Chapter XI
THEORIES OF THE ORIGIN OF LIFE

According to our hypothesis life always has existed and
always will exist under all conditions in some form, though that
form may be quite different from any form of life that comes
within our experience. If we trace back the ancestry of present-
day life, we will always be able to trace it back to some life,
though it may be in such a form that it might be extremely
difficult to recognize it as life. Thus, there never was a time
when life started on the earth; It merely developed into its
present complex form from some simpler form that existed on
earth when the earth was in a molten or even in a vaporous
condition; still farther back, it can be traced to some extremely
simple form of life that existed as far back as the nebula out of
which the solar system originated; we shall later attempt to
trace it back beyond the nebula.
Our theory of the origin of life is thus that there was no
origin, but only a constant development and change in form.
This belongs to the class of theories known as the Biogenetic
theories, which assume that at some previous time life did not
exist, and that under certain special circumstances that
existed when the earth was in a heated condition the necessary elements came
together somehow and assembled themselves into a living body from which all
other living bodies are descended. The nature of this automatic assemblage of
constituents remains, of course, rather mystical; not to speak of the fact
that the assumption of spontaneous generation is rather contrary to observed
facts.
Such abiogenetic theories have very frequently been advanced, especially
since every now and there there is a recrudescence of the belief that
spontaneous generation of life is possible under present circumstances, that
life could be produced in the laboratory, in spite of all observed facts to
the contrary. Haeckel represents this abiogenetic theory in its most general
form; that, when water first liquified on the earth, its reaction on various
substances then present produces proteid, which was the original life from
which all life has descended.
How this proteid was formed remains a mystery. We have, however, a more
detailed explanation in Pflger's theory, which is to the general effect that
the original combination was that between carbon and nitrogen, forming
cyanogen, which in its turn united with other substance, especially the
hydrogen and oxygen of water, to form more and more complex cyanogen or other
similair carbon-nitrogen compounds, such combination forming as a final
result proteid, the chemical bsaes of which would thus be the cyanogen
radical, CN. Here we have a very likely explanation. In the first place, even
many simple cyanogen compounds have many chemical reactions very similair to
those of proteid; in the second place, whereas proteid has, in itself, been
found to constitute a very great poison, is it also known that cyanogen is
one of the most powerful poisons known, and that its compounds are, in
general, extremely poisonous, though in certain combinations found in living
bodies (e.g., almonds) such compounds seem to be quite harmless.
One difficulty with this is that this idea of spontaneous generation is
somewhat contrary to observed facts; there is no instance observed of such a
thing as spontaneous generation of life. But the main difficulty is to
explain the formation of cyanogen and especially of its compounds from their
elements. It is perfectly true, as alleged that carbon and nitrogen being
together at a high temperature will form a little cyanogen, but, with the
large amount of oxygen present, this cyanogen could not last long, since
cyanogen is a very endothermic substance, and under the second law of
thermodynamics, it will reduce to the combination that has less chemical
energy, losing the difference in the form of heat; resulting in carbon
dioxide and nitrogen as a product. Accordingly we must suppose some peculiar
sort of carbon and nitrogen that will not only unite into cyanogen, but which
will form such a peculiar form of cyanogen that, instead of oxidizing on
contact with oxygen (as ordinary cyanogen would), it not only holds itself
aloof from oxidation but even forms more complex and more endothermic
compounds. We must suppose some form of carbon and nitrogen which would
reverse the ordinary chemical reactions under those circumstances; or, since
those reactions are based ultimately on the second law of thermodynamics, we
must suppose that there was at that period of the earth's history some carbon
and nitrogen that possessed the ability to reverse the second law of
thermodynamics. If we suppose that, our theory of life can easily harmonize
with the Pflger idea as to the origin of organic life from cyanogen
compounds. In fact, as we have seen, our theory of life is such that we would
theoretically suppose that living organisms would have a chemical
construction based on the cyanogen radical, thus falling in exactly with
Pflger's idea that life on the earth originated in cyanogen and its
compounds.
So much for the abiogenetic theories. Turning now to the biogenetic
theories, we can hardly find them much more satisfactory. We have, for
instance, Preyer's theory that the eart itself, in the heated state, was
itself an immesnse living organism, from which all living organisms existing
at present are descended; all inorganic matter on the earth being merely the
rejected excretions of the former living earth, while the living substance
came more and more to resemble protoplasm.
Absurd as this theory may sound, there is nothing impossible about it.
However, the astronomy of the proposition is rather poor. There is no reason
to believe that the earth, in a heated state, was in any different condition
from all other known bodies which we find in a similarly heated state (e.g.,
the major planets and the sun); and these heavenly bodies are hardly in a
condition which could by any stretch of imagination be called living.
However, if by living is meant that there is a potentiality of the generation
of life, of course the earth in a heated condition must have come under that
heading. But since the heated planets have no particular resemblance to life,
what is more likely is, that on the earth in a heated state, there was life,
and there was such life even in the nubula, almost as different from the life
that we know at present as the kind of earth-organism that Preyer supposes,
but having some properties in common with present life. This is precisely
what our theory of life would lead to.
We come now to the biogenetic theory most commonly advanced, one which
numbers among its supporters Helmholtz and Sir William Thompson. This is the
so called theory of cozomzoa, otherwise known as the theory of seed-bearing
meteors. This theory is to the effect that two planets, at least one of which
had developed life on it, came into collision, so that each of the planets
was broken into small pieces which were scattered all over in different
directions. Some of the pieces of the life-bearing planet, in the form of
metoerites, passed another, always bearing within them the seeds of life.
These meteorites finally came into the solar system and entered the earth's
atmosphere, then striking the earth and planting these seeds of life on the
earth, which afterwards developed into the various forms of life that now
exist.
This theory sounds very plausible, but again it is based on very poor
astronomy. The common meteors, or shooting-stars, which are the actual bodies
that seem to have passed from one system to another in this manner, never
actually reach the earth's surface, but are completely burned up before they
have penetrated very far into the atmosphere. The larger bodies that actually
reach the earths surfaces are the so-called meteorites which are as much
parts of the solar system as the planets, and even move round the sun in the
stray asteroids. Tracing life to such bodies is not tracing it to any other
steller system, but merely to the solar system, and makes it more impossible
than ever to trace back where these supposed seeds of life from, or how they
got into the meteorite. There is, of course, nothing to prove that such a
meteorite as this hypothesis assumes could not be formed, or that it could
not thus transplant life from one planet to another. But, since such
meteorites as are large enough to reach the earth's surface and at the same
time are not members of the solar system do not seem to be a regular
occurrence, there being no known instance of such a body, it would seem that
such as occurrence is a very rare one, if indeed it can happen at all that
any life in its present form could survive such a collsion or such a long
trip through space. Should two planets happen to collide as the hypothesis
assumes, and should any life on those planets survive the collision, the
chaces are almost nil that, in the case when it happens, any of the pieces of
wreckage would strike another planet at all, much less that it would strike
one at the very period when that planet was ready to receive the very form of
life carried by the meteorite. Thus not only is the hypothesis improbably per
se, it is also contrary to any ovserved facts, since the actual bodies that
could be supposed to come from other stellar systems are, as far as
observation goes, so small that they are burned by friction with the
atmosphere long before they can reach the surface of the earth.
It might be interested to note that, in the time of Helmholtz and
Thompson, the distinction between the meteors or shooting-stars that come
from other stellar systems, and the meteorites or aerolites which form part
of the solar system, was a distinction which had not yet been clearly drawn.
We thus come to the conclusion that the theory of Cosmozoa is entirely
unacceptable in view of present facts, which Preyer's theory of the
earth-organism can only be accepted in the extremely modified form that the
earth, in its molten and vaporous states, contained life (instead of having
been alive, as Preyer himself would have it). Thus we come to the conclusion
that life is as eternal as the inanimate, and is to be found as universally,
under as varying conditions, as inanimate phenomena. On the other hand, we
can also accept the Pflger idea that life as it exists on this earth
originated from the formation of cyanogen and its compounds.
Our theory of the origin of life is really Biogenetic, in that it
supposes that all life originated from life for an eternity past; but, on the
contrary, inasmuch as the past life from which the present life is derived
was in an almost unrecognizably different form from that in which life at
present appears, it supplies a basis for the Abiogenetic theories of the
origin of life from non-living organisms which are, according to our theory,
inorganic life.