The gift that keeps on giving: Darwin and the Origin of Species

In conjunction with Darwin2009 Houston, a year-long celebration of Darwin’s 200th birthday and 150th anniversary of the publication of “On the Origin of Species,” HMNS will host a series of events exploring the contributions of this famous scientist.

Today’s guest blogger is Francisco J. Ayala, who shares some his findings here prior to his Feb. 24 lecture at the Museum, on “Darwin’s Gift to Science and Religion,” a part of HMNS’ Distinguished Lecture series.

The Origin of Species #1
Creative Commons License photo credit: gds

Darwin occupies an exalted place in the history of Western thought, deservedly receiving credit for the theory of evolution. In The Origin of Species, he laid out the evidence demonstrating the evolution of organisms.  However, Darwin accomplished something much more important than demonstrating evolution. Indeed, accumulating evidence for common descent with diversification may very well have been a subsidiary objective of Darwin’s masterpiece.  Darwin’s Origin of Species is, first and foremost, a sustained argument to solve the problem of how to account scientifically for the design of organisms. Darwin seeks to explain the design of organisms, their complexity, diversity, and marvelous contrivances as the result of natural processes. Darwin brings about the evidence for evolution because evolution is a necessary consequence of his theory of design.

The advances of physical science brought about by the Copernican Revolution had driven mankind’s conception of the universe to a split-personality state of affairs, which persisted well into the mid-nineteenth century.  Scientific explanations, derived from natural laws, dominated the world of nonliving matter, on the Earth as well as in the heavens.  Supernatural explanations, which depended on the unfathomable deeds of the Creator, were accepted as explanations of the origin and configuration of living creatures. Authors, such as William Paley in his Natural Theology of 1802, had developed the “argument from design,” the notion that the complex design of organisms could not have come about by chance, or by the mechanical laws of physics, chemistry, and astronomy, but was rather accomplished by an Omnipotent Deity, just as the complexity of a watch, designed to tell time, was accomplished by an intelligent watchmaker.

It was Darwin’s genius to resolve this conceptual schizophrenia.  Darwin completed the Copernican Revolution by drawing out for biology the notion of nature as a lawful system of matter in motion that human reason can explain without recourse to supernatural agencies. Darwin’s greatest accomplishment was to show that the complex organization and functionality of living beings can be explained as the result of a natural process—natural selection—without any need to resort to a Creator or other external agent.  The origin and adaptations of organisms in their profusion and wondrous variations were thus brought into the realm of science.

crab on the rocks
Creative Commons License photo credit: angela7dreams

Evolution can be seen as a two-step process. First, hereditary variation arises by mutation; second, selection occurs by which useful variations increase in frequency and those that are less useful or injurious are eliminated over the generations. “Useful” and “injurious” are terms used by Darwin in his definition of natural selection. The significant point is that individuals having useful variations “would have the best chance of surviving and procreating their kind.” As a consequence, useful variations increase in frequency over the generations, at the expense of those that are less useful or injurious.

Natural selection is much more than a “purifying” process, for it is able to generate novelty by increasing the probability of otherwise extremely improbable genetic combinations.  Natural selection in combination with mutation becomes, in this respect, a creative process.  Moreover, it is a process that has been occurring for many millions of years, in many different evolutionary lineages and a multitude of species, each consisting of a large number of individuals. Evolution by mutation and natural selection has produced the enormous diversity of the living world with its wondrous adaptations.

Francisco J. Ayala is a noted biologist and philosopher at the University of California at Irvine’s Department of Ecology and Evolutionary Biology. Don’t miss his lecture on Feb. 24 - or any of the other Darwin2009 events planned at HMNS this year.

Darwin2009: An “Aha!” moment worth celebrating

Archimedes
Archimedes: the original
“Aha!” moment.
 photo credit:
kimberlyfaye (away)

Behind many momentous scientific discoveries there seems to have been what we call an “aha moment.” Consider Sir Isaac Newton and the apple which is said to have hit him, causing Newton to hit on the notion of gravity. Consider Archimedes in his bathtub and his “Eureka” moment, which is just Greek for the German “Aha!”

Insights like these are different from those derived from problem solving. It seems that in this case, there is a sudden realization that we can explain something in a way we have never thought of before. In some cases the insight might have come almost immediately, in other cases it took years, if not decades for that lightning bolt to strike.

Consider Charles Darwin.

Charles Darwin
Creative Commons License photo credit:
CATR *Recomiendo ver
fotos con su tamaño original

Darwin was invited to be part of the second voyage of the HMS Beagle. It appears it was a last minute invitation (Here I could segue into what constitutes a ‘what if” moment, but I won’t.)  During his five-year long trip, Darwin spent most of his time on land, a good thing for a person prone to sickness, and a good thing for us too, as he was able to collect a lot of samples and make copious notes. This trip, which took him around the world, lasted from 27 December 1831 to 2 October 1836. Even though he was able to collect lots of data, it also appears that he was not until he was back home and reviewing his materials that the “aha!” moment came. When studying rare Galapagos mockingbirds, Darwin started considering the notion that that species changed over time. In other words, Darwin started to think of what we call “evolution.” (The mocking birds are currently part of an exhibit at the Natural History Museum in London.)

It was not until 1859 after further research and after much prodding from third parties, that Darwin finally published his famous tome “On the Origin of Species by Means of Natural Selection.”  It has been a bestseller ever since.

This year marks the 200th anniversary of Darwin’s birth and the 150th anniversary of the publication of his famous book. These two dates are celebrated across the world, although in the United States, Darwin will have to share birthday cake with a fellow called Lincoln, who happened to have the same birth day. In Houston, activities surrounding Darwin, his work and influence will be coordinated through the Houston Darwin 2009 organization.

A host of Houston-based institutions participate, including the Houston Museum of Natural Science. We have several events lined up, including a Darwin Day Festival on February 7 and a lecture series, starting in March 2009. Come help us celebrate one of history’s most famous Aha moments.