hello virtual audience and happy Monday
thank you for joining us here on this lovely screen tonight my name is Kate
Bruns and on behalf of Harvard bookstore the Harvard University division of
science and the Cabot Science Library I am very excited to welcome you to our
program tonight with Neil Shubin presenting his latest book some assembly
required decoding for billion years of life from ancient fossils to DNA and I
even have the book as a prop right here tonight's event is the first virtual
installment in our Harvard science book Talk series we are so excited to
continue the work of bringing the authors of recently published science
related literature to our community during these unprecedented times coming
up - next month on May 21st we are going to welcome mario livio virtually for a
discussion of his new book Galileo and the science deniers and just like always
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authors for publishing for Indy book selling and especially right now for
science because it really does matter and now I'm very pleased to introduce
our speaker tonight called a natural storyteller and a gifted scientific
communicator by The Wall Street Journal paleontologist and Harvard alum Neil
Shubin has conducted landmark research on the evolutionary origin of anatomical
features of animals he's currently the Robert R Bensley professor of organismal
biology and Anatomy at the University of Chicago and he's a best-selling science
officer his previous books include the universe within and your inner fish a
journey into the 3.5 billion year history of the human body which was
named the best book of the Year by the National Academy of Sciences in 2009
tonight she is presenting his new book some assembly required which science
calls an intimate exciting and thoughtful sweeping evolutionary history
of the book BBC wildlife writes it's light of touch anecdote rich funny and
satisfyingly informative fossils DNA scientists with a penchant for suits of
armor what's not to love we are so delighted to host this event here
tonight so without further ado I'm going to turn things over to me well thank you
so much and so it's a delight to be here with you virtually this evening I hope
this finds you and you're as well at this unprecedented time so thank you for
joining me at this time to talk about some assembly required when I was
thinking about some assembly required I was basically the idea of the whole
conceit of the book is to think about the great transitions in evolution how
do we know them how do they happen you know because when you think about you
know how fish evolved to walk how birds evolved to fly you know our existence on
this planet when you think about them at one level they may seem impossible to
many people but when we break them down we begin to use fossils and DNA and
embryos and pull together many lines of evidence to see how the world came to be
in particular how many of these great transformations actually happen and as I
was writing the book I talked about contingency and evolution contingency in
my own life I was reading it by autobiography of
lillian hellman lillian hellman as you can see here I had a hard living hard
living life and she was blacklisted by the house on American Activities
Committee she famously hard living human being who in looking at her own life had
a quote that struck me as absolutely perfect for this book and her quote is
when thinking about her own life she said nothing of course ever begins when
you think it does and that in a nutshell is how we think about evolution nothing
ever begins when you think it does like let me give you an example if you think
that lungs evolved to help animals live on land you know at the transition from
fish to land living in if you think feathers evolved to help animals that
creatures birds fly you'd be in really good company in thinking that you'd also
be entirely wrong furthermore we've known this some of this for over a
century since the work of Darwin in fact an is-6 addition to the Origin of
Species it's a truly remarkable thing and when we start to think about it
evolution couldn't happen in any other way so I'd like to do is tonight just
for the next 2025 minutes and then we can answer your questions to go through
what we think about DNA what we think about fossils we think about embryos and
how that tells us how great a trip and transitions have happened and how
surprising that can often be let's just step back and think about DNA for a
second every single one of the cells in our bodies has DNA inside obviously we
have trillions of cells let's just say taken numbers let's say it's four
trillion give or take two trillion but in each of those cells inside the
nucleus of the cell is a 6-foot long strand of DNA that is crumbled and
folded in on itself to be inside a small cell think about that six feet if you
were to take all the DNA of our bodies of every single cell each one six feet
long from trillions of cells and lay them end to end our DNA individually
mine yours everybody's will go essentially from
Earth almost to Pluto that's an enormous amount of genetic
material inside our bodies furthermore the DNA is very active it's very dynamic
that's what we've been learning in the last last decade or so that crumpled
ball that six foot long ball is crumpled up inside the nucleus but it's opening
it's closing its folding in on itself it's actually dynamic
as genes are being turned on and off as we live our daily lives lots of
surprises there we've lived through genome projects which are telling us
surprises about about our own DNA and let me start with one huge surprise it's
actually very relevant viruses on everybody's mind and I want to open with
with what one is very surprising example Jason Sheppard is a neurobiologist at
the University of Utah now Jason's not a viral gist he's not a microbiologist
Jason is a neuroscientist biochemist physiologist and he's been focusing for
most of his career on a gene involved in making memories
it's called Park AARC so he's been studying arc and it's a very wise choice
for a memory gene mice have Ark and mutations in arc the gene when mice have
that mutation they can solve a maze but they can't remember the solution the
next day humans that have mutations in arc also have cognitive deficits and
other things suggesting that's also developing in our memories and it's in
seen another in other animals as well so Jason was looking at arc and he was
looking at the protein that the gene makes and so he popped the protein that
the gene makes he isolated it popped it on a slide and he was kind enough to
send me the slide that got him going on this this is the slide park he popped it
under the microscope and you can see there there are little clumps all
through the slide you could see those circular clumps he was looking at those
circular clumps and he's thinking seen those before so we dug out a textbook
and lo and behold he had seen them before
here's another here's a slide he sent this one to me as well you see the arrow
pointing to clumps these are virtually identical to the clumps a made by the
arc protein but the surprise here is though close clumps are made by HIV the
virus that causes AIDS he was surprised obviously so he know he's in a medical
school at the University you tall he calls colleagues in the building next
door who are in biology actually experts in HIV biology they he invites them over
he doesn't shows him his arc slide doesn't tell him what's on it it says
you know what do you think that is they said oh it's HIV virus that causes AIDS
like new bits of memory gene in mice you have it too so they studied it more they
studied the structure of the protein they studied in structure of the gene
and it turns out that arc is a repurposed virus one of our genes
the genes that involved in memories was once a virus that they when they looked
at map its structure and they looked at its distribution in other animals the
hypothesis is supported by lots of data that at some point in the distant past a
virus invaded the genome went into the genome but was later instead of being
infectious was later repurposed how by some means we don't know was repurposed
to function in memory so a gene involved in memory was once a virus that invaded
the genome now that's not just one surprise there are other surprises as
well if you look at gene proteins involved in the placenta during
reproduction some of those were ancient repurposed viruses as well we see this
again and again and there are so many surprises in our genome turns out if you
look at our genome only two percent of our genome contains genes like the genes
that code for proteins there's a whole 98 other 98% of stuff that does other
things very important but does other things well when we look at that turns
out that 8 percent of our genome were ancient viruses that invaded the the the
genome invaded and then got knocked out no longer infectious but they sit there
like fossils in a graveyard inside the inside the genome but is we have four
times more genetic material derived from viruses in our own genetic genome than
we do our own genes and that's just the tip of the iceberg of surprises these
are the sorts of surprises that we see nothing ever begins when you think it
does and that's so genes involved in memory where once or once ancient
viruses but there other surprises as well and these relate to one of the
great mysteries of biology which we've made incredible progress in the last
several decades thinking about you know from Brust it all begins here right in a
fertilized egg a single cell that single cell through the course of embryonic
development eventually gives rise to an individual with trillions of cells and
each of those cells packed in the right place there are brain cells in the right
place nerve cells in the right place our eyes muscles and so forth so it's this
highly organized collection of an enormous number trillions of cells
we call this process of going from one cell to a four trillion cell body we
call that body building so to go from the thing on the left to the creature on
the right a lot has to happen and much of that depends on the DNA inside the
egg because DNA inside the egg is turned on and off during the process of
development genes are activated genes are turned off genes interact with one
another and it's those interactions which produce which produced the tissues
and diverse repertoire of cells inside our bodies the processes of development
has been so important to Volusia nary biologists you know in the last century
and a half and as we think about it in fact we now have tools that can probe
that at the molecular level and they just work at it from a classical level
as some of our predecessors did over a century ago and think about it at the
level of molecular biology now there are many classical biologists who thought
about development as it relates to diversity but one of the great waste
stations here is really with the work of a herpetologist Auguste Duma real he was
a keeper of reptiles and in the Museum of Natural History
in Paris and he was very fortunate to be in Paris at this particular time in
1800s right around the darwinian time about 1859 1860 and so forth he was
recipient of many organisms that expedition x' were collecting they'd
bring them back to paris and he would study them and rear them well one one
day he got a shipment of salamanders such as this one here these were
collected from Mexico and the reason why this shipment of salamanders was given
to him was because the researchers saw that this salamander is an adult
salamander big one it is sexually they can sexually reproduce but look at it it
has external gills it has a big fleshy tail clearly aquatic so they gave them
to do real thinking well you know this is a sort of a half aquatic F
terrestrial creature you know maybe this can inform Darwin's new theory of
evolution because by studying it maybe you can understand how fish evolved to
walk on it great idea so you know doing real good
salamanders you put him in a menagerie took care of him it came back at some
time a little while later and he found to his great surprise
not just one kind salamander an enclosure but there are two kinds of
salamander there was a new fully mature sexual sexually mature adult this one
was fully terrestrial this one had no external gills this one had a totally
different tail in fact the whole body looked different the mouth and feeding
structures looked different hoping two different kinds it's almost as if
someone put a chimpanzee in a cage you know one month and then came back a
little while later and found chimpanzees and gorillas cohabiting the cage really
remarkable so do Morel was good scientist and he thought about well how
could this possibly happen well of course he looked at development and he
saw something very important when he looked at development what you when he
saw like is that you know salamanders beginning eggs they hatch as larvae as
you can see here those larvae are aquatic and you could see those larvae
have you know external gills and big fleshy tail well normally development
goes on and the salamanders metamorphose they metamorphosis little tadpole like
larvae metamorphose to a terrestrial adult you see on the left but if you
don't metamorphose then what you have is a big sexually mature and aquatic adult
so it's a simple shift whether the animal metamorphose is or not what
happened inside that which happened inside that enclosure was a simple
trigger of change in a level of a hormone that basically chech changed
whether in the animal metamorphosed or whether it didn't the big thing you see
here is a simple change to development can have massive ramifications across
the entire body of the animal and this kind of study really set off in a whole
new area of research people in the field really looked at how subtle changes in
the timing and developmental events may be stopping early or extending looking
at subtle shifts of development how they can have profound impacts on an
evolution when we stone the whole body itself well now we study development
using a variety of molecular tools and what I wanted to do is to talk a little
bit about what those molecular tools are showing us about how development can
evolve so we can look at genes and throughout the genome we can
characterize the entire genome we now look at individual tissues and see
all the genes that are turned on in individual cells and whole tissues we
can begin to map what happens to the two DNA as it turns on and off as genes are
turned on and off as the genome opens and closes and as this slide suggests
pretty graphically is we can now edit the genome we can knock out genes we can
rewrite the genetic code in many different ways not with tweezers we do
it with enzymes and little pieces of RNA but the result is the same we can cut
and paste different parts of the gene so once this tell us about development well
I'm gonna talk about some studies that were done by a colleague of mine nepa
Patel at the the Marine Biological Laboratory in Woods Hole Massachusetts
Sonne pom is interested in development and development and evolution and he's
for part of his work is focused on this tiny little creature it's about a
centimeter long sorry I on the scale on it and it's called para hi Alli and look
at it you can see its head is on the Left tails on the right these are
creatures if you've seen them in the Kalama pods if you've seen them like dig
in the sand in Cape Cod or whatever you'll see these little clear things
that jump around might consist of chrome jumpy's because they jump around the
tiny little things don't problem what's interesting is look at that they have
all kinds of different legs they have some forward-facing legs some
backward-facing legs some legs that kind of looks feathery and you really wanted
to see what is controlling the legs in par hi Alli can we make any inferences
from that what he found was that I focus on this a little bit is that there is a
genetic address for the different legs in par hi Alli look at the at the red
arrow the red arrow is pointing to backward facing legs and that is an area
that's been coated gray because a gene ubx which can see it's labeled here is
is turned on in that area so where you BX is turned on you get a backward
facing life in the area where there's a blue arrow
there's forward-facing legs and that is an area you can see it's hatched there
where two genes are turned on ubx and Abda that is when you have those two
genes in that genetic address you get a forward-facing leg and then there's a
there's legs in the back what nee pom did was he was you used
those gene editing tools to change the genes that are active in different parts
of the body and what he found was he can control which legs form in each segment
really remarkable stuff so that when he got rid he knocked out a be da he got
rid of that he basically turned that whole midsection into an area that just
has his gray with the UV X and he essentially made an animal that has only
backward facing legs and no forward facing life so really that subtle shift
and changing a genetic address in the body controls what organs form in which
place really remarkable stuff and it's a truly elegant study and this has been
done with other creatures as well manipulating the genome to manipulate
the ultimate form now why this is particularly important with these genes
is because these genes are present not only in power highly but they're present
in flies you can see it we've color-coded it here to show that how
these genes are turned on in different parts of the body in the embryo what you
see in the top which that look will avoid things and you can see where where
what it looks like in in the adult but it turns out that we have versions of
these genes to along with mice and reptiles and birds and so forth we can
see them active in air embryos and what are they doing they're patterning our
body axis in this case the vertebrae from the neck region the cervical region
to the tail so this is truly serving Universal code in some ways versions of
the same genes are working in flies and vertebrates as well as in as well as in
mice and people well can we do the same experiments that knee pump did in in
mammals well we all do them in people but they've been done in mice let's look
at it so here's the mouse no sir and you can see they were focusing in on the
vertebrae that are in the the base the the back of near the base of the tail
let's zoom in we're gonna look at genes and we're gonna look at genetic
addresses to see what's happening in the vertebrae so now we're looking at these
genes they and us they're called Hox genes h o x they're different names but
what you're looking here at the red arrow the red hour is poignant you can
see there's a gene called Hawks 10 which is turned on in the back area and a
Hawks 11 area so there's three regions that you see genetically there's an
address where only Hawks 10 turned on and address were and further
than the backward hawks the Lebanese turned on and then where the arrow is
pointing there's an area of overlap we're both Hawks 10 and Hawks 11 are
both turned off well it turns out the area that only sees the activity of
Hawks 10 those vertebra become what are known as lumbar vertebrae based the
spine the area we have an overlap between Hawks 10 and Hawks 11 that area
becomes sick reverb well let's do the same experiment that happened with with
with me palm in power hi Ally this is done by a team at the University of
Michigan if they make a mouse that only has Hawks 10 that is when there's no
Hawks 11 the prediction would be you'd have a mouse with only lumbar vertebrae
that those sacral vertebra were turned into lumbar vertebra and that's exactly
what happens the sacral vertebrae were transformed in the lumbar vertebrae so
basically nothing ever begins when you think it does the genetic elements that
controlled the formation of a revert of our vertebral column it took much of our
body axis actually had their deepest roots and in creatures it looks such as
flies and a common ancestry share of flies and power hyolyn and other things
like that deeply deeply ancient so thinking what does all this mean so
let's just put some of this together and then I'll take your questions um this
diagram shows kind of in a cartoon form of what we think about the transition
from fish to tetrapod in fact this was the limbed animal this was done in the
1980s we now have many more fossils but when you look at this is just the end
points fish on top limbed animal in the bottom it seems kind of impossible right
I think about what has to happen for animals to crawl on land you know
animals have to have lungs they have to have arms and legs with wrists and
ankles and fingers and toes they have to have a neck there's all kinds of
structures that need to come about for animals so to be able to walk on land
when you think about the long list of changes that have to happen it almost
seems impossible that you know that that could have happened you know to get back
in the Devonian 375 million years ago for creatures to walk on land but there
are real surprises here again nothing ever had nothing ever begins when you
think it does turns out if we look at fish many fish
won by the way this is a lung fish Australian lung fish I want to hug it
okay it is arguably the cutest little fish ever these are really
adorable fish they're adorable always because they have gills but they also
have lungs and it's been known for over a century that they had lungs their
lungs are used to breathe air they've reused the lungs to breathe air
when the oxygen content of the water is not sufficient for them to breathe their
gills so they have both lungs and gills and they trade off between one and the
other you might think that that's a one-off and just you know just have one
kind of lung fish no we have at least three different kinds of lung fish and
indeed when we look at the Tree of Life when we look at their structure of their
lungs what you can see is their lungs are by
lobes like ours they have alveoli like ours they're structured like ours and in
fact many of the genes that are behind the formation of their lungs are similar
to the genes that are behind the formation of our own lungs and when you
look at the distribution of lungs in the in the record evolutionary record this
is an evolutionary tree and it's highly prune on the right you see a limbed
animal you could be there or lizard anything anything blimps was there then
the lung fissure or the next lower down and then you have other kinds of fish if
you look at the distribution of lungs in fish that's what you see that is lung
fish have them and also all kinds of primitive rafe and fish have them indeed
their suggestion that some very ancient fish in the fossil record had lots so
long as we're around in the evolutionary record well before animals ever took
their first steps on land they rose to help creatures live in water that likely
had a variable oxygen content and the story doesn't stop there that is - you
know flesh out this diagram my colleagues and I would go to places like
this this is the Devonian of Ellesmere Island we led expeditions there for a
number of years we found fossil like this this is Tiktaalik Rosia we now have
20 specimens of this other teams have found similar fossils in other parts of
the world namely and in Quebec as well as in Eastern Europe and Latvia and when
we look at these things we see here's a fish that has a neck you could see its
fin right there when you crack open the fin it has bones that correspond to the
upper arm forearm even parts for wrists like ours this is a fish that could walk
with these appendages and even support its body a fish with the neck of fish
with fish for the neck of fish with limbs so fins with arm bones inside fish
with both and gills this is a fish that basically
had all the tools needed to live on walk on land but it was still living in water
what does this mean what this means is that that fish living in aquatic
ecosystems in the Devonian already had lungs and wrists and arm bones necks and
all the stuff needed to go walk on land such that when the opportunity came when
those when those when those features were needed to walk on land all they had
to do was changed their function that they repurposed for that much of
evolution does not consist in the origin of new structures new inventions it
comes down to using old inventions in new ways and evolution could not happen
in every in in any other way and in fact when you think about birds I'm just
going to end here with this case you know birds well they have they have
feathers they have wings they have high metabolisms they have hollow bones they
have wishbones lots of features if you're to think about that you think how
could those features all come about at the same time
birds would never have arisen that way but it turns out all those features came
about in dinosaurs very fast running theropod carnivorous dinosaurs they had
feathers they had wishbones they had you know wing like structures
in their bodies my meaning the inventions that birds used to fly arose
and dinosaurs living on land the story is the same as the as the one with with
with that reproach and that's why Lillian Hellman's statement is nothing
of course every begins when you think about it so it's so prescient because it
really solves a problem for evolution that is there's much of evolution
consists of repurposing copying modifying structures that already
existed and much of this comes down to changing functions so you can ask the
question you know why should I care about any of this well there's a reason
why we should care because much of human health depends on our knowledge of
evolution in our connection to the rest of life on our planet if you look at the
Nobel Prizes that have gone to medicine and physiology to to the discoveries
that have you know really affected our health and well-being who have they gone
- they've gone - people working on mice they've gone - people working on flies
look when a person working on corn they've gone back to Nobel Prizes or the
five people in the last 12 years I've gone to folks working on
seeing their Rabb died is elegant a tiny little worm the size of a column a piece
of paper yet that little worm is telling us how our genes are turned on or turned
off in health and disease and what goes wrong in diseases like cancer I like to
think that as we discover cures to everything that ails us from Alzheimer's
to different cancers that the breakthroughs that will extend and
enrich our lives will in some way be based on flies worms and in some cases
even fish I can't imagine a more powerful or more beautiful statement on
the importance of evolution than that thank you very much and I'm happy to
take your questions let's see we got am I doing this yes awesome
are you gonna carry the questions or should I just answer you should I just
take some and read them out to you if you'd like us miss one that the 15 votes
looks pretty good what do you think secondary science
teachers can do to make evolutionary biology more relevant and engaging for
our teenage students sometimes this topic is a tougher sell as compared to
other topics with more hands-on lab options request great question um I
think you know the power of evolution and the resistance to understanding
evolution which you sometimes get for students disappears or as is mediated
when we focus on the stories of discovery when we focus so for instance
when I talk about when I talk to my classes I talk about the pollak in fact
I the and so I'd love to tell the discovery stories the discovery stories
of you know how we predicted where we find it you know then we found it you
know that would we use the tools of evolutionary biology I think the more
you can focus on discovery stories whether it's about genetics
whether it's about embryos whether it's about functional Anatomy whether it's
about fossils the more you focus on that I think you can tell the human stories
that are behind discoveries when people got lucky or worked hard or you know or
it's just the human stories of making mistakes and learning from failure and
all these things have have a resonant appeal and I think it's much easier to
teach you know the evolutionary evolutionary ballads when we focus on
how we know right because how we know is this important as what we know and I
think the more we can get into that space with our students the
we'll be will there be signed copies of the book on sale by any chance well you
know I wonder how they but I have a mailroom here I'll be more than happy to
sign your books email them to me but I unfortunately have no working mail room
here at the office will cope in nineteen our human DNA well one thing we know is
that many of the proteins and many of the cellular processes we have going on
inside us happen in response to you know virus and it's usually through evolution
much of the evolution that's going on inside of us and and that there are
signatures of natural selection going on inside our own genomes we see it in in
our metabolic processes we see it in physiological processes but we also see
it in the balance with microbes with bacteria and yes with viruses as well so
there's a paper published a few years ago out of stanford showing like the
signature of natural selection on on some of the cellular processes that go
on inside of us and that means bridge it was hypothesized to be in response to
observed viral invasions and so forth so i've no idea what code that nineteen
will do but but that would be that would be one example of how viruses affect us
do you think viruses should be part of the Tree of Life viruses are one of the
Peter Medawar called them what trouble wrapped in a protein basically they're
tiny little bits of genetic material not much genetic material usually wrapped in
a protein they are sort of sit at the margins of what we think about living
creatures right they they don't really have don't really do anything until they
find a host cell then once they find that host cell then a whole chain
reaction is turned on where they essentially turn the host cell into a
factory to make more viruses right and they have different ways of doing it
there's a whole diversity in the huge diversity of these things in fact there
when somebody counted on the side there are more viruses in the ocean than there
are stars in the known universe that's pretty amazing I saw that calculation
that blew my mind anyway there's a lot and they're also
highly diverse but there are little machines to turn their hosts and the
factories to making themselves but they don't do anything until they find a host
cell so it's almost like they're not alive until they find a host cell so I
yeah so I wouldn't put them on the tree of life just because that alone but
there other reasons come out like do any of you I don't know how long
viruses have been around how they get started they've been around for a while
but there's two theories either they're really primitive or like a lot of or
like a lot of parasites they're stripped down you know so there's a couple
different theories of that but they definitely been around for a while I
mean you know the ark gene if you by Jason Sheppard's work he suggested that
the ark gene invaded the genome of a distant ancestor that we share with fish
375 million years ago but there are other signatures of viral invasions that
goes back even further what are a few of the most pressing questions in the
science of evolution well there are a lot of great questions about evolution I
mean one is you know there a couple really big ones the one is how random is
evolution you know if you were to replay the tape of life when we get to the same
state you know one thing we're seeing when we look at evolution is we see that
you know oftentimes similar structures evolved independently in different
creatures so evolution doesn't appear sometimes to be as random as we'd like
to like to think so one issue is that how random is evolution is it lower or
they're loaded dice - evolution is there that's one big one rates of evolution is
another big one why do some types of species who types of groups evolve very
rapidly and leave many different kinds of descendants and you know huge
branches of the Tree of Life why do others not change at all over
long periods of time that's a very big one as well other big questions are mass
extinctions you know what controls how selective extinctions are what controls
why some creatures live and why some creatures die in mass extinctions such
as the one that that wiped out the dinosaurs so lots of open questions
which is good for people like me because that keeps us in business one of the
questions I really like to think about that'll probably occupy much in my
future is the origin of vertebrates you know how did creatures with back bones
and skulls those kinds of skeletons how did they come about from worm-like
creatures we have some fossils but not a lot so that's for me as a fossil hunter
that's like perfect because I'd like to focus on that and you know the time
periods probably do it would be late Cambrian earlier in addition things like
that we're now where people have them look so
yeah so stay tuned to this channel once I can get on the field again
so that's good yeah so my son wants to understand why as a paleontologist you
need to study biology as you wonder very much the biology annuals yeah so
paleontology to be a paleontologist there are there there's like two
pathways both of them really important you need training in both. Some people
some people take it from the biological side which is what I do others people
take it from the geological side which is also what I did but I just didn't
major in a virus student but it's it's you know to be a paleontologist you
really have to be as fluid with and it's facile with geology as you are with
biology they're the two you can't really separate the two disciplines when you're
working as a paleontologist and I find that that's what's invigorating about it
right because it's it's multiple disciplines to make it work and it's
always exciting that way because when I'm in the field looking for fossils I'm
wearing my geology hat right we're trying to figure out which rocks are
going all the fossils and you're trying to think about what environments are
represented here trying to figure out what places are most likely to hold the
best fossils preserved. But you know once I find those fossils I really have to
think about the evolutionary side. How did these things evolve? What are they,
how do they function? You know what was the ecosystem
like? What other creatures were they living with you know? Who was eating whom?
That kind of thing. And so I mean how did they work? How do they walk about or swim or what have you? And that's all biology. You know so what I love about
paleontology is it's really kind of a fluid mix of biology and geology. My lab
is also molecular so we also work on hox genes the ones I showed you in the in the
vertebral column. We work on those genes as well. And so really when you're
working scientists honestly it's it's about the questions. You know and the
questions for me or how the big big evolutionary changes happen?
The tools are finding fossils like you know like this one here, studying DNA,
studying how creatures work, how their biomechanics the kinematics of how they
might have when it moved about or fed or what-have-you.
So that's what's exciting about it is that it's just not one discipline I'm
trying to you know we're getting tools from all over science to answer these
fundamental questions. So for me it's about the questions and
then I try to collect the tools, learn the tools to answer those questions. Dr. Shubin I'm eight but I'm your biggest fan. Well thank you.
I've been watching Your Inner Fish since I was three. Oh my god. Do you know any
camps for becoming a paleontologist for young people? No I don't. It's a great idea.
I know there are summer courses that are taught by museums. Like there's one here
at the Field Museum called Stones and Bones and it's for students and they
have a part classroom experience for like a week or two and then they go out
to Wyoming and work for a few weeks there. And I know there are a number of
programs like that another Museum so I'd encourage you you know if this is your
interest I'd encourage you to check out museums and what sort of programs they
have for summer, summer work. Also there's some summer schools. Will you be hosting any
more zoom chats for science teachers? Yeah I will most definitely. So what
happened was when my book tour was cancelled (this is actually my first book
talk my book came out March 17th), when my book tour was cancelled I realized I had all this time on my hands to travel to these different cities. And so I realized
teachers need content. You're switching to remote remote learning so basically
you can email me. You find it just Google me, you can email me and learn how to
schedule a zoom drop in and do a Q&A with students who are learning about
Tiktaalik or review my books or TV show what have you. It's so fun. I've done
about 20 I have about 70 more scheduled through May. And yes it feels good at this time
you know in the age of coronavirus to to give back in that way and to meet students
the teachers and and share their enthusiasm for evolution and learning
about evolution. So yeah please get in touch with me, it would be awesome. In fact I've got about 10 this week we're doing. Who has been the most influential scientist in your life? Ah good question. I've been really privileged to work with some
amazing people. I think so when I was at Harvard I worked with a professor named
Farish Jenkins, he was a paleontologist at the Museum of Comparative Zoology
there. Museum of Comparative Zoology is an amazing institution, just incredible
place. I was fortunate to be a student there in the in the 1980s. I worked with
Farish he was the one who taught me fieldwork like particularly extreme
fieldwork like in the Arctic so much of what I've done I've learned you know
with Farish but there been other people who've been influential in other ways.
There's um when I went to University of California when I graduated
Harvard I went to Berkeley for a period of time. I was very fortunate to work
with somebody by a scientist by the name of David Wake. David Wake is just a
phenomenal scientist and a great human being. And he is just like an evolutionary biologist's evolutionary biologist. He just knows the field so well well and his his lens in evolutionary
biology are salamanders. He knows pretty much everything you need to know about
salamanders and they're a window into a whole world of evolution. So yeah David
Wake was another really big one for me. So one paleontologist one neontologist,
hence the salamander example that was a reference to David. How does the
epigenome to the extent that we know it today contribute to the turning on or
turning off of the genes you've been talking about? Yeah that's a good
question. So the much of what we're doing here is not really the epigenome is part
of that so there are epigenomic changes that that happen but for the
most part it's other parts. It's transcription factors and other things. The lasting kinds of changes that we see are not epigenetic but many of the
changes in gene activity do can relate to epigenetics. And the question how Hox
genes like these developmental genes have been affected by epigenetic changes
is really actually only being now recently explored so I don't really have
an easy answer to that. You said lungs arose to help creatures
live in water. What were the first lungs repurposed from? More generally how did
genuinely new traits arise? Well there that's there's nothing genuinely new.
Okay that's number one. Everything is repurposed something else. That is
everything has antecedents and those antecedents as Lillian Hellman said you
know kind of don't don't look the way necessary think. But let's step back a
bit. Fish that don't have lungs many of those fish that don't have lungs have
another kind of air sac that lies adjacent to the gut tube and that's a
swim bladder. And it turns out the swim bladders and lungs are very very
similar developmentally. That is if you look at the early developmental stages
they both begin as out pockets of the esophagus the gut tube. You know one
migrates to the the back to the so called dorsal surface the other migrates
to the ventral surface, lungs are more ventral, swim bladders are more dorsal but
they share so much. So the primitive thing is probably you know
generally air sacs that are that bud out from the that bud out from the from the
the gut tube. You mentioned that all those primitive arm bones existed in
fish prior to the move to land. They did. What was the selective pressure for a
purely aquatic fish to begun developing those bones without walking on land. Well
remember what these fish are likely doing. They're likely moving about with
appendages in water. That is, a lot of fish walk on the water bottom or they're
maneuvering through weed-choked you know streams and swamps and so forth. So
they're clearly using the appendages to move about and a form of walking
actually arose in well before animals walk on land. What we see is
alternate gates and fish in many different fish and many different fish
that walk on the water bottom so it turns out we think that a lot of these
fish are actually maneuvering on the water bottom maybe even the shallows and
maybe even partially in the mud flats using arm and leg bones set in a fin so
they sort of had a multi-purpose into this kind of organ let's go back if some
assembly required written in a story like format yeah it is so go to the
Amazon page and you'll see like as an excerpt or the chapter you'll get a
sense of how it's written I like what I like to do is tell the stories of
wonderful people and and I like to use a couple people like that to tell the
larger story of science so one story I'll just tell you it's one of my
favorite ones which which I didn't copy book talk but I just love it so much I'm
gonna do Regina Julia Barlow Platte Julia Barlow Platte was born in mid
1800s in pretty much to the University of Vermont and she wanted to become a
biologist and she ended up going to Harvard for graduate school but she
couldn't get a PhD she couldn't get the final degree the reason why is they
weren't offering degrees to females at the time so I undeterred this is the
story of her life under she went to Germany and finished a PhD
there where was more friendly to women and then came back to the United States
and worked at the Marine Biological Laboratory that's how I found out of it
when I was at the Marine Biological Laboratory she went back to the Marine
Biological Laboratory in the late 1800s to work with an early nineteen hundred's
worked with OSI Whitman who was the director there at the time he was also a
professor here at Chicago but with Whitman she started to develop
techniques to trace cells during develop and she was looking at head development
in salamanders and sharks and she was tracing cells and she found something
surprising that the the cells that gave rise to some of the bones in the skull
weren't coming from where people thought they would be they were coming from a
different place and that doesn't sound like much but it was huge because people
had set theories on where it cells that gave rise to skeletons came from and she
was showing that they weren't coming from the known set of cells so she
published a paper like that and it was uniformly derided I mean she was
insulted and to the point where you know she was like begging people to stand up
for her so one famous biologist did from from Anton Doren
very famous biologist defended her but it was too late she couldn't get a job
in science she ended up writing David Starr Jordan the president of Stanford
University at the time begging him for a job I almost cried when I read her
letter she was leave saying I have to leave the field I made a biggest I made
this great discovery but no one believes me and which is went on with she
couldn't get a job and so she ended up leaving science and moving to Pacific
Grove California in the early 1900s in Pacific Grove California
she became mayor Pacific Grove California what did she do she saved
Monterey Bay Wow I think it's amazing and I mean and she was vindicated by
other discoveries that showed that that those cells that were giving rise to the
crazy part of the Britain is crazy cells that were given rise to the skeleton
which were surprising or a whole new token type of germ layer called neural
crest and you know is one of these stories it's like oh my god ever gave up
never made great discoveries you know and found a way to contribute you know
just I love telling stories like that so yeah it's orys like that are in the
books long way to answering a question but I hadn't comes really about the
Platt story because amazing how did you begin your career in
education and studies in evolution well my career in evolution began when I was
in in college really I am when I went to college I took a class I was in New York
went to Columbia I went to New York and my freshman year I took a human
evolution course taught by a curator at the American Museum of Natural History
so I went to the curator after the class and I said hey my name is Neil Shubin
I'd like to be a paleontologist can I volunteer for you it's like sure he said
yes okay so I went and and worked in his lab in his collection area and then I
got invited on a dig and and went and collected fossils well I was college
student in Wyoming and I was an utter disaster he's got another destroyed my
fossils they like them but I liked it enough that I wanted to stick with it so
I decided go to graduate school that's what it took brought me to Cambridge
yeah and then one thing led to another that's how I you know got into science
and then once I was in graduate school thinking about paleontology I was led to
think about embryos and embryology kind of like the story we talked about today
how to get nation education well you know one of the things that's the more
you study a field the more and if you love a field there's nothing better than
to talk about in the teacher to students so education naturally flowed you know
from a passion for evolution and paleontology and embryology and things
like that so it's you know it's that's and so I teach courses here I teach a
course in human anatomy time undergraduates evolutionary Anatomy I
teach a course here with a cosmologists about from the Big Bang to human
evolution we go through all like origins of everything kind of things so it's
really fun course listen to fall ten weeks
13.7 billion years what is a misconception you often find yourself
fighting against well one big one is what you heard about today that there's
like these missing links and evolution that's a continual progress you know one
mutation that that the great inventions of the history of life arose with the
great revolutions that's not the case you know I mean the great inventions
that are that have propelled the great revolutions in the history of life
always came about well before the revelation that your that you're
interested in so you know lungs aren't involved you know came out well before
the invasion fish about the walk on land feathers well before you know birds ever
flew that kind of thing and you see it and trade after trade and by the way
that applies to teens as well rights and the genes that are patterned much of our
hand and feet like a nice and lost and so forth they rose and fish in fact they
even had a deeper origin and you know implies and lots of surprises I wonder about the title some assembly
required the phrase alone is just a sense of agency involves and
do-it-yourself project now yeah I was just choosing it because it's it was I
enjoyed I like the you know like the some assembly required as a parent with
the kid I spent a lot of time trying to put together toys that you never work
basic components provided must combine them yourself yeah so when you're
talking about evolution and evolution development you could talk about
developmental processes think about it as a recipe right a recipe has processes
but it also has ingredients you know so the ingredients of the proteins and the
genes the processes are the ways that those genes interact and the way that
cells and tissues interact and build organs yeah so how do you handle deep
time or geological time I find that it's one of the hardest concepts to
understand but one that allows for the diversity we see today into the fossil
record yeah deep time I mean one of the great there's so many great teaching
tools for deep time and we always use analogies so Carl Sagan always used the
Earth's you know the year the cosmic year you know from the Big Bang to today
thirteen point seven years scale it to you know calendar from you know January
1st to December 31st you know that's a great way to do it I've had colleagues
who do it with a roll of toilet paper you know they take the roll and you know
somebody takes one end I just walk across the lecture hall you know and
they have them stop and rip off toilet paper for different events how much how
much paper there is so they're different analogies levo clever tools to do it and
using different analogies to teach it with all of them you know come out with
you know we humans have only been here for a sliver of the history of neither
life or the cause what are the biggest challenges between
scientific writing journals versus popular sighting time science writing
books Oh gotcha so this whole talk my whole book is based on a concept called
exaptation some people call pre adaptation which is jargon for changing
much of evolution happens by changes in function the prefixes pre-existing
structures not new structures themselves inner fish was a whole book about
homology you know how we compare similar strict features and different critters
right yeah in both books I never used those words and that creates opportunity
and that creates problems because we use jargon in science because it's so
precise there's so much information when I use scientific jargon word people know
exactly they know the history they know my meaning they know where I'm going
with it you know there's so much unsaid in a
single word now when you remove but jargon can really hurt your science
writing for general public because people can get tripped up on words
you're slowing them down it's it's a word that's kind of between them and the
concept and so I'll use jargon I'll use the jargon judiciously when I have to
but I prefer not to and I the workarounds are really tough because
once you get away from jargon you're kind of doing walking on a tightrope
you're walking a tightrope without a net so you have to use analogies you have to
use stories you have to use other things to tell that you know if you're not
going to get into the jargon so I find that's one of the biggest jobs another
really really big challenge is how much detail to layer in you know because we
scientists the details the term that I love you know it's that's the details
I'm studying you know I study like you know when I look at Tiktaalik you know
I'm studying the details of individual bones and you know and what's in the
head and how they get together you know that detail is important to me as a
scientist but you know for me to communicate to colic to the general
public you know those details you know where do
I stop with the details so one of the that's one challenge often times is you
know kind of know when when when details are important when they're not important
you know and sometimes you get it right sometimes you get around that's best
thing I can say how did you know where to look for
Tiktaalik yeah so we we looked for places in the world and rocks of the
right age to and you know they answer the question so basically in late
devonian we knew the late devonian was the time period when fish about middle
to late devonian when fish evolved walk on land so we'd looked at that age rock
about 375 million years old we look for places in the world under rocks in the
right age to hold the fossils I mean the right type to hold the fossils so not
every kind of rock holds fossil some are superheated some are super squeezed you
know some don't reflect the right environments so we you know so rock
straight edge rocks that I type and then we go to places where the rocks are
exposed to surface like deserts and things like that so you apply those
three filters a big world but lots of rock becomes a lot smaller you can
select the handful of places turns out the Canadian Arctic was absolutely
perfect as is the Antarctica as well which is where we're working now well
not now but where I've been working did Tiktaalik look like you expected it to
yeah I did we were looking for a flat headed fish and so yeah when I first saw
two colic this one here we were looking for a flat
head you know so the first thing we saw in Tiktaalik was this little D in a rock
right there but I saw his teeth it's actually this specimen this I cast I saw
these teeth and I saw the snout here and I knew when I saw this snap that it was
a flat it's nowt of a flat headed fish so I knew we found what we were looking
for when I saw that though that was a good day their good days their bad days
that was a good thing system is a long I know Kent for the disc
Shepard was only one viral gene repurposed for memory I believe so yes
that's do he talks about the one of them he can the you could do a Google search
on his on arc and Jason you can see the original paper came out about three
years ago how could he possibly determine if covin 19 occurred naturally
as opposed to experimentation in a bio lab well all I mean I everything look
people have been talking about spillover from viruses like corona virus you know
three years you know I mean Laurie Garrett wrote a book in the mid 1990s
called the coming plague where she was focused on you know viral escape from
wet market kind of things to society David qualms and wrote a book called
spillover which is exactly this you know a number of years about seven years ago
so and if you look at the molecular sequence of the virus it's it's it's
similar to a bat virus and so I mean the Occam's razor the simplest conclusion is
that likely came naturally natural rotation from the wet market from that
maybe some other vector in the in between but you know can you absolutely
exclude that it was you know didn't get released accidentally from a lab now you
can't really exclude it but I mean doesn't seem likely probably not given
that all the other fact it conforms exactly to what people predicting for
years so unfortunately see what are you most excited about exploring next that's
obviously the origin of vertebrates it's a big one one thing we're doing in the
lab now is we're looking at regeneration and how regeneration can evolve you know
so it turns out that you know salamanders take a salamander you cut
off its limp it'll regenerate pretty thoroughly
you know the muscles the nerves the bones you know in a high fidelity to the
original pattern here's how a fish can do that with their fins as well and lots
of other structures can regenerate and fish and things so we're looking at the
comparative biology and evolution of regeneration in the lab that's what
we're doing before things shut down about a month ago and likewise the
origin of vertebrates in the field that would be the next thing a lot of questions on viruses I've been
doing a lot of those I don't know all right well I think so what's on the
horizon for life-forms today do you have some bets on how today's structures will
be repurposed for tomorrow no I wish I knew one thing I can say though when you
think about humans natural selection is definitely acting on our genome it's
acting on the physiological traits our relationship with microbes as I said
before but you know if we were all to get to a time machine and then you know
come back in ten thousand years fifty thousand years and we'd see humans you
know what's driving the performance among humans what's driving the
differences about humans you know how long we live our cognitive capacity our
physical attributes and so forth you know it's hard to escape the fact that
we have this right and we have inventions we have cultural practices we
have educational practices we have medicines we have weave devices and
tools that affect our performance you know so much of our lives today are
driven by human inventions and technologies so when you think about
human biology and culture and the ways we spread that information you know the
people that's sort of like an important factor so like the yin and yang of human
evolution is from now is really our biology sort Darwinian evolution but
also the cultural practices and the results from the fruits of our brains
let's put it that way our inventions and practices and devices and so forth so i
you know i think you know futures is largely under our control with our brain
so let's do let's do right by at home I think we have time for about one more
one more question all right I'm listener I'm here let's do
we gotta have modern molecular tools revealed any concepts that Darwin got it
wrong yeah I mean there's lots of them there's lots of areas well you know one
of things I should say right off the bat do yourself a favor if you haven't read
Darwin's the sixth edition of the Origin of Species it's an amazing piece of work
in effect you know it's uh it's we the first and six but the six is kind of a
defendant one it's really it's it's really amazing one of the things that we
see you know the viral piece you know he would never
he wrote a book before there is any theory of genetics let alone DNA okay
and yet all his ideas apply to that except for a few that is what we have is
lateral turn you know viruses can invade different species so you know the the
genes of one of the proteins that's inside placentas came from a virus as I
told you in ours but it also invaded lizards as well and they independently
have that as well there's no way Darwin could have known
that you know that the way that these genes can move from species to species B
via viruses but what's even more remarkable than that though is how right
he is how many of his ideas that he came up with you know in 1859 um before apply
so well to DNA and he wrote it at a time that he didn't know even though genes
nor DNA exists that it's pretty amazing stuff now I'm not muted and I'll say
that again you have any closing words before I take us out here no I thank
everybody for coming tonight and just wish you and your families and your
loved ones the best at this time and I look forward today we can all were a day
when we can all be together me too so on behalf of the bookstore the
Harvard division of science and the Cabot Science Library I just really want
to thank Neil tremendously especially because it's his first book talk for
some assembly required which is so exciting and thank you to all of us for
spending your evening with us tonight we really do appreciate your support now
and always I also want to thank technology for
working tonight I'm really excited about it
please make sure to check out some assembly required at that green link
below and thank you again for your time and your purchases so have a great night
everyone please stay well thank you
