>> About 12,000 years ago, agriculture
and animal domestication emerged
in southwest Asia and Mesoamerica.
But before that, foraging culture was the only
sustainable lifestyle.
Hunter-gatherers had a variety of strategies they used to hunt
and trap their prey, such as mammoths and bison.
Nowadays, to include bison in your diet, you can just head
to your favorite burger spot and take a seat.
This change in lifestyle, over time,
has also changed the very structure of our bodies
and at Penn State's Center for Quantitative Imaging,
those changes are being studied.
>> My main research interests are in the variation
in skeletal morphology in different primates and in humans
and the relationship of that variation in bone shape and form
to behavior and other aspects of primate and human biology.
A lot of what our research is showing is that earlier,
hunter-gatherers - people who were more active -
have much more bone, even at the same body size.
So, they are probably growing stronger skeletons
because of the types of behaviors
that they're engaging in.
As we moved into more sedentary lifestyles,
and moving into the present,
more recent historical times, we have less bone.
And the less bone you have as a young adult predisposes you,
essentially, to potentially getting osteoporosis,
or having deleterious bone loss when you are older.
>> Learning more about these changes can lead
to a better understanding of causes and solutions
for modern day diseases.
>> We'll be able to potentially provide a baseline of variation
that will allow us to then compare what modern people are
doing and potentially, come
up with some preventative mechanisms
for increased activity, better diets,
and other intervention type approaches
that would help alleviate some of the stress
on the medical system that osteoporosis is posing.
>> To get a closer look at the bones they've studied,
Tim and Lilly use a specially designed micro CT scanner.
>> So, this is a computer tomography scanning system
that allows us
to nondestructively image the internal geometry and structure
of objects, a variety of types of objects.
Primarily, we're interested in both biological questions,
things like skull morphology
and skeletal morphology in different animals.
>> In our lab, we're interested in bone morphology
and how it changes over time, and - as well as between species
and different populations of humans specifically.
So, with the CT scanner, we'll able to look not only
at the outer morphology, but also on the inside
to get a little bit more detailed look
at the variation between populations.
>> So, what's the difference
between the x-rays this machine produces compared
to the x-rays you get at the dentist?
Well, it's all about the resolution.
>> If you go to a hospital or to a doctor's office
and get a medical CAT scan,
what you're typically doing is seeing internal structure
in your body at a certain resolution,
approximately 1/2 a millimeter or a little bit less.
This scanner is capable of going
down to submillimeter resolutions at the level
of about 5 microns, all the way up to maybe
about 200 or 300 microns.
>> The research shows how our bones have changed
over the course of many centuries but it also looks
at differences between someone like me,
a self-proclaimed carnivore, and my friend, the proud vegan.
>> It's been pretty clear
that environmental loading has been a big impact
on bone variation but I'm really interested in seeing
if there are other aspects that also influence it,
like if there's socio-cultural factors that make people choose
to behave differently and their if diet changes.
>> Dietary effects on bone are still not completely clear
and so one of the aspects of what we're looking at is
that if you have very different diets, what are the effects.
We used to say something about lifestyle and activity
and these images allow us to go even deeper so we can see
at a much finer scale some of the internal structure of bone
that has not been accessible
without destroying the bone until very recently.
>> Vital research indeed; make no bones about it.
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