-= THE DARWIN TIMES =- A Column on the Field of BIOLOGY and other Related Fields With an E
-= THE DARWIN TIMES =-
A Column on the Field of BIOLOGY and other
Related Fields
With an Emphasis on MEDICAL NEWS, ANIMAL BEHAVIOR,
PSYCHOLOGY, and EVOLUTIONARY THEORY
by
RAY LOPEZ
MC 414500
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Issue #2 September 27, 1991
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Contents of This Issue:
* Viewer Mail
* QuickBioPrimer-- A Look at Taxonomy
* Part II of Charles Darwin and His Legacy to Science: A Look
at Evolutionary Thought Before Darwin
* Commentary: Evolution or Evilution?
-=*=-
* Viewer Mail
In response to my very first column, I received nothing but many
VERY supportive letters, and even got a chance to meet a new
scientist collegue. This was great, and was nothing like I
expected. I thank everyone out there in STLand who took the time
to write, and to everyone who is reading the column. I am an
Email junkie, and would greatly appreciate any and all feedback
regarding this column.
Someone out there DID bring up an interesting point. When I said
that, for some reason, evolution is not being taught in the
schools, I ABSOLUTELY DO NOT IN ANY WAY, SHAPE, OR FORM BLAME
TEACHERS FOR ANY OF THAT!!!! In my opinion, the teachers in
this country work selflessly under some very adverse and sometimes
downright ridiculous conditions and rules. They are quite often
the victims of some very bad decisions made at higher levels, and
should actually be canonized for their efforts.
Even after all of the mail I have received, I am still not quite
sure how to approach this column. I will continue to write
about things I think people might be interested in, but PLEASE
do not hesitate to write me if you want to see something different
in this column, or if you do not like how it is evolving.
A quick note: I will try my best to update this column on a
bi-weekly basis.
-=*=-
* QuickBioPrimer-- A Look at Taxonomy
TAXONOMY: the science of classification
WHAT IS IT FOR: Taxonomy is the science (some would say the art)
of classifying all organisms, extinct and present, into groups
within the 'tree of life' (this is my own term)
WHAT GOOD IS IT: Due to evolution, all life forms came from
other life forms, and so all life on this planet is related
to all other life on this planet in at least SOME distant way
(ponder this thought: you and your rose bush use DNA in the
same basic way to preserve and replicate your respective
and unique genetic information). Since we are all related,
it makes sense (in doing "good" science) to come up with
methods of classification that allow us to determine where
in the sprawling tree of life all the critters of this planet
belong.
HOW DOES IT WORK: As a new organism is encountered, its
characteristics are measured and recorded, and it is placed
into a category with similar organisms. This is by no means
an easy or noncontroversial task. Many modern debates in
biology have to do with how best to classify organisms, and
how best to construct and define groupings. If you
are interested in learning a bit more about this, pick up
any good introductory textbook on EVOLUTIONARY BIOLOGY.
There are several of them out there. Look under
CLASSIFICATION or TAXONOMY. One way that organisms are placed into
categories is by how they look (their MORPHOLOGY). Some
people who do this go even further by looking for certain
"primitive characteristics" that an organism might have, and
then grouping together organisms with these same
characteristics (this is called CLADISM). There are many
other ways to classify organisms. Many organisms can even
been classed according to different BEHAVIORS. The methods
of classification are complex and don't always work right the
first time. There have been cases (such as with birds) where
the male and female of a single species have looked so
different from each other that each was classified as a totally
different species!
WHAT DO YOU END UP WITH: A big picture of how life on this
planet is organized and interrelated. There is a specific
heirarchical ordering of groups of organisms. Any one of
these groups, at any level, is called a TAXON. The highest
taxa we have are the five KINGDOMS: Monera (e.g. bacteria),
Protista (e.g., Paramecium and amoebas), Mycota (fungi),
Plantae (plants), and Animalia (animals). Each of the
five kingdoms then has sub-taxa as shown below.
KINGDOM
\
PHYLUM
\
CLASS
\
ORDER
\
FAMILY
\
GENUS
\
SPECIES
Below is a tracing of the PHYLOGENETIC RELATIONSHIPS for our
own species.
KINGDOM: Animalia (we share this with all animals)
PHYLUM: Chordata (we share this all animals with a backbone)
CLASS: Mammalia (we share this with all animals who are warm-
blooded, bear live young, and produce milk)
ORDER: Primates (we share this with "monkeys" who all live in
trees, have good hands and vision, etc)
FAMILY: Hominidae (all present and extinct forms of humans)
GENUS: Homo (includes some of the most modern forms of humans,
including two species which are gone, Homo habilis
and Homo erectus)
SPECIES: sapiens-- the modern human!!
Keep in mind that all of the taxa discussed above have within them
numerous sub-taxa, so we do speak of things like SUB-PHYLA,
SUB-GENUS, SUPERFAMILIES, etc. The ways in which taxonimists
create and orgnaize taxa have been and always will be debated.
It is a monstrously complex task, as you can well imagine.
-=*=-
* Part II of Charles Darwin and His Legacy to Science: A Look
at Evolutionary Thought Before Darwin
Contrary to at least a few popular misconceptions, Darwin did not
singlehandedly invent the idea of evolution and everything that
goes with it. Indeed, the idea of evolution has been around for
many hundreds of years, as many great thinkers throughout history
have noticed some of the things in nature which give us some
clues that evolution has occurred. As a preview of coming
attractions, let me say now that what Darwin DID manage to
contribute to science was a very carefully thought out and well
defended MECHANISM for evolution to occur, that mechanism
being NATURAL SELECTION.
Many people trace the first roots of evolutionary thought back to a
Greek philosopher named Anaximander, a student of Thales (the
founder of Greek philosophy) who lived about 2000 years before
Darwin. Anaximander beleived that all life arose from water, and
that humans arose from the fishes. This DOES sound a bit
familiar! Other Greek philosophers, such as Empedocles,
Democritos, and Lucretius, all followed-up on these sorts of
ideas, in that they all taught that complex life-forms arose
from the simpler ones.
The ideas of Empedocles were notable because he described a sort
of mechanism by which different forms of life could evolve.
Empedocles speculated that life started out as a mixture of
formless bodies and body parts, such as arms, legs, heads, etc.
These parts all came toghether in various and sundry forms.
Some of these chance combinations produced monstrosities
completely unable to survive (maybe he got this idea from seeing
some birth defects in humans and animals first-hand?). Other
combinations produced organisms able to survive, and thus they
thrived. This is a very interesting speculation, especially when
looked at from a modern genetic perspective. If you substitute
"genes" in the passage above for "body parts," you at least
begin to get very close to describing the way many feel that
evolution at the genetic level occurs (more on this later!!).
Many different ideas regarding the origins of life and of
material things in general were brought together by the Roman
poet Lucretius during the first century B.C. In his poem
_De Rerum Natura_ (On the Nature of Things), Lucretius comes
up with what many believe is a very early forerunner to
Darwin's idea of natural selection. He writes that some
random combinations of body parts are better than others, and
the ones which are less well ADAPTED to do certain things,
like eat, will not survive, while those organisms with a
combination of body parts which allows them to survive the
best will survive and thrive.
Very nearly all facets of modern science can somehow be traced
back to Aristotle, and biology is certainly no exception.
Indeed, it seems as though Aristotle were more of a biologist
than anything else! One of Aristotle's most important
contributions to biology was his idea of a _scala naturae_, the
idea that some forms of life are more superior than others.
Briefly, Aristotle believed that any object possessed of life,
from a plant on up to a human, had to have at least one
of his three "souls". There were the vegetative soul, animate
soul, and rational soul. Plants just had vegetative souls.
All animals had vegetative plus animate souls, and humans
alone posessed these two souls along with the rational soul,
which gave us our superior intellectual abilities, and made
us superior to the brutes. Aristotle also originated the concepts
of GENUS and SPECIES.
The _scala naturae_ persisted thoughout subsequent history, and
even persists to some extent today. The idea of the _scala_ gave
rise during the Renaissance to the science of TAXONOMY. It was
here where the new scientists of the Renaissance were beginning
to understand how life on this planet is interralated. Linnaeus
published his _Systema Naturae_ in the 1730's. This was the first
systematic classification of all life known at the time. As
scientists studied closer and closer the life on earth, and as
they discovered new, strange forms of life in the New World, it
started to become apparent that maybe the life on this planet has
not always been the way it exists today, as had been previously
thought. The new science of GEOLOGY did much to change this
view as well.
As discoveries were further made in Europe and the New World, one
fact became clearer: it seemed as though differences in species
could somehow be related to differences in the ENVIRONMENT!!
This point of view came about for a variety of historical and
philosophical reasons as well, but many scientists were certainly
beginning to note relationships between the environment an
organism lived in and the way that organism looked. For example,
tropical species certainly looked as though they were designed
to handle hot weather, and polar species sure looked like
they were best fit to live in cold weather. AN EXTREMELY
IMPORTANT CONCEPT BORN OF THIS ENVIRONMENTALISM MOVEMENT WAS
THE CONCEPT OF * ADAPTATION * OR THE IDEA THAT AN ORGANISM IS
SOMEHOW SUITED TO ITS ENVIRONMENT!
Well, here we are at the end of the 18th century. Many now famous
biologists began to put forth ideas as to the hows and whys of this
adaptation Amon the wer th Frenc biologis Etienn Geoffro Sain-Hilaire
and Erasmus Darwin, Charlie' granddaddy. It was now apparent
that a theory of evolution was necessary to explain
some of the findings of these biologists, and these men were
trying to do just that.
The most famous of these pre-Darwin attempts at describing the
mechanism of evolution and adaptation was that of Jean Baptiste
Lamarck. We'll wrap it up there for now. Next time, I'll
breifly tell you what Lamarck did, and then it will finally be
time to introduce into the picture the quiet, religious man
known as Charles Darwin.
-=*=-
* Commentary: Evolution or Evilution?
We have all heard it before for our entire lives. Unfortunately,
many people are under the mistaken impression that to believe
life evolved and IS evolving on this planet is to NOT believe
in God and the Bible. In my view, nothing could be further
from the truth.
This anti-evoutionary perspective has been around for as long as
evolutionary theory has. One of the earliest opponents to
evolution in general was the Reverend William Paley. In 1802,
he published a book wherein he described all of the remarkable
beauty, utility, and diversity of nature, and used this to defend
his claim that God created everything by design. These ideas
form the roots of modern creationist thought.
Nowadays, people read the Book of Genesis in the Bible and
basically say to themselves, "Yes, the Lord put together the
universe, including all of the critters on this planet." Why
should this view of Genesis preclude the existence or validity
of Darwinism and of evolution in general? Because (supposedly)
the Lord made everything AS IT IS! To say otherwise is to say
that somehow the Lord is imperfect, that He must sort of try
different things to find the right things that work.
Well, I do not quite know how to respond to that. All I can say
is this: Why does the story of Genesis recount, very broadly, the
basic story of the EVOLUTION OF LIFE AND MATTER ON THIS PLANET?
Let's look a little more closely at the first chapter of Genesis.
First, there was the earth, formless and desolate. Then came
light, along with night and day. Then came the sky (our
atmosphere), followed by dry land, called Earth, and patches
of water called Sea. Then came the plants, then the creatures
of the sea, and the birds. Then the Lord commanded that the
earth produce animal life, herds and herds of it. Finally,
we came along, and on the seventh day, the Lord rested.
As a maven of science and evolutionary theory, this scenario
sounds very familiar to me. As a matter of fact, it is the
same, basic scenario that science recounts as the way in which
the earth was formed, and the way in which life evolved on this
planet. A formless planet forms an atmosphere from the gases
it emits from volcanic eruptions, etc. Land is formed, and the
seas are defined. Primitive plants begin to thrive as they
evolve from some sort of "primordial soup." Millions of years
later, there are primitive sea animals. They evolve into ever
more complex animals, and eventually come to land, where they
thrive and diversify. The reptiles give way to the mammals
and before you know it, after only about 4 or 5 billiion years,
here we are, reading StarText!
Why did God tell us this story the way in which He did? I
mean, if He wanted to, it seems to me that He could have just
said, "The universe and earth were all created in one big
swoop." Why didn't He? In my view, it was because He was
telling us THE TRUTH. The truth being that He formed all of
the life on this planet by letting evolution take its course.
There is nothing wrong with saying this, in my view. Religion
and the Bible tell us WHY things have happened the way they
have. Science is telling us HOW things happen the way they
have, with absolutely no reference to WHY. When Sir Issac
Newton introduced his laws of physics, people did not chastise
him for somehow messing around with the Lord's natural order
of things. Instead, Newton was praised by some for having
been able to describe the inner workings of the Lord's
universe, and nothing more. In the same way, it seems to
me that the mechanisms of evolution worked out by Darwin
(i.e., natural selection) simply describe the inner workings
of how our Lord has managed to create such a beautiful
diversity of life on this planet. To ask HOW something
came about and to ask WHY something came about are to ask
two completely different questions. This is a fact most
do not realise.
Something else that often comes up is the fact that evolution
has occured over billions of years, while the Bible clearly
states that it took six "days." What is a "day" to the Lord?
To me, it seems very presumptuous of us to think that one day
is the same length to the Lord as it is to us. To the Lord,
billions of years are probably the same as a day, or a week,
or whatever. Who are we to say that God and the Book of Genesis
must stick to a 24 hour day? Who's not to say that the Book of
Genesis says six days because people then (and now) could
not possible conceive of ANYTHING occuring over billions of years?
These are some of the basic reasons why I feel that modern
evolutionary theory need not contradict religious beliefs or
thought. All of this is simply my opinion. Science and
evolutionary theory deal with the HOW question of life on
our planet. Religion deals with the WHY question of life on
earth. These are entirely different questions, and must be
looked at from entirely different perspectives.
-=*=-
Some Contents of the Next Issue:
* Some Fun with Evolotionary Theory and Animal Behavior at
Home: Here, Kitty Kitty Kitty!!!
* Part III: Charles Darwin and His Legacy to Science
* Tour of the World of Biology: Zoology
* QuickBioPrimer: Gregor Mendel and the laws of inheritance
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Thank you very much for reading THE DARWIN TIMES. Any reader
responses via StarMail would be greatly appreciated, and will
be answered as soon as possible (send to mail code 414500).
The contents of this column may be freely distributed or used
by anyone, so long as credit is given to the author and to
StarText.
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