Tag Archives: Charles Darwin

Boobies and Such Encountered In The Galapagos

I have returned from The Galapagos and a most amazing Voyage on the Samba.

Early AM kayak departure from the Samba

The experience was exhilarating, enlightening and enchanting (therefore exhausting) and at some point I shall edit a brief movie/slideshow and post it somewhere for those interested.

Until then, here’s a red-footed booby I encountered on the island of Genovesa where a veritable cornucopia of exotic birds feed, nest and fly about,  seemingly unconcerned  about human visitors.

Red-footed Boobies are spectacular divers, plunging into the ocean at high speeds to catch prey. They are beautifully adapted for diving, with sleek, torpedo-shaped bodies, closeable nostrils, and long wings that wrap around their bodies as they slice into the water. This one, nesting in a red mangrove, seemed unperturbed by me standing a foot away but was intrigued by my red (Olympus TG-5 underwater) camera.

Charles Darwin did not visit Genovesa and none of the boobies (blue or red-footed or otherwise) played a role in his Theory of Evolution to my knowledge. They are not endemic or unique to the Galapagos.

The Song Of the Flightless Cormorant

There are many endemic animal species in the Galapagos which likely influenced Darwin’s thinking. On the youngest island,

It is found on just two islands; Fernandina, and the northern and western coasts of Isabela. Distribution associates with the seasonal upwelling of the eastward flowing Equatorial Undercurrent (or Cromwell Current) which provides cold nutrient rich water to these western islands of the archipelago. The population has undergone severe fluctuations; the 1983 an El Niño-Southern Oscillation (ENSO) event resulted in a 50% reduction of the population to just 400 individuals. The population recovered quickly, however, and was estimated to number 900 individuals by 1999.

Fernandina,  I encountered the flightless cormorant. The Galapagos cormorant is the only flightless cormorant in existence.

Evolutionary biologist Patricia Parker (who is the senior scientist at the St. Louis Zoo) appears to be the leading researcher on endemic Galapagos bird species. She collected blood from the Galapagos cormorants, searching for mutations that might explain their useless wings.

She and her fellow researchers  discovered about a dozen mutated genes in the Galapagos cormorants known to trigger rare skeletal disorders in humans called ciliopathies, often characterized by misshapen skulls, short limbs, and small ribcages. Since Galapagos cormorants have short wings and an unusually small sternum, the researchers suspected this link was significant.

The Sexual Attractiveness of The Male Blue-footed Booby 

The blue-footed booby (BFB) is more famous on the Galapagos, primarily because of its mating dance but also because of its fascinating bright blue feet. During the mating dance the male booby prominently displays his sexy feet.

Blue-footed boobies on Isabela Island. Note the varying shades of blue in their feet

A fascinating study published in 2006 suggests that the brighter the blueness of the male booby feet, the healthier he is and the more likely he is to hook up with a female booby.

When male boobies were food deprived their feet became duller and when re-fed fresh fish the blueness brightened within 48 hours.

Variation of dietary carotenoids induced comparable changes in cell-mediated immune function and foot colour, suggesting that carotenoid-pigmentation reveals the immunological state of individuals.

In a second experiment the researchers captured male BFBs after their female mate had laid a first egg and painted a dull blue make-up on the male BFB feet. The females “decreased the size of their second eggs, relative to the second egg of control females, when the feet of their mates were experimentally duller. Since brood reduction in this species is related to size differences between brood mates at hatching, by laying lighter second eggs females are facilitating brood reduction.”

Another  study in 2011  found that  damage to the DNA  of sperm increases with the age of male blue‐footed boobies. Furthermore, like humans sexual attractiveness (foot colour) declines with age in the BFB and is correlated with sperm DNA damage. The authors speculated that. “By choosing attractive males, females might reduce the probability of their progeny bearing damaged DNA.”

I will leave discussions on the technique for acquiring BFB sperm and for applying make-up to their feet to less squeamish authors. In the meantime we can all rest easy with the knowledge that female BFBs like their human counterparts prefer youngish males with brightish  blue suede shoes.

Galapageinosly Yours,

-ACP

(Featured image credit: Cassiano “Zapa” Zaparoli)

We Are Soon Bound For The Galapagos Islands In Search Of Darwin, The Giant Tortoise, and Dangerous Ideas

This is not the Samba. It is Her (or His) Majesty’s Ship, The Beagle

In August, the skeptical cardiologist and his eternal fiancée (and our friends Dave and Barb) will be visiting the Galapagos Islands on the 78 foot yacht, the Samba.

I’ve long wanted to visit this archipelago with its fascinating geographic and biologic features and its connection with Charles Darwin.

Darwin, born in 1809, was the son of a successful Shropshire physician and financier. By the age of 8, he writes in his Autobiography, “my taste for natural history, and more especially for collecting, was well developed. I tried to make out the names of plants and collected all sorts of things, shells, seals, franks, coins, and minerals. The passion for collecting, which leads a man to be a systematic naturalist, a virtuoso or a miser, was very strong in me, and was clearly innate, as none of my sisters or brother ever had this taste.”

After 2 years of studying medicine at Edinburgh University, Darwin writes, “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.”

In the course of obtaining the undergraduate degree needed to join the ministry, Darwin  developed a passionate interest in natural history, and two books in particular, instilled in him the desire to be a scientist:

During my last year at Cambridge I read with care and profound interest Humboldt’s Personal Narrative. This work and Sir J. Herschel’s Introduction to the Study of Natural Philosophy stirred up in me a burning zeal to add even the most humble contribution to the noble structure of Natural Science.

After graduating Cambridge, Darwin, being recognized as “a young man of promising ability, extremely fond of geology, and indeed all branches of natural history,” was offered a position on a ship destined for a 5 year voyage around the world. This would profoundly influence his life and mankind’s vision of its origin.

The Voyage of the Beagle

In preparation for my visit to the Galapagos and our voyage on the Samba, I have been reading (from a free digital download) Darwin’s account of that historic voyage:  “The Voyage of the Beagle” (originally entitled “Journal of researches into the natural history and geology of the countries visited during the voyage of HMS Beagle round the world,” published in 1839), which Darwin introduces thusly:

Captain Robert Fitzroy..As Darwin gathered the threads of what would later become his ‘dangerous idea’, FitzRoy guided them safely through treacherous waters, measured tides, studied weather systems, surveyed new territory, corrected existing charts and, for the first time, established a series of reference points around the globe that others would calibrate their instruments by. courtesy RNLIWhen Darwin published On the Origin of Species, FitzRoy admitted that it caused him the ‘acutist pain’. As a passionate creationist, he was wracked with guilt at unwittingly playing a part in its construction. This, along with mounting debts and failing health, soon locked him into a losing battle with depression. Just weeks before his 60th birthday, Vice Admiral FitzRoy  took his life.

HIS MAJESTY’S ship, Beagle, under the command of Captain FitzRoy, was commissioned in July, 1831, for the purpose of surveying the southern parts of America, and afterwards of circumnavigating the world. In consequence of Captain FitzRoy having expressed a desire that some scientific person should be on board, and having offered to give up part of his own accommodations, I volunteered my services; and through the kindness of the hydrographer, Captain Beaufort, my appointment received the sanction of the Admiralty.

The Beagle was only 12 feet longer than the Samba motored sailing boat that we, along with 12 other adventurous passengers, 5 crew men and a guide, have selected for our Galapagos tour. However, Darwin’s vessel carried, in addition to Fitzroy and Darwin, 71 other passengers (whose names you can ponder here).

The Beagle Sets Sail

On the 27th of December, 1831, the Beagle sailed from Devonport with the object of completing:

“the survey of Patagonia and Tierra del Fuego, commenced under Captain King in 1826 to 1830, — to survey the shores of Chile, Peru, and of some islands in the Pacific — and to carry a chain of chronometrical measurements round the World. ”

The Beagle spent four years surveying the east coast of South American and didn’t reach the Galapagos until the fall of 1835, nearly 4 years after its launch.  Darwin describes the islands as follows:

“SEPTEMBER 15th. — This archipelago consists of ten principal islands, of which five exceed the others in size. They are situated under the Equator, and between five and six hundred miles westward of the coast of America. They are all formed of volcanic rocks; a few fragments of granite curiously glazed and altered by the heat, can hardly be considered as an exception.

Darwin disembarked on San Cristóbal (September 17-22), Floreana (Charles)(September 24-27), Isabela (Albemarle)(September 29-October 2) and Santiago (James)(October 8-17).

FitzRoy and his officers developed updated charts of the archipelago, while Darwin collected geological and biological specimens on the islands.

(Our voyage below, visits the northwestern Galapagos, islands crossing paths with Darwin when we land in Isabella and Floreana

 

 

 

 

 

 

 

 

The Giant Tortoises of the Galapagos Islands

Darwin learned much on his voyage, not just about the geology and biology of the islands, but also about himself and the importance of reason and observation:

I discovered, though unconsciously and insensibly, that the pleasure of observing and reasoning was a much higher one than that of skill and sport. The primeval instincts of the barbarian slowly yielded to the acquired tastes of the civilized man.

Apparently his acutely observant father identified these changes in thinking just by looking at Charles:

That my mind became developed through my pursuits during the voyage, is rendered probable by a remark made by my father, who was the most acute observer whom I ever saw, of a sceptical disposition, and far from being a believer in phrenology; for on first seeing me after the voyage, he turned round to my sisters and exclaimed, “Why, the shape of his head is quite altered.”

So, dear friends and patients, pay close attention to the shape of my head upon my return from the Voyage of the Samba. You might assume the large occipital protuberance is a result of a nasty fall from the top of a giant tortoise when, in fact, it is the outward representation of all the brilliant observations and dangerous ideas I have acquired on my trip.

Galapaghostly Yours,

-ACP

N.B. Of the many observations that Darwin made while he was on the Galapagos Islands, I found his comments on the pericardium of the giant tortoises the most intriguing. My next post on Darwin and the Galapagos will explore in detail this fascinating cardiologic observation.