0:00

This is the BBC. This

0:03

podcast is supported by advertising outside

0:05

the UK. BBC

0:09

Sounds. Music, radio, podcasts.

0:12

Hello, I'm Brian Cox. And I'm Robin Ince. Welcome

0:14

to The Infinite Monkey Cage. Now today

0:17

we are exploring the scale of life.

0:19

Why are some organisms large and some

0:21

small? From the prokaryotic cell

0:23

to the grandest dinosaur, how does

0:25

the modern synthesis explain the observed

0:27

variation in scale, form and function?

0:30

Eloquently put. And I presume that

0:32

everyone who ever listens to this knows that

0:34

we spend most of our time exploring

0:37

deep questions and carefully formulating our

0:39

prose to transfer these ideas to

0:41

listeners with economy and precision not

0:44

dissimilar to the ideas of the

0:46

Darwin paradigm. It didn't go out of the... We've

0:49

actually spent the whole afternoon, after about five minutes

0:51

of doing some research, talking

0:54

about why do big things always talk like this if you

0:56

have a big elephant? And all the

0:58

little things always talk like this, like if they're in bad

1:00

puss, we will fix it, we will mend it. We

1:02

did that for three hours. And that's

1:04

basically the show that we've got. It's the

1:06

equivalent of watching Johnny Morris' Animal Magic with

1:08

him doing the voice, Hello, I am a

1:10

very big bear. I'm a very small

1:12

thing. I'm Brian Cox. Look

1:15

at that. Today

1:18

we are exploring the scale of living things

1:20

and the advantages and disadvantages that come with

1:23

being big or small. To discuss these matters

1:25

without silly voices, well probably with some silly

1:27

voices, but anyway, mainly

1:29

without silly voices we're joined by a paleontologist, an

1:31

evolutionary biologist and a comedian

1:33

who came to fame by asking the question, are you

1:35

Dave Gorman? Now I don't know if I've given away

1:37

any of the panel there with that

1:39

introduction. We'll find out in a moment. They are...

1:42

I'm Susie Maidment. I'm a paleontologist at

1:44

the Natural History Museum. And I

1:47

think the most astounding fossil

1:50

ever found was the stem

1:52

tetrapod, Acanthostega. Acanthostega is

1:54

a fish, but it has limbs. It's

1:56

from a Devonian period. It's very, very old, about 450 million

1:59

years old. ago, something like that. And

2:01

it's a fish, it lived in rivers, it's

2:03

got quite a fish-like body, a fish-like tail,

2:05

but it has limbs and it has digits.

2:08

Biomechanical modelling suggests that it couldn't stand

2:10

on these limbs. And this has been

2:12

used to indicate that actually limbs first

2:15

evolved, they're kind of moving through shallow

2:17

water and pushing off the bottom. So,

2:19

you know, this is basically our oldest

2:21

relative. And just to set the

2:24

scene there, so 450 million years ago, so

2:26

the land was, there was no plants on

2:28

the land at the time. Yeah, some early plants,

2:30

yeah, very early plants, not much else, though, some insects

2:32

and things like that. But of course, yeah, it was

2:34

the first sort of vertebrates to come

2:36

out onto lands, yeah. Hello!

2:39

I love that idea, so people

2:41

at home can go, oh, so,

2:43

so Torrey's very, very small. So's

2:47

he very big. Hello,

2:51

I'm Torrey Herridge, I'm an evolutionary biologist

2:53

from the University of Sheffield, and

2:56

I think the most astounding fossil

2:58

ever found, I'm cheating, it's not

3:00

quite a fossil yet, is the

3:02

permafrost remains of woolly mammoths, because

3:04

they still have all of their

3:07

innards. Sometimes I have literally

3:09

had the chance to hold a woolly

3:11

mammoth liver and floppy,

3:15

gooey, corpsey,

3:17

and when you get to

3:20

hold the floppy flesh of your extinct animal,

3:22

it doesn't get better than that. Your

3:25

choice there was excellent in the speed in

3:27

which an audience have gone from woo to

3:30

eww. I'm

3:33

Dev Gorman, I'm a comedian, I live

3:35

in Bournemouth, and I think the greatest

3:38

fossil discovery is actually quite a simple

3:40

fossil, it's an ammonite, but they found

3:42

so many of them, they

3:44

were able to package them and give

3:46

one to everyone on a recent budget

3:48

airline flight I took, they

3:51

call them Danish pastries. That's

3:55

very good. And this is our panel.

4:05

Could you just define the premises here?

4:08

What are the largest animals that have ever

4:10

lived? What are the smallest animals? Okay, well

4:12

the largest terrestrial vertebrates that have ever

4:15

lived, so things that are walking on

4:17

land that we know of, are

4:19

the Titanosaurian dinosaurs. So these were things

4:22

that lived in the Cretaceous period and

4:24

the largest one is about 60 tonnes.

4:27

Now we can get to how you

4:29

estimate mass in an extinct animal at

4:31

a later point in the show, but that is fraught

4:33

with difficulty as you might be able to guess. It's

4:36

about 30 metres long, absolutely enormous, if you

4:38

want to see one, there's one on display at

4:40

the Natural History Museum right now, and they are

4:42

absolutely huge. And so they're the largest

4:44

terrestrial animals. Of course we also have

4:46

things like blue whales which are also

4:49

very, very, very enormous. And

4:51

then in terms of the smallest? For mammals it's

4:53

the bumblebee bat I think it is, and for

4:55

birds... And a few grams I think. Yeah, for

4:58

birds it's the same, bee hummingbirds, but I mean

5:00

if we're going to insects and we're getting... Yeah,

5:03

and then you go down to the bumblebee organisms

5:05

and everything. I mean that's the thing about size,

5:08

it covers everything. Yeah. Well

5:11

Brian originally wanted to spend the whole show just

5:13

going, so if we start with the subatomic part

5:15

of it, it gets to the size of the

5:17

universe, but that might be a time problem, you

5:19

know, whether it exists. It

5:21

brings me to the obvious question

5:23

from an evolutionary perspective, why that

5:26

huge range? Clearly we started with

5:28

single-celled organisms. Why do things

5:30

get so big? That's