0:07

So Cam,

0:07

question. Let's say we lived on a planet

0:09

where somehow living things were made up of

0:12

little plastic bricks. Just like Legos,

0:14

you could mix and match them and snap them and break

0:16

them to make all sorts of things. For the sake

0:19

of argument, let's say that the smallest bricks were about

0:21

the size of a regular earth-like protein.

0:23

How would Darwin say that entities composed

0:26

of these bricks would evolve?

0:27

I think as a gradualist, he'd say

0:30

if there was heritable variation and

0:33

some combination of these bricks had

0:35

a fitness advantage over other combinations,

0:38

then through small additions and subtractions

0:40

of bricks and enough time, natural

0:43

selection would lead to complex

0:45

groups of bricks, like maybe

0:48

brick elephants and brick jellyfish

0:50

and brick palm trees. Good,

0:52

fair story. Darwin would be proud. But

0:54

here's the important thing that Darwin's thinking

0:57

misses.

0:58

The only future thing any individual

1:00

can be is an extension of

1:02

that which came before. Oh no. I

1:05

don't think he missed that. That's

1:07

just another way of saying there's descent

1:10

with modification.

1:11

That was his focus, right? Leave

1:13

it to you to say something so obvious and try

1:15

to make it sound like it's profound. Fair.

1:19

I have been accused of occasional

1:22

hyperbole, but stick with me.

1:23

What if instead of bricks, life

1:25

on this fake world started with big

1:28

globs of stuff, blobs of fatty

1:30

acids, kind of like really little balls

1:32

of grosser, greasier Play-Doh?

1:35

How then would life evolve? Oh boy.

1:37

I know there's a trick here, but I'm going to

1:40

say the basic same way. Eventually,

1:43

after enough time, there'd be shapes and sizes

1:46

of different species. And in this

1:48

case, they'd be made up of little fat Play-Doh

1:50

instead of ultra tiny Legos. In

1:53

a general sense, that's probably right.

1:56

But think about the rate and extent of extreme

1:58

forms in such different systems.

1:59

The force of gravity would be very different

2:02

on a T-Rex made out of fat than one

2:04

made out of bricks, right? Okay,

2:06

I think I see where you're going. There could never

2:08

be a big fat blobby

2:10

T-Rex.

2:11

Unless the fat blobs evolved

2:14

into something more rigid, no species

2:16

like that would ever get that big, unless

2:18

it stayed in water. Yes, and this is the basic

2:20

idea of inherency. The focus

2:22

of our conversation today was Stuart Newman, a

2:25

professor of cell biology at the New York Medical

2:27

College. Stuart says that the natural

2:29

physical propensities of living matter enable

2:32

systems to evolve differently than Darwin

2:34

and other gradualists would have us believe. Just

2:36

like the dipole of a water molecule allows

2:38

it to absorb a lot of heat before it changes

2:41

temperature,

2:41

the materials that compose life

2:43

on Earth imbue them with particular

2:45

abilities to stay viable and exploit

2:48

opportunities. Okay, wait, isn't

2:50

that just a fancy way of saying constraint?

2:53

That evolution can only follow a path based

2:55

on what a lineage presently has and

2:58

elaborating on the things that came before. I

3:00

mean, we'll never find a lineage of sea cucumbers

3:03

with backbones, no matter how long we look,

3:05

because new species have to be variants on

3:07

a theme.

3:08

They have ancestors. And on a similar

3:10

note, you and Art always talk about

3:12

body size constraints. Life

3:14

forms and processes are limited just

3:17

because of simple surface to volume relationships.

3:20

I think we already know that stuff. Do we need

3:22

a new name for it? Well, Stuart says yes,

3:24

and I kind of agree. If we think of

3:27

size and phylogenetic history just as limits

3:29

on life, we might miss a potentially major

3:31

factor in life's evolution. Just because the first

3:34

life on Earth was made of my cells, little

3:36

orbs of fat molecules, major evolutionary

3:38

changes were possible. New morphological

3:41

and even functional doors were opened just

3:43

because life was originally composed of fatty

3:45

acids and not little plastic breaks.

3:48

Okay, let's hear from Stuart himself on

3:50

this.

3:51

As you'll hear, I was a bit skeptical on

3:53

some points, but it was a super interesting conversation.

3:56

On today's show, we talk with Stuart about the

3:58

potential role

3:59

of Inherent Sea and Evolution based

4:02

on work he and others have done with placozoans.

4:05

Placozoans are an extant lineage of organisms made up

4:07

of just six to nine cell types that

4:09

probably resemble the ancestors of all

4:11

modern animals. Stuart says that the

4:14

physical characteristics of these lineages have

4:16

had really important ramifications for how

4:18

evolutionary processes have unfolded.

4:20

Let us know what you think. I'm Cameron Gallenbore.

4:23

And I'm Marty Martin. And this is Big Biology.

4:37

Stuart, thank you so much for joining us on Big

4:39

Biology. It's really exciting to talk

4:41

to you about a paper that you wrote not too long

4:43

ago on Inherent Sea and Agency and

4:45

the Origins and Evolution of Biological Functions. I

4:49

think your main motivation, you wrote about

4:51

it in the abstract as such, was to question a central

4:53

aspect of evolutionary biology, the adaptationist

4:56

selected effects notion of

4:58

biological function. So that's a heavy

5:00

duty concept, I think. Can you

5:02

tell us what this selected effects notion is?

5:05

And what's wrong with the sort of perspective about

5:08

that in theory so far?

5:09

Yes, so it's

5:12

come out of philosophy of biology,

5:15

but it relates to standard

5:18

ideas and evolution. And it's

5:20

the idea that if

5:22

you see a function in

5:24

an organism, like the ability

5:27

of the heart to pump blood or the ability

5:30

of the lungs to absorb

5:32

oxygen, that

5:33

this has come about over

5:35

long

5:36

periods of evolution,

5:39

because the organisms

5:41

in the population were better adapted

5:44

to some external challenges

5:46

and they acquired that function in

5:49

a gradual stepwise fashion, according

5:52

to changes in their

5:54

genome, and we genes of small effect

5:57

iterated over many, many generations.

5:59

And the philosopher

6:02

Ruth Milliken kind of initiated

6:04

this and she said proper functions

6:07

or functions that have come up through

6:09

that route and that

6:11

there are what you might call functions

6:15

of organs like the heart's ability

6:17

to make sounds. Doctors

6:20

can use them, but those aren't proper functions.

6:23

Those are maybe side effects or something

6:26

because they haven't come up through this

6:28

kind of winnowing of natural

6:31

selection.

6:32

Later on, the philosopher

6:34

Karen Deander called

6:37

it the selected effects

6:39

model or theory of the

6:42

evolution of functions.

6:44

And I

6:45

took issue with that.

6:48

I had been looking at the evolution

6:50

of morphology for many years. The

6:54

initial entry into biology was

6:57

through limb development and looking

6:59

at

7:00

physical mechanisms

7:03

of pattern formation and so on.

7:05

I hadn't really thought

7:07

too much about functional evolution,

7:10

but I started looking into

7:13

how

7:15

differentiation occurs in

7:17

present day organisms and also

7:21

in the difference between

7:23

prokaryotes and eukaryotes, between

7:26

metazolins and other eukaryotes.

7:29

It really struck me that some

7:32

ideas about differentiation that had

7:34

been long held

7:36

were also flawed.

7:39

Stuart, I read the paper

7:41

and I wasn't familiar

7:44

with a lot of the philosophical

7:46

background on form

7:50

and function. I

7:53

was

7:54

pleasantly surprised by

7:56

how rich and what I thought was

7:59

a relatively straight forward, simple

8:02

perspective that form refers

8:05

to physical like structures

8:08

like bone, muscle, heart that you were mentioning,

8:11

but even cells and that

8:13

you know, you, you

8:14

look at these structures and

8:16

you, you can infer

8:19

something about their function,

8:23

you know, what they do, what they contribute to, if it's

8:25

muscle, how it contributes to running, you

8:28

know, what other measure of performance, but,

8:31

but then, you know, as somebody who works

8:33

primarily at the whole organism level,

8:35

I was also still

8:37

struggling with trying to see

8:40

why this

8:42

kind of more standard, maybe simplistic

8:44

view of form and function is

8:46

really problematic for for,

8:48

you know, people who work at the whole organism level,

8:51

because I think it's a very common assumption for

8:54

us. Right. So looking

8:57

at present day organisms, we

8:59

have extent

9:01

forms like sponges and plagozoans

9:03

and everything that we can't call them

9:06

ancestors, but we can infer backwardness

9:09

and looking at the fossil record

9:11

and looking at the

9:13

genealogy of the genes, we

9:15

can say that

9:17

the the earliest metazolins,

9:20

the earliest animals

9:22

were something like plagozoans,

9:25

which are kind of sandwich like white

9:27

simple organisms and

9:30

sponges,

9:31

which are a labyrinthine,

9:34

relatively simple

9:36

morphologies. And

9:39

we could say that the earliest

9:41

animals were clusters of cells that

9:43

took on

9:44

certain forms and they had cell

9:47

types,

9:48

but they didn't have many cell types. And

9:51

sponges have I think that 18 cell

9:54

types,

9:55

plagozoans,

9:57

some people say six, some people

9:59

say nine. But

10:01

they're much simpler. And

10:03

then you could ask about

10:06

those presumptively

10:08

or earlier organisms.

10:11

What were their functions? What these

10:13

cell types bring to them? And

10:16

they brought things like motility and

10:19

the ability to absorb nutrients from

10:21

the environment.

10:22

But particularly, if you look at

10:24

the placazons, you can

10:26

see that the cells are

10:28

not organized into tissues.

10:31

And there are no tissues that are

10:34

forming organs. But

10:36

there are cellular

10:38

functions, like the

10:41

fluttering of cilia, for example, that

10:44

for a cell, that cells

10:47

often don't have exposed cilia. The

10:50

exposed cilia comes in

10:52

with more complex organisms. But

10:55

cilia are

10:58

inversions of intracellular

11:01

structures.

11:02

So placazons have them on the

11:05

outside.

11:06

And they move around through

11:08

the environment

11:10

using cilia

11:12

in a concerted way. There

11:14

are these waves of cilia

11:16

that act like flocks of birds. And

11:19

they create this concerted

11:22

movement in which you can understand by

11:24

physical models. So

11:27

you can see how

11:31

cellular, what I call

11:33

functionalities, things that cells

11:35

do are kind

11:38

of recruited or

11:41

appropriated in the multicellular

11:44

system to do more complex

11:47

functions.

11:59

to dwell on the Placazones,

12:02

the sponges as well, but really the Placazones,

12:04

you make some fantastic cases about those

12:07

potential steps by which this happened and how

12:09

complexity may have emerged from these inherents.

12:13

But not too long ago, Cam

12:15

and our other co-hosts of the show, Art Woods, they

12:18

spoke with Nick Barton about

12:20

many different things, but one of the main themes was

12:22

Ronald Fisher's infinitesimal model. And

12:25

I think you mentioned that in your paper. The

12:27

basic idea in the model is that most traits are determined

12:29

by many, many genes of small effect. What

12:33

did he say that meant for evolution?

12:36

And what is your perspective on

12:38

the infinitesimal model given the ideas

12:41

of cellular dispositions? So

12:43

Fisher was basing

12:45

his

12:47

ideas and his mathematical models on

12:50

Dorwin's theory of natural selection. It

12:52

was a very clever theory. It said that

12:54

you could get arbitrarily

12:57

complex forms

12:59

by building them up little by little

13:02

and over long periods of time.

13:05

And

13:08

let's hypothetically say that you

13:10

have an organism that changes

13:13

radically to another organism. What's

13:16

the trajectory between the two?

13:18

Well, Dorwin has

13:20

a gradualist

13:22

trajectory, and he says that

13:25

there's variation and that organisms

13:28

are a little bit different. And if

13:30

they're more prevalent in the

13:32

next generation, that's

13:33

a step to become a little bit different

13:36

from that and so on.

13:37

And you have this continuous trajectory.

13:40

So that's basically the

13:42

infinitesimal model is like a

13:44

mathematical rendition of that

13:47

idea.

13:48

But in fact, developmental biology

13:50

shows us that with

13:53

small changes

13:56

in the genome, you can

13:58

have very large changes in morphology.

14:01

and you can have large changes in

14:03

even functions. So you

14:05

can have genes of large effect

14:08

and then the question becomes

14:10

could those survive

14:13

if you have a population

14:15

with some extreme outlier

14:17

because of some developmental change. And

14:20

Darwin knew about these things, he called them sports,

14:23

and he considered them just random

14:25

occurrences and that there was no

14:28

rhyme or reason to, he couldn't explain

14:30

them and he said that they really didn't contribute

14:32

to evolution.

14:33

And

14:35

that's Fisher's position. Fisher

14:38

had another paper called the geometric model.

14:41

He said that

14:42

mathematics of natural selection don't

14:45

work if you have big changes,

14:48

because they're not tolerated

14:50

by the population in the midst of the population

14:53

that it's swimming in. So

14:56

those two things together are very much in keeping

14:58

with Darwin's model, but I think that bringing

15:02

development into evolutionary theory

15:05

changes the whole terrain. I

15:07

kind of want to push back a little bit on that because

15:10

I think the idea

15:12

with the geometric model is

15:14

really more that

15:16

if a population is close

15:18

to its kind of adaptive peak,

15:21

then any mutation

15:23

of large effect is going to have a

15:26

negative deleterious effect and kind

15:28

of push them further away from that optimum.

15:32

But I think what you're talking about is more at

15:34

a sort of macro evolutionary scale,

15:37

as opposed to sort of that that kind of

15:39

local micro evolutionary scale

15:41

that both the infinitesimal

15:43

model and the geometric model are

15:46

kind

15:46

of more concerned with. You know, I see

15:49

this a lot in both

15:52

historically and currently that there's

15:55

a long history of skepticism about the

15:57

importance of natural selection.

15:59

acting on continuous

16:02

variation on genes of many small

16:04

effect. And I guess

16:07

to me, one of the problems here

16:09

is, and when we want to, I think when

16:11

we want to incorporate development into

16:14

evolutionary theory, is

16:16

that we have to also be cognizant

16:19

of the mechanisms that

16:21

are associated with generating

16:23

variation. So

16:26

genetic changes, developmental programs,

16:29

some of which can have,

16:30

without a doubt, large effects,

16:33

rapid effects, with the process

16:35

of selection, which is just acting on

16:37

the variation that is

16:39

available to it. I don't see

16:42

the process of selection kind

16:44

of as a creative force

16:47

here. It's just acting with whatever variation,

16:50

genetics and development, and

16:52

physiology and behavior kind of put out

16:54

there. So how do you see these

16:57

two sets of processes? The processes that

16:59

generate the variation versus the

17:01

process of selection acting on that variation?

17:04

Okay, so

17:06

let's say that we have some

17:08

large effects change, and

17:10

this could come about

17:12

by maybe

17:13

the import of

17:15

a new gene into a lineage. You

17:18

have some more lateral transfer, and this

17:21

happens with the head crest of

17:23

pigeons.

17:24

You have

17:26

different lineages of pigeons, and

17:28

they have an introgression

17:30

of a particular gene, and then they get

17:32

the head crest instantly.

17:35

So

17:36

it could happen that way, or it could happen

17:39

by the environment

17:41

changing, and

17:44

different rates of existing

17:46

processes change

17:49

in relation to each other, and then you get some

17:52

developmental alteration

17:54

that gives you a

17:55

new morphology. So there are many

17:58

ways that you can get jumps. then

18:00

the population is faced with whether

18:03

these things are going to survive or not.

18:05

Okay, so

18:07

it might be that variant

18:09

groups can form, you know,

18:12

by

18:12

sympatric selection.

18:14

You can have the

18:16

possibility of compatible

18:20

subpopulations

18:22

within a given

18:25

environment that's possible. Or

18:28

organisms can kind of strike out on

18:30

their own if this happens to a group

18:32

of organisms.

18:34

Somehow their

18:37

particular genome makes

18:39

them susceptible to an environmental change

18:42

so that you have a novel subgroup

18:44

with novel properties. They can stake

18:46

out a different niche.

18:48

This happens in plants

18:50

a lot and the

18:53

organisms are quite different from their

18:56

parental population

18:57

and they just stake out a new niche. This

19:00

is where

19:02

I kind of bring the concept

19:04

of agency into evolution

19:07

and other people have too. Organisms

19:10

don't just kind of sit there and say, well,

19:12

I'm not really

19:13

good enough for this niche that I've arisen.

19:16

I'm just going to stay here and die. They'll

19:19

just kind of explore the environment

19:21

and find some way of

19:24

kind of mobilizing their new properties

19:27

so that they can

19:29

survive. And living

19:32

systems have this drive to

19:34

kind of prosper. So

19:38

Richard Lewington talked about the

19:40

organism

19:42

as the object

19:44

and subject of evolution.

19:47

And

19:47

it seems to me that the

19:50

kind of standard natural selection idea

19:53

says here you have some novelty.

19:56

The organism is sitting there as an object

19:58

of selection.

19:59

doesn't kind of comport

20:02

with the originating

20:04

population's

20:06

adaptation to its niche, so it just

20:09

dies because

20:10

the effect is too large.

20:12

But the organism

20:15

as the subject of evolution says,

20:17

well,

20:17

look, I'm

20:20

bipedal and my

20:22

cohorts are not, so what am I going to

20:24

do with it? I'm just going to walk to

20:26

a different place and be a different kind

20:28

of organism.

20:31

So basically, that's the

20:33

idea that developmental processes,

20:35

if modified in various ways, can

20:38

give you new kinds of organisms. And then

20:40

the question is, are the organisms

20:43

content to just be selected

20:46

the way their cohorts are, or

20:48

will they just

20:50

become new kinds of organisms by founding

20:53

new niches? Yeah, I mean, I

20:55

know Cam has strong feelings about

20:57

the concept of agency, as do I,

21:00

but we come at different, we come at

21:02

that from different sides. Maybe we can say

21:04

a little bit more about agency in a

21:06

minute. But what I'm hearing you to

21:08

say, Stuart, is that, you know, I think

21:10

Cam's question was whether selection could

21:12

be a generative force,

21:14

like, you know, where the variation, where this

21:17

new stuff is coming from. And I'm sort of

21:19

hearing you say that it's

21:21

kind of what Cam was talking about, that where

21:23

the variation comes from is going to be from

21:26

other processes. And you named a lot of them, but

21:28

it's not so much that selection is generating

21:30

the new force, selection is acting as some sort of a

21:32

filter. Right. Okay,

21:35

okay. Maybe let's turn then

21:37

to this, getting into the

21:39

details about, you know, the sources

21:42

and kinds of this variation, and

21:44

this word of, word inherency

21:47

that we've mentioned a couple of different times. You

21:50

say that multicellular

21:53

aggregates, particularly those in plants and animals

21:55

during development, have evolutionarily

21:58

important natural. physical propensities,

22:01

physical propensities, due to their nature

22:03

as biological matter. And this made

22:05

the acquisition of morphological motifs almost

22:08

inevitable. So I think that's a beautiful

22:10

sentiment and yet complicated. Can you

22:12

explain what that is and how that means inherency?

22:15

Sure. So first

22:17

I'll use a simple physical analogy.

22:20

So if you look at

22:22

water molecules, water molecules

22:25

have certain properties, but

22:27

you wouldn't say water molecules

22:29

have waves or whirlpools

22:32

or anything like that. They're just molecules.

22:34

But if you put them together, forces,

22:38

kind of chemical Van der Waals forces

22:40

them, so kind of make them cohere.

22:43

And then you have liquid water.

22:45

And liquid water can

22:48

just be a drop or it can be a kind

22:50

of a still surface. But if you

22:52

disturb it a little bit, it can

22:55

generate waves or it can generate

22:57

whirlpools or it can generate

22:59

water seas of kind of

23:02

chaotic nature. So

23:04

there are various inheritances

23:07

of liquid water

23:09

that you wouldn't have necessarily predicted

23:11

from molecular water.

23:13

And water at certain temperatures

23:16

can also freeze. It's very difficult

23:18

to make a branched

23:20

structure from liquid

23:22

water.

23:23

But if you have frozen water, it

23:26

organizes into

23:28

crystals like snowflakes and branches

23:30

and so on.

23:31

So

23:33

different forms of matter

23:35

have different inheritances. And

23:39

the inheritances create a

23:41

morphous space. So

23:44

if you look at water,

23:46

you can't say that it's all those things at the same

23:49

time. But you can put it under different

23:51

conditions and it will express

23:54

those different forms. Now, when

23:56

you look at

23:57

animals, for example, arose

24:01

from cells that are called

24:03

holozoans. Holozoans

24:05

are a lineage of

24:08

single-celled organisms who are transiently

24:10

multicellular

24:12

organisms, or they include

24:14

animals.

24:15

And when the metazoans,

24:19

which are the animal

24:21

branch of the holozoan

24:23

lineage, emerged,

24:25

the cells became attached to

24:27

each other by a protein that

24:29

was newly acquired, newly

24:31

evolved in some way.

24:33

These are the coherence,

24:36

classical coherence, and

24:38

they allow cells to

24:40

remain attached to each other and

24:43

at the same time move relative

24:45

to each other.

24:46

So when you have

24:48

a material whose subunits

24:50

are simultaneously changing

24:53

position but remaining coherent,

24:56

that has liquid-like properties. Contrast

24:59

it to plants.

25:00

If you look at plant cells, they

25:02

have a solid matrix, cellulose,

25:05

that connects them to each other and

25:07

they're not moving relative to each other.

25:09

Those types of materials have different

25:12

inheritances and

25:14

you

25:14

could predict ahead of time by looking

25:17

at

25:18

aggregates, animal cell aggregates, that

25:20

if you had subgroups

25:23

that were differentially

25:25

cohesive,

25:26

that you would get layers.

25:28

Or if you had subunits

25:30

that had polarity,

25:32

you could get cavities inside the

25:35

massive tissue. So basically

25:37

there are inheritances

25:39

that came about when this

25:41

material first appeared on the

25:43

face of the Earth that had certain inheritances.

25:46

And if you wanted to ask

25:48

how could it evolve, you can make

25:50

changes to it if you maintained

25:52

its nature

25:53

but made small changes. What could happen?

25:56

Well not everything could happen,

25:58

but some things could happen.

25:59

and it could take you into

26:02

different realms. It could get segmented

26:04

structures, it could get hollow structures, it could

26:06

get structures with appendages,

26:09

it could get structures

26:12

that had internal hard skeletal

26:14

structures, you could get organisms that

26:16

had external hard skeletal

26:18

structures and so on. So if

26:21

you can almost generate

26:23

the whole panoply of animal

26:25

forms by looking at the inheritances

26:28

of the

26:29

original metazoan aggregates. So

26:32

I find this idea really fascinating

26:34

Stuart, but Cam and I have talked,

26:36

we prepare for these episodes, and one of the things that came

26:39

up in our conversation, and I think it was a great point, Cam

26:41

I'm gonna speak for you, I'm just gonna steal your thunder. Why

26:44

is this not a constraint? What's

26:47

the difference between physical constraint

26:49

versus inherently because

26:52

of the underlying physics? Is

26:55

there a difference there that's important? Well,

26:57

I think that a constraint says

27:00

that it's a limiting factor. If

27:02

something is an enabling factor,

27:06

if I told you that a mass

27:08

of tissue,

27:09

if you just kind of

27:11

retuned some of the adhesive

27:14

and metabolic components,

27:17

you could get segments. Would

27:19

you say well, segmentation

27:22

is a constraint

27:23

of a mass of tissue? Yeah.

27:25

Yeah, that's fair. I

27:27

think also like in the evolutionary

27:30

literature, the term bias

27:33

is also used kind of

27:35

in the same context that

27:37

a bias may act as a

27:39

constraint, but it also may enable

27:43

certain outcomes over others. And perhaps,

27:46

inherently then is kind of capturing

27:48

both sides, the bias

27:51

enabling side and the preventive

27:54

side as well. hymnals

28:06

So

28:07

if I understand you correctly, you

28:09

know, inherency seems to be a very

28:11

important concept because it means that the

28:13

cells have certain properties

28:16

that predispose them to make

28:18

these particular types, I think, of structures.

28:21

I think you refer to these as motifs, which

28:24

in turn are then modified during the evolutionary

28:27

process. However, unlike

28:29

water molecules, the cells

28:31

have their own evolutionary history

28:34

and they have the ability to be dynamic

28:36

and

28:37

plastic depending on the environmental

28:40

context or I think, you know,

28:42

in reading your work in the type

28:44

of organism that they're found in.

28:46

So we think a lot about that

28:49

type of context dependency

28:51

in the framework of phenotypic

28:53

plasticity.

28:55

And I'm curious how you

28:57

see inherency related to the

28:59

concept of plasticity.

29:01

Yes, well, I think that it's

29:03

very related. If you look at

29:05

the

29:07

capabilities with the inherences

29:09

of any mass of tissue, then

29:12

you could say under what circumstances

29:15

will one or another of the inherences

29:18

be manifest and be expressed. Once

29:21

you can

29:23

take a particular organism

29:26

and put it in a new environment

29:28

and it will manifest. So

29:31

if you look at our bodies, if you put

29:33

us in water and

29:35

you have turbulence and so on, our bodies don't

29:37

change shape. If you take a jellyfish

29:40

and you put it in water, its

29:43

body changes shape. So basically,

29:45

the physical properties

29:47

of its body accommodate to

29:50

the environment in a way

29:52

that ours don't. We

29:55

have ways of resisting those

29:57

forces, those simple forces.

29:59

in the environment. But

30:01

if you look at the developmental

30:03

process, you could look at

30:05

how segments are formed, for example.

30:08

Segments are formed

30:09

by some oscillating

30:12

gene expression process, and

30:15

that gets coupled with growth. And if

30:17

growth

30:18

has a certain pace and

30:20

the oscillation has a certain pace, you'll

30:22

get a certain number of segments. And

30:25

that

30:26

segmentation number is

30:28

characteristic whether

30:30

it's a mouse or a human, which

30:32

has a couple of dozen segments, or

30:35

a snake which might have a couple of hundred

30:38

segments. But you can

30:40

take organisms like centipedes, and

30:42

they have a certain number of body segments,

30:45

and you can change the temperature. And

30:48

the number of segments will be different

30:51

at different positions on a climb,

30:53

a temperature climb. So there's a kind of a modulation,

30:56

and that's plasticity that's modulating.

31:00

And that's why we need to take some inherency

31:02

to make the organism different

31:05

under different circumstances. Okay, I wanna come

31:07

back though, Stuart, to something that you

31:09

said at the beginning, now that we've defined

31:12

inherency in a more explicit way,

31:15

and we've talked through some other things. One of the first things

31:17

that came up was function, these

31:20

proper functions of Milliken. So in the context

31:22

of inherency and

31:25

generating morphological novelty, I can follow that.

31:28

What is inherency and function?

31:32

Can you get us there? I mean, what

31:34

are examples of inherency leading to Milliken's

31:36

proper functions?

31:37

Sure, well, it

31:40

wouldn't necessarily be a proper function

31:43

in her sense, because her sense of the

31:45

proper function is one that has

31:47

arisen by natural selection. Okay,

31:49

good point, yeah. But I would say that

31:52

if we just look at things

31:54

that our bodies do, like we

31:57

have muscles that

31:59

contract.

31:59

and allow us to locomote,

32:02

or if they're smooth muscle, they

32:05

may allow us to convey food down our

32:07

digestive tract.

32:09

Where did the muscles come from?

32:12

And if you look at single celled

32:14

organisms, particularly

32:16

the hoizoan

32:17

cells that gave rise to the animals,

32:20

they have contractile functions. Cells

32:24

have a meepoid motion. And

32:26

if you look at the meepoid motion

32:28

inside a single cell,

32:30

it's mediated by actin and bias

32:33

to proteins and a number of accessory

32:36

proteins like tropomycin. And

32:38

if you look at muscles, both skeletal

32:41

and smooth muscle, and also cardiac

32:44

muscle,

32:45

the same proteins

32:47

are involved, the ancestral proteins,

32:50

but now they're involved in specialized

32:53

cell types and tissue types.

32:55

So what's happened is that those cells

32:58

differentiate. They give up certain

33:00

properties that are common to

33:03

most other cells or even with the ancestral

33:06

cells. So for example, ancestral

33:08

cells use those

33:10

cytoskeletal proteins to divide

33:13

and to multiply into

33:16

more cells. Skeletal muscle

33:18

doesn't do that. It gives up the ability

33:20

to divide.

33:22

Nerve cells are other

33:25

differentiated sometimes that don't divide.

33:27

So what's happened here is that

33:29

they're part of a more complex

33:32

organism

33:33

and they're kind of carried along and sustained

33:35

by the

33:36

circulation system. Other things they

33:38

don't have to divide

33:40

to

33:41

keep going. And they

33:43

have a specialized function now

33:45

that's an appropriation

33:47

of this ancestral contractile

33:50

function.

33:51

But now it is in the service

33:54

of a more complex organism that

33:56

is sustaining that tissue

33:58

type. in ways that it can't

34:01

sustain itself. So it gives up

34:03

something and it's appropriate in something.

34:05

One thing that I'm having a little bit of a difficult time

34:08

with is,

34:09

well, can you say something more specific

34:12

about the original roles

34:15

or what was it about actin and myosin

34:17

or proteins like that that sort

34:19

of has this flavor of inherently?

34:23

Because eventually, there's

34:25

sacrifices made by those cells

34:27

that eventually evolved to become muscle cells. Now

34:30

they can do contraction, which used

34:32

to be used in amoeboid cells for locomotion. Where

34:35

did the inherency initially come in? Because the inherency

34:37

part isn't really there.

34:39

There's a legacy, an evolutionary legacy

34:41

when we go from cellular cell to multicellular amoeboid

34:44

to... But what was the inherency,

34:46

the very first step of inherency with actin myosin?

34:49

So that I don't know. In

34:52

all of the things I've written about this, I

34:55

try to make it clear that I

34:57

don't know

34:58

how cells evolved.

35:01

There are people that study the origin of life,

35:03

the origin of cells, and there

35:05

are

35:05

people, particularly

35:07

philosophers that talk about things

35:09

like auto-pouisis or

35:12

the organizational approach

35:15

of Moreno and

35:17

Mocio. People

35:20

talk about those things. There are very

35:22

few

35:23

molecular models of how

35:25

that works, but it's very clear

35:27

that cells are self-sustaining

35:30

systems that interact with the environment.

35:34

That's not my area. My area is

35:37

the evolution of multicellular organisms.

35:40

And when I talk about inherency there,

35:43

I'm not saying that the

35:45

function of actin and myosin

35:47

in single cells

35:50

is an inherent process. But

35:52

if I ask, how did

35:54

multicellular animals first

35:57

acquire the ability to

36:00

have specialized cell types that

36:02

allow the whole organism to locomote,

36:06

to move around.

36:08

What I

36:09

have concluded is that

36:12

they did it by appropriating

36:15

inherent properties of cells.

36:17

Now, what are inherent properties of cells are

36:19

motility.

36:21

So

36:22

motility is a property of cells

36:24

absorption is property of cell

36:27

excitability, the

36:29

ability to bind oxygen, the property

36:32

of cells, the ability to detoxify

36:34

the property of cells. So when

36:37

you look from the point of view of

36:39

a multicellular organism

36:41

and you say, what can I use

36:44

based on what I'm made of

36:46

that will allow me to do new things? Well,

36:49

there are inherent seeds of cells that

36:51

I can appropriate to become tissues

36:54

and cell types. Let's move to the placazolins.

36:57

I just love some of the word choices that you

37:00

have in this paper. So you

37:02

talk about the placazolins as a

37:05

potential ground state of

37:07

animal identity. What does that mean?

37:09

And maybe connect it to the points that you're making about

37:12

the different cell functions that have

37:14

been embellished in modern forms.

37:16

So it's important to realize that the

37:19

different kinds of animals, and

37:21

particularly

37:24

what has been identified historically

37:26

as the phyla, actually have objective

37:30

differences from each other. The sponges

37:33

and the placazolins are

37:35

often called basal metazolins.

37:38

I think that's not a good term because

37:41

these are extant modern day

37:43

forms. They're not basal to anything.

37:46

So there's another term that's used which are called

37:48

parazolins. They're in contrast

37:51

to the eumetazolins. The

37:53

eumetazolins are things

37:55

like chordates and

37:57

molluscs and arthritic.

37:59

and so on. So those are all

38:02

eumetazones.

38:03

And even there's a kind of an

38:06

intermediate, like Hydra, Ciderians,

38:09

and their antenna forts, which

38:11

are called comb jellies. Those

38:14

are, they're eumetazones, but

38:16

they're diploblast.

38:19

They only have two layers, they're not triple

38:21

blast, they don't have three layers. And

38:23

if you look at what's the objective differences

38:26

between these different classifications,

38:29

you find that there are certain

38:32

genes that

38:33

are present, beginning with the

38:36

Ciderians

38:37

and Ctenophores that

38:39

allow layers of cells,

38:42

which we call epithelia, to sit on

38:45

a surface called the basement

38:47

membrane.

38:48

And the enzyme

38:49

that produces the basement membrane

38:52

from collagen, collagen is

38:54

a very ancestral molecule that's

38:56

present in all animals. But the

38:58

collagen does not polymerize into

39:01

a surface,

39:02

into a substratum until you get

39:04

an enzyme called peroxidase,

39:07

which only comes in with the

39:10

diploblasts. Okay,

39:12

so it's a little bit technical here,

39:15

but the point is

39:17

that there are new genes

39:19

that kind of seem to appear

39:22

suddenly. And they may

39:24

have had a gradual evolutionary

39:28

trajectory. There's no evidence that

39:30

they have been laterally transferred

39:32

from other organisms. They

39:35

just are not found anywhere but in

39:37

the organisms that have them.

39:39

And in the case

39:41

of animals like us, triple

39:44

blast, things like fiber nectar

39:46

didn't exist in earlier forms.

39:49

And that's an extracellular matrix that's

39:51

important for our connective tissues and so

39:53

on. Things like hydrodon't

39:56

have connective tissues,

39:58

but triple plastic organisms.

39:59

like us have connective tissues and

40:02

that is accompanied

40:03

by new genes that

40:06

perform functions that were not present

40:08

in the earlier forms. So

40:11

getting back to the question about

40:14

plaqueazones being the basal

40:17

anazones, they have basically

40:20

two layers of cells, they're epithelial

40:23

like layers, it's a top

40:26

layer and a bottom layer but they don't

40:28

have basement membranes so

40:30

they're not

40:31

what we call true epithelia, they're

40:34

kind of

40:35

flimsier, much flimsier and they

40:37

can't put out appendages,

40:40

they can't make limbs, they can't make even

40:43

hairs or projections that

40:47

they just can't, you need

40:50

a basement membrane to make appendages.

40:53

So they're just two flat layers but

40:55

they're covered with cilia

40:57

and the cilia

40:58

are present in ancestral cells

41:01

so they didn't have to evolve

41:03

de novo in the

41:05

plaqueazones, they were already there, they're just

41:07

appropriated

41:08

but they do new things in the plaqueazones

41:12

because they're acting in a kind of a concerted

41:14

wave-like fashion, they're doing things

41:18

that were never

41:20

foreseen in the individual cells

41:23

in which the cilia first evolved.

41:26

So the thing is that when you get

41:28

onto the multicellular scale

41:30

you can appropriate

41:32

ancestral functionalities to

41:34

do completely

41:35

new things just because of the

41:38

scales like the molecular water,

41:41

when it finds itself as part of a

41:43

drop of water or a body of water

41:46

it can do new things, it can make waves and

41:48

so on

41:49

that weren't possible before.

41:52

So if I can like jump in

41:54

and kind of ground this in a particular

41:57

species of plaqueazones so there's

41:59

trichoplax adherens

42:02

is the species. And so this is a very

42:04

small placozoan, maybe only a

42:07

millimeter long. As

42:09

you mentioned, it has these two

42:11

epithelium layers and is

42:14

only made up of six or

42:16

nine cell types. And

42:19

so you were talking about the cilia. I'm

42:22

very curious then,

42:24

what else do we know about the origin

42:27

of these different cell types before

42:29

they show up in trichoplax? Can

42:32

you talk about other cells and

42:34

their functions and

42:37

what their evolutionary history is

42:39

prior to showing up in placozones?

42:42

Do we have a phylogeny

42:45

of these individual cell lines that

42:47

goes back to the unicellular ancestors?

42:50

Yes. It's a very interesting

42:52

thing I just want to say about the

42:54

placozoan. So is it? Lots

42:57

of people were several groups

43:00

that look at the genetics

43:04

and relate them to the genetics of

43:07

non-animal holozoans. And

43:11

one of the most prominent things about

43:14

the metazoan, sea animals,

43:16

is the use of enhancers

43:19

to amplify

43:21

gene expression.

43:23

And enhancers

43:25

are not universal in all eukaryotic

43:28

cells.

43:29

They're really used

43:32

in a very special way in the animals. And

43:34

they congregate in

43:36

these expression hubs for amplified

43:40

genes in the animals. And they're

43:43

kind of central to the development of

43:45

cell types.

43:46

And it turns out that nobody's ever

43:48

found enhancers

43:50

in placozones. So

43:53

placozones

43:54

have specialized

43:56

cell types. But they're kind

43:59

of.

43:59

They're very primitive. The

44:02

specialization is kind

44:05

of the overproduction

44:07

of certain molecules. So the placosomes

44:09

have digestive cells,

44:11

which means that they

44:14

have degradative enzymes that they secrete

44:17

into the environment

44:19

that are similar to our digestive

44:21

enzymes in some way, and they're similar to pre-existing

44:29

lytic enzymes that were made by

44:31

single celled organisms. But they're

44:33

not

44:35

digestive cells like we have digestive

44:38

cells.

44:40

They're not as complex, and

44:42

they're just kind of the overexpression

44:44

of certain

44:45

genes. So there's a kind of an

44:48

abortive attempt at differentiation

44:50

in placosomes, and it's a bit

44:52

of a controversy as to whether

44:55

placosomes are

44:57

a form

44:59

that was from kind of a more complete

45:01

metazoan

45:03

repertoire that just lost

45:05

the ability

45:07

to use enhancers or something, or if

45:10

they in fact are the

45:12

primitive state. But in

45:15

any case, placosomes don't really have

45:17

genuine cell types the way even

45:20

sponges do, because sponges do

45:23

use enhancers,

45:25

and all other

45:27

other metazolins

45:29

use enhancers.

45:31

The other thing about placosomes

45:34

is that there's a pathway that's also

45:37

almost universal in the animals for the

45:39

notch pathway,

45:41

and the notch pathway is very important in

45:44

creating patterns

45:46

of cell types that we see in tissues

45:48

and organs. So

45:50

the notch pathway, if

45:53

the cell expresses

45:54

one component of

45:56

the notch pathway, it will

45:59

interact with a nearby cell and say, don't

46:02

do what I'm doing.

46:03

Just do something different. It

46:05

kind of suppresses the

46:08

adjacent cell from following

46:10

the same route

46:11

as the notch

46:13

expressing cell. And placazons

46:17

are missing some components of the notch pathway.

46:19

It's not that they don't have it at all,

46:21

but they don't have it. They don't have

46:24

it as efficiently and they're good as well.

46:26

And this is also an

46:29

impairment

46:30

in the ability

46:32

of placazons

46:34

to take whatever cell types they

46:36

have and turn them into organized

46:38

tissues.

46:40

And

46:42

even sponges have some

46:45

aspect of organized

46:46

tissue. It's not as advanced

46:49

as it is in the

46:50

imput glass and so on, but it's there.

46:53

But it's less there in the

46:55

placazons. So they're deficient

46:58

in a number of

46:59

things. And it's not clear whether their

47:01

ancestors never had it or

47:04

their ancestors never,

47:07

or their ancestors lost

47:09

it.

47:10

In any case, with

47:12

the placazons, they have

47:15

some

47:16

cells, crystal

47:18

cells,

47:19

that form

47:23

little crystalline inclusions

47:26

that allow a kind of

47:28

gravity sensation.

47:30

So they're kind of a primitive

47:33

form of a sensory cell.

47:35

And they also have

47:37

kind of a primitive neurosynaptic

47:43

types of components. They

47:46

don't have nerves.

47:48

They don't form synapses, but they

47:50

have cell types

47:53

that have

47:54

some excitatory

47:57

functions that you

47:59

could see.

47:59

or the makings of where eventually

48:02

became nerve

48:03

cells and

48:07

more about the neurons.

48:09

Yeah. So this is really cool and

48:11

I have so many questions about placazones

48:15

and especially what you were talking about a minute ago with the

48:17

evolution of this enhancer sort

48:20

of scenario for gene regulation. However,

48:22

we'll have to save that for another time

48:25

because I want to get us, I want to stay in

48:27

this area of inherency and

48:29

I want to bring in a new player to this conversation.

48:32

I mean, literally new in the evolutionary

48:34

sense because this guy Mike

48:36

Levin at Tufts University and his colleagues

48:39

literally invented these new forms

48:41

of life, what they call biobots.

48:45

And you tell a really compelling story and

48:47

in full disclosure, Mike has been a repeat

48:49

guest on this show. So we're really, really big fans

48:51

of Mike's work. But how do you

48:54

understand inherency? I mean, what

48:56

kinds of inherency have you seen in these

48:58

biobots? Maybe for the listeners that

49:01

didn't hear those shows or don't know Mike's work, tell

49:03

us a little bit about what these biobots are. Right.

49:05

It's remarkable work and I'm also

49:07

Mike's work on that and also

49:09

on the electrical field

49:12

scaffolding of structures. Yeah,

49:14

it's really brilliant work.

49:16

So with the biobots, what

49:19

they do is that they take cells

49:21

from frog embryos,

49:24

and of his embryos from the it's

49:26

called the animal cap.

49:28

And it's a homogeneous population

49:30

of cells

49:31

and they dissociate them

49:34

and they re aggregate them into spheroids

49:38

and spheroids have

49:40

externalized cilia. So

49:43

basically, spontaneously, they take

49:46

structures that might

49:47

be active internally

49:50

in the animal cap cells, but

49:52

they get externalized

49:54

and these little spheroids can

49:56

kind of scoot around

49:58

and they can find their way through mazes.

49:59

and things like that. And

50:02

this is nothing that they do when

50:04

they're part of the frog embryo. Frog

50:07

embryo, they may have these capabilities

50:10

inherently, but

50:12

those capabilities are suppressed

50:14

in the service of certain

50:16

stages of frog development. So

50:18

they're not doing that. But here they're

50:21

put in a completely new context. They

50:23

haven't undergone any kind of Darwinian

50:26

selection.

50:28

But they're just

50:29

cells that are in a new context.

50:32

They're given sources of nutrients

50:34

which they navigate towards.

50:37

So they act like organisms that

50:39

never existed. So yeah, I

50:42

want to really drive this home steward because I think

50:44

that what we've been talking about with holozones

50:46

and placozones, this is great. This is what happened

50:48

on the planet. But this is really

50:51

amazing because these cells have

50:53

never had the opportunity evolutionarily

50:56

to exist as these entities. And yet when

50:58

you put bunches of them together, you

51:01

said they navigate mazes. How

51:04

is that? These are just embryonic frog cells.

51:06

Can you say more about

51:07

how Mike found that to

51:09

be the case? Well, I

51:11

think that they just observe things carefully

51:14

and then they set up challenges to see if they

51:16

can meet the challenges. They've

51:18

done similar things with phyzorum. Phyzorum

51:20

is a slime mold.

51:23

But

51:24

I would say, and I think

51:26

Mike would agree, that their

51:29

ability to do this is based on the

51:31

fact that individual cells

51:33

have an agency of their own.

51:36

They have what has been called

51:38

primitive cognition.

51:41

They basically exist

51:45

in the world as living entities

51:48

and they're not simply passive.

51:50

It's not like if you take a cell

51:53

type,

51:53

an individual cell, and

51:55

put it in a new place, it will instantly

51:58

die because it's never seen

51:59

people.

52:00

It'll figure out how to get away from toxins.

52:03

It'll figure out

52:05

how to get to something that might

52:07

sustain its life. Living

52:09

things

52:11

have this impulse to live and

52:13

survive and that's what people

52:15

call agency and agency

52:18

doesn't have to be reinvented

52:21

every time there's an evolutionary step

52:25

towards more complexity.

52:27

So it's basically

52:30

appropriated and

52:34

in this case

52:35

these spheroids

52:38

they're made of cells. Cells have

52:41

this impulse to survive and

52:43

to

52:44

nourish themselves and they have the capability

52:47

of doing it. So basically

52:50

agency is one of the inherent

52:52

sees of

52:54

living cells and can

52:57

we explain it? No, as I said there

52:59

are philosophers that have been pondering over

53:01

it but I haven't tried to

53:03

explain it but I've tried to see

53:05

how

53:07

it works when it's placed in

53:09

a new context. The new context can

53:11

be the experimental context of the

53:14

bio bots

53:15

or the new context

53:17

can be some novelty

53:21

that

53:21

has arisen

53:23

through the inherent sees of

53:25

the multicellular tissue.

53:36

So Stuart I kind of want to maybe

53:39

push back a little bit on that because Levin's

53:41

work with these bio bots is really

53:44

phenomenal but I guess my

53:46

confusion here

53:47

is that these

53:52

cells have

53:54

obviously an evolutionary history that

53:56

we've talked about and it's

53:59

true.

53:59

historically the environment

54:02

and the context that they occurred

54:04

in was embedded within the

54:06

tissue of a frog. But released from

54:09

that context in this

54:11

new sort of environment of the biobot,

54:14

because of this evolutionary history,

54:17

the cells essentially

54:20

have a form of plasticity. And

54:22

so I guess what I call

54:24

the capacity for being plastic

54:27

is what you're referring to as agency.

54:31

How

54:32

are those two different from each other? Plasticity

54:36

versus agents. Yeah, in this case,

54:38

I mean, you take

54:40

the cell out of the historical

54:43

context. I mean, it's still a

54:46

biological entity and it has

54:51

amazing

54:53

complexity that reflect

54:56

its long evolutionary history. And

54:58

so in this new kind of environment,

55:02

without having to, I guess, invoke any

55:04

kind of primitive cognition

55:07

or anything, I'm

55:09

sure that if you put any kind

55:11

of cell in other kinds of contexts,

55:14

they would do different kinds of things just

55:16

again, based on the

55:18

mechanisms that are currently

55:21

present within the cell.

55:22

Right.

55:23

So plasticity, you

55:26

can define plasticity

55:28

to include behavioral plasticity,

55:30

and then you're

55:31

basically overlapping with the concept

55:34

of agency. But if plasticity

55:36

was simply, if I take

55:39

a cell and the cell

55:41

normally has a cuboidal shape

55:44

in an embryo

55:46

and I put it on a flat surface, adhesive

55:48

surface, and it becomes flat,

55:51

well, I'd say that's morphological plasticity.

55:54

I wouldn't call that agency. So

55:57

plasticity is very, very important.

55:59

by analogy to certain

56:01

physical processes. If

56:04

you look at water

56:07

and say that it's a material with

56:12

plasticity, it can form waves or

56:14

it can form whirlpools

56:15

or it could be still

56:18

just flat.

56:19

Well, that's physical plasticity.

56:22

I wouldn't call it agency. So

56:26

cells

56:27

really have this kind of impulse

56:29

to stay alive.

56:32

And it sounds vitalistic

56:34

and I'm not a vitalist, but

56:37

I understand that there are certain

56:39

things about cells that we don't

56:42

really have a good

56:45

molecular and biochemical

56:47

explanation for now. So you

56:50

could kind of bracket that as a

56:52

kind of practical vitalist,

56:55

but not a commitment

56:57

to vitalism.

56:59

Yeah, I think, I mean, from an evolutionary

57:02

sort of biology perspective, we

57:05

broadly define plasticity as just

57:08

saying the capacity

57:10

for any like genetic background

57:13

to change its phenotype,

57:15

whatever that phenotype might be. It could be behavior,

57:18

it could be morphology, it

57:21

could be physiology in response

57:23

to the environment and that it is a predictable

57:27

response to the environment. It's not a random

57:30

response to the environment. And so if

57:33

you go to a population and you

57:35

see that different individuals

57:38

exhibit different responses to

57:40

the same environmental cue, then we kind

57:42

of think about that as a genotype by

57:44

environment interaction. And it's

57:46

that variation that selection

57:49

acts on and so,

57:52

I think at the cellular level, I could imagine

57:54

that in the past, cells

57:56

that didn't respond

57:57

in particular ways,

57:59

that were maybe adaptive to the environment would

58:02

have

58:02

been eliminated and those that did persisted. And

58:08

we see their sort of offspring

58:11

living today in

58:14

modern organisms. So let

58:16

me push back against that. So

58:20

if you have a

58:22

population

58:23

and the population cells

58:26

have

58:28

kind of little

58:30

algorithms or computers in them

58:33

that have been evolved

58:35

according to the history

58:37

of the species to make the cells

58:39

do a certain thing,

58:41

then you could say the cells are little automata

58:44

and

58:45

they may respond differently like

58:48

a slime old amoeba,

58:51

a de-teostelian amoeba.

58:53

We'll see a gradient

58:55

of cyclic AMP and navigate

58:58

gradient towards

59:00

the high point.

59:02

But certain cells in that population

59:04

won't

59:05

and they're not necessarily eliminated.

59:09

Maybe they don't have that computer in them

59:12

in the fully evolved form, but

59:17

they remain in the population and

59:21

the difference can't be attributed necessarily

59:24

to genetic difference in cells. Just

59:26

have different behavioral modes.

59:29

There was a recent study of fireflies

59:32

and it was thought that

59:33

fireflies blinked in synchrony

59:36

because of some mathematical

59:39

property of some internal oscillator.

59:42

And that if they

59:44

are part of that collective

59:47

that is blinking in synchrony,

59:50

they'll blink in synchrony. And then they found that

59:52

there's some fireflies that

59:54

just don't do it.

59:56

And

59:58

their progeny could do it.

1:00:00

but they didn't do it. And

1:00:03

basically organisms have

1:00:06

quirkiness to them. And the quirkiness

1:00:09

is

1:00:11

kind of associated with just

1:00:13

not following the crowd sometimes.

1:00:16

Maybe that's kind of a pre-adaptation

1:00:19

to being able to exploit

1:00:21

new environments if they turn up. But

1:00:24

the thing is, but maybe it's not. Maybe it's just

1:00:27

agency. Maybe organisms just

1:00:29

have different

1:00:30

tastes and propensities. It

1:00:33

could be. I guess if

1:00:36

you think about organisms,

1:00:38

whole organisms that live in

1:00:41

ecologically complex

1:00:43

environments that are shifting,

1:00:46

having a diversity of personalities

1:00:48

at

1:00:51

the whole organism level, different

1:00:53

kinds of behaviors. Some

1:00:56

individuals might do better under certain

1:00:58

conditions and then other individuals do better

1:01:01

under other conditions. And so you

1:01:03

can also maintain variation at

1:01:05

a population level in response

1:01:08

to kind of fluctuating environments that way.

1:01:10

So I think it's hard to know, obviously.

1:01:14

But I do think of it as

1:01:16

a fascinating question to

1:01:19

move from the level of population of individual

1:01:21

organisms to

1:01:24

looking within the organism at a population of cells

1:01:26

or

1:01:29

these different cell types that

1:01:32

have to each have their own

1:01:35

sort of functions. And

1:01:37

as you use the term, the inherently that they bring, but they

1:01:40

also have to cooperate with one another at

1:01:45

the tissue level or at the organ level. And

1:01:48

then certainly at the whole organism level

1:01:52

to work together. And so

1:01:55

to me, that's

1:01:56

also a very fascinating kind

1:01:58

of level. of selection kind

1:02:00

of problem?

1:02:03

Right, yeah, I would just question

1:02:05

whether

1:02:07

all this quirkiness is something,

1:02:10

I think it's a kind of a kind

1:02:12

of a matter of almost a matter of

1:02:14

faith to say that

1:02:16

if you see some feature of an

1:02:18

organism that doesn't seem to conform

1:02:20

to

1:02:21

the expectations of evolution, like the ability

1:02:24

to have birds to hybridize with

1:02:26

each other, well then that kind of erases species

1:02:29

difference,

1:02:30

so it seems to be kind of going against

1:02:33

standard evolutionary theory, but

1:02:35

you create new species by hybridization.

1:02:38

So

1:02:39

are those propensities

1:02:41

specifically evolved, and

1:02:43

what was the adaptive scenario

1:02:47

that led to them to be discordant

1:02:49

with the rest of the members of their population?

1:02:53

Did

1:02:53

all possible

1:02:55

adaptive scenarios existed

1:02:58

to bring us to the point where all

1:03:00

the latencies of

1:03:02

possible futures are

1:03:03

present in a population

1:03:05

by natural selection,

1:03:07

or is there just

1:03:09

kind of an openness to

1:03:11

the nature of organisms? What you guys

1:03:13

have been talking about in the last couple of minutes, it really

1:03:16

relates well to something that Cam

1:03:18

and I have been thinking about for over a decade, and

1:03:20

the kind of bumper sticker

1:03:22

version of this is whether organisms

1:03:25

are in scare quotes, special

1:03:28

as a level of biological organization. Now

1:03:30

let me try to frame that in

1:03:32

the words that you used in your paper. You

1:03:34

wrote about organizational closure,

1:03:37

and what you said was that organizational

1:03:40

closure is this emergent regime of causation

1:03:42

such that constituents of the system constrain the

1:03:44

operations of others, but also collectively

1:03:47

maintain itself by mutual dependence. Beautiful.

1:03:49

I love it. But here's my question. So

1:03:51

cells and tissues, I think, clearly do that. We've been talking

1:03:54

about that. It almost has to happen that way. Organisms

1:03:56

probably do that. Do you think communities

1:03:59

and populations... do that? You started

1:04:01

to speak about that with the hybridization example,

1:04:04

but if they don't do that, does

1:04:06

it mean that organisms are this kind of special

1:04:08

level organization?

1:04:10

So let me just say that what you

1:04:13

quoted by saying that

1:04:15

the organizational closure

1:04:17

comes from the philosophical

1:04:20

work of

1:04:21

Alvaro Moreno and his colleagues,

1:04:24

and it's called the organizational approach,

1:04:27

and that's something that

1:04:30

I've quoted and used in

1:04:33

some of my work, but that's not

1:04:36

my idea.

1:04:37

But

1:04:39

I would say that organisms

1:04:42

have this

1:04:44

cohesiveness

1:04:46

to them, this internal cohesiveness,

1:04:48

and it actually goes back to the

1:04:51

philosopher Immanuel Kant,

1:04:54

who talked about

1:04:56

organisms as natural purposes.

1:04:58

He said that organisms

1:05:01

will

1:05:02

produce the means for

1:05:04

their perpetuation

1:05:06

in a way that we don't see anything

1:05:08

in the non-living world

1:05:11

do, and that idea, which

1:05:14

Kant acknowledged that he couldn't explain,

1:05:16

was taken up by

1:05:20

Naturana and Varela,

1:05:22

two Chilean philosophers

1:05:24

in the concept of

1:05:26

auto-polesis, and

1:05:27

it's extended by

1:05:29

Moreno and his colleagues in

1:05:31

the organizational approach. So

1:05:33

this is quite important, and

1:05:36

it characterizes people have tried

1:05:39

to apply it to higher-level

1:05:41

entities like societies,

1:05:44

ecosystems,

1:05:45

and so on. My

1:05:48

feeling is that those are different kinds

1:05:51

of things. There are higher-level

1:05:54

things like use social societies

1:05:56

and sex

1:05:58

that are organized.

1:06:01

in a way that is

1:06:03

somewhat cohesive or quite cohesive. There

1:06:07

are flocks of birds

1:06:09

that interact with each

1:06:11

other in a way that looks like it's one

1:06:14

cohesive entity

1:06:16

and so on. My feeling about all

1:06:18

this is I'm very anti-reductionist.

1:06:22

So I believe in different

1:06:24

forms of matter and each

1:06:27

form has its own inerrancy. But

1:06:30

I also, I

1:06:31

don't believe that these things

1:06:32

are irretrievably separate

1:06:35

from each other. Things like

1:06:38

there are particles

1:06:40

that form atoms. The atoms are different

1:06:42

from the particles, but you can understand

1:06:45

how the atoms

1:06:47

emerged in the history of the universe from

1:06:49

fundamental particles. So I'm not

1:06:51

saying that there's no continuities

1:06:54

between different forms of matter, but

1:06:56

what I'm saying is that once you have a

1:06:58

new form of matter

1:07:00

like

1:07:01

the 100 plus atomic

1:07:04

elements, they have inherent

1:07:06

properties that are very different from anything

1:07:08

that preceded them.

1:07:10

And they're also

1:07:11

things that

1:07:13

build on them like cells and

1:07:15

organisms are not reducible

1:07:17

to the chemistry of

1:07:20

the atomic elements.

1:07:22

They are dependent on it, they're

1:07:24

based on it,

1:07:25

but new features come in

1:07:28

as you get new forms of matter.

1:07:31

And I think that the animals

1:07:33

are a different form of matter than the plants.

1:07:36

I mean, we know that they've

1:07:38

had common ancestors at some point,

1:07:40

but they're different forms of matter with

1:07:42

different inerrancies, so they have different

1:07:45

developmental properties. So

1:07:47

if you talk about an ecosystem,

1:07:49

there are certainly kind

1:07:53

of

1:07:53

laws of,

1:07:55

organization, thermodynamic

1:07:58

regularities.

1:09:59

that you just haven't seen

1:10:01

anywhere before.

1:10:03

You can relate them to the properties and

1:10:05

the things they're made of, but you can't reduce

1:10:07

them to the properties of the things they're made of. Yeah,

1:10:11

wow, that's well said. Well, I think on

1:10:13

that, I mean, this has been a fascinating conversation.

1:10:17

We always like to end by giving

1:10:19

our guests the opportunity

1:10:21

to say something that, you know, anything

1:10:24

else that you'd like to say that we haven't covered

1:10:26

today?

1:10:27

Well, I just think that people should be

1:10:30

open-minded about plurality of

1:10:32

evolutionary mechanisms. I

1:10:34

know that a lot of evolutionary

1:10:37

theorists are very loyal to Darwinian

1:10:39

natural selection, and I think it obviously

1:10:41

goes on, but I think there

1:10:44

are more things in the world

1:10:47

than even Darwin contemplated. Good.

1:10:50

Well, I think we'll end on that note, Stuart. Thank

1:10:52

you so much for joining us. We really appreciate

1:10:55

your time. Likewise. Thanks a lot. Thank you very

1:10:57

much.

1:10:58

Thanks for listening

1:11:01

to this episode.

1:11:07

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1:11:09

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1:11:17

is good feedback. Thanks to Steve Lane, who

1:11:19

manages the website, and Ruth Demery for

1:11:21

producing the episode. Thanks as well to interns

1:11:23

Dana DeLaCruz and Kyle Smith for helping

1:11:25

produce the episode. Keating Shamari produces

1:11:28

our fantastic cover art. Thanks to the

1:11:30

College of Public Health at the University of South

1:11:32

Florida, the College of Humanities and Sciences

1:11:34

at the University of Montana, and the National

1:11:37

Science Foundation for support.

1:11:39

Music

1:11:39

on the episode is from Pottington Bear and Taryn

1:11:41

Costello.