Wednesday, January 25, 2017

Back to the Galapagos!

                                                                 The Cormorant

Today, my wife and I leave for our second cruise on The Cormorant around the Galapagos Islands (January 28 to February 4).  As I did for the first cruise in 2013, I will write a series of posts on our tour after we return.  The posts on the first cruise begin here.  The Cormorant is a yacht that is about the same size as the Beagle on which Darwin sailed.

After our 8-day cruise in 2013, we spent a week in Puerto Baquerizo Moreno, on the island of San Cristobal, where I participated in a special meeting of the Mont Pelerin Society at the Galapagos campus of the Universidad San Francisco de Quito.  The theme of the meeting was "Evolution, the Human Sciences, and Liberty."  I was one of the speakers--speaking on "The Evolution of Darwinian Liberalism."  I wrote a series of posts on all of the lectures and discussions, which begins here. 

This was a wonderful way to think about Darwinian evolution--first following Darwin's steps through the Galapagos as the natural laboratory of evolution, and then thinking about the implications of evolutionary science for classical liberalism at the MPS conference.  On this second trip, I want to continue thinking about how evolutionary science might support liberal social thought.

I realized that one 8-day cruise was not enough time to see the full range of life in the Galapagos.  That first cruise took us to the central, western, and northern islands (Santa Cruz, Isabela, Fernandina, Marchena, and Genovesa) during the cool and dry season of the year.  This second cruise will take us to the central and southern islands (Santa Cruz, Santiago, Santa Fe, San Cristobal, Espanola, and Floreana) during the warm and wet season of the year.

The ecological circumstances of the Galapagos are fundamentally shaped by the geological and climactic conditions.  The geological features of the Galapagos arise fundamentally from the islands being products of volcanic eruptions.  The volcanoes on the western islands of Fernandina and Isabela remain active.  The Wolf volcano in northern Isabela erupted as recently as May 25, 2015.  The volcanoes on the eastern and southern islands are inactive.

Darwin noticed that the volcanoes seem to lie along parallel straight lines.  He inferred that there were rifts on the ocean floor from which lava had been blurted and formed the islands. He spoke of "fissures of eruption."  Today, geologists agree with this, but their story is a bit more complicated.  They see the western islands as sitting on a deep-seated "hotspot" of volcanic activity that periodically sends volcanoes bubbling to the surface of the Nazca plate, which is moving to the south-east. As the Nazca plate moves, it carries each island away from the hotspot like a conveyor belt.

                                             Wolf Volcano Erupting in May of 2015

                                              Plate Tectonics of the Galapagos Islands

The Creation and Movement of Volcanoes in the Galapagos

As the islands move away from the hotspot over millions of years, they eventually sink under the sea.  The newest islands--Fernandina and Isabela--are rugged and inhospitable to life.  The older islands have had time for soil and vegetation to grow on what originally was pure lava, and thus they are somewhat more hospitable to life.

The other fundamental ecological factor for the Galapagos is climactic fluctuations due to ocean currents.

Between June and November, the cold Humboldt Current flowing up from the south lowers the temperature in the islands and causes some moisture in the warmer air to condense into a drizzling mist.  Beginning in December, the warm Panama Current flowing down from the northeast becomes more powerful, which raises the temperature of the water, creates a hot season, and with evaporation from the warmer water, clouds form and rain falls.  During an El Nino year, the Panama Current is particularly warm, which creates heavy rains.

So while in my first tour, I saw the youngest and most volcanically active islands during the cool and dry season of the year; in this tour, I will see the older and volcanically inactive islands during the warm and wet season.  Even in the wet season, however, the rain is confined mostly to the higher elevations, and so those of us who are hiking mostly at lower levels can be comfortable.

For anyone who is thinking about touring the Galapagos, I can recommend The Cormorant and the other two yachts of Haugan Cruises.  It's a luxury cruise with 16 passengers and 11 crew members.  Each stateroom has a balcony.  The food is good. The experienced naturalist guides are intelligent and engaging.  And as I indicated in my previous series of posts on the first trip, the guides offer a well-informed commentary on the evolutionary science of the Galapagos.

Of course, to speak of the evolutionary science of the Galapagos points to the deepest questions raised by any visit to the Galapagos: Does the variety of wildlife in the Galapagos provide evidence for the evolution of species by natural selection and other Darwinian mechanisms?  Or does it rather show the work of a Divine Creator or Intelligent Designer?

How do we explain the origin of those many species of life that are endemic to the Galapagos--species found here and nowhere else in the world?  There are over 4,000 species that are native to the Galapagos.  And of these about 1,600 species (40%) are endemic.  How exactly were so many species produced in these islands?

Those Biblical believers who read the first chapters of Genesis as a textbook of science say that God specially created these 1,600 species for the Galapagos, just as He created all other species.  The proponents of Intelligent Design Theory don't follow this literal reading of Genesis, but they do argue that all species must have been originally designed by some intelligent mind.

Doesn't it seem a little strange that the Creator chose to specially create these 1,600 species for the Galapagos and no where else?

Both the Creationists and the Intelligent Design proponents argue that the failure of Darwinian biologists to explain exactly when, where, and how a process of evolution created these species shows that we must assume that this requires a Divine Creator or Intelligent Designer.

But notice the rhetoric of negative argumentation here.  The Creationists and Intelligent Design proponents challenge the Darwinians to explain the step-by-step pathway by which the species endemic to Galapagos evolved by purely natural causes.  If the Darwinians cannot do this, then it's assumed that this failure proves the truth of Creationism or Intelligent Design. 

The sophistical fallacy in such argumentation becomes clear as soon as one notices that the Creationists and Intelligent Design proponents do not explain exactly when, where, and how the Creator or Intelligent Designer created the species for the Galapagos.  So they don't satisfy the standards of proof that they apply to the Darwinians.

So, for  example, the Creationists and Intelligent Design proponents have conceded that Peter and Rosemary Grant have observed evolutionary change in Darwin's finches in the Galapagos, particularly in the size and shape of their beaks.  But they argue that this is only microevolution--evolutionary change within a species--and not macroevolution--the evolutionary emergence of new species from ancestral species.  And yet, these proponents of Creationism and Intelligent Design have not provided any explanation of exactly when, where, and how God or the Intelligent Designer created the finches and other species endemic to the Galapagos.

The Grants have spent over 40 years of their life carefully studying the finches in the Galapagos as they empirically test hypotheses about evolution.  Have any creationist scientists made the same effort to test their hypotheses about how the Creator did His work in the Galapagos?

There is  another possibility--theistic evolution.  In the beginning, God might have created the laws of nature, but then allowed the natural laws of evolution to create all the species of life, including those endemic to the Galapagos. 

Darwin suggests this in the last paragraph of The Origin of Species:
"It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us.  These laws, taken in the largest sense, being Growth with Reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the conditions of life, and from use and disuse: a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms.  Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows.  There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved."
The Galapagos  Islands are perhaps the best place in the world to feel the grandeur in this view of life.

1 comment:

sykes.1 said...

The Catholic Church and its Popes have repeatedly endorsed the reality of evolution, but they have objections to Darwin's theory.