Cyril Ponnamperuma -- The Origin of the Cell From Oparin to the Present Day

7/27/2019 Cyril Ponnamperuma -- The Origin of the Cell From Oparin to the Present Day

http://slidepdf.com/reader/full/cyril-ponnamperuma-the-origin-of-the-cell-from-oparin-to-the-present-day 1/7

Journal of Biological Physics20: 3-9, 1994. 3© 1995 Kluwer Academic Publishers. Printed n the Netherlands.

T H E O R I G I N O F T H E C E L L F R O M O P A R IN T O T H E P R E S E N T D A Y

C Y R I L P O N N A M P E R U M A

Laboratory of Chemical Evolution

University of Maryland

College Park, Maryland 20742, U.S.A.

I ask the question, W hy was i t that Oparin mad e such a difference? Perhaps the answer

lies in the fact that Oparin was an unusual scholar. He loo ked upon a proble m that was

philosoph ical in essence, but brou ght to bear upon it history and all science. His

writ ings referred l iberal ly to the ph ilosophy of A ris totle of ancient Greece and to the

wo rk of the c hristian savant Aug ustine, and y et he also described in detail the scientific

work of Louis Pasteur . Although a biochemist by training, Oparin moved freely from

astronom y to chemistry, f rom geology to biology, with the thread of philosophy wov en

throughout. Oparin demonstrated an insight into the writ ings and teachings of the

philosophers .

After the collapse o f the the ory of spontaneous generation following Louis P asteur 's

epoch-making experiments , the concept of l i fe as eternal , with changes only in form,

cam e back to the fold. Oparin in his analyses points out that the same vitalistic

concept, the same dualism, was at the bottom of the theory o f the continuity or eternity

of l i fe. The "Actus Dei" of Augustine, the "Entelechy" of Aris totle , the "Spiri tus

Vitae" of Paracelsus , the "Archai" of Van H elmon t - no matter what form the theories

of the continuity of l i fe assume, they always leave an unbridgeable gap between the

king dom o f organisms and inorganic nature. Oparin was able to demonstrate by hisanalyses of this philosophical thought that there was another path to follow.

W e have followed such a path. I t is Oparin who gave us the idea of the continuity

in the universe from the inorganic to the organic, from the elements to the small

molecules . The concept of cosmic evolution, then, comes to us from his ear ly writ ings .

In a w ay, h e personified the student of chemical evolu tion as described by J. D . Bernal,

wh o said that "Even the formu lation of this problem is beyond the reach o f any one

scientist. Such a scientist wo uld have to be at the same time a comp etent

mathematician, physicis t , and experienced organic chemist . He should have a very

extensive knowledg e of geology , geophysics , and geochem istry, and besides al l this beabsolutely at hom e in all biological disciplines." W hat Bernal wro te in 1948, Oparin

had a lready revealed to us in the '20s. Since it is difficult to find a single person

competent in al l disciplines , we bring a group together, different people wh o will

interact and then pu t their know ledge together .

It was Oparin w ho, in 1957, organized the first international conference o n the



4 CYRIL PONNAMPERUMA

origin of life. That meeting established a pattern for study of the subject by having

been organized under the auspices of the International Union of Biochemistry. Oparin

was there as the host and organizer.

It was my great pleasure to later have met Alexander Ivanovich Oparin at the

Wakulla Springs Conference in 1963, convened by Sidney Fox. That conference was

another landmark gathering. Also attending was another great thinker in the field,

J.B.S. Haldane. To those of us who at that time were groping our way through the

first steps o f chemical evolution, however, Oparin stood out as a giant. NASA had

begun its work on exobiology, and the National Academy of Sciences of the United

States had declared the search for extraterrestrial life a prime goal of space biology.

Great activities sprung up from many angles, ~pecially in relating the origin of life to

the possible existence of life beyond the Earth. Oparin's work now began to have a

cosmic implication.From Wakulla Springs we move to our next highlight in this sequence of important

conferences - Cortina D'Ampezzo. Sidney Fox and I were once again privileged to be

part of this special conference on the origins of life. It was here, at Cortina

D'Ampezzo, in Oparin's hotel room looking out at the dolomites and in this wonderful

atmosphere, that the International Society for the Study of the Origin of Life (ISSOL)

was bern. Oparin was its first president, Sidney Fox its vice president, and your

humble servant its secretary. Alas, today many members of this society, which now

numbers over 500, hardly know its beginnings or the fact that it was Oparin himself,

egged on by Sidney Fox, who felt the time was right to bring together from all overthe field these different researchers.

From there Alexander Ivanovich Oparin traveled widely. He went to NASA's

Ames Research Center in California. There he lectured to groups and continued his

interaction with young people, activities that he devoted much time to over the years.

In 1977, after the Viking landing on Mars, the famous meeting in Kyoto was held.

One might say that at that meeting Oparin had truly reached the pinnacle of his

international stature. ISSOL decided to establish a medal in his honor, to be awarded

every three years for the most meritorious scientific work on the origins of life.

From a scientific point of view, possibly the greatest contribution Alexander

Ivanovich Oparin made to the study of the origins of life was his careful analysis of the

nature of the primitive atmosphere. He suggested that the carbides in the crust of the

Earth may have given rise to hydrocarbons. Indeed, the carbides may have come from

meteorites, and it is interesting now for us to combine some of this thinking. (The

presence of hydrocarbons in meteorites was established by Wohler when he analyzed

a piece of the Kaba.) Here, then, was a source of the reduced carbon necessary for the

organic molecule.

Oparin also argued that in the amino acids the carbon and nitrogen are in the

reduced form and that, therefore, the starting materials may have been in that form.

This was a remarkable proposition to make at the time, of course, knowing as we donow the amount of time and trouble in the laboratory it has taken students since then

to arrive at the same conclusion. (It was Harold Urey who showed at that time the

reduced nature of the primitive atmosphere.) Much of the work being done at the time

was therefore being done as a result of this early hypothesis Oparin put forward almost





6 CYRILPONNAMPERUMA

intuitively - not by the study of equilibrium data,but simply by his contact with the

carbides and his understanding of the composition of amino acids. He realized that the

amino acids must have had reduced nitrogen, and so he argued for the reduced nature

of primitive materials.

As a matter of fact, Oparin concentrated a great deal on the possible role of the CN

fragment. This is also remarkable, considering what we now know of organic

chemistry as related to chemical evolution. In 1961 John Ore used ammonium cyanide

to produce adenine. In the work that has been done since then, we have realized that

the role of cyanide plays an important part in the prebiotic synthesis of the generation

of amino acids from the nitrile. So Oparin's insight into that fragment, the CN

fragment, which he postulated as important, is indeed remarkable from our point of

view. Radio astronomers have now observed nitriles and hydrogencyanide in the

interstellar medium.While emphasizing the need to study the chemistry of cyanide molecules, Oparin

realized that fundamentally the main question had to do with organization. According

to him there were at first the simple solutions of organic substances whose behavior

was predicated by the properties of their component atoms and the arrangement of these

atoms in the molecular structure. But gradually, as the result of the growth and

increasing complexity of the molecule, new properties were emerging, and a new

colloidal chemical order was imposed on the simplest organic chemical reaction. So

here we get the first hints that Oparin was studying self-organization. According to

him, the new properties were determined by the spacial arrangement and mutualrelationship of the molecules. In this process biological order is already coming into

prominence.

Taking his cue from the Dutch physical chemist, Bungenberg de Jong, Oparin

looked at the formation and concentration of materials from diluted solutions. He

realized that coacervates could easily be contained under laboratory conditions by the

simple mixing of a solution of different proteins and other substances of high molecular

weight at ordinary temperatures and, in most cases, with very little acidity. Molecules

that were previously distributed throughout the medium would now come together in

coacervate formation. Then our components would attract one another, and at a pretty

low concentration would collect in the liquids to form swarms or clumps that would

separate them from the solution until they reached a particular size. They would appear

to be very well defined. Indeed, here are the coacervates of Oparin's that could have

been forerunners of modem cells.

In his monumental studies on the coacervate droplets, Oparin showed that they

could have internal structures different from those found in simple droplets of liquid.

In a series of very comprehensive experiments, he showed how easily these reactions

could take place within the coacervate. Indeed, in some experiments he showed how

enzymatic reactions could be possible. The whole school of Russian scientists who

work on coacervates owe their knowledge and background to the first experiments ofAlexander Ivanovich Oparin. He argued further that from these molecules, complete

multimolecular systems could have been formed.

Oparin's reflections on the origins of life led him to examine the possibility of life

beyond the Earth. He postulated that the conditions suitable for the origins of life had



THE ORIGINOF THE CELLFROM OPARINTO THE PRESENTDAY 7

exis ted on the p r imi t ive Ear th , bu t tha t the p r imi t ive Ear th was on ly one of many

sui table locat ions in the universe. Mo dern as t ronom y, of course, tel ls us that there are

bi l l ions and bi l l ions o f si tes in the universe wh ere l i fe is possible. So from that one

successful experiment on the Earth , we can turn to places elsewhere in the universe.

Astronomers tel l us that there are 10~3 stars in the universe. To u s chemists, that is a

happy num ber - the Avogadro number . I f we take a conservat ive es timate , 1 percen t

of these Stars can have around them condi t ions sui table for li fe . W e are s t il l ta lking

abo ut a colossal num ber - 10 ~ possibil i t ies. Planets are plen tiful in the universe.

Opar in ' s model o f the p r imi t ive Ear th can be ex tended e l sewhere in the un iverse .

W e have jus t ce lebra ted the 25 th ann iversary o f the lunar l and ing . Opar in was wi th

us in Cal i fornia whe n that magnif icent even t took place. Soi l samples were bro ugh t

back to the l abora tory , where Sidney Fox , John Ore , mys el f and o thers p roceeded to

analyze them. Oparin was one of those most exci ted about the analysis and what i twould possibly reveal to us .

Th e M oon did not show us ver y much, but then came the meteori tes , especial ly the

Mu rchiso n me teori te; Oparin had referred in his wri t ings to their possible relevance in

origin-of- l i fe s tudies, pr ima ri ly going back to what he had read abo ut W hole r and

others . Tw enty -f ive years ago, on September 21, 1969, this meteori te fel l in

Murch ison , A us tra li a . W e were ab le to smuggle ou t a chunk of i t. We w ere p repar ing

for the lunar analysis, a nd al though the lunar samples had no t yet arr ived, w e we re able

to apply the techniques developed for their subsequent analysis to the Murchison

sample. Lo and beho ld, the Murchiso n meteori te gave us the f i rs t conclusive evidenc eof extraterres t r ial amino acids . Once again, th is is another landmark e vent in the s tudy

of the origin of l i fe .

Fol low Oparin beyond his ins ight on meteori tes to the inters tel lar medium once

again - the organic chemist ry that was postulated as primordial now enter the

inters tel lar medium . Then to Mars , w here in 1976 the Viking spacecraft landed. Th e

reason I ment ion this i s because there was a very close relat ionship between some of

Opa rin 's th inking and the possibi l ity of l ife on Mars . Rem ember, Oparin looked upon

the Earth as one example of a laboratory. The f i rst opportun i ty for us to tes t the

hypothes i s o f the evo lu tion of l i fe was on Mars . I f there was l ife on Mars and we

could de monstrate i t s independen t origin , then certainly we w ould ha ve unquest ionable

eviden ce of the p ossibi l ity of l i fe elsewhere in the universe.

Fo r Mars we had one se t o f exper iments fo r the o rgan ic analys is , the GCM S, and

another fo r b io logy . The exper iments conducted were s imple ones : the gas exchange ,

the label release, and the pyrolyt ic release. Th e whole idea was to take a handful of

the soil , expos e i t to a medium , and see whethe r l i fe was detected there. Indeed, the

resul ts indicated something posi t ive. Even the team leader of the biolog y experime nt ,

Chuc k K lein, conclud ed that the biology experiments , i f taken alone, wou ld indicate

that there was l i fe on Mars .

But then came the GCM S. The G CM S exper iment ind ica ted tha t there was l essthan 5 parts per bi l l ion o f organic mat ter . I t was then our task to point out that th is

was i n de ~ the surface o f Mars mimick ing b io logy . Inorganic analys i s had ind ica ted

to us a com posi t ion of the Mart ian surface, and in our laboratory we had a tu be

containing s imulated surface. Up on examinat ion we fou nd that the i ronoxide on the



8 CYRILPONNAMPERUMA

surface of Mars, when exposed to ultraviolet light, behaved just as though it were

biological. The paper we published in Science that year on the results of the Viking

mission seemed conclusive.

Now we have a different story. During the course of our studies, we found that

the GCMS used in the Viking mission had also been used to test soil from the Antarctic

in which there were microbes. The GCMS could not detect organic matter in the

Antarctic sample. This information comes to light only now. We have therefore

requested NASA to impound the two model prototypes that are available: one at Jet

Propulsion Laboratory and one at the Smithsonian. They will soon come over to my

laboratory, where they will be retested. The understanding is very simple: A single

microbe in the Antarctic soil, from what they call the dry valley, could multiply and

give the biology result, but a single microbe could not be detected by the GCMS. So

now we have an opportunity to reexamine the Viking findings. In a way, we owe thisinsight to the early thinking of Alexander Ivanovich Oparin.

From Mars we move to the other planets. Voyoger's results have been very

prominent recently beeanse of the impact of the Shoemaker-Levy 8 Comet. Voyager

gave us a magnificent picture of Jupiter's red spot. Laboratory work showed that

organic matter could be produced there. The colors in a photograph of Jupiter are the

result o f the chemical reactions that will occur between methane and ammonia in highly

reduced conditions - Oparin's idea of the primitive atmosphere of any planet. The

droplets seen in a photograph of Titan are collections of organic molecules that are

there. So in a way, the reducing atmosphere of this planet can be connected toOparin's early thinking.

A 1986 photograph of Halley's Comet does not reveal as much as one from 1910,

but in observing its trek we were able to detect the presence of various hydrocarbons,

hydrogencyanide, and so forth. We are moving, then, from the idea of the primitive

atmosphere of the Earth to the primitive atmospheres of other planets to the general

presence of organic matter under interstellar conditions. If this is indeed the case,

surely life would have evolved to the point where intelligent life is present elsewhere.

In 1960, Frank Drake used the Tatel telescope at the Green Bank Observatory to

search for signals from outer space. Unfortunately, the two-month search - named

Project Ozma after the Princess of Oz - did not yield evidence o f extraterrestrial

intelligence. However, Drake's work eventually led to an international program. On

October 12, 1992, to commemorate the 500th anniversary of the landing of Columbus

in America, NASA launched its ambitious SETI program, the High Resolution

Microwave Survey. Unfortunately, the project was cut from NASA's budget the

following year. Thanks to the work of private citizens around the world, however, the

SETI Institute, with Frank Drake as its president, is now privately funding the

continuation of this project. The institute has developed some major proposals, one of

which is to act on a recommendation that came out of Project Cyclops, funded by

NASA in 1973, to construct a whole array of 10-meter wide antennae that would pickup signals from outer space. A whole range of them placed somewhere without

interference - perhaps someday even on the further side of the Moon - would give us

knowledge of what is happening out there.



THE ORIGINOF THE CELLFROM OPARIN TO THE PRESENTDAY 9

We come back here , then - a f t e r our odyssey f rom the Ear th to the Moon to the

meteori tes to Ma rs , to comets to the giant planets to the s tars bey ond - to the possibi li ty

of l i fe beyo nd. This i s indeed an idea that came from that f i rs t publ icat ion in 1923.

One could say that what Darwin is to biological evolut ion, Oparin is to chemical

evolut ion. Oparin spoke of the general or igins of li fe . No t as a special event , but as

a phenom enon tha t cou ld commo nly take p lace . And th is b r ings us back to someth ing

tha t i s happen ing on the Ear th today . The Ear th i s the on ly p lace where we know there

is l ife.

A few years ago , Alv in , the submar ine tha t went down to the bo t tom of ocean ,

brought back to us samples f rom the hydro thermal ven t s. Fo r a lmos t fo r ty years we

had worked in our laboratories on the assumption that the condi t ions sui table for the

or ig ins o f li fe had d i sappeared . But here we f ind them. Therefore , we mus t ra t iona l ly

accept the l ikel ihood that l i fe is ar is ing there now . As a m at ter of fact, the condi t ionsthere are far sup erior to those in the laboratories at Col lege Park, San Diego, Hou ston,

o r Miam i . W e kn ow there a re micro-organ isms l iving under these condi tions , even

though there is som e dispute regarding the actual temperatures . Th e wo rk of Barros

and his col leagues fro m the San Juan D eFu ca hydrotherm al vents indicates that micro-

organisms possibly can exis t a t 160 degrees cent igrade under those condi t ions , and at

about 760 a tmospheres o f p ressure because o f the p resence o f liqu id water . So here

we hav e an opportun i ty to examine what Oparin described as the general appearance

of l i fe , that i t i s not something confined to one place or on e t ime on Earth , but perhaps

to the end of the {lnlverse.Of course , each d ive o f the Alv in cos ts $5 mi l l ion . W e have been urg ing NAS A,

NR L, and the NS F for the las t few years to fund such a project because i t wou ld give

us a unique opportuni ty to es tabl ish the basis of a problem of major importance.

Already we have pieces of the vents in the laboratory and are analyzing them in the

way we ana lyzed the meteor it es . There i s a ray o f hope: Thanks to the end of the Cold

War, there is now an at tempt to use mil i tary hardware for peaceful purposes , and we

have been able to persuade U .S. Senator Inouye of Hawai i to declare that one

submarine b e cal led a "whi te submarine ~ for science. If the Senate appropriat ions

process underw ay r igh t now prov ides the money , we wi l l have an oppor tun i ty o f t ak ing

Alv in dow n to the bo t tom of the oceans to study some o f these ven t s. There a re ,

accord ing to the geophysic i st s , some 40 ,00 0 k i lometers o f hydro thermal ven ts . W e

have loo ked at some o f these: the San Juan DeFu ca in the area near S eat tle , the one in

Southern Ca l i fornia, and the one at 21 degrees lat itude. So here we have an

oppor tun i ty to ver i fy the idea o f Alexander Ivanovich Oparin , who long ago descr ibed

as a possibi l i ty the general emergence of l i fe .

I t rus t that in these int roductory remarks I have been able to give you in smal l

me asure w hat we ow e to Oparin , and I hop e that wi th this lOOth anniversary celebrat ion

we h ave had , f i rs t in M oscow and no w in Tr ies te , there wi ll be fu r ther in te res t in and

en thusiasm fo r the s tudy of what O par in began so man y years ago .

Documents

Cyril Ponnamperuma -- The Origin of the Cell From Oparin to the Present Day