Sunday, November 08, 2009

The Darwinian Revolutions Video Series


The Darwinian Revolutions

An online video lecture series
in honor of the 150th anniversary
of the original publication of
Charles Darwin's Origin of Species


Produced by:
The Cybertower at Cornell University

Written, directed and narrated by:
Allen MacNeill, Senior Lecturer
The Biology Learning Skills Center
Ecology & Evolutionary Biology

Videography by:
Dina Banning

Sound Engineering by:
Colbert McClennan

Technical Direction by:
Becky Lane

Videotaped at:
The Museum of the Earth
The Paleontological Research Institution
Ithaca, New York

Voiceover Narration Recorded at:
Fall Creek Studios
1201 North Tioga Street
Ithaca, New York

Images Obtained at:
WikiMedia Commons
Stebbins/Simpson/Dobzhanky photo credit: Martin Tracey

Galapagos Video Credit:
Prof. William Provine

It's finally done! After more than a year of meetings, writing, image acquisition, videotaping, sound recording, editing, revising, captioning, and (most of all) thinking, our video series on the Darwinian revolutions is now online!

This series of six online videos is a brief introduction to Darwin's theory of evolution by natural selection and its implications. Here is a brief synopsis of the six episodes (click on each episode title to go to the linked video):


Episode One: Darwinian Revolutions
We begin with an overview of the series, which has been released to coincide with the 150th anniversary of the publication of Darwin's Origin of Species. Darwin's theory of evolution by natural selection revolutionized both the biological sciences and our understanding of ourselves and the world around us. In this episode we learn that Darwin's theory has itself evolved in the 150 years since it was published. We also learn that Darwin actually presented two theories:
• a theory of descent with modification from common ancestors, and
• the theory of natural selection, Darwin's mechanism for evolution.


Episode Two: Evolutionary Ancestors
Beginning with an overview of Darwin's predecessors, we learn how the idea of evolution by natural means alone goes back more than two thousand years, to ancient Greece and Rome. Democritus of Abdera first proposed the "ground rules" for naturalist evolution, which were later extended by the Roman poet and philosopher, Lucretius. However, these early naturalistic theories were eclipsed for almost two millennia by the ideas of Plato and Aristotle.


Episode Three: Lamarck's Theory
In the 19th century, Jean Baptiste Lamarck set the stage for Darwin's monumental achievement with his Philosophie Zoologique (published in 1809), which advanced a theory of evolution by means of the inheritance of acquired characteristics. Lamarck's theory was the first theory of evolution to include a testable mechanism for evolutionary change — the inheritance of acquired characteristics — and provides a useful comparison with Darwin's theory.


Episode Four: One Long Argument
Darwin, whose academic training at Cambridge University was in Anglican theology, became an acclaimed naturalist and science writer following the five-year voyage of HMS Beagle. Using the notes and specimens that he had collected during the voyage, Darwin spent twenty years refining his theory, first published in 1859, of evolution by natural selection.


Episode Five: Mendel and the Eclipse of Darwin
Darwin's theory of descent with modification was accepted by most scientists worldwide within ten years of its publication in 1859. However, his theory of natural selection was widely criticized, and by the turn of the 20th century was widely considered to be dead. However, the work of Gregor Mendel, who discovered the foundations of what we now call genetics, provided a mechanism by which Darwin's theory could be revived and expanded.


Episode Six: The Evolving Synthesis
In the final segment of this series, we visit the The Museum of the Earth in Ithaca, New York, whose director, Dr. Warren Allman, discusses the importance of such museums to the science of evolutionary biology. We also hear from Cornell professor William Provine, who discusses Darwin's work and its importance to the history and philosophy of biology. He tells us how Darwin's original theory of natural selection was integrated into the sciences of population genetics, ecology, physiology, paleontology, embryology, and botany, to produce a "modern synthesis" of evolutionary theory. Prof. Provine also tells us how the "modern synthesis" has continued to evolve, and that today is the most exciting time yet in the history of Darwin's scientific revolution.

This has been an exciting year: the 200th anniversary of the publication of Lamarck's Philosophy Zoologique, the 200th anniversary of the birth of Charles Darwin, and the 150th anniversary of the publication of Darwin's Origin of Species. There have been many events marking these anniversaries, and there will be many more. As Will Provine says, the theory of evolution is more dynamic, more exciting, more widely accepted, and more widely applied than at any time in the past century and a half. With the accelerating pace of discoveries in evolutionary biology and their applications in biology, medicine, psychology, economics, and even literature and art, the 21st century shows all indications of being what the founders of the "modern synthesis" called it back in 1959: the "century of Darwin" and his theory of evolution by natural selection.

************************************************

As always, comments, criticisms, and suggestions are warmly welcomed!

--Allen

Labels: , , , , , , , , , , , ,

Monday, February 23, 2009

Chance and Necessity


AUTHOR: Allen MacNeill

SOURCE: Original essay

COMMENTARY: That's up to you...

One of the main disagreements between evolutionary biologists and "intelligent design" supporters is the role of "chance" (also called "randomness") in the origin of biological objects and processes (especially adaptations). In many cases, it seems that this disagreement is exacerbated by a disagreement about what the antonym of "chance" might be. In my experience, many people on both sides of the EB/ID disagreement think that the opposite of a "chance" event is an event that was "caused". However, this ignores the fact that many scientific explanations now include "chance" or "random" processes in causal explanations of natural objects and processes.

In this context, therefore, I propose that the antonym for "chance" is "necessity", as was first pointed out by Democritus of Abdera in the 4th century BC, whose two famous aphorisms were:

"All things are the fruit of chance and necessity"

and

"Nothing exists except atoms and the void".

The phrase "chance and necessity" is often used as a descriptive term in modern science. It means essentially "all natural/physical causes", or what one might consider to be the "Newtonian" world view. The reason that evolutionary biologists consider that Darwin founded the science of biology is that he proposed a theory of descent with modification and the origin of adaptations that was based entirely on "chance and necessity", thereby "unifying" biology with the other natural sciences.

However, it is clear that there is a myriad of objects and processes in the universe that are not entirely the "fruit of chance and necessity", just as there are clearly "things" that are neither "atoms" or "void". In purely physical terms, we now recognize at least three "things" in nature: mass, energy, and information. Only the first of these three qualifies under Democritus second aphorism, as neither energy nor information qualify as "things". Energy, of course, is interconvertable with matter according to Einstein's famous energy/matter equation. However, in the form of "pure" energy (such as electromagnetic radiation), energy is not detectable unless and until it interacts with matter (this is why outer space appears black, even though it is filled with light).

The "detectability" problem of energy is even more difficult in the case of information. It seems clear that all forms of information involve some sort of "translation", in which matter/energy relationships are "translated" into information, which can be stored and transmitted in forms that are not entirely reducible to the original matter/energy forms which they represent. As Korbzybski famously said, "the map is not the territory"; the representation (in the form of information) is not the "thing" represented".

No one, including hard-core "naturalists", suggests that information doesn't exist. The problem (and this is where EB and ID run into serious difficulty), is how (and perhaps by whom) information can become "translated" in the first place. It is not even completely clear that simple "natural" processes (such as the photoelectric effect) do not include an exchange of "information" as well as an exchange of energy (in the form of a photon, for example). In quantum electrodynamics, does the exchange of a photon (or, even worse, a virtual photon) constitute an exchange of "information" between the interacting particles?

In classical physics, there is no "arrow of time". Newtonian mechanics can be run forward or backward in time, with no contradictions (and no way to tell which way the process is happening). However, in those branches of modern physics in which random processes play a part (statistical mechanics, thermodynamics, and quantum mechanics), randomness is necessarily tied to "time's arrow". The same is apparently the case with information, at least in its Shannon form.

Ergo, it seems to me that the problem of information is one that is necessarily tied with the concept of "chance". Indeed, I have come to think that information is a manifestation of one of the operations of "chance" in nature; without information, chance overwhelms everything and the universe disintegrates into permanent incoherence.

This is clearly the case in biology. The "fixing" of information in the physical form of the genetic material is the only thing that makes biology possible. Without such "physicallization" of information (in the form of DNA, RNA, proteins, etc.) biological systems would be impossible, as they would disintegrate into incoherence.

Ergo, the transition from purely physical (i.e. mechanical/Newtonian) processes that do not include the translation and transfer of "translated" information to biological processes that necessarily involve the translation and transfer of "translated" information is the central problem of both biology and the physical sciences. As I have written before, I am not sanguine about our ability to answer this problem using historical information, as the transition occurred at a time (and perhaps in a place) which has left no traces from which we can infer its dynamics.

This leaves us with theoretical models, which are of course based on metaphysical assumptions about reality. I believe it would be fair to say that IDers assume that information can exist without a physical referrent (i.e. something that "carries" or "transmits" the information), whereas EBers (along with most other natural scientists) assume that information must have a physical referrent (i.e. it cannot exist in purely "disembodied" form).

Furthermore, it seems clear from previous discussions in this forum that IDers assume that information can be "foresighted"; that is, it can somehow anticipate future outcomes, not by "induction" from the past but by some kind of "deduction" from the future. EBers (again, like most other natural scientists) assume that "time's arrow" cannot point backward, and that the future is therefore relentlessly driven by the past.

It seems to me that the foregoing lays out the problems which which any scientific theory of "origins" must come to grips:

• whether information can exist in purely "disembodied" form in nature, without a physical referrent

• whether the origin of the "translation" of information into physical form (i.e. the origin of the genetic translation machinery of living organisms) cannot take place without an input of "disembodied" information

• whether any form of information transfer can be genuinely "foresighted" (i.e. can be modified by events that have not yet happened, rather than simply predicting future events based on events that have happened in the past).

Evolutionary biologists (and the vast majority of all natural scientists) begin with a metaphysical world view in which their starting assumptions answer these three questions with NO. By contrast, most of the ID supporters with whom I have had such discussions begin with a metaphysical world view in which their starting assumptions are exactly the opposite: they answer these three questions with YES.

Personally, I believe that the metaphysical world view of most scientists is easier to work with, as it requires fewer "YES" answers to these questions (i.e. it requires fewer unverifiable assumptions about things that must exist for the universe to work). However, I freely admit that this belief is on a par with my acceptance of "Occam's razor" as a basic principle of scientific explanation. That is, "Occam's razor" clearly isn't "true", it's just useful as a rule of thumb in doing science.

So, where does this leave us? I think it explains why most scientists are uncomfortable with the word "design" being applied to biological objects and processes. As I have pointed out, Ernst Mayr argued for the legitimacy of the concept of design in biology, when what was meant by that term was the idea that organisms are "designed" by the information encoded in their genomes, interacting with the information obtained from interactions with their environments. This is because this view of biological "design" conforms to the three answers to the three questions listed above as answered by most scientists.

However, Mayr (and virtually all other evolutionary biologists) was uncomfortable with the idea that the process by which genomes and environments came into being was also "designed" - that is, that there was some foresighted process in which intention played a part in the bringing into existence of the physically embodied objects and processes in biology. Again, this is because this view of biological "design" does not conform to the three answers to the three questions listed above as answered by most scientists.

Where do we go from here?

As always, comments, criticisms, and suggestions are warmly welcomed!

--Allen

Labels: , , , , , , , , , , ,