Wednesday, February 08, 2017

Thinking About Galapagos: Divine Creation? Intelligent Design? Darwinian Evolution?



Having completed my second cruise around the Galapagos Islands on board the Cormorant, I have spent a total of 24 days in the Galapagos.  Of the 14 notably large islands, I have been to 11.  I have also been to some of the dozen or more small islets.  I have been there both in the hot and wet season (January to May) and the cool and dry season (June to December). 

My first trip, in June of 2013, included a week on the island of San Cristobal, in the town of Puerto Baquerizo Moreno, where I participated in a special meeting of the Mont Pelerin Society, cosponsored by the Universidad San Francisco de Quito, on "Evolution, the Human Sciences, and Liberty."  In July of 2013, I wrote a series of blog posts on my cruise around the islands and on the lectures and discussions at the MPS conference.

On board the Beagle, Charles Darwin anchored near the northwest end of San Cristobal on September 16, 1835.  On October 20, the Beagle sailed away from the Galapagos.  During his time there, Darwin walked on four islands--San Cristobal, Floreana, Isabela, and Santiago.

Like Darwin, I have found that Galapagos is good for thinking--particularly, for thinking about the origins and history of life on Earth. 

So, for example, consider the Galapagos tortoise--the animal from which the name Galapagos is derived.  The giant tortoise is one of the many species that are endemic to Galapagos--that is, found naturally only in Galapagos.  It is also one of the many species that varies across the islands.  When Darwin was on Floreana, he was told by Nicholas Lawson, the Ecuadorian Vice-Governor of Galapagos, that he could tell which island a tortoise came from by the shape of its shell.  For example, some of the tortoise shells are dome-shaped (as in the first picture above), and others are saddleback-shaped (as in the third picture).  The saddleback tortoises live predominantly on the low islands--like Pinta, Pinzon, and Espanola.  The dome-shaped tortoises live predominantly on the larger and higher islands with highland areas that get more moisture and thus have denser vegetation.  It is generally assumed that saddleback shells allow tortoises to stretch their necks to reach vegetation that is high up, while dome-shaped shells are more adapted for feeding on dense vegetation near the ground.  It is believed that there are at least 10 existing species of Galapagos tortoise and at least 2 extinct species, although there is disagreement as to whether these are really distinct species or sub-species or varieties of one species.

This raises lots of questions.  Why is the Galapagos tortoise unique to Galapagos?  Where did it come from?  If it came from an ancestral species on the mainland of South America, how did the ancestor make the trip across 600 miles of ocean?  And once it arrived, how and why did it radiate out over the islands and become different on the different islands?  How could it survive and reproduce on such inhospitable volcanic islands?  Does this show the macroevolution of new species from ancestral species?  Or does it only show the microevolution of varieties within a single species?

The Galapagos tortoise has been driven to the edge of extinction by competition with invasive species, such as black rats that eat tortoise eggs and goats that eat up the vegetation that tortoises need.  Is this an example of Darwinian survival of the fittest?  Or is this an unnatural disruption by human beings of the balance of nature?  Does Darwinian science suggest that there is no such thing as a fixed balance of nature, but only a constant evolutionary flux?  Should we intervene to restore the conditions for the survival and reproduction of Galapagos tortoises?  If so, what would motivate us to do that?

There are at least three general kinds of answers to these questions.  Galapagos tortoises arose either by divine creation, by intelligent design, or by Darwinian evolution.

There are various ways in which God could have created them.  If one is a young-earth Biblical creationist who accepts Bishop James Ussher's chronology, then one believes that God created the Earth and all species of life, including the Galapagos tortoise, in 6 days 6,000 years ago.  If one is an old-earth creationist, then one believes that God could have taken millions of years to create all the species of life.  A creationist who reads the Bible as literal scientific history will believe that all the species were on Noah's Ark, and that after the great flood subsided, the Galapagos tortoises somehow migrated from Mount Ararat in the Middle East to the Galapagos Islands.  But why did the giant tortoises migrate to Galapagos and no where else on Earth?

The Bible speaks of God creating the "kinds" of life (in the King James translation).  And so some scientific creationists argue that "kinds" might refer not to species but to some higher level of modern taxonomy--maybe "genus," "family," or "order."  This is necessary, they argue, to explain how there could have been enough room on the Ark for two of each "kind" of life, but not for each species.  So God did not have to specially create the Galapagos tortoise.  He could have created "kinds" of reptiles, and then Galapagos tortoises and other species of reptiles could have evolved naturally within these "kinds."  But doesn't this concede a lot to the action of natural evolution rather than divine creation?  Is this theistic evolution?

In 2002, Mike Pence delivered an entire speech in the House of Representatives endorsing creationism and intelligent design and rejecting evolution. “I believe that God created the known universe, the earth and everything in it, including man,” Pence said.  “And I also believe that someday scientists will come to see that only the theory of intelligent design provides even a remotely rational explanation for the known universe.”  He also argued that the signers of the Declaration of Independence affirmed this in declaring that human beings were created in God's image and thereby endowed with inalienable rights.  So Darwinism contradicts the American creed.  We can expect that as Vice President, Pence will continue to promote this position, which he shares with other members of the Trump administration.

In the early 1800s, the great French naturalist George Cuvier proposed a new form of creationism that he thought conformed to the fossil record, which shows a long history of species emerging and going extinct.  There could be a series of creation events and extinctions over a long time, and these could be explained as miraculous interventions by God or by creative forces within nature. 

This latter view was taken by David Porter, commander of the U.S. frigate Essex, who cruised the Galapagos from April to September in 1813, and wrote about this in his Journal of a Cruise Made to the Pacific Ocean.  (The drawing above of the Galapagos tortoise is from Porter's book.)  "I shall leave others to account for the manner in which all those islands obtained their supply of tortoises and iguanas, and other animals of the reptile kind," he wrote.  "I shall merely state, that those lands have every appearance of being newly created, and that those perhaps are the only part of the animal creation that could subsist on them."  Porter asked, "Nature has created them elsewhere, and why could she not do it as well at those islands?"  But if this creative force is natural, is there any need for divine creation?

Another alternative, favored by the folks at the Discovery Institute in Seattle, is Intelligent Design Theory.  Instead of looking to the Bible as a literal scientific history of creation, we can infer that all forms of life, including the Galapagos tortoise, were created by an Intelligent Designer, regardless of whether we identify that Designer as the God of the Bible.  But as I have indicated in my posts on Intelligent Design, the proponents of Intelligent Design Theory rely on a sophistical rhetoric of negative argumentation--arguing that Darwinian scientists have not yet explained the step-by-step process by which every species has evolved--without themselves explaining where, when, how, and why the Intelligent Designer created the Galapagos tortoise and all other species of life.

Darwinian evolution can be understood as a radical alternative to both divine creation and intelligent design in explaining the origins of Galapagos tortoises and all other forms of life.  But as Darwin himself suggested, natural evolution can also be understood as compatible with some forms of divine creation or intelligent design.  One can see natural evolution as showing the "secondary causes" of life, while the Creator or Intelligent Designer can be seen as the "primary cause" of those laws of nature that make evolution possible.  This is the theistic evolutionism adopted by a long line of thinkers from Asa Gray to C. S. Lewis to Francis Collins.

When Darwin was in the Galapagos Islands, he was not yet a Darwinian evolutionist.  Contrary to the common legend, Darwin did not have a "eureka" experience when he saw the Galapagos tortoises or finches.  It was not until he returned to England in 1836, and began to study his notebooks and the specimens he had collected during his voyage, that he slowly began to move towards his theory of evolution by natural selection.

While he was on the Beagle, Darwin was reading Charles Lyell's new book The Principles of Geology, Lyell revived and extended the evolutionary geology of James Hutton's Theory of the Earth, which argued that the Earth was not permanently fixed in its form by God at the beginning, but was rather in flux, with "no vestige of a beginning--no prospect of an end."  Over millions of years, volcanic mountains could be pushed up from beneath the ocean's floor to become islands that could be weathered back down to create soil to become inhabitable by human beings, but then it could eventually be resubmerged under the sea.  Darwin saw evidence for this in the Galapagos.

In his Voyage of the Beagle, published first in 1839, Darwin indicated that he was also astonished by the "creative force" that he saw in Galapagos.  And then in the second edition of this book, published in 1845, Darwin gave his first published hint of his new theory of the transmutation of species: "Hence, both in space and time, we seem to be brought somewhat near to that great fact--that mystery of mysteries--the first appearance of new beings on this earth."

While he was voyaging on the Beagle, Darwin seemed to be a creationist like Cuvier and Lyell, who believed there were "centers of creation" in places like Galapagos.  The giant tortoise and other species unique to Galapagos could be understood as created there.  But then by 1837 and 1838, he was considering a purely natural process of the evolution of new species.  In 1842, he used the term "natural selection."

Eventually, in The Origin of Species (first published in 1859), and later publications, Darwin defended his "theory of natural selection" as better than the "theory of special creation" in explaining the emergence of giant tortoises and other new species in Galapagos and elsewhere.

Galapagos provided three kinds of evidence for his new theory.  First, oceanic islands like the Galapagos have many species unique to them, and this is best explained by the migration of plants and animals from the mainland of a nearby continent, which then must undergo modification to be adapted to their new circumstances.

Second, isolated places like Galapagos lack some types of plants and animals, and their places will be filled by others.  So, for example, in Galapagos, reptiles rather than mammals are dominant, because it was easier for reptiles to reach the islands and then evolve to fill the niches available there.

Third, the distinctive plants and animals of islands like Galapagos resemble the plants and animals of the nearest mainland.  "Why should the species which are supposed to have been created in the Galapagos Archipelago, and nowhere else, bear so plain a stamp of affinity to those created in America?" Darwin asked.  "I believe this grand fact can receive no sort of explanation on the ordinary
view of independent creation; whereas on the view here maintained, it is obvious that the Galapagos Islands would be likely to receive colonists, whether by occasional means of transport or by formerly continuous land, from America."

Of course, the creationist or intelligent design theorist can always say that the Creator or the Intelligent Designer just liked to create species unique to the Galapagos that resembled those on the South American mainland.  But this is nothing more than an unsubstantiated assertion unless there is some scientific explanation of exactly where, when, how, and why the Creator or Intelligent Designer did this.

And so it is that the Galapagos tortoise and the other unique forms of life in Galapagos provoke deep questions about the origins of life.

But not only is the Galapagos tortoise good for thinking, it is also good for eating!  Darwin testified to the good taste of tortoises.  And indeed hundreds of thousands of Galapagos tortoises were taken away from the islands by whalers who stored them on their ships as a ready supply of food, because tortoises can survive for six months or more without food or water.  Even as late as the 1970s, local people in Galapagos were eating tortoises as tasty food for special occasions. 

Galapagos conservationists have had to try to persuade the local people that it's better to preserve tortoises for the pleasures of observing and studying them, and for attracting tourists, than to kill them for food.  The second picture above, showing a naturalist guide hugging a tortoise, illustrates this.

Darwinian scientists and conservationists have to persuade us that preserving or restoring the original conditions of Galapagos before human settlement and the arrival of invasive species is good for us, because it satisfies our evolved human desire for intellectual understanding of the natural world, the desire that sustains the philosophic or scientific life.  That's the argument for Darwinian liberal ecotourism.

Over the next few weeks, I will be writing a series of posts about my most recent tour of Galapagos.

2 comments:

Roger Sweeny said...

Does Darwinian science suggest that there is no such thing as a fixed balance of nature, but only a constant evolutionary flux?

It doesn't just suggest it; it demands it.

I enjoyed Emma Marris' breezy, positive little book, Rambunctious Garden: Saving Nature in a Post-Wild World, which considers some of the questions raised in the paragraph the quotation comes from. A little more scholarly (and not nearly as much fun) is John Kricher's The Balance of Nature: Ecology's Enduring Myth.

Daniel Botkin has thought long and hard about these issues. I loved Our Natural History: The Lessons of Lewis and Clark, which sent us exploring the Missouri River on two summer trips. A highlight was standing in the middle of a forest at Arrow Rock State Historic Site (Missouri) and being informed by a plaque that the Missouri River used to flow on the other side of the plaque. His Passage of Discovery: The American Rivers Guide to the Missouri River of Lewis and Clark is animated by the idea of constant change.

TeeJaw said...

Intelligent design mixes science with religion leading to bad forms of both.