Darwin's finches

Most people are familiar with Darwin's finches as an example of divergent evolution and how this influenced Darwin. The story behind the finches is this: Darwin went to the Galapagos and he collected some birds. The finches were so different he thought they were from different families (e.g., wrens, finches, and orioles). Back in England, Darwin runs into ornithologist and illustrator extraordinaire (and creationist) John Gould. Gould tells Darwin that the finches are actually all related. Darwin is like "wth Gould."  Some of the details are left off the labels so he can't tie specific location (island) to a specimen. Mind you, Darwin is a novice and recent graduate and in his early 20's so he should get some slack. It's actually the mockingbirds and tortoises that get Darwin thinking. Why should each island have its own species of mockingbird and tortoise?  The rest is evolution and natural selection. The finches come later when thinking about why there is divergence and the different beaks allow different species to exploit different resources. 

On Galapagos our local guides didn't know the different species of finches. I don't blame them - they all look very very similar and they're not trained to ID them. Our guides were very good organizers and knew tons, just not the finches.

Here are some of my best pictures of these little buggers. 

My Year of Darwin: 7/28/2014 Natural selection arrives with a whimper

"our joint productions excited very little attention, and the only published notice of them which I can remember was by Professor Haughton of Dublin, whose verdict was that all that was new in them was false, and what was true was old" Charles Darwin, Autobiography

Darwin was thinking and writing about natural selection before Alfred Wallace but Alfred Wallace had pulled the trigger to publish first by send Darwin a manuscript. Darwin and his crew were worried about him being scooped so they presented their work together so it could be called a tie. 

My Year of Darwin 5/29/2014: Darwin summarizes the situation in the Galapagos

 

"But it is the circumstance that several of the islands possess their own species of the tortoise, mocking-thrush, finches, and numerous plants, these species having the same general general habits, occupying analogous situations, and obviously filling the same place in the natural economy of this archipelago, that strikes me with wonder" Charles Darwin, Voyage of the Beagle

Yes, why would be their separate, but related species, living on islands so close together? If you were a creationist (and that species were created) that would mean each island required a series of creations (no wonder He needed a break). I doubt very much, even so early in Darwin's career, that we was of such a mind set. More likely, he was already thinking they evolved. But how? 

My Year of Darwin 5/28/2014: Darwin's Mockingbirds?

 

" My attention was first thoroughly aroused by comparing together the numerous specimens, shot by myself and several other parties on board, of the mocking-thrushes, when, to my astonishment, I discovered that all those from Clarles Island belonged to one species (Mimus trifasciatus) all from Albemarle Island to M. parvulus; and all from Hames and Chatham Islands (between which two other islands are situated, as connecting links) belonged to M. melanotis. These two latter species are closely allied, and would by some ornithologists be considered as only well-marked races or varieties; but the Mimus trifasciatus is very distinct. Unfotuntely most of the specimens of the finch tribe were minged together" Charles Darwin, Voyage of the Beagle

There were two groups groups of birds that were important to Darwin and his development of natural selection: the finches and the mockingbirds. Each of these groups were important for different reasons. The finches show how one ancestral species can evolve into different phenotypes - various shapes. By his own admission, he did not carefully document locations of finches. Mind you, he was essential an early twenty-something fresh out of college, we could probably cut him some slack. The mockingbirds show the importance of geographic separation in the formation of species. 

Hopefully banding falcon chicks today... pictures to follow

My Year of Darwin 5/27/2014: Galapagos Islands - so close yet far enough

 

"I have not as yet noticed by far the most remarkable feature in the natural history of this archipelago; it is, that the different islands to a considerable extent are inhabited by a different set of beings. My attention was first called to this fact by the Vice-Governor, Mr. Lawson, declaring that the tortoises differed from the different islands, and that he could with certainty tell from which island any one was brought. I did not for some time pay sufficient attention to this statement, and I had already partially mingled together the collections from two of the islands. I never dreamed that islands, about 50 or 60 miles apart, and most of them in sight of each other, formed precisely the same rocks, placed under a quite similar climate, rising to a nearly equal height, would have been differently tenanted; but we shall soon see that this is the case."  Charles Darwin, Voyage of the Beagle

Each of the largest islands has a set of organisms that are largely not found on the other islands. The first example presented is that the governor could identify the origin of a tortoise from the shape of the shell. But there are more as Darwin hints and I'll let him tell the rest.

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Celebrated 45th birthday yesterday. It was nice. Wife gave me the Game of Thrones book series. 

My Year of Darwin 5/22/2014: Maybe... just maybe... evolution

 

"One might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends"  Charles Darwin, Voyage of the Beagle

So phylogenetics tells us that this scenario is most likely true; a population of finches composed of a single species flew out to the Galapagos and speciated into twelve or thirteen new species. Interesting that Darwin chose the phrase "had been taken" and not just "flew" or "found their way". Wish we could ask. 

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Rain today so not field work. Staying home and working on a poster for the joint Wilson Ornithological Society - Association of Field Ornithologist meeting. Wish I could find that data from 2004!  

Wishing you a great day reader. 

My Year of Darwin 5/21/2014: There's something about those finches...

 

"The most curious fact is the perfect gradation in the size of the beaks in the different species of Geospiza, from one as large as that of a hawfinch to that of a chaffinch, and (if Mr. Gould is right in including his sub-group, Certhidea, in the main group) even to that of a warbler. The largest beak in the genus Geospiza is shown above in Fig.1, and the smallest in Fig. 3; but instead of there being only one intermediate species , which a beak of the size shown in Fig 2, there are no less than six species with insensibly graduated beaks"  Charles Darwin, Voyage of the Beagle

My Year of Darwin 5/20/2014: The finches

 

"The remaining land-birds form a most singular group of finches, related to each other in the structure of their beaks, short tails, form of body plumage: there are thirteen species which Mr. Gould has divided into four sub-groups. All these species are peculiar to this archipelago; and so is the whole group, with the exception of one off the sub-group Cactornis, lately brought from the Bow Island in the Low Archipelago."  Charles Darwin, Voyage of the Beagle

http://people.rit.edu/rhrsbi/GalapagosPages/SlideShow/SlidePages/Darwin's%20Finches.html

My Year of Darwin 5/19/2014: Psst.... I'm thinking about evolution

 

"Considering the small size of these islands, we feel the more astonished at the number of their aboriginal being, and at their confined range. Seeing every height crowned with its crator, and the boundaries of most of the lava-streams still distinct, we are led to believe that within a period geologically recent the unbroken ocean was here spread out. 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." Charles Darwin, Voyage of the Beagle 

This is, I believe, Darwin's first explicit statement that he was interested in the origin of species (lower case is intentional). Earlier in the Voyage, in a footnote, Darwin says "This is merely an illustration of the admirable laws, first laid down by Mr. Lyell, on the geographical distribution of animals, as influenced by geological changes. The whole reasoning of course, is founded on the assumption of the immutability of species; otherwise the differences in species in the two regions might be considered as superinduced during a length of time." 

Exceedingly profound thought - in a footnote. C'mon Darwin. I understand; get the evidence but in these two passages, Darwin is pointing out where he is going and where his thoughts are.

My Year of Darwin (2/19/2014)

"I may mention one very trifling anecdote, which at the time struck me more forcibly than any story of cruelty. I was crossing a ferry with a negro who was uncommonly stupid. In endeavouring to make him understand, I talked loud, and made signs, in doing which I passed my hand near his face. He, I suppose, thought I was in a passion, and was going to strike him; for instantly, with a frightened look and half-shut eyes, he dropped his hands. I shall never forget my feelings of surprise, disgust, and shame, at seeing a great powerful man afraid even to ward off a blow, directed, as he thought, at his face. This man had been trained to a degradation lower than the slavery of the most helpless animal." Charles Darwin - Voyage of the Beagle 

Let us never forget the indignity and injustice of slavery. 

My Year of Darwin (2/18/2014)

"I thought they must belong to an enormous Armadillo, living species of which genus are so abundant here." Charles Darwin - Letter to J.S. Henslow, October 1832

Darwin has explored the Atlantic coast of Brazil and, with great sea-sickness, turned Cape Horn, and is now exploring the west coast of South America. There he finds a huge relative of the modern armadillos. Seeing related but phenotypically different species in the past was key to Darwin's thinking. What forced shaped organisms through time. That was the question. 

 

My Year of Darwin (2/9/2014)

"It is positively distressing, to walk in the glorious forest, amidst such treasures, & feel they are all thrown away upon one." -Charles Darwin, Letter to Professor J.S. Henslow, July 1832

Upon leaving England, Darwin has visited a number of oceanic islands that were relatively species poor. Selecting representatives to collect was probably easy. But once Darwin steps into the mainland tropics of South America, he's overwhelmed by the diversity. What is rare? What is common? He was obviously flustered.  

My Year of Darwin (2/5/2014)

"To a person fond of natural history, such a day as this brings with it a deeper pleasure than he can ever hope to experience again" -Charles Darwin, Voyage of the Beagle

Darwin is speaking of his first walk into the Brazilian rainforest. Not the Amazonian rainforest, but the Atlantic rainforest or Mata Atlantica. Sadly, most of the Atlantic rainforest has been converted to agriculture to produce soy beans or sugar cane. Moreover, many urban centers are expanding into the rainforest and very little of the remaining forest is protected. Look for a few articles on the Mata Atlantica to come out at the end on 2014 or early 2015 in Biological Conservation. 

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Snow day in Wilkes-Barre and much of the ne US. At least 20 cm of snow and lots of birds at the feeders including a horde of house sparrows, a few song sparrows and white-throated sparrows. Reviewing manuscripts today. Joy joy joy. 

My Year of Darwin (1/27/2014)

"The very first place which I examined, namely St. Jago in the Cape de Verde Islands, showed me clearly the wonderful superiority of Lyell's manner of treating geology" -Charles Darwin, autobiography 

Before leaving on the Voyage, Darwin received the first volume of Principles of Geology by Charles Lyell and published by John Murray (who published Origin of Species) in 1830. The other volumes were forthcoming but the first already influenced Darwin. Lyell was a enthusiastic proponent of uniformitarianism - the belief that the laws of nature were constant through time. For geology this meant that processes we observe today (rates of erosion, results of earthquakes, etc) were the same as those working in the past. The uniformitarian view of geology was not widely accepted but was increasing in popularity as the theists, with their laws of nature, were showing scientific success in all areas of science. 
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Two Bald Eagles flew by this morning. I'll take that as a good sign. Teaching phylogentics to ecology course and hopefully showing how some life history traits evolve. Might be interesting. 

MY YEAR OF DARWIN (#YEAROFDARWIN)

10 Jan 2014: "I had the bump of reverence developed enough for ten priests" Darwin autobiography

Darwin was leaving medical school at Edinburgh for a BA of divinity at Cambridge. The move was not immediate. He took a year off to catch up on his Greek and to convince himself that becoming a parson was acceptable. Which he did with the help of a private tutor. During this time his father died and there's no discussion of this in the autobiography. 

Later in life, Darwin sent a photograph to German phrenologists. Phrenology is the study of the shape of head and the once-believed link to abilities. Phrenology is classic pseudoscience; science jargon is used and plausible statements are made but there is either no support for these statements or there is contradictory evidence. Other popular practices I consider pseudoscience include homeopathy, subluxation-based chiropractic, chemtrails, bigfoot, intelligent design, and so on. 

MY YEAR OF DARWIN (#YEAROFDARWIN)

9 Jan 2014: "my father perceived, or he heard from my sisters, that I did not like the thought of being a physician, so he proposed that I should become a clergyman" Darwin autobiography

Darwin did not enjoy dissection of animals, was horrified by surgery, and was bored by most of his professors. Being a medical student was not for him. Once his father knew his unhappiness, he transferred CD to Cambridge where he was to study divinity. Darwin had to do something useful. Darwin's father was "vehement against my turning into an idle sporting man, which seemed my probably destination." 

MY YEAR OF DARWIN (#YEAROFDARWIN)

8 Jan 2014: "I heard Audubon deliver there some interesting discourses on the habits of N.American birds" Darwin autobiography

Darwin's professors would either take students or encourage them to scientific meetings. Publications are the currency of scientific thought and meetings are like the golf outings of science. Deals are made, gossip is exchanged, people are scooped or learn they're about to be (and that is useful too). As a college student Darwin attended a meeting an John James Audubon gave a talk. He must have been famous enough that Darwin didn't think if necessary to include his full name. 

John James Audubon was a celebrated ornithologist during his lifetime and is the namesake of The National Audubon Society. I read one biography of Audubon as a teenager and found him fascinating and I hope to read Richard Rhodes' biography, which I hear is excellent. J.J. Audubon lived in Pennsylvania and there was one of the first banders in North America. He tied a silver thread on an Eastern Phoebe that build a nest on his porch and the bird return to his house the following year. Eastern Phoebes nest throughout eastern North America and winter along the Gulf Coast in winter. Audubon explored North America when there was endemic diphtheria, malaria, and a host of other maladies (but no Lyme or West Nile, either). Audubon produced the over-sized book Birds of North America, wherein birds were painted their actual size. Large birds, like herons, were presented neck bent to fit the pages and small birds were presented with vegetation in the background. I was able to view an original Audubon painting at the Jules Collins Smith Museum of Fine Art at Auburn University. The paintings are amazing with brilliant colors that I've never seen reproduced in any of the prints. I currently have four prints. Interestingly, these were picked out of the garbage in Miami Beach and passed on to me. Below is one print that I really like. 

Red-shouldered Hawks on a gum tree with Spanish moss. 

Audubon's method was shoot, pose, and paint. It worked. Both Audubon and Birds of North America became famous and Audubon followed this work with a book on mammals. 

MY YEAR OF DARWIN (#YEAROFDARWIN)

7 Jan 2014: "saw two very bad operations, one on a child, but rushed away before they were complete" Darwin autobiography

Darwin enrolled as a medical student at Edinburgh University. Bored by his anatomy professor and disgusted by dissection, it was not looking good for his career as a doctor. Moreover, he was figuring out that his inheritance would allow him to live comfortably without working so there was little incentive to push himself at his studies. One could not be idle but there was no rush. 

After watching, almost watching, an operation on a child, Darwin never returns to the surgery room. At the time patients were held down and cut open "before the blessed days of chloroform."

Hot water pipe is frozen. Blow driers going like mad on the basement pipes. Coffee maker works and the internet is functional. We're good. 

MY YEAR OF DARWIN (#YEAROFDARWIN)

4 Jan 2014: ""I do not believe that any one could have shown more zeal for the most holy cause than I did for shooting birds" CD autobiography

As a college student, Darwin developed a love for shooting and had his gun at Cambridge, where he was studying theology. In his college dorm, he would practice in front of a mirror and would shoot at candles with just the cap. The cap is filled with a powder that fires under compression and sends the fire to the main charge. Just firing the cap creates enough pressure to create a puff of air at the end of the barrel. Darwin used this puff of air to blow out a candle held by a friend - obviously a very good friend. This practice would serve him well as he toured the world and collected birds. 

Though collecting birds sounds like a hobby, it is the term used to describe the practice of killing and stuffing birds. In Darwin's day the product was a bird that would be put into a museum and not rot since all the tissue that easily breaks down has been removed. In fact, Darwin's birds that he collected are still in museums and can be used for study (though I don't know how easily they can be accessed). Today, birds are still collected and we store stomach contents, muscle and other tissue for DNA. A smaller number of birds are pickled or skeletonized. The number of birds collected is typically a fraction of a percent of the birds that are killed by other means (e.g., free-roaming cats). A recent paper in Nature puts collecting into perspective. 

My Year of Darwin

My Year of Darwin (#yearofdarwin)

In the midst of too much to do, I like to distract myself. So I devised a distraction that might be less destructive than Solitaire or watching one of the many sci-fi TV shows that I love. For 2014, I would like to post a Charles Darwin quote every day that I find interesting and insightful. I'll pull quotes from his books and a collect of letters. 

#1 "I believe I was in many ways a naughty boy" -CD, Autobiography 

Charles Darwin was born February 12, 1809 to Robert Darwin, MD and Susannah Wedgewood Darwin. Darwin describes himself as being an average boy - a bit slow and naive. His mother died when he was very young and his earliest memories were being outside.