Biophysic course Ws 2006, Roma3P.L.Luisi

From self-organization to the transition to life,from the origin of life to synthetic biology

Biophysic course WS 2006, Rome.

Lecture number one:

1.Science confronting the origin of life on Earth.

1.1.Introduction:Main assumptions of modern science. Science and the creationistsThe „crypto-creationists“Paley and DawkinsDeterminism and contingency

transition to life

biologicalevolution

first cell *

ORIGIN OF EARTH

- 3.5 billion years

- 4.5 billion years

" molecular evolution "

- 3.9 billion years

eldest rocks

LIFE

INANIMATE MATTER

( NON - LIFE )

cellscells

metabolic networksmetabolic networks

polymer complexespolymer complexes

macromoleculesmacromolecules

biomonomersbiomonomers

moleculesmolecules

atomsatoms

Aleksandr Oparin ( 1894 – 1980 )

The traditional definition:Science is the attemptto explain the phenomenology of the world in terms of the laws of physics and chemistry

..not the only way to explain the world

Friedrich Rolle, a German philosopher and biologist, writing about the hypothesis that life arose from inanimate matter in 1863, stated:

The general reasons for this assumption are really so impelling, that no doubt soon or later it will be possible to show this in a clear and broadly scientific way, or even to repeat the process by experimentation. (Rolle, 1863)

William Paley, the Anglican priest who became famous for having introduced one of the most famous metaphors in the philosophy of science, the image of the watchmaker (Paley 1802):

… when we come to inspect the watch, we perceive… that its several parts are framed and put together for a purpose, e.g. that they are so formed and adjusted as to produce motion, and that motion so regulated as to point out the hour of the day; that if the different parts had been differently shaped from what they are, or placed after any other manner or in any other order than that in which they are placed, either no motion at all would have been carried on in the machine, or none which would have answered the use that is now served by it. … the inference we think is inevitable, that the watch must have had a maker – that there must have existed, at some time and at some place or other, an artificer or artificers who formed it for the purpose which we find it actually to answer, who comprehended its construction and designed its use.

Living organisms, Paley argued, are even more complicated than watches, thus only an intelligent Designer could have created them, just as only an intelligent watchmaker can make a watch. According to Paley:

That designer must have been a person. That person is GOD.

RICHARD DAWKINS

THE BLIND WATCHMAKER(Norton & Co., NY1986)

why the evidence of evolution reveals a universe without design

Paley‘s argument ...is wrong, gloriously and utterly wrong. The analogy between telescope and eye, between watch andliving organism, is false.... Natural selection, the blind, unconscious, automatic process that Darwin discovered...has no purpose in mind...it does not plan for the future, it has no vision, no foresight, no sight at all....(p.5)

Example of the flagellum:

How complexity is built by biological evolution-slowly and continuosly

cellscells

metabolic networksmetabolic networks

polymer complexespolymer complexes

macromoleculesmacromolecules

biomonomersbiomonomers

moleculesmolecules

atomsatoms

About the philosophical framework

Determinism vs Contigency in the origin of life

The deterministic view of the origin of life

…given the suitable initial conditions, the emergence of life is highly probable and governed by the laws of chemistry and physics…

together with the “continuity principle”

no unbridgeable gap between inorganic and living matter;each stage in evolution develops continuously from the previous one, at each stage there is a continuous path backwards to the prebiotic

state and forward to modern organisms

Orgel; Morrowitz; de Duve

The deterministic view of the origin of life

…given the suitable initial conditions, the emergence of life is highly probable and governed by the laws of chemistry and physics…

together with the “continuity principle”

no unbridgeable gap between inorganic and living matter;each stage in evolution develops continuously from the previous one, at each stage there is a continuous path backwards to the prebiotic

state and forward to modern organisms

Orgel; Morrowitz; de Duve

…from Christian de Duve, 1991:

life arose throughout the succession of an enormous number of small steps,

…each with a high probability of happening.

This assumption has to be made becausethe alternative amounts to (accepting) a

miracle

The science of the origin of life has toadopt the deterministic, continuity view-

otherwise it would not be possible to adopt a scientific method of inquiry

…from Christian de Duve, 1991:

life arose throughout the succession of an enormous number of small steps,

…each with a high probability of happening.

This assumption has to be made becausethe alternative amounts to (accepting) a

miracle

The science of the origin of life has toadopt the deterministic, continuity view-

otherwise it would not be possible to adopt a scientific method of inquiry

as opposite to this, the view by which:

life originated as a entirely chance eventas a highly improbable event

as a “happy accident”comparable to the assemblage of a 747 Boeing

by a tornado whirling through a junkyard (Hoyle 1981, 1993)

the origin of life as an impenetrable barrier to science and a residue to all

attempts to reduce biology to chemistryand physics

(Popper (1972, 1982)

we cannot give a causal explanation of the origin of biological organization. We have

to do as if the biological organization isgiven by an external organizer

Kant, 1790

See Iris Fry, Biol and Phyl. 10 (1995) 389

as opposite to this, the view by which:

life originated as a entirely chance eventas a highly improbable event

as a “happy accident”comparable to the assemblage of a 747 Boeing

by a tornado whirling through a junkyard (Hoyle 1981, 1993)

the origin of life as an impenetrable barrier to science and a residue to all

attempts to reduce biology to chemistryand physics

(Popper (1972, 1982)

we cannot give a causal explanation of the origin of biological organization. We have

to do as if the biological organization isgiven by an external organizer

Kant, 1790

See Iris Fry, Biol and Phyl. 10 (1995) 389

The science of the origin of life has toadopt the deterministic, continuity view-otherwise it would not be possible to adopt a scientific method of inquiry

Christian de DuveHarold MorowitzAnd others…

...we also reject the suggestions of Monod that the originrequires a series of highly improbable events...The study of origin of life is useful only if that beginningtook place under probably deterministic conditions, otherwise ...it becomes a branch of history rather thannatural science...

H. J. MorowitzBeginning of Cellular Life, Yale Univ. Press, 1992

…”I favor the view that life was bound to arise under the physical-chemical conditions that surrounded its birth”De Duve, 2002

We have no reason to believe that biogenesis was not a series of chemical events subject to all of the laws governing atoms and their interactions.”Morowitzt, 1991

“..It is self-evident that the universe was pregnant with life and the biosphere with man. Otherwise, we would not be here. Or else, our presence can be explained only by a miracle…”De Duve, 2002

Other „crypto-creationists“????

Anthropic principle

Panspermia

SETI

“If life follows from (primordial) soup with causal dependability, the laws of nature encode a hidden subtext, a cosmic imperative, which tell them: ‘Make life! And, through life, its by-products, mind, knowing, understanding…’”. Paul Davis, 1991

THE NOTION OF PANSPERMIA

LIFE AS AN UNIVERSAL IMPERATIVE

OPPOSITE TO THAT....

CONTINGENCY

WHAT IS CONTINGENCY?

WHEN SEVERAL INDEPENDENT PARAMETERSOR ACTIONS OCCUR SIMULTANEOUSLY IN A GIVEN SPACE/ TIME SITUATION AND DETERMINE THE OUTCOME OF AN EVENT

This replaces in the current literature the notion of chance,random event, and similar. Note that the each of the single determinants can be defined by a causal law; but there are son many of these determinants, and They have such an unknown statistical weight, that the result isunpredicted and generally not described by any single causation

4.5

3.5

2.5

1.5

0.5

now

}}

originof earth

billionyears

originof life

unicellularorganisms

PRECAMBRIAN

multicellularorganisms

aer.photosynt.

O2 in atmosph.

eucaryotessexualreproduction

first fish

first mammals

primates

Neanderthal

{

{

{{

...run the tape again,and the first step fromprocaryotic to eucaryoticcell may take 12 billionyears instead of 2...

Stephen J.Gouldin "Wonderful Life"1991 Penguin Science

WE WOULD LIKE TO THINK OURSELVESNECESSARY, INEVITABLE, ORDAINED FOR ALL ETERNITY.ALL RELIGIONS, ALL PHILOSOPHIES, AND EVEN PART OF SCIENCE TESTIFY TO THE UNWEARYING, HEROIC EFFORTOF MANKIND DESPERATELY DENYING ITS OWN CONTINGENCY

J.Monod, Chance and Necessity, 1971

ARE WE ALONE IN THE UNIVERSE??

2.2. The chemical process(es) to transition to life can beThe chemical process(es) to transition to life can bereproduced in the laboratory with the presentlyreproduced in the laboratory with the presentlyavailable chemical techniques and chemicals.available chemical techniques and chemicals.

3.3. And this can be implemented in a reasonableAnd this can be implemented in a reasonable(hours or max. days) experimental time span -(hours or max. days) experimental time span -once you know the right combination of prebiotic compoundsonce you know the right combination of prebiotic compoundsand theconditions.and theconditions.

LIFELIFE

inanimateinanimate mattermatter

1.1. Life originated from inanimate matter as a spontan-Life originated from inanimate matter as a spontan-

eous and continous increase of molecular complexity.eous and continous increase of molecular complexity.Chemical continuity principle - no transcendentalChemical continuity principle - no transcendentalprinciple.principle.

SOME MAIN ASSUMPTIONS OF PRESENTSOME MAIN ASSUMPTIONS OF PRESENTDAY RESEARCH ON THE ORIGIN OF LIFEDAY RESEARCH ON THE ORIGIN OF LIFESOME MAIN ASSUMPTIONS OF PRESENTSOME MAIN ASSUMPTIONS OF PRESENTDAY RESEARCH ON THE ORIGIN OF LIFEDAY RESEARCH ON THE ORIGIN OF LIFE

4.4. Since there is no documentation on how things reallySince there is no documentation on how things reallyhappened, there is no obligatory research pathway.happened, there is no obligatory research pathway.

Questions to the reader:

1.                 Do you accept the view that life on Earth originated from inanimate matter without any contribution from transcendent power?

2.                 Do you accept the idea that biological evolution is mostly shaped by contingency? If not, what would you add to this picture?

3.                 Are you at peace with the idea that mankind might not have existed; and with the idea that that we may be alone in the universe?

4.                 Do you accept the idea that a rose is made up only by molecules and nothing else?