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From YouTube: DevoWorm (2021, Meeting 6): Darwin Day, DevoLearn, and Kindle book, PI theory, and assorted embryos.
Description
Darwin Day blog post (origins of cognition, model evo-devo-neuro systems, and phylogeography), lineage population prediction update, Ant, Spider, Centipede, and Plant Embryogenesis, and Positional Information (PI) theory. Attendees: Susan Crawford-Young, R Tharun Gowda, Bradly Alicea, Krishna Katyal, Mainak Deb, Richard Gordon, and Shruti Raj Vansh Singh
A
D
C
C
C
C
C
C
C
Philosophical
transactions
of
the
royal
society
and
it's
a
really
good
special
issue.
They
have
a
lot
of
different
articles
spanning
plants
and
origins
of
the
nervous
system
and
different
types
of
like
the
evolution
of
neurotransmitters,
elementary
nervous
systems
which
we'll
get
to
in
a
little
bit
and
so
reafference
in
the
origin
of
the
self
and
the
early
nervous
system
evolution.
C
C
C
This
is
a
review
elementary
nervous
systems,
uncovering
cognitive
similarities
and
differences,
conservation
and
innovation.
That's
another
good
article,
so
I
definitely
urge
you
to
check
that
out
then
move
on
to
darwin
online,
which
is
a
repository
for
all
sorts
of
historical
things
having
to
do
with
darwin's
work
and
things
going
on
in
the
late
19th
century.
So
there's
a
lot
of
good
stuff
in
that
repository.
C
E
B
C
C
I
don't
think
so.
This
is
the
newest
work
so,
like
we
talked
about
this
a
couple
weeks
ago,
and
a
lot
of
the
simulations
of
continental
drift
are
like
maybe
a
half
a
million
years
at
best.
They've
pushed
this
back
to
a
billion
years,
and
I
don't
there's
a
paper
associated
with
this.
That's
this
paper
here
we
talked
about
this
a
couple
weeks
ago,
but
it's
they
kind
of
go
through
their
methodology
here
and
they
kind
of
talk
about
it.
C
C
C
C
There's
a
field
called
phylogeography,
which
is
this,
is
basically
phylogeography
where
you
have
these
phylogenetic
trees
and
they're
mapped
to
some
sort
of
geographic
space.
You
know
like
continents
or
or
a
range
of
a
species
or
something,
and
but
you
know
a
lot
of
the
work
that
are
out
there
and
I
don't
know
I
haven't
really
done
a
deep
dive
into
it.
I
don't
really.
They
haven't
really
done
this.
They
do
stuff
like
they'll.
C
D
C
C
So
this
next
feature,
this
is
a
paper.
This
is
actually
an
evo
devo
paper,
so
we're
now
going
to
development,
and
this
is
nervous
system,
anatomy
of
the
brain.
It's
called
evolution
of
new
cell
types
at
the
lateral
neural
border,
and
this
is
in
develo,
developmental
biology,
journal,
so
they're
using
converging
evidence
from
genetic
regulatory
networks
and
anatomy
to
demonstrate
common
mechanisms
shared
between
invertebrates
and
vertebrates,
and
so
let
me
see
if
I
can
get
to
the
paper
here
yeah.
So
this
is
the
paper
here
and
you
know
they
have.
C
This
is
a
more
of
an
anatomical
study,
so
we're
not
talking
about
geography
anymore,
we're
talking
about
different
things.
Animals
have
become
increasingly
complex
by
the
addition
of
novel
cell
types
and
regulatory
mechanisms,
and
so
they
use
the
lateral
neural
border
of
the
the
brain
as
a
way
to
look
at
that.
B
C
B
C
C
B
C
So
that's
that's
that
paper,
and
so
that's
that's
a
evo
devo
paper
on
the
cell
types
and
then,
of
course
this
is
now
we
can
move
into
theory
and
we're
talking
about
neural
systems.
Now,
there's
neutral
theory,
the
neutral
theory
molecular
evolution.
This
is
the
50th
anniversary
of
a
famous
nature
paper
by
khmer
and
ota,
where
they
talk
about.
They
talk
about
neutral,
neutral
theory
or
the
molecular
neutral
theory,
and
so
that's
that's.
An
interesting
point.
C
Neutral
theory
postulates
that
most
biological
variation
is
expressed
in
selectively
neutral
genes,
meaning
that
they're
sort
of
random
and
they're
not
selected
for
so.
This
is
something
that
if
you
look
in
the
literature-
and
I
think
I
have
a
citation
here-
there's
a
controversy
between
neutral
processes
and
selectionist
evolution,
so
some
people
think
that
selection
plays
a
very
dominant
role
in
evolution,
and
some
people
think
that
this
these
neutral
processes
play
a
role
in
evolution
and
driving
the
diversity
that
we
see
on
the
planet.
C
C
C
Talking
about
tectonic
plates,
we
had
an
earthquake
two
days
back
here,
so
that
was
in
surety,
where
surety
is
located,
they
are
moving,
and
this
is
the
research
profile
of
carlos
alvarez.
Okay.
So
this
is
the
guy
who
was
doing
the
work
on.
Actually
he
did
the
that
graph
I
showed
of
the
of
the
plate
of
of
plate
tectonics
and
phylogeny
and
he's
actually,
I
think,
a
biomedical
scientist
mainly,
but
he
does
he's
done
this
work
as
well.
So.
E
C
I
think
yeah
someone,
I
don't
think
that's
yeah,
it's
krishna
came
in
late,
so
you
can
read
that.
So
that's
good-
and
I
might
add
to
this
I
might
add,
a
few
more
references
to
it.
There's
a
data
set
on
egg
size
and
shape
for
more
than
6
700
insect
species.
That
looks
really
interesting
and
I
don't
know
yeah.
This
is
a
scientific
data
paper.
So
it's
a
description
of
the
data
set.
C
C
B
C
Well
I'll
have
to
check
into
this
and
yeah,
we'll
have
to
maybe
look
at
some
egg
size
data
soon
see
what
that
looks
like,
because
I
know
we
talked
about.
We've
talked
about
egg
size
in
the
group
before
actually,
I
know
krishna
actually
isn't
kind
of
interested
in
that,
but
you
know
maybe
we
can
do
a
deep,
deeper
dive
into
that.
C
C
Okay,
the
next
thing
I
want
to
talk
about
was
in
in
preparing
that
blog
post
and
then
just
kind
of
interesting
stuff
that
I've
run
across
there's
some
other
kinds
of
embryos
that
we
might
think
about.
I
know
we
talked
about
in
this
group
c
elegans
embryos
and,
of
course,
there
are
human
embryos
and
mouse
embryos,
and
then
we
have
the
drosophila,
which
is
the
fruit
fly,
and
then
we
have
the
zebrafish.
C
I
think
that's
something
we've
worked
on
in
one
of
the
papers,
then
they
also
have
sea
squirts,
which
are
the
embryos
which
are
really
interesting.
Embryos
from
you
know
for
marine
invertebrates,
and
so
we
worked
on
that
I've
been
thinking
about
anson
plants,
so
I'm
going
to
talk
a
little
bit
about
ant
and
plant
embryos
and
spider
embryos
actually
too.
C
So
this
is
an
ant
embryo
here
this
is,
they
lay
their
eggs
in
their
embryos
that
they
lay
and
they
actually
have.
This
here
is
an
ant
carrying
this
cluster
of
eggs
that
the
embryos
inside
and
they
actually
have
this
interesting
symbiosis
between
carpenter
and
embryos
and
some
bacteria
and
there's
this
paper.
Well,
this
is
actually
a
quantum
magazine
article
that
talks
about
this.
C
C
Then
you
go
to
the
pupa
and
then
you
have
the
adult
hand.
So
you
have
these
these
different
life
stages,
and
I
should
say
that
c
elegans,
you
have
something
somewhat
similar.
You
have
a
an
egg
for
c
elegans
and
then
you
have
larval
stages
which
are
actually
they
look
like
more
like
a
small
version
of
the
adult
worm
than
ant
larva.
C
C
C
C
Of
them
in
this
case
this
isn't
a
very
good
shot
of
the
cells
per
se,
but
this
is
an
intracellular
adapter
protein
that
they're
looking
at,
and
this
is
actually
in
drosophila,
but
so
and
then
oh,
this
is
drosophila,
but
this
is
the
ant
comparison
here.
So
you
can
see
that
there's
a
a
you
know,
a
relationship
between
ants
and
drosophila
as
well.
D
C
C
No
not
compared
to
you,
but
so
then
we
move
on
to
spider
embryos
and
again
these
are
like
spiders
are
not
diffic
that
difficult
to
find.
Generally,
I
mean,
if
you're,
in
a
in
the
middle
of
winter
time
in
north
america,
it's
very
hard
to
do,
but
you
know
you
can
find
spiders
in
most
parts
of
the
world.
This
is
a
the
embryonic
development
of
the
central
american
wandering
spider
coupeenius
away,
and
this
is
a
nice
shot
of
a
spider
embryo
sort
of
in
a
stage
of
of
development.
C
Here
you
can
see
the
top
of
the
embryo,
and
you
can
see
this
part
here
which
is
starting
to
differentiate
spider.
Embryos
have
a
lot
of
interesting
sorts
of
phases
to
their
evolution,
so
this
or
their
their
development.
So
they
have
this
these
different
stages
of
development,
so
this
is
the
morphogenesis
of
the
head
region.
Oh,
this
is
a
spider
with
a
bunch
of
eggs
in
it
it's
going
to
lay
the
eggs,
so
this
is
their
egg
sac.
C
C
C
C
So
these
are
well
somewhat
well
characterized.
So
again
there
and
there.
I
know
we
have
some
spider
dad
I'll
talk
about
it
later
in
devo
zoo,
but
this
is
just
giving
you
an
idea
of
what
what
they
look
like
then
I
said
ants
and
plants,
so
I
talked
about
ant,
spiders
and
now
plants,
so
this
is
arabidopsis,
which
is
thale
crest,
and
this
is
something
it's
a
flowering
plant
that
you
find
around
the
world
again.
C
This
is
an
example
of
an
embryo
here
of
arabidopsis.
This
is
a
light
microscopy
image
here.
This
is,
you
know
the
different
stages
of
development,
so
you
have
the
octant,
the
16
cell,
the
globular,
the
transition
and
the
heart,
the
late
heart,
the
torpedo
and
the
seedling.
So
these
things
go
from
like
little
balls
of
dna
and
a
couple
cells
and
they
grow.
C
C
Let
me
walk
you
through
this
image,
so
this
is
actually
an
em
or
an
electro
electron
microscopy
image
of
the
ovules,
so
the
ovals
are
like
the
places
in
the
plant
that
house
eggs
or
seeds,
and
this
is
a
nice
high
resolution
image,
but
then,
when
they're
fertilized
and
they
start
to
grow,
you
have
these.
So
you
have
the
heart
here,
and
this
is
a
close-up
of
the
heart,
the
cells
heart,
the
torpedo,
the
walking
stick,
which
is
this
longer
one,
the
bent,
cotyledon
and
so
they're
kind
of
going
in
this
sequence.
C
C
C
So
we
have
spider
in
place.
We
don't
have
anything
from
the
plant
kingdom,
I
don't
know
what
is
publicly
available
in
arabidopsis
and
I
don't
know
what's
publicly
available
on
ants,
but
that
might
be
worth
looking
into
and
again
we
might
also
look
at
the
egg
what
people
have
in
terms
of
eggs
and
egg
morphology,
and
I
haven't
put
anything
there.
We
might
actually
process
some
data
for
that
and
put
it
up
with
sort
of
in
this
format
where
we
have
the
csv
files.
People
can
work
from.
C
So,
let's
see
dick
said
in
the
chat
table
of
eggs,
so
this
is
the
tsinski
and
gordon
reference
for
mean
ice
field
icing
model
for
cortical
rotation
in
amphibian,
one
stage,
one
cell
stage,
embryos.
This
is
a
paper
that
was
published
about
eight
years
ago
and
then
quail
eggs
can
wait
for
an
incubator.
C
B
B
B
B
C
B
B
C
B
C
C
C
C
E
C
E
E
E
E
E
Busy,
so
I
couldn't
really
send
the
p
app
so
I'll
be
sending
the
pr
by
tomorrow
or
at
most
friday
after
tomorrow,
so
yeah,
that's
something
I
was
working
on
and
yeah
I'll
send
the
pr
and
I'll
let
bradley
in
when
I
grow
so
yeah.
That's
what
I
wanted
to
talk
about
so
yeah
thanks
for
your
time,
yeah
yeah.
C
So
that
was
something
that
we
talked
about
last
week.
Sort
of
you
know
it
was
kind
of
in
progress,
so
yeah,
that's
and-
and
I
like
the
results,
it
looks
pretty
good.
So
for
the
most
part,
it's
it's
identifying
it
with
less
loss
and,
of
course,
in
some
of
the
data
I
know
what
data
set
you're
working
on
so
you're
working
on
the
I
think
the
epidemic.
E
C
C
E
E
C
C
C
C
Sure,
that's
that's
good
yeah.
We
also
talked
about
well.
I
talked
about
with
krishna
about
doing
a
a
separate
session
for
some
of
the
summer
of
code,
like
basically
like
an
onboarding
session.
So
this
would
be
something
that
would
be
separate
from
the
monday
meetings,
something
we
can
focus
on
the
onboarding
for
potential
contributors
or
students.
They
want
to.
You
know,
learn
things
about
the
data
sets
or
whatever,
and
I
think
that
would
be
a
good
idea.
C
So
it'd
be
your
evening,
otherwise
I
can't
really
make
it
because
I
can't
make
it
at
like
four
in
the
morning
my
time
and
then
my
time
like
in
the
afternoon
would
be
too
late.
I
think
for
you
yeah,
so
why
don't
we
find
a
time?
Why
don't
we
send
out
a
a
schedule?
We
can
do
that
and
then
set
up
a
time
and
then
it'll
work
for
I
think,
for
every
time
zone
I
mean
north
america,
europe
and
india.
C
I
think,
if
krishna,
if
you
want
to
send
out
a
schedule
on
that,
we
can
organize
it,
and
then
I
know
they're
ruining,
are
interested
in
this
and
contributing
as
well.
So
they
might
get
involved
and
then
mayak,
because
I
think
he's
he
well
he's
gonna
be
a
mentor
for
this,
so
we'll
try
to
get
him
on
board
as
well.
C
C
Okay,
you
can
see
my
screen,
so
we
don't
have
a
lot
of
stuff
on
here
right
now.
We're
kind
of
knocking
down
some
of
these,
so
this
evolution
kill
the
winners.
This
is
something
that
krishna
is
proposed
for
evolution,
2021
and
he's
says
that
he's
got
some
progress
on
that,
and
so
this
deadline
is
march.
1St
and
again
we
don't
have
to
me,
you
know
if
this
isn't
the
best
venue
we
can
submit
to
something
else.
I'm
just
matching
up
these
submissions
with
venues
and
times.
C
I
also
have
something
called
euler
paths
for
life,
which
is
this
thing
that
I
presented
on
I
think
last
year,
and
that
is
let's
see
here.
It
is
so
I
have
two
versions
of
this.
I
have
a
network
science
version
and
an
evolution
of
development
version,
and
the
difference
is:
is
that
the
the
jargon
is
this
is
more
sort
of
biologically
friendly.
C
It
doesn't
have
a
lot
of
network
jargon
in
it
and
then
this
version
has
more
network
jargon
in
it,
because
it's
for
network
science
bless
you-
and
this
is
you
know
this
will
be
worked
out
over
time.
This.
This
version
here
is
going
to
be
submitted
as
a
full
paper,
so
this
will
be
worked
out
as
a
full
paper,
but
this
this
one
here,
the
evolution
development
version
is
going
to
be
submitted.
C
I
think
to
evolution
as
a
just
a
abstract
and
we'll
see
if
they
go
for
it
or
you
know
I
think
it'll
be
good
to
have
like
these
two
tracks,
because
it's
an
interesting
topic,
but
it's
not
you
know
we
have
this
difference
in
language
between,
like
you,
know
more
by
a
more
biological
audience
and
a
more
sort
of
computational
audience,
but
in
any
case
that's
something
if
you're
interested
in
contributing
to
that
it's
open
for
contributions.
The
deadline
here
is
march
1st.
C
C
So
that's
the
link
for
that
repository
and,
if
you're
interested,
you
can
make
a
pull
request
and
push
some
changes
to
that.
If
you
think
there's
something
we
should
cover
in
that
the
diva
learn
flash
talk.
I
did
this
monday
or
actually
tuesday,
last
tuesday.
So
this
is
this
conference
on
education
and
in
virtual
worlds.
Basically,
like
you
know
online
education
so
forth,
it
was
a
pretty
interesting
conference.
It
was
a
lot
of
unconference
topics.
C
They
talked
about
running
hackathons,
for
example,
which
is
like
you
know,
a
sort
of
an
event
where
you
can
work
out
problems
and
you
meet
virtually,
and
I
know
that
the
open
worm
foundation
has
had
a
couple
of
hackathons
on
different
topics,
and
so
I
had
some
insights
to
share
with
the
people
there.
We
were
putting
together
a
guide
for
you
know
where
we're
gonna
be
working
on
this
guide.
For
you
know,
academic
hackathons,
so
we'll
see
how
that
goes,
but
I
actually
gave
this
flash
talk.
C
I
haven't
had
any
you
know,
contacts
about
it
since,
but
I
mean
you
know
it's
something
that
people
saw
and
I
think
they
were
pretty
excited
about
it.
So
we'll
have
to
work
on
the
paper
that
we've
been
talking
about
and
get
that
out
as
well,
and
then
maybe
you
know
this
is
something
that
we'll
build
upon.
We
can
use
the
paper
and
this
flash
talk
to
advertise
it
to
people,
so
they
can
learn
more
about
it.
C
G
G
C
G
G
G
D
E
G
C
G
C
C
D
C
G
E
C
G
E
G
C
G
C
E
G
D
C
C
C
B
C
Yeah
the
waves
issue,
so
this
is
the
let
me
put
in
details
here
waves
issue,
and
then
we
have
the
other
paper
here,
the
periodicity
and
the
embryo,
which
of
course,
we've
talked
about,
and
that
has
there's
some
still
some
work
to
do
on
that.
We
have
to
find
a
video
for
that.
So
people
know
about
like
a
good
sort
of
public
like
a
public
access
like
a
wikimedia
style,
video
of
of
cell
division
and
and
things
like
that.
Let
us
know
because
we're.
E
C
I
also
have
this
paper
or
this
abstract
and
submitting
to
networks
or
netsci
2021
on
embryo
networks
and
connectomes.
I'm
going
to
submit
that
in
a
couple
days
the
deadline's
coming
up.
What
but
we'll
we'll
you
know.
Hopefully,
if
it
gets
accepted,
we
can
talk
more
about
it
in
the
meetings
and
other
people
maybe
can
participate
in
it.
C
C
C
If
you
want
to
work
on
anything,
let
me
know
we
can
go
over
the
deadlines
again
in
the
near
future.
I
think
you
know
if,
if
you
have
some
new
ideas,
we
can
put
them
on
there,
but
I
think
right
now
we're
pretty.
We've
got
a
lot
going
on
so
so
finish
off
and
I
know
some
of
you
have
to
leave
at
the
top
of
the
hour,
but
I
wanted
to
go
over
a
couple
papers
that
I
found.
C
This
is
the
paper
again
like
I
mentioned
in
when
I
was
going
over
the
the
blog
post.
This
is
the
scientific
data
paper
on
a
data
set
of
egg
size
and
shape
for
more
than
6
700
insect
species,
so
they
have
morphological
descriptions
of
insect
eggs
with
records
for
six
thousand
seven
hundred
and
six
unique
insect
species
and
representatives
of
every
extant
exopod
order.
C
So
this
is
a
lot
of
data
here
and
it
shows
this
data
set
includes
ex's
volume
span
more
than
eight
orders
of
magnitude,
and
so
this
this
data
set
was
assembled
by
automating
the
extraction
of
egg
traits
from
the
primary
literature.
So
a
lot
of
the
primary
literature
has
like
a
lot
of
descriptive
aspects
to
it,
and
you
know
they're,
just
basically
extracting
those
and
making
a
data
set.
So
this
is,
you
know
a
nice
way
to
get
a
big
data
set
together.
C
We'll
have
to
investigate
this
and
then
there's
this
associated
paper
insect
egg
size
and
shape
evolve
with
ecology,
but
not
developmental
rate,
and
so
in
this
paper
they
talk
about
over
the
course
of
evolution.
Organism
size
is
diverse,
has
diversified
market
markedly
changes
in
size
are
thought
to
have
occurred
because
of
developmental
morphological
and
ecological
pressures
to
perform
these
phylogenetic
tests
so
they're
looking
at
like
the
effects
of
each
of
these.
C
So
this
is
either
the
developmental
process,
the
actual
shape
and
physical
aspect
of
the
egg
and
then
or
organism
size,
and
then
ecological
pressures
like
you
know,
drought
or
temperature,
or
something
like
that,
and
so
they
generated
this.
So
this
is
talking
about
the
data
set
that
they've
generated
and
then
combine
these
with
genetic
and
life
history.
Data
set
so
they're,
actually
combining
more
data
sets
in
this
paper.
C
C
C
I
don't
really
know
how
they
define
that,
but
it's
something
about
how
they're
laid-
and
you
know
it-
helped
to
explain
the
diversification,
the
size
and
shape
of
insect
eggs.
Our
study
suggests
that,
where
eggs
are
laid
rather
than
universal,
elementary
constraints
underlies
the
evolution
of
insect
egg
shape
and
size,
so
this
must
be
aquatic.
Oval
position
must
be
where
they're
laid
in
like
an
aquatic
environment,
so
they
go
through
this
paper
and
you
know
it's
pretty
technical,
but
they
give
you
some.
You
know
they.
They
analyze
their
data.
C
C
So
you
have
different
groups,
like
you
know,
genus
what
they
call
genera,
so
they're
different
groups
of
species
along
this
axis,
and
they
show
that
egg
volume
does
correspond,
something
you
know
somewhat
to
this,
but
there's
a
spread
in
terms
of
the
actual
shape
of
the
egg,
and
so
that
you
can
see
that
these
colored
dots
are
colored
based
on
these
taxes.
So-
and
so
this
is
so,
they
have
this
really
long
very
detailed
graph
here,
but
they
basically
show
this
this
idea
of
a
llama
tree.
C
So
you
have
these
linear
functions
that
describe
growth
relative
to
some.
You
know
as
like
you
might
have
like
in
this
case
it's
egg
length
versus
egg
width,
and
so
you
have
all
these
like
trends
across
species,
and
you
can,
you
know,
plot
them
out
and
then
draw
a
function
through
those
points
and
describe
some
sort
of
scaling
relationship
between
you
know.
Is
you
have
like
an
egg
of
a
certain
size
and
shape?
C
C
Of
things
in
in
this
graph
that,
like
an
increase
in
slope
here,
is
like
where
certain
asp,
like
the
width,
is
sped
up,
and
this
slope
here
is
where
the
length
is
sped
up
relative
to
the
width,
and
so
you
can
see
in
development
how
you
can
get
differences
in
shape
this
slope
where
it
equals
one
is
like
a
spherical
egg
and
the
size
of
the
egg.
Is
you
know
it
it?
C
It
grows
much
wider
than
it
does
long,
and
then
this
in
this
case
it's
longer
than
it
grows
wide
and
that's
and
that's
how
that
works
so
yeah.
This
is
an
interesting
paper.
I'm
not
going
to
go
too
much
more
into
it.
But
if
you
want
to
read
more
about
it
so
I'll
see,
then
we
also
have
another
paper
on
centipede
embryos.
So
I
didn't
talk
about
centipedes
in
the
ants
and
plants,
but
they're
also
centipede,
embryos
and
centipedes
again
are
you
know
available?
You
can
harvest,
you
know
centipedes
and
hence
their
embryos.
C
I
don't
know
how
easy
they
are
to
work
with,
but
this
kind
of
goes
through
the
embryonic
development
of
a
certain
centipede
here,
strigamia
muritama
or
etima,
and
this
kind
of
goes
through
this
description
of
embryonic
development
of
the
species
of
centipede
and
again
this
is
another
arthropods.
So
we
have.
You
know
it's
very
similar
to
drosophila
and
ants
and
and
spiders.
So
we
have
this
this.
C
These
are
images
of
the
embryo
that
they've
taken
different
ways
here,
so
they
look
at
the
different
developmental
stages
of
the
egg,
using
different
markers
using
a
bright
field
approach
and
they
show
the
different
developmental
stages.
So,
if
you're
interested
in
sort
of
an
exotic
embryo,
this
is
a
paper
you
should
read
through.
E
C
A
little
bit
well,
it's
still
biology.
I
guess
this
is
a
new
paper.
It's
a
book
chapter
on
dynamic,
positional
information,
patterning
mechanism
versus
precision
and
gradient
driven
systems,
and
this
is
a
good
review
if
you're
interested
in
talk
in
thinking
about
the
position
of
cells
and
development.
C
Quote
claude,
shannon
who's,
the
father
of
information
theory
in
here,
and
the
quote
is
well.
We
feel
information.
Theory
is
indeed
a
valuable
tool
in
providing
fundamental
insights
into
the
nature
of
communication
problems.
It
is
certainly
no
panacea
for
the
communication
engineer
or
for
anyone
else,
and
so
they
they
talk
about
information.
The
reason
they
bring
up.
C
Positional
information
defined
as
shannon
information
helps
us
understand,
decoding
and
error,
propagation
and
patterning
systems.
They
also
talk
about
general
relativistic,
positional
information,
which
is
provide,
which
provides
a
metric
to
assess
the
output
of
pattern,
forming
mechanisms
so
they're
interested
in
pattern
formation
in
the
embryo
and
the
role
of
positional
information.
They
kind
of
get
into
these
two
definitions,
and
so
this
is
the
the
sort
of
thing
they're
going
to
cover
in
this
paper.
B
So
yeah
put
a
an
article
just
published,
which
critiques
these
kinds
of
views
of
the
additional
information
on
this
thought
supposedly
thought
up
like
lewis,
walker
and
he
he
waxed
and
weighed
whether
he
thought
it
was
true.
But
this
is
a
comparison
of
this
fresh
flag,
radiance
and
differentiation.
Waste.
C
Okay,
yeah.
That
looks
like
a
good
paper,
so
this
is
the
french
flag
gradients
entering
reaction
diffusion.
This
is
yeah,
so
check
this
paper
out,
and
so
I
I
think,
with
this
paper,
I'm
just
gonna
kind
of
leave
it
at
that
for
now,
so
they
talk
about
positional,
information,
developmental
biology
and
it's
you
know
it
may
or
may
not
be
the
case
I
mean
we're
trying
to
you
know
we
have
these
hypotheses,
and
so
they
go
through
a
lot
of
the
sort
of
the
argument
for
actually
they
talk
about
here,
because
this
is.
E
C
So
this
was
actually
lewis
woolper.
We
talked
about
a
couple
weeks
ago
and
he
just
died,
but
he
did
this.
He
had
developed
this
notion
of
positional
information,
so
we
have
this
model
called
the
french
flag,
which
is
what
dick
mentioned,
and
you
know
this
is
a
basically.
This
is
a
basic
pattern
formation
problem,
so
you
have
this
flag
that
you
want
to
replicate,
which
has
these
three
stripes
and
they're
different
colors
and
the
question
is:
how
do
you
arrange
the
cells
so
that
they
replicate
this
striped
pattern?
C
The
straight
pattern
exists
in
space,
so
in
this
hypothesis
there
is
this,
this
positional
information
that
the
cells
have
about
their
location
and
the
you
know
it's
done
by
what
they
call
morphogen
concentrations,
and
so
the
cells
will
differentiate
according
to
this
positional
information,
which
is
the
existence
of
this
morphogen
in
a
certain
part
of
the
embryo
or
the
in
this
case,
a
string
of
one-dimensional
cells.
And
so
you
know
the
question
is
whether
you
can
replicate
these
stripes
or
whether
it's
you
know
unsorted
or
what,
and
so
the
idea
that
you
have.
C
B
C
C
C
So
this
is
a
this
pretty
long
paper.
Actually
so,
but
they
do
talk
about
a
number
of
technical
issues
that
are
really
interesting.
If
you're
interested
in
development,
if
you're
interested
in
how
cells
you
know,
sort
themselves
and
form
patterns,
and
of
course,
this
paper
here,
okay,
dick
put
some
more
papers
in
the
chat
here,
mechanics
and
embryogenesis
and
embryonic.
So
that's
the
embryonic
stuff
and
then
he
has
a
paper
from
2001
making
waves,
which
is
in
cybernetics
and
systems.
C
So
this
is
a
very
cybernetics
oriented
thing,
and
so
we
can.
You
can
follow
up
on
that.
If
you're
interested,
I
think
that's
all
I'm
going
to
do
for
today.
I
think
we've
covered
enough
ground.
I
know
it's
somewhat
overwhelming.
Sometimes
I
go
through
these
papers,
but
I
wanted
to
give
people
a
taste
of
what's
out
there.
So
so
are
there
any
questions?
Anyone
have
any
comments
before
we
go.