to drop
dramatically in the Sea of Galilee and
as well as the mud and slime the
receding Shoreline revealed something
else something
spectacular an ancient human Camp
belonging to a prehistoric band of
hunter gatherers who had lived some
23,000 years
ago the small settlement was made up of
six brush Huts several long extinguished
hearths and a lone grave holding the
skeleton of a man hardened silt in the
lake bed had sealed off the site in low
oxygen conditions leaving the whole
settlement exquisitely preserved and
amid all this archaeologists uncovered
something perhaps even more remarkable
the Char remains of ancient plants
including some ancestors of today's
weeds well few people nowadays would
celebrate the discovery of a weed the
presence of these pesky plants was a
Telltale archaeological clue weeds
thrive in environments disturbed by
human activity having evolved to
tolerate altered soils suck up water
voraciously and spread prolifically that
meant that these ancient Proto weeds
hinted at something astonishing they
suggested that people had been
disturbing the soil and cultivating
plants 23,000 years ago long before the
onset of
Agriculture and as staggering an idea as
it is other objects in the site
reinforce this hypothesis a stone sickle
with clear patterns of wear strongly
suggests it had been used for harvesting
wild cereals like wheat oat and barley
the site also contained a crude grinding
slab surrounded by fossilized grain
parts that the inhabitants would have
used to grind down their Harvest as well
as this fossil evidence shows that the
inhabitants of the site had been able to
live at this Camp year round dependent
on foods that they cultivated for
themselves remarkably this early
four-way into agriculture predated the
first large-scale agricultural societies
by some 11,000 years and though this way
of life would not last generations of
hunter gatherers would follow it was an
early trial of a lifestyle that would
eventually change the course of the
human diet and evolution
forever returning to Africa more than a
million years ago as our earlier homin
ancestors crafted two tools and
coordinated elaborate Scavenging and
hunting missions they were still
hundreds of thousands of years away from
developing the cognitive skills that it
would take to plan manage and exploit an
agricultural site for food and so how
did these remarkable scavengers make the
leap to the organized farmers of
today over Generations they evolved
slowly their bodies got bigger and
little by little so did their brains
then just under a million years ago our
ancestors underwent a dramatic change
captured in the fossil record their
brains jumped in size while their bodies
stayed about the same paleontologists
had long linked this expansion in brain
size to the beginning of a meat-based
diet they hypothesized that eating meat
which is relatively simple to digest had
freed up some of the energy that had
once been needed to power the digestive
system allowing our guts to get smaller
at the same time bigger brains were
becoming more important for
communicating and coordinating
activities like hunting and Scavenging
introducing a selective pressure in
favor of bigger
brains this is called the expensive
tissue hypothesis since brains and guts
both demand a great deal of energy a
trade-off between gut and brain size
made sense
mathematically however the fossil record
hasn't held up this story our ancestors
have been eating meat since around 3
million years ago and although brain
sizes were slowly increasing the big
jump only happened within the last
million
years so if not meat consumption what
was it that drove this immense jump in
brain size it's a question scientists
still debate but one possible
explanation is
fire deep in a cave in the Hills of
South Africa
archaeologists have uncovered burnt
bones and plant ashes dating back 1
million years when premodern hominins
lived throughout this region the
existence of this burnt material so deep
in the cave suggests that it wasn't the
work of some stray Flames from a
wildfire but rather manipulated by early
humans possibly Homo
erectus if these homins had learned to
control fire by 1 million years ago and
began using it to cook their food this
could have had a drastic impact on our
Evolution because cooking food doesn't
just make it taste better it also lets
us get more energy out of
it heat from fire helps prepare food for
digestion by breaking down starches and
proteins into smaller bits that are
easier for our body to absorb it also
breaks down the molecules that tend to
encase fats freeing these nutrients as
well indeed long before humans began
cooking food they'd been Outsourcing
some of their digestion to processes
outside their body even simple processes
like slicing and pounding food reduce
demands on digestive systems freeing up
energy for other processes and cooking
takes things one step further allowing
our bodies to do less work even as they
extract more energy from the same amount
of
food and this was potentially crucial
because our brains require a colossal
amount of food
despite only taking up 2% of our body
mass the modern human brain takes up
around 20% of our body's energy even if
we're doing nothing but daydreaming our
ancestors brains would not yet have been
so large but they would still have
required an extraordinary amount of
energy and cooked food could explain
where that extra energy came
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from however not all researchers agree
that the evolution of our big brains was
driven by the Advent of cooking and the
energy it redirected from digestive
duties some doubt whether our smaller
brained forbears were up to the task of
building and managing fire others argued
that the jump in brain size would have
happened regardless of whether or not
they were cooking
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food but regardless of the role it
played in jump starting the growth of
our big brains cooking food as a way of
pre-digestion our meals has undoubtedly
allowed us to reap greater rewards from
what we eat and shifted the way our body
spends its energy it's a reminder that
on some level processed food is part of
our evolutionary
Heritage processing food to some degree
outside our bodies is what ease the load
on our digestive systems allowing our
bodies to devote resources to other
systems and evolve the way they did and
these shifts set the stage for the next
major change in our long dietary
history between 200 and 300,000 years
ago the changing climate once again had
our ancestors on the Move various groups
of hominins were migrating to new homes
and intermingling with each other as
they settled into new regions all over
the African continent and by 200,000
years ago modern humans had emerged from
the mix for tens of thousands of years
homo sapiens lived in migratory bands of
hunter gatherers that continued to
forage and hunt for each meal they
spread outside the African continent to
Southern Asia Australia and eventually
Beyond but then 23,000 years ago our
ancestors who had been foraging since
the time of the dinosaurs first started
cultivating wild plants in the Levant
they settled in around their food
sources and began staying in place for
long periods of time how exactly the
rise of Agriculture played out over the
Millennia that followed is an active
topic of research and debate indeed
agriculture did not take off all at once
but evidence from various human
settlements suggests that over the
course of several thousand years
different bands of people who knew
nothing of each other's existence began
cultivating plants around roughly the
same time in history as for what
triggered so many parallel attempts at
agriculture around the same time we
can't know for sure but some researchers
have pointed to a link between this
dramatic cultural change and a
fluctuating climate changing climate
would have altered the landscape
affecting the availability of
traditional food sources perhaps even
pushing people towards agriculture as a
way to ensure some food stability during
Changing Times but however it began in
the last 5,000 years almost all humans
have made the switch from hunting and
Gathering to some kind of farming what
had been small groups of Nomads grew
into larger more complex communities
that settled into Villages before long
great civilizations went up in the
Fertile Crescent China and the Americas
farming became a way of life around the
world the onset of Agriculture
precipitated a huge change in how humans
live and it came with many consequences
both for better and for worse as
societies grew around centers of
Agriculture close crowded living
conditions led to an increase in
infectious diseases our bones got
thinner as we traded kilometers of daily
walking for a more sedentary lifestyle
and our Jews shrank as our bodies
adapted to the relative ease of chewing
cooked food leaving many people with
mouths overcrowded with teeth but for
all their downsides these civilizations
became centers of culture where people
shared ideas
knowledge and
traditions our entire modern way of life
grew out of a change in how our
ancestors acquired their
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food and yet even this the rise of
modern society was not the end of the
dance between our changing diet and
evolution in just the last few thousand
years small genetic differences emerged
within our species as people around the
globe adapted to the food available to
them and those differences persist today
the indigenous people of Greenland have
adaptations for processing high amounts
of fat allowing them to subsist on a
diet that has traditionally included
many fatty animal foods such as seals
and whales meanwhile people whose
ancestors traditionally ate a high
starch diet such as Europeans have
special adaptation that allow them to
process relatively High quantities of
starches and so in the end
reconstructing the diets of our paleo
ancestors can only tell us so much about
how to feed our modern bodies or indeed
what is natural for us to eat if our
early ancestors had continued to eat the
way they did indefinitely we simply
wouldn't exist each change in diet set
them on a new evolutionary path that
eventually led to us if early primates
hadn't switched from eating mostly
insects to eating mostly fruit we might
not have had our sharp Vision or depth
perception if our homin forbears hadn't
had to seek out seasonal Foods in a wide
habitat our memory and cognitive skills
might not be what they are if they
hadn't started eating meat and cooked
food we might still be spending a
quarter of the day chewing like our ape
cousins rather than using our energy for
cognitive functions or anything else and
if modern humans hadn't started farming
we might not have plagues or high blood
pressure but we might also not have
cities or the wide range of Rich
cultures we have
today our dietary history is embedded in
our genes in the size of our guts and
brains and the shape of our jaws and
teeth but also in our societies our
culture and perhaps in our ability to
reflect on what we should eat at
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