A POOL OF IDEAS.
I was watching a series on PBS, all about Darwin and evolution. The approach
was not so much on Darwin’s insight and the supporting evidence for this
insight, but more on his conflict with his culture, a static world of the Classics
and the Renaissance. It was fairly obvious that the presenter of the series
thought that evolution is opposed to the idea of creation. Many times it was
mentioned that nature “tinkers” as she, sort of by chance, comes upon
adaptive solutions, and that “god” (as they think about God) would
not tinker but create something that is “perfect” and needs no modifications.
I believe that God created a tinkering natural process, which with all its randomness
did eventually lead to you and me. We have the privilege to observe this process
in all its complexity. It is like a branching tree that is alive with many leaves
fading and many thriving green. I look at what is, and I know that is what God
made.
One of the examples the presenters used was the evolutionary changes in the
structure of the eye from the simplest eye spot to the complex human eye, which,
by the way, is not perfect because the retina can detach and is inverted with
all the stuff right in front of the light sensitive cells, and so on. It is
working fine though most of the time. The presenters concluded that this is
nature’s “tinkering” and not the work of a creating Supreme Being.
It is their privilege to think so. It is all a matter of faith. We either have
it or we don’t, and we interpret everything accordingly. Faith does not
come from looking at nature. But to look at nature with faith is an awesome
and beautiful experience.
•
Data, hypotheses, knowledge, theories, assumptions, probabilities, possibilities,
and fiction; they all swirl around and around in the world of science. What
do they mean?
Scientific data are the results of observations. A hypothesis is an educated guess, based on the data and on the knowledge we already have. Knowledge is the true answer to our hypothesis verified by well designed experiments, all in line with the scientific method. A scientific theory is a generalized conclusion based on all the knowledge we obtained in a given field. Examples are the unified field theory in physics, and the theory of evolution in biology. Some people use the word theory in place of hypothesis or some other form of speculative guessing. That should be avoided. It is sloppy thinking, and it only leads to confusion.
What about assumptions? They are the tricky ones. In some circumstances it
is not possible to use the scientific method because direct observations are
not possible. The only way to proceed then is by making a reasonable assumption.
Statements about the origin of life, the characteristics of the primitive earth,
the interpretation of the fossil record, the interpretation of morphoclines
in comparative anatomy, embryology, and behavior, are all in the category of
being formulated by reasonable assumptions. Of course, the question is, what
makes an assumption reasonable? I believe the more an assumption remains based
on available knowledge obtained by using the scientific method, the more reasonable
it is. Were the evolutionary factors which we observe today operative in the
past? Probably. What we discover about evolution using the scientific method
is the gradual nature of the process. For this reason, statements on the appearance
of sudden major changes in the evolution of life may be more reflections on
the incompleteness of the fossil record then real. At least that was Darwin’s
opinion. More recently the idea of punctuated equilibrium has been proposed
according to which there are long periods of stasis alternating with periods
of rather short but very active evolutionary change. This idea has been proposed
by Stephen Jay Gould and Niles Eldredge in 1972 based upon the accumulation
of more and more fossil data. May we assume that the idea is correct? Unfortunately,
apart from the fossil data themselves, we have no good evidence about the postulated
mega-mutations needed for such major changes, neither do we know about the mechanisms,
which might have produced them. Is it possible that punctuated equilibria and
gradualism may have run in a complementary fashion? And, as you see, slowly
we slide into a world that is farther and farther away from the observable,
and moves more and more toward the less reasonable. To learn more about the
evolutionary process itself, the approach of Peter and Rosemary Grant seems
to be more in the line of evolutionary research. They spent over twenty years
on the Galápagos observing and measuring Darwin’s finches, and so
witnessing several actual events of evolutionary change.
•
The comparative method is an essential tool for revealing evolutionary relationships.
The work of Edwin S. Goodrich, to mention only one example, the Studies of
the Structure and Development of Vertebrates, available today in the two
volume version of 1958, Dover Publications, is based upon the comparative method.
The strength and aim of the method is the discovery of homologies of structures
in members of a contemporaneous group, which have common ancestry. Some would
assume that homologies are manifested in the similarity of structures. This,
however, is not necessarily so. By definition, two structures are homologous
if they have common ancestry, irrespective of their present shape, position,
or function. However different may be the end product from the original, it
is often possible to construct a sequence of changes through the similarities
of the intermediate forms.
The evolutionary process of cephalization in vertebrates provides good examples of homologous series. A study of the fossil record reveals a temporal sequence of movements of anterior visceral arches or gill structures into a more and more developed head region. For instance, the third visceral arch of Ostracoderm of the Paleozoic was a simple skeletal rod supporting the gill. In Devonian sharks and fishes the same skeletal rod moved forward to support the jaws. Its upper portion then later became modified in amphibians and lungfishes to form a primitive ear bone, the columella auris. The same structure was found in primitive reptiles and birds. Then, as cephalization progressed further the columella of reptiles became modified into the stapes, one of the ear ossicles of mammals. We can find all these structures in present living vertebrates from lampreys, through fishes, amphibians reptiles, birds to mammals. The shape, position, and function of the original structure has changed as it appears in modern vertebrates, but because of common origin, these modern forms represent a homologous series or morphocline, reflecting the evolutionary history of the group.
Are studies of the fossil record and studies in comparative anatomy proofs
of evolution? Strictly speaking, they are not. This is quite apparent in the
statement that we conclude to homology from knowledge about common ancestry,
and not the other way around. It is more realistic to say that we interpret
both, the fossil record, and our studies in comparative anatomy in evolutionary
terms. The internal coherence of such studies, however, presents us with a strong
support in favor of evolutionary interpretations.
•
It is interesting to compare in a visual manner the various flavors of positions
on creation.
The biblical view, or more precisely the view of the time when the first three
chapters of the book of Genesis were written is this. There was a moment in
time, when creation started and then run its course in a time sequence of six
days. After that, God rested on the seventh day. The moment in time is called
“In the Beginning,” when it all started. After creation was done,
nothing has changed but ran its given course. Once in a while, God interacted
with the created world, when such intervention became necessary to correct the
evil people had done. Otherwise, there was nothing new ever under the sun.
The way Darwin understood creation was very similar to the biblical view except
for the static character of interpretation. In Darwin’s view, God created
a process by giving life to one or more simple forms, and then “from so
simple a beginning endless forms most beautiful and most wonderful have been
and are being evolved.” (The last sentence of the Origin.) In this view,
the human species is produced by this created process.
There is a third possible interpretation of the creation story. Creation is
a divine act, and as such it is not in time for God, because time and space
are the created frameworks of the created world, which we understand in our
created way, that is in time and space. God is in God’s absolute present.
God is thus present as the Creator in every moment of every process, including
the process of evolution. Since we are in time, we can only express the timeless
divine act of creation in the framework of time, and so we talk about six days,
and evolution, depending on whether we are in a static or dynamic cosmology
of a given culture. In any case, we can only be anthropomorphic as we express
everything in terms of human experiences.
•