- Welcome everybody.
My name is Gail Gasparich
and I'm the dean of the College of Arts and Sciences.
And it is my great honor to welcome you
to the 2021 annual Darwin Festival.
2021 marks the 42nd annual Darwin festival.
But this year is unique in that it is the COVID version
and all the programming will be online.
The event is held to celebrate Charles Darwin's birthday
which is February 12th.
In 1980, two Salem State University faculty,
Dr. Ginny Keville, who I believe is joining us today,
and Dr. Phillip DePalma,
we're teaching human and social biology for non-majors
and initiated the first festival.
It has grown and developed through the years
to include other SSU departments, student clubs,
and the City of Salem, which in part supports the event
through the Charles Albert Read Trust Fund.
The Darwin Festival welcome scientists and non scientists
who share an interest in learning
about the world around them.
Some well-known speakers have presented
at the Darwin Festival including Lynn Margulis,
Stephen Jay Gould, Ernst Mayr,
E. O. Wilson, B. F. Skinner, and Jan Pechenik,
just to name a few.
A full list of past speakers and titles of their talks,
it's available on the website if you're interested.
The planning committee incorporates
an interdisciplinary and broad definition of evolution
to include a wide range of speakers.
This year is no different.
I hope you have had a chance to look at the schedule
as there is a wide range of talks presented
by a diverse group of speakers with areas of expertise
in the biology of cities, the evolution of skin color,
which you're just about to hear,
the diversity of coral reefs,
and the mating habits of cannibalistic spiders,
just to name a few.
I would be remiss if I did not extend my sincere gratitude
to the members of the Darwin Festival Planning Committee,
as any event this large requires
a lot of behind the scenes planning
that starts right after the last festival
to get the speakers lined up
and the logistics all figured out.
So again, I extend my warmest welcome
to the start of the 42nd annual Darwin Festival.
I hope you all have an opportunity
to learn from the amazing speakers and films made available
to you throughout the week.
And now I would like to hand it over to Dr. Jason Brown,
to share more information to kick off
this morning's program.
- Great, thank you, Gail.
So welcome to the Darwin Festival.
First, I need to let you know
about a few housekeeping issues.
If you're ever dropped from a webinar
you can reconnect from the link
in the webinars services email that you received.
Your questions for the speaker
can be submitted throughout the talk
using the Q&A feature of Zoom.
Your questions may be posted anonymously if you prefer that.
And during the last 15 minutes,
a selection of those questions
will be asked by our moderators,
Dr. Ryan Fisher and Dr. Nelson Scottgale.
Since we may not have time to get to all the questions,
we apologize if we don't get to your question,
but Dr. Jablonski has very kindly agreed for us
to put together any questions that didn't get answered
and send those to her after the talk.
So please feel free to post your questions here.
So to remind Salem State students,
each talk this week is designed to fit
into a single class period
and attendance lists will be sent to your professors.
There's also a link to the list
of Darwin Festival streaming videos
on the online Darwin Festival schedule.
So now to our first speaker for the Salem State University's
42nd annual Darwin Festival,
I'm pleased to introduce Dr. Nina Jablonski,
Dr. Jablonski is the Evan Pugh University Professor
of Anthropology at the Pennsylvania State University
where she directs
the Center for Human Evolution and Diversity.
She earned her bachelor's degree in biology
from Bryn Mawr College and her PhD in anthropology
from the University of Washington.
Her research on primate evolution
and the evolution of human skin, skin pigmentation and touch
has led to the publication
of over 170 peer reviewed journal articles.
Her research on STEM education
with her collaborator Henry Louis Gates Jr.
led to the development of the Finding Your Roots curriculum
focused on fostering an interest in health sciences
in middle school aged children
through personalized genomics.
She has been honored with numerous awards
including a prestigious Guggenheim Fellowship
and election to the American Academy of Arts and Sciences.
Her books include "Skin: A Natural History"
and "Living Color: The Biological
"and Social Meaning of Skin Color"
She also does a lot of work on public education,
her TED Talk and her HHMI BioInteractive video
together have been viewed around 2 million times.
And she's also written extensively for the popular press
including Scientific American, New Scientists,
and the Huffington Post.
So now with no further delay, Dr. Nina Jablonski.
- Thank you very much, Jason and greetings.
Welcome to this wonderful Darwin Festival.
I'm really delighted to be with you today.
Excuse me, I'm just trying to get the screen share working.
Okay.
I've been interested in skin color for a very long time.
The Brazilian artist, Angélica Dass,
who's beautiful Pantone shade skin color pictures
you're seeing right now,
is also interested in skin color
from an artistic perspective.
And because she recognized that in her native Brazil,
people graded in their color from one shade to another
with no distinct boundaries.
I share Angelica's basic curiosity,
but I've been interested in why skin colors evolved
the way they are today and why we make of them what we do.
So what I'm gonna try to do very quickly today
is take you a bit through my own career and my own study
and my educational projects
on the evolution of skin pigmentation,
so that you can share part of my life and my own curiosity.
I wanna talk about skin color
as a genuine evolutionary adaptation,
and then emphasize that color-based races
don't exist in nature,
but have become very durable psycho-social templates
that have influenced us as people and scientists
for hundreds of years.
And lastly, I want to talk briefly
about the educational programs that we've developed
to help kids think about their origins
and their appearance differently.
We know that the sun has been very important
to the evolution of life on earth
and it certainly has been extremely important
in forging skin pigmentation,
because humans evolved under intense sun.
Our ancestors lived primarily in Equatorial Africa
and the Horn of Africa region.
What we see in this map are some localities,
shown in little balloons,
for early members of our human lineage
and then next dot in the pink and blue color,
this is the range of distribution
of our close primate relatives, chimpanzees,
with whom we last shared a common ancestor
about eight or 7 million years ago.
So there is no doubt that the human lineage
began in Equatorial Africa,
all of the earliest fossils are African
and all of our early evolution
right up through early Homo sapiens
occurred primarily in Africa.
So we really need to look at the solar situation in Africa.
And when we begin to think about the main characters
who were living under the sun in Africa,
this is a beautiful example to start out with,
an early member of our own genus Homo.
This one often referred to as Homo ergaster
from about a million and a half years ago
right on the equator in Kenya.
What's key about this individual
is that he looks remarkably modern in his skeleton,
although he has a smaller brain than we do,
his arms and his legs are in about
the same proportions as us.
And when we look in detail at his body,
we can see that he basically
had the same patterns of movement as we do.
He was capable of strong bipedal striding, and running.
In other words, he could get hot during his exercise
and he didn't do exercise just for fun.
He was doing exercise to live, to find food,
and to escape from predators.
What we've done as we've tried to understand
the evolution of skin color
is understand how this process was related to,
first, the loss of most of our body hair,
which occurred as the result of the need
to have more unfurry skin to help us lose heat,
the heat that we were generating
through all of this running and chasing.
Basically, if you have a fur coat on,
it's hard to keep cool.
And so one of the key things that we see in human evolution
and the beginning of the genus Homo
is the loss of most body hair.
And the increasing density of eccrine sweat glands
that produce a lot of sweat that help us keep cool.
We'll come back to this hairy timeline of human evolution,
but what's critical to see
is that by about one and a half to 2 million years ago
we began to get mostly hairless and the skin color changes
in order to help protect us from the intense sun.
When we reconstruct the appearance
of this early member of the genus Homo,
he and she have mostly naked skin,
probably some hair on our heads
and that mostly naked is darkly pigmented.
When we lost our hair, we lost a lot of our sun protection.
And the way we compensated for this
was through the evolution
of permanent dark, protective skin pigment.
The sun feels good and is very nice,
but at the equator, it's very, very intense.
And within the entire tropics, it's very intense,
not only with visible light,
but a lot of ultraviolet radiation,
which is potentially very damaging.
And so all organisms have to protect themselves in some way
from these harsh effects of ultraviolet radiation
and other very high energy forms of radiation
coming from the sun.
Ultraviolet radiation is really
gonna be the focus of today's talk,
because that is the really bioactive entity
that we're going to be dealing with
that has specific effects on the skin.
And when we imagine that we're living at the equator,
just like our distant ancestors were,
we can think about in this simulation
the UV coming from the sun, the very short wave length,
UVC being completely absorbed
by the atmosphere surrounding the earth.
And then UVB which we hear a lot about these days,
UVB is also falling to the earth surface
penetrating the atmosphere at the equator
and fairly strongly, but the strongest entity is UVA,
which travels basically through the atmosphere
with visible light.
The takeaway point here is that at the equator year round,
the UV is strong.
And so organisms, including our ancestors
had to protect themselves from the strong sunlight.
When we look in detail at the distribution
of this strong UV and weaker UV, it's really telling.
And I'll come back to this map a few times,
because this is really our guide
to the evolution of skin color.
Skin color is directly related
to ultraviolet radiation intensity.
And really we could end the lecture here,
because the rest is just sort of details.
The most protective skin coloration.
The darkest skin occurs in areas
where ultraviolet radiation is highest,
shown here in red and hot pink.
And then we have incrementally lower
and more seasonal amounts of ultraviolet radiation
as we get closer to the poles.
These maps have been created from NASA remotely sensed data
that have been rendered into map form
by my collaborator and husband George Chaplin.
And he's made a variety of such maps.
I'll only use this annual average map
by way of illustration today.
But the other thing that I wanted you to take away
from this map is okay, it's very, very strong.
The UV is very strong around the equator,
but in areas where there's a lot of humidity
like Amazonia here in South America,
or Equatorial West Africa, the UV levels are lower.
Similarly, as we get out of the tropics
and begin going into the Northern Hemisphere,
whoa, look at Northern North America, Northern Eurasia,
very, very low levels of ultraviolet radiation.
This is the roadmap for understanding
the evolution of human pigmentation
as humans begin to disperse
into these different zones millennia ago.
So in early Homo, we've got this handsome guy
with his beautiful dark skin
capable of doing a lot of sweating.
And the dark skin is made dark
by this remarkable eumelanin pigment,
which absorbs ultraviolet radiation and visible radiation.
It's dark because it absorbs all these wavelengths.
It's a remarkable molecule,
and it's used by thousands, millions
of different vertebrates and invertebrates species
to protect from ultraviolet radiation,
as well as to impart color.
In our work, we've identified
that the most important selective force,
the most important reason in evolutionary theory
for the evolution of dark skin pigmentation
has been to protect foliate availability.
Foliate is a B vitamin that is absolutely essential
for making and regulating DNA.
Basically, if you can't make and regulate and repair DNA
you can't make new cells, you can't repair cells,
you're sunk basically,
and you can't make an early embryo and you can't make sperm.
We came to this realization when we realized that foliate,
which we get from a variety of dietary sources
like green vegetable and citrus fruits,
is actually sensitive to ultraviolet radiation.
So when you've got something sensitive
to both ultraviolet radiation
and processes that depend upon it,
you've got to protect that light sensitive entity.
Folate as I said, is derived
from a variety of green leafy vegetables,
citrus fruits, whole grains and it's really super important.
All the women in the audience
will certainly sort of understand
why there's so much foliate supplementation
that they are encouraged to ingest
when they're thinking of being pregnant,
because folate is so important
to a normal, healthy pregnancy,
because there's all this cell division going on.
You have to have folate to fuel that.
And if you have any processes that interrupt folate,
or cause it to be depleted or destroyed you're in trouble,
hence a lot eumelanin pigmentation
that forms a natural sunscreen in the skin
to help protect the integrity of the bioactive
and important foliates in the circulation.
So here we are with our hairy timeline again.
There's the evolution of the genus Homo approximately
and the evolution of Homo sapiens in Africa
beginning around 300,000 years ago.
Basically our lineage,
although we do have some representatives
who leave Africa at various times,
this Homo erectus, for instance, going into Eurasia
about a million and a million and a half years ago,
most of those populations become extinct.
What we're concerned with is Homo sapiens
that continues to evolve in Africa
and basically our Homo sapiens, our species,
the first skeletal evidence around 300,000 years ago,
we become modern in every respect,
with respect to our culture,
our capacity for language and symbolic behavior,
very sophisticated technologies, art, you name it.
All of these things evolved
when we were in our early days of Homo sapiens in Africa,
exclusively in Africa between
about 300,000 and 80,000 years ago.
So when we think about the evolution
of early African Homo sapiens
and the populations in Africa that remain there today,
we can think easily of this continuity of selective forces
and the evolution of dark pigmentation
to protect people from intense ultraviolet radiation.
But we know that there are lots of people
with more lightly pigmented skin that exist in the world.
So really we have to figure out, well, what's going on?
What happened?
How did this,
I would argue, loss of pigmentation,
or depigmentation occur?
Well, let's look at our UV map and think just generally
about the pattern of dispersals,
movement of people that occurred at periods
after around 80,000 years ago, out of Africa.
Remember most people over this time
are living and moving within Africa.
So what we're talking about here are small groups
that are leaving Africa in pursuit of food,
usually prey animals of various kinds.
We know that people started moving
into the Afro-Arabian Peninsula,
as well as along the coast of East Asia,
probably 60 to 70,000 years ago.
These arrows just give you a general idea
of where these dispersals are going,
but I want you to watch the arrows
relative to the UV zones.
So here we have people going
into Southern and Southeast Asia, an island, Melanesia
from a hinterland position
in between the Caspian and the Black Sea,
we have people going northwestward into Europe
and northeastward into Northeast Asia,
and then considerably later beginning
probably around 15,000 years ago into the new world.
Now what's important here is that not only are people going
or dispersing into these zones of different UV,
especially into these very low UV zones
in the Northern Hemisphere,
But also we know from genetic and genomic studies
that these populations of people are small.
And so these populations have experienced
what geneticists call population bottlenecks,
restrictions of genetic variability.
The combination of bottlenecks
plus intense natural selection
really is the story of human skin pigmentation evolution.
It's important to remember
even though humans are dispersing over thousands of years,
that during individual human lifetimes
people didn't travel much.
There were no vacations per se.
There was not a lot of sort of commuting that went on.
They spent most of their time outdoors
and there really wasn't until about 20 to 30,000 years ago,
there wasn't much in the way of sewn clothing
or built environment, shelters.
People took shelter in rock shelters and caves,
but they spent most of their time outdoors
without sewn closing.
The point is, is that skin was the primary interface
between our bodies and the environment.
And so we adapted to the UV regimes
that were outside at any particular time,
whether they were intense or not so intense,
the skin was the primary interface.
So what was it like?
What were the sun's rays like,
let's say in the extreme Northern Hemisphere
during the winter time?
Let's look at this simulation,
again, UVC is gonna be completely absorbed by the atmosphere
as is the UVB.
Now, I dwell on UVB here because it turns out,
although, it's monumentally destructive
in terms of its effects on biological systems
including the human body,
UVB does one positive important thing,
which is to begin the process
of making vitamin D in the skin.
UVA also comes to the earth surface with visible light,
just like it did in the earlier simulation.
But the key point here is that UVB
isn't missing in the sunlight during the winter
outside of the tropics.
So when we think about these two guys,
we need to think about
well, how is their skin reacting to sunlight?
Now, if this is mid-summer,
judging by the intensity of the sunlight
and their sunglasses,
what we know is that the man on the right
who has more eumelanin natural sunscreen in his skin
will be well-protected,
but he'll also make vitamin D in his skin
at a slower rate than the man on the left.
And this is really where the next phase
of this evolution pigmentation timeline is going.
When populations are dispersing into higher latitudes,
the only way that they're gonna stay healthy
year in and year out
is to lose some of their protective sunscreen pigment.
So what we really have to think about here is
light skin being depigmented skin having lost its eumelanin,
and the less eumelanin you have
the easier it is to make vitamin D in the skin.
So here we are thinking about
what's going on as people go into these high latitudes
first in Eurasia and then in the Americas?
It's salutary to remember too that
that there are no really high latitude environments
in the Southern Hemisphere,
apart from the lower portion of South America,
there's very little in the way
of extreme high latitude environments there.
So we're talking about primarily
a Northern Hemisphere phenomenon.
And what we see as people are dispersing over time
into the Northern Hemisphere is a combination of biologic
i.e. genetic and cultural adaptations
that allow them to live healthy lives.
And this is really what we want to look at
in a bit more detail, is these just how this all worked out.
In a variety of excellent genetic studies
that have been conducted in the last 15 years,
we've been able to look at the genetic architecture,
so to speak, for pigmentation
in many populations of the world.
And there's been great attention focused
on Western Europeans and Eastern Asians,
because both of them have lightly pigmented skin.
And it was quite surprising when it became evident
a little bit more than 10 years ago
that these two populations
who have roughly very similar looking skin
actually evolved the same skin tones independently
via independent genetic means.
This is one of the most remarkable examples
of natural selection occurring independently
in these recently split lineages of modern humans.
They split apart completely around 40,000 years ago.
And they underwent increased depigmentation
from 40,000 years ago to the present time,
largely on the basis of different genetic mutations.
Remember, mutations aren't all bad.
So you can have mutations that are favorable
under certain environmental conditions.
And what we're talking about here are mutations
that are favorable under low UV conditions,
that allow the skin to have less eumelanin
so that it can absorb more UVB to make more vitamin D
out of available sunlight.
This is such a beautiful example of natural selection.
So really what we can identify here
is that the primary selective force
for loss of eumelanin pigmentation for depigmented skin
is the promotion of UV induced vitamin D production.
And we see these at higher latitudes
with not only less intense,
but much more highly seasonal UV.
We have just tremendous amounts of depigmentation occurring
plus a lot of sort of cultural buffering.
In addition to depigmented skin,
we see people using a lot
and making use of a lot of vitamin D rich food sources
like oily fish, marine mammals, caribou reindeer,
this kind of thing,
because they need to replenish their diet
with as much vitamin D as possible
because the UVB is so weak at these extreme high latitudes,
they can't make enough vitamin D in their skin.
Vitamin D is really important
for the absorption of calcium from the diet
and in the absence of normal calcium absorption
and the absence of sufficient vitamin D,
we see kids developing nutritional rickets,
probably very common in much of the world
during historical periods,
certainly in the United States, this is true.
And it is particularly serious
with respect to its evolutionary consequences
when it affects normal birth,
as it does in the case of this young woman's pelvis.
The outlet of which is very constricted
as the result of rickets during her early development.
But equally important we now recognize,
and this is something that physicians emphasize
to us simile every day during the winter,
is that vitamin D is really important
to help keep our immune systems in good condition.
So having enough vitamin D in the diet,
or taking vitamin D to maintain healthy levels
is really important for the health of our innate
and adaptive immune systems.
So when we think about what's going on here,
again, I wanna think now about what happens
when people are dispersing not only into high latitudes,
but then back into lower latitudes.
For instance, when we think about people who dispersed
into the Indian subcontinent,
many populations went into lower UV areas
and then came back into higher UV areas.
What happened to those populations?
And again, what we see is a combination
of biological and cultural adaptations.
When we look at these three men,
all of whom have darkly pigmented skin,
one of the things that we now appreciate
is that the genetic architecture
for dark and highly tangible skin is actually distinct,
is different in these three major groups
from East Africa, Australia, and Melanesia,
and Southern India.
Again, this is a beautiful example
of natural selection in action.
Having the same skin colors
evolved multiple times independently
and from a distinct pools of genetic mutation.
It turns out in our studies of skin pigmentation genes
that there are dozens and dozens of genes
that have effect on skin pigmentation.
There are probably a large handful that have a major effect,
but there are many that have smaller effects.
And often in genetically restricted populations
that have undergone bottlenecks,
these genes of minor effect have been used
to enhance tanning mechanisms for instance.
So the research in this area is still ongoing.
It's very exciting, but it's so interesting
because we have natural selection being played out
on our own bodies.
So there are many genetic loci
that are associated with both depigmentation and tanning,
and these processes occurred
under strong positive selection.
So we could really think about skin pigmentation
being a beautiful evolutionary compromise
between the demands of photoprotection,
especially under the extreme UV conditions
in drier parts of the world near the equator
and closer to the poles incline
or gradient favoring photosynthesis of vitamin D.
And in-between these two zones,
we have people adapting to seasonal levels
of seasonal changes in UV
and often with different tanning mechanisms
so that they can gain and lose eumelanin pigment
throughout the year.
This really warrants some Darwinian celebration,
because this is one of the best examples
of natural selection on the human body.
And so when you're talking to your friends about this,
or teaching your classes
you can think about this being one of the best examples
that you can bring it to your classes and students.
Another important point is that these features of the skin,
this highly tangible dark pigmentation
is not associated necessarily with other physical features.
So when we look at the hair texture of these people,
the skeletal proportions, the skull shape,
this shape of the physical features,
these are all very different in these individuals
with darkly pigmented skin.
And this is important that skin color,
whether we're talking about darkly or depigmented skin
is determined by genes that travel for the most part
entirely independently of the genes
that determine the form of these other traits
that are physically evident.
So this again is an important point.
A big takeaway, similar skin colors evolved independently
under the same UV conditions,
and that means that we can't use skin color
as any kind of marker of unique group identity,
or as a classification entity to create a race of humans.
Skin color is simply to label
a beautifully adaptive characteristic,
but totally useless for purposes of classifying people.
So when we think about this beautiful, beautiful CP
or rainbow of skin colors,
such as produced by Angelica Dass here again.
We don't see any sharp differences between people.
So why did we end up with various schemes around the world
in which people are grouped
by seemingly well demarcated skin colors?
Well, the origin of human races
is all about the origin of human bias,
the origin of inadequate information
and the origin of really the ability
to promote certain ideas under certain social circumstances,
this is a long story.
So you're gonna get the very short version.
Two of the important characters here to mention are
Linnaeus the systematist, the person who first thought
about putting species of plants and animals
into a system of binomial nomenclature.
He thought about humans deeply,
and Kant, Immanuel Kant the philosopher
who also thought deeply about humans and human diversity
as he ruminated over what made
for a civilized, moral human being.
Now, what's key about these guys
is that they used skin color.
And first Linnaeus used skin color to define human groups.
And this is important because Linnaeus thought
a lot about color.
He was a botanist.
And for him being able to distinguish flowers,
for instance, by skin color was really important.
And so when he became aware of the fact
that people came in different colors,
he never traveled very much outside of Europe.
So he wouldn't have seen people, but he heard about them.
He defined
those groups of people by color,
just as he would with the plants that he studied.
So in his earliest classification,
we see humans according to continent
classified only by their color.
Later he classifies things a little differently,
but he only sort of adds to those classifications
with some other attributes, which I won't go into now.
Kant takes this one step further.
We have Linnaeus working in 1740,
Kant is deliberating about the nature of human diversity,
physical diversity in the 1770s.
And he writes an important treatise in 1775,
in which he articulates this scheme of four races.
And he calls them races, in Germany, Rassen.
The key thing here is that he does distinguishes
these four groups as a hierarchy.
Linnaeus hadn't put these people in any kind of order,
Kant did as did Kant's contemporary in Scotland, David Hume.
Both of them importantly put the race of the whites on top.
Again, these men didn't travel,
they had access to very limited data,
but important for the rest of our story
is that they had enormous influence
on the history of scholarly thought,
but also on the history of political
throughout Europe and North America.
So according to the Kantian view,
which we can also say it was championed by David Hume,
races were physically and culturally distinct
from one another.
Kant felt that the intensity of the sun
affected one's ability to reason,
ability to work creatively, to have moral judgment
and develop civilization.
And in these attributes
he felt that the white race was entirely superior.
What we see in the 1780s and '90s
is this racial hierarchy, a framework of named races,
in order becoming a durable template
that describes variation.
There are all sorts of economic reasons for this too,
because in the late 1700s,
there is increasing pressure to end the slave trade,
the transatlantic slave trade,
but in a way and a terrible irony
is that science rescues the slave trade
by giving this framework, this hierarchy of races,
whites followed by blacks and others.
According to this hierarchical scheme,
if blacks, so-called, from Africa
are biologically inferior to whites,
then it is okay to enslave them.
And this sadly and ironically turns out
to be one of the major justifications
that was embraced not only by European slave traders,
but by avid slave owners who wanted to acquire more slaves
through the transatlantic slave trade
through the late 1700s and into the 1800s in North America.
This hierarchical framework decisively affects
the way human variation is considered and studied
in science and in politics, basically to this very day.
We really have to scrutinize this as a historical process
and say how can we begin to better understand
and undo this in light of the better knowledge
that we have today?
Why use an 18th century compass
when you have a 21st century GPS?
Because what we see is that these racial stereotypes
lead to what I would call color memes
from which developed the psychosocial templates
of racism as they developed
in the late 19th, 20th, and early 21st century.
We can see now this clear progression,
a tragic progression in human history.
But we can think about these things differently.
And in the last few minutes,
I just want to share with you a program
that I've developed with Henry Louis Gates, Jr.
to try to get at this,
to try to change the way that we think,
and not geared at old folks or older students,
but geared primarily at young people
who are interested and not jaded,
who want to figure out what the world is all about.
And we want to get them more interested
in understanding science, in understanding facts,
so that they can make observations
and make sense of the world
and make sense of their place in it.
To make a long story short, we created a working group
and we started to create a curriculum
that we thought would work to help kids get interested
in science and the world through studying themselves.
We got some great financial support
and we started developing summer camps
for middle school aged kids, genetics and genealogy modules
and undergraduate biology classes,
as well as developed a series of outreach documentaries
and online materials.
Starting with our camps,
we were really gratified when these things
finally came together and we had kids doing it.
They were investigating their own personal DNA,
ancestry and genealogy,
and studying the nature of human variation on themselves.
They extracted DNA on strawberries and kiwifruit.
They extracted their own DNA from cheek swabs.
They basically were in charge
as young scientists of the process of discovery.
They discovered details of their own genealogies.
Some kids had more success than others, of course,
because of their individual family histories.
They looked at variation in human physical attributes,
like skin color, and tried to make sense of them
with respect to evolution,
just like I did in the beginning of this lecture
They did projects.
Some of them on skin color,
some of them on entirely different things.
They were autonomous young scientists,
self-empowered and motivated to study the world themselves.
And to recognize that they could make observations
just as well as anyone else.
We partnered with our public broadcasting station WPSU.
And here are the two key producers with Skip Gates.
We created a series of webisode modules
about one of our camps
in which we developed in a series of nine episodes,
basically the key foundations of our curriculum.
And you can find this on the web
easily Finding Your Roots: The Seedlings nine webisodes.
When you get to our www.fyrclassroom.org website,
what you'll see is this lovely screen with some of our kids.
You can look at the series of webisodes, the curriculum,
and there's a whole bunch of new at home resources,
especially for at homeschoolers.
Here's the website again.
And one of the wonderful things that we saw
is that when our young people left the camp
they didn't just sort of zone out and not do stuff.
They were really excited in their own lives to do this,
to carry on observing the world,
thinking about their place in it,
thinking about learning science.
And one of our campers, when she got to high school,
she not only continued studying science,
but also went back to her middle school
to introduce some of the same lessons
to her middle school young colleagues.
So we had this framing question of who am I?
Being transformed to who I am,
in these empowered self-actualized young scientists.
Thank you, thank you for your attention.
And I hope we have time for some questions.
This is a wonderful time to think about evolution,
human history and how we can do better
in teaching our children about how the world came to be
and how we think about it.
- [Nelson] Dr. Jablonski I wanna thank you very much.
This is Nelson Scottgale, I'm one of the moderators.
We really appreciate this.
And I would like to start by asking
actually two questions, if I may,
one is to clear something up
and then the other is a more involved question.
The first is, can you explain the relationship
between folate and folic acid?
- Ah, yes.
Folic acid is sort of the non-biological form of folate.
So you have this vitamin B9
and when you buy it in a little vitamin pill,
let's say in the pharmacy,
you're buying folic acid which is the synthesized form.
But when you ingest folic acid
is quickly converted in your body
to different forms of foliate.
And so the real bioactive form is folate
as opposed to folic acid.
- [Nelson] Thank you, and then I wanna follow that up with,
this is from a participant,
regarding human skin pigment
during the transatlantic slave trade,
many of the members of the Negro peoples were enslaved
and transported to climates vastly different
than their ancestral home.
Disregarding interracial breeding
over centuries of enslavement in colder climates,
did the generations of slaves adapt to the relative extremes
with their new climate?
- This is a really important question.
There actually was no change
in genetically determined skin pigmentation,
but what we did see in many enslaved African people,
especially those people who were living
at higher latitudes in the North American colonies
and who lived indoors
is that they're excellent sunscreen
worked to their disadvantage,
because they couldn't make enough vitamin D in their skin
from available sunlight.
So nutritional rickets was extremely common
during the years of the slave trade,
but also throughout the rest of the 19th
and early 20th century.
it was in some places almost considered,
and I use the quote here
from a previous historian of science "The Negro disease"
because vitamin D deficiency caused rickets
was so common.
So we don't see actually a change
in the genetically determined skin pigmentation.
This would have taken quite a few generations
and much stronger selective pressures.
What we do see is that many people developed rickets
early in their lives.
(coughing) Excuse me.
- [Ryan] Thank you for a lovely talk, Dr. Jablonski.
This is Ryan Fisher.
Also one of your question moderators.
I have two questions.
The first is compiling a number of different questions,
you mentioned in your talk that the genes for skin color
and other attributes are separate.
That is indeed the case, correct?
- Yes, that's correct.
So for instance, the genes that determine skin color
in any one of us are different from those
that determine the shape of our ears,
or in most cases the color of our hair,
or the shape of our lips.
And that's really important,
because often there's this thought
that we have these groups of so-called racial features,
that sort of travel together.
Genetically, they do not travel together.
What we see is, in modern humans today,
are sort of this sort of frozen in time picture
of a clump of genes working to create a beautiful organism.
But the way that people have looked over the years
has depended very much on where they are,
who they have admixed with at any one time,
and how isolated they've been.
So humans in the past have probably looked very different
from how they look today.
- [Ryan] Thank you, and then a different question
a sort of medical associated question,
and I quote are people with darker skin
kinda are less likely to develop skin cancer.
And additionally if medical science
did not exist to treat such conditions,
would natural selection favor
traits of more pigment over less pigment?
- It is true that people with very dark,
(coughing) excuse me,
very dark skin pigmentation
are less susceptible to skin cancers.
But when people live, regardless of their skin color,
when they live under very sort of indoor conditions,
normal sort of American conditions, let's say,
and we don't have much exposure to outdoor sunlight,
even people with darkly pigmented skin
can experience severe sunburns
when they go out into intense sunlight,
let's say on vacation.
So dark skin is less susceptible
to skin cancer and to damage,
but it is still potentially damageable.
Dark skin is extremely good
under conditions of intense or changeable sunlight.
It's less adapted to extremely
low levels of ultraviolet radiation
and seasonal levels of ultraviolet radiation.
Under those conditions, people with darkly pigmented skin
really have to make sure
that they're getting enough vitamin D.
So it isn't a case of one skin pigmentation
being superior to another,
it's just that these different levels of skin pigmentation
work under certain environmental conditions.
And when we live under different environmental conditions
we have to compensate.
And everything about modern culture is about compensating.
and we do a lot of this,
naturally we keep ourselves warm in the winter
by compensating for the lack of fur
by wearing clothing and so forth.
So we have to make new compensations
for having dark skin in high latitudes,
or light skin in low latitudes and everything in between.
- [Ryan] Thank you, I'll pass it over
to my colleague, Dr. Scottgale,
and just to remind our participants in the audience,
we'll try to get to another handful of questions,
but we have about five more minutes.
Nelson I'll pass it back to you.
- Thank you very much, Ryan.
I wanted to ask you a very important question.
You've mentioned about seeing
your different types of programs for people,
but there's a question,
can we get involved in the camps as volunteers?
And I wanted to make sure to give you
a chance to ask them. - Well, absolutely.
What we've done, if you go to our website,
you can download all of these materials
and you can make any of these lessons
into afterschool programs, lessons, for homeschooling,
or create your own summer camps.
If your university or your high school
has a summer camp program,
you can actually use our materials to create summer camps.
And you can take a few bits and not all of it,
or all of it and modify it.
We encourage people to sort of modify this
and I'm happy to say that we have a new injection of funds.
And so for the next two years,
we're going to be making more of these modules available,
especially for high school and undergraduate audiences.
So watch our website
and we'll be keeping lots of materials up to date
and completely freely available.
- [Nelson] Thank you very much.
And I'm gonna ask one more question,
if less melanin means more vitamin D,
how would we explain higher propensity
of bone density problems like osteoporosis
in lighter skinned people.
- It turns out that vitamin D levels in the body
and vitamin D that works on bone density and bone deposition
is again controlled by a wide variety of genes.
And so what we see in people
with lightly or depigmented skin
is that if they have a calcium rich diet
and get plenty of vitamin D,
and if they undertake lots of exercise,
like our ancestors did,
they have good strong bones throughout their lifespan.
However, modern life on the couch and in the office,
doesn't necessarily make that easy.
And so there are many people
who live, especially in the Northern Hemisphere
with lightly pigmented, depigmented skin
under conditions, indoor conditions most of the time,
they may not have a vitamin D rich diet,
their calcium levels might not be very good.
And so there are some 20th and 21st century bones
aren't doing very well
under these modern cultural conditions.
What we see is that many of our genes
were sort of designed or evolved
under conditions of our early history as a species.
When we work outdoor active Homo sapiens at high latitudes
doing all sorts of stuff, not sitting in an office.
So I think we just need to sort of bring ourselves
back to, okay, what was it like,
let's say 10,000 or 15,000 years ago for our ancestors?
Okay, I don't want you to become a hunter or gatherer,
but what you have to do is try to
include more calcium and vitamin D in your diet
and undertake more exercise
so you can keep normal, healthy bone density
throughout your lifetime.
- [Ryan] Dr. Jablonski I have a question
from a seventh grade student here in Salem.
What do you would have happened to the early humans
without their natural ways to protect them from the sun?
- Well, I mean, what we have in most of our evolution
is that we have minimal levels of culture.
We were able to seek some shelter,
but we didn't have anything like sewn clothing,
or built shelters until about 30,000 years ago.
And so basically our skin, as I said earlier,
was the primary interface
between the environment and the insides of our bodies.
So the skin underwent a lot of changes
and including in skin color.
And what we see as in more recent human history
is that our cultural adaptations
become more and more sophisticated.
We get really good at making clothes and shelter,
basically whether we're living under extreme cold
or extreme heat conditions.
So what we see in modern peoples, we look around us today
and we see people with all these bewildering varieties
of different kinds of clothing, protective clothing,
ways to keep themselves warm and cool,
different kinds of buildings.
Basically, we played out this natural experiment
throughout the early millennia of our species existence
from our origin 300,000 years ago,
basically until about 30,000 years ago,
when populations started adopting more sophisticated means
of bodily protection and building protection.
Basically the skin did most of the work.
- [Ryan] Thank you, I think perhaps,
if Dr. Scottgale agrees with me
this would be the final question
and to our audience we've had over, or around 40 questions,
we'll collate them and perhaps Dr. Jablonski
if we could pass some-- - Yes please.
- [Ryan] And check back with the Dawn Festival Committee.
So the final question, with the climate
getting exponentially warmer around the world,
you expect to see a microevolution of skin color,
where humans, especially Northern Hemisphere become darker.
- Well, what we see happening now in human evolution
is cultural evolution.
People are changing their position.
Sometimes they might move, or they get a better fan,
or a better air conditioner.
I'm not being flippant here.
We see humans engaging than ever more cultural buffering
in using sophisticated means to protect themselves
from fluctuations in the environment
including higher temperatures.
In places where people can't afford these added protections
we will see greater mortality, there's no doubt,
but probably there will be cultural corrections
that occur quite quickly so that this mortality
is not associated with a natural selection event.
- [Ryan] Thank you very much.
I'll now pause the microphone
and back to my colleague, Jason Brown
to formally thank you and end the webinar.
Thank you very much.
- Thank you so much, Dr. Jablonski for a wonderful talk.
And thank you all for attending the webinar.
We're excited to kick off our Darwin Festival this year
with this wonderful talk by Dr. Jablonski.
Thank you all.