July 25, 2012 update:
Rémi Wattier, author of a recent paper on phylogeny of American flamingos (see citation at end of post), said:
"Unpublished molecular phylogenies are pointing out that Greater, American and Chilean flamingos are closely related while being divergent from the three last species (Adean, Puna and Lesser flamingos) which are also related together. Therefore speciation before inter-continental migration is the most likely scenario."
A visit to Chile last month (November 2009) gave me a chance to consider questions of biogeography that had been bothering me since I first read Charles Darwin’s Voyage of the Beagle. Darwin saw what he called “ostriches,” now classified as rheas, but so closely related that they look almost identical and live in similar flat, dry habitats. One bears his name, Darwin’s Rhea. How could the ostrich of Africa be so closely related to the rhea of South America, with ratite relatives also in Australia (Emus) and New Zealand (Cassowaries)? How is it that three species of flamingo live in the two-mile high deserts of northern Chile, Bolivia and Argentina, while the world’s other three species are scattered from the Americas through the Mediterranean and Africa ? Darwin also recognized vicuñas and guanacos (and of course their domesticated descendants the alpaca and llama) as relatives of camels: what biological or geological forces of nature caused camelids to occur in South America and Africa/Arabia and nowhere in between? Finally, what combinations of geology and evolution caused these disparate groups—ratites, camelids and flamingos—to have the same disjunct distribution?
Usually, when mountains rise up, forced by tectonic forces deep in the earth at rates of only millimeters per year, the water running off them finds its way down to lower levels and eventually to the sea, cutting rills that become canyons and then wide valleys along the way. But in the Andes Mountains of northern Chile, western Argentina, Bolivia and southern Peru, something different happened. The land rose as one over a vast area, creating not sharp mountains and deep valley but a high plain, the Altiplano. The land folded a little, creating north-south ridges that prevented the water from running to the oceans, either Pacific or Atlantic. Instead, what little water there was pooled in the depressions and evaporated in the dry air. These eventually filled with silt, creating many broad salt flats. No matter how salty the flats are, the springs feeding them ensure that there is always a gradient of fresh to brackish water. The less salty parts are filled with plants and animals. The plants are microscopic algae and the animals include such tiny arthropods as brine shrimp, brought to each isolated salt flat on the legs of wading birds. These are the habitats of the flamingo and another wading bird unique to Altiplano salt flats, the Andean Avocet.
Although the Altiplano kept rising for so many millennia that it reached heights unequalled anywhere outside of the Himalayas, not all of its rise was gradual. Through this high plain burst volcanoes, not one or two, but hundreds. They showered the land with ash and cinders, colouring it in reds, greys and yellows as if by an artist gone mad.
Although inland from the Atacama desert, where it may not rain for years at a time, the Altiplano is high enough to get a little moisture. Driving from the airport at Calama to my base at San Pedro de Atacama, I passed through one of the driest deserts on Earth. Hardly a living plant grew there and I saw no birds, not even a lizard. The ancient oasis town of San Pedro, still built of mud brick despite the bustle of adventure tourism, is watered by a network of tiny canals running through the town, although the San Pedro River itself was dry when I was there.
North and East of San Pedro, the roads climb to the Altiplano. Unlike the desert drive from Calama, there is some little vegetation—even a patch of trees—but still the land is parched, dry and grey, with shades of brown and red from the volcanic cinders and the dry vegetation. Suddenly at around 3000 meters, the colours dramatically change. Here there is enough moisture for grass and the land suddenly changed from grey and brown to yellow. And what a yellow! The clear air and strong sunlight made this the brightest yellow I have ever seen in a grass. Its brilliance contrasted with the deep blue of the sky and the reds of the volcanoes. I can only imagine what it looks like in spring when the grass is green. This vast grassland is the habitat of the guanacos of middle elevation and vicuñas and rheas of high elevation—we crossed one pass at 5000 meters. I had been afraid that I might go all this way and not see guanacos, vicuñas, rheas or the three species of flamingos, but they were all there in abundance, as well as two dozen other species of birds found nowhere else and unique mammals including the Andean fox, highland tuco-tuco (a relative of the guinea pig), and mountain viscacha (in the chinchilla family).
And everywhere loom volcanoes, many above 6000 meters, most with a little snow, and some even with glaciers. Their melt water sometimes cuts deep canyons before disappearing into the ground, but then it reappears as springs at the edges of the salt flats.
A little research answered some of the biogeography questions. These ratites, camelids, and flamingos diverged from their African counterparts too recently for their disjunct populations to have resulted from the tectonic separation of Gondwana Land into the eastern and western hemispheric land masses we know today, about 100 million years ago (MYA). The rheas and ostriches diverged a mere 65 MYA, much too late for the South America-Africa split, but while Australia, Antarctica and Madagascar were still connected. DNA analysis showed the emus to be the base of the ratite tree, and the high diversity of tinamous, a sister clade to the ratites that occurs only in South America, suggests a long history there. Ostrich ancestors may have gone from there (or Australia) to Antarctica, and thence to Madagascar, where ratite relatives (Elephant Birds) have also been found.
The camelids have a different story: their family evolved in North America and then dispersed to South America and Asia, thence to central Asia (the Bactrian Camel) and Arabia/Africa (the Dromedary) after which, during the Pleistocene, all North American and east Asian species went extinct.
The flamingo story has not yet been unravelled. They are one of the most ancient of avian lineages, having separated from (probably) grebe ancestors in the Middle Eocene around 40 MYA. Currently they are classed in two genera, Phoenicopterus, with two species in Africa and two in the Americas, and Phoenicoparrus, the two species of which (Andean Flamingo and Puna or James’ Flamingo) are restricted to the Altiplano. One can imagine how the migratory Chilean Flamingo, Phoenicopterus chilensis, might have reached Chile: it is closely related to Africa’s Greater Flamingo, Phoenicopterus roseus, and the American Flamingo, Phoenicopterus ruber, which occurs from the Caribbean to the Galapagos. From there it is a few short hops following the coastal lagoons and Altiplano lakes loaded with brine shrimp and other macroscopic animals to Chile. Once there, during Pleistocene glacial advances, it may have gotten isolated and diverged a little from its American counterpart. But the Andean and Puna Flamingos? They are quite different: although nomadic within the Altiplano, they do not migrate to the coast like the Chilean Flamingos. Their bills are differently constructed and they are vegetarians, filtering diatoms and other microscopic algae and blue-green algae from the water. In this they are unlike every other flamingo except the Lesser Flamingo, which I had previously seen in Namibia and feeds in flat, briny lakes in eastern and southern Africa. It also feeds on algae and blue-green algae. The Lesser Flamingo, although currently classed as a Phoenicopterus species, was formerly classed in a third genus, Phoeniconaias because of morphological differences that are different from other Phoenicopterus species, but similar to the two Phoenicoparrus species. Is its morphological and dietary similarity to the Andean and Puna Flamingos a coincidence of evolutionary convergence? Or are they more related to each other than to the Greater and American species? This is not known, but if so, it would imply two dispersals: one that populated both the Americas and Africa with ancestral flamingos, and a later one that saw a lineage evolve to filter microscopic plants instead of macroscopic animals, with a subsequent dispersal from Africa to South America or vice-versa. This is speculation. No one knows. It is why science is so exciting: so many mysteries still to explore.
Travel Notes
I stayed at the Hotel Tambillo, http://www.hoteltambillo.cl/, tambillo@sanpedroatacama.com. A great, inexpensive hotel with a shady courtyard surrounded by high adobe walls. It has a restaurant and the proprietor, Veronica, is full of helpful information about the town and all the roads and places of interest. I hired a mountain guide (Ivan Mery, rutacien@gmail.com) for one day to reach a place near the Bolivian border that I doubted that I could find by myself, and am glad I did.
Key References
Darwin, C. R. (1839). Narrative of the surveying voyages of His Majesty's Ships Adventure and Beagle between the years 1826 and 1836, describing their examination of the southern shores of South America, and the Beagle's circumnavigation of the globe. Journal and remarks. 1832-1836. London, Henry Colburn.
Haddrath, Oliver and Allen J. Baker (2001). "Complete mitochondiral DNA sequences of extinct birds: ratite phylogenetics and the biogeographical vicariance hypothesis." Proc. Royal Society B 268(939-995).
Kadwell, M., M. Fernandez, et al. (2001). "Genetic analysis reveals the wild ancestors of the llama and the alpaca." Proc. of The Royal Society B 268: 2575-2584.
Cui, Peng, Rimutu Ji, et al. (2007). "A complete mitochondrial genome sequence of the wild two-humped camel (Camelus bactrianus ferus): an evolutionary history of camelidae." BMC Genomics 8: 241.
Olson, Storrs L. and Alan Feduccia (1980). Relationships and Evolution of Flamingos (Aves: Phoenicopteridae). Washington D.C., Smithsonian Institution Press.
Morgan-Richards, Mary, Steve a Trewick, et al. (2008). "Bird evolution: testing the Metaves clade with six new mitochondrial genomes." BMC Evolutionary Biology 8: 20.
Geraci, J., Béchet, A., Cézilly, F., Ficheux, S., Baccetti, N., Samraoui, B., and Wattier, R. Greater flamingo colonies around the Mediterranean form a single interbreeding population and share a common history. Journal of Avian Biology.
Showing posts with label Charles Darwin. Show all posts
Showing posts with label Charles Darwin. Show all posts
Monday, December 28, 2009
Sunday, December 27, 2009
Following Charles Darwin in Chile
Entering the port of Valparaiso by boat, I marvelled to see the same sight that Charles Darwin saw after rounding Cape Horn and its ferocious storms on the HMS Beagle. On the first day after his arrival at Valparaiso, in the middle of the Austral winter July 23, 1834, he wrote:
“When morning came, every thing appeared delightful. After Tierra del Fuego, the climate felt quite delicious—the atmosphere so dry, and the heavens so clear and blue, with the sun shining brightly, that all nature seemed sparkling with life. The view from the anchorage is very pretty. The town is built at the very foot of a a range of hills, about 1,600 feet high and rather steep…In a north-easterly direction there are some fine glimpses of the Andes.”
On the 150th anniversary of his publication of Charles Darwin’s On the Origin of Species in 1859 (24 November 2009), it is well to remember that he didn’t go just to the Galapagos. Some of his greatest insights into the mechanisms of evolution were in Chile and retracing his journey there makes for a fascinating vacation. Following Darwin through the exciting city of Santiago and the wine region of the Maipo Valley adds additional delights.
Darwin spent two and a half years in Chile (December 17, 1832 to June 29, 1835), fully half of his round-the-world voyage, and one whole year in just in the Valparaiso-Santiago area (July 23, 1834 to June 29, 1835). From the Beagle’s base in Valparaiso, he made numerous trips around central Chile and seems to have thoroughly enjoyed every minute—as do visitors today.
Darwin described Valparaiso as a “picturesque” town consisting of “one long, straggling street… parallel to the beach [with] low, whitewashed houses with tile roofs.” Today it has grown into a sprawling city and bustling seaport, but just across the bay, the village of Viña del Mar, long a resort favourite of Chileans, retains the small town charm that Darwin appreciated. On my last visit I found a quaint, clean hotel, conveniently a few steps from an empanada stand on the main street.
From nearby hills, Darwin got a better view of the Andes and the highest mountain outside of the Himalayas at 6962 metres (22,841 ft). We begin to realize that, besides becoming the world’s first and foremost evolutionary biologist, he had the soul of a poet:
"…the volcano of Aconcagua is particularly magnificent... the Cordillera [range of mountains] owe the greater part of their beauty to the atmosphere through which they are seen. When the sun was setting in the Pacific, it was admirable to watch how clearly their rugged outlines could be distinguished, yet how varied and how delicate were the shades of their colour.”
The “range of hills” Darwin saw beyond Valparaiso is topped by pyramidal form of La Campana, the “Bell of Quillota.” After so long at sea, Darwin couldn’t wait to stretch his legs and within days of his arrival he was riding to Quillota to climb La Campana.
Of all the areas he saw in Chile, he seemed to like the town of Quillota and its fertile valley the most:
“…The valley of Quillota…was exceedingly pleasant, just such as poets would call pastoral: green open lawns [actually, alfalfa fields], separated by small valleys with rivulets, and the cottages, we will suppose of the shepherds, scattered on the hill-sides… Any person who had seen only the country near Valparaiso, would never have imagined that there had been such picturesque spots in Chile… The little square gardens are crowded with orange and olive trees, and every sort of vegetable. On each side huge bare mountains rise, and this from the contrast renders the patchwork valley the more pleasing. Whoever called Valparaiso ‘the Valley of Paradise’ must have been thinking of Quillota.”
Quillota today is just as pretty. A city of 75,000, it retains its Spanish colonial character with continuous, low buildings surrounding the Church of St. Martin and the Convent of Santo Domingo. An archaeological museum contributes to the community’s culture by sponsoring poetry recitals. It nestles against La Campana National Park.
Following Darwin’s route, my companions and I took a trail to a high waterfall, “la cascada” on the maps. The photo of La Compana at the head of the blog was taken on this trail. Climbing up gradually through semi-desert, it passes a forest of giant palm trees, the endemic Chilean Wine Palm. It intrigued Darwin because “its stem is very large, and of a curious form, being thicker in the middle than at the base or top”—and because its sap can be made into wine, sugar, or a sweet, sticky desert that he called “treacle.” Its edible fruit and tastes like coconut. The world’s largest palm by weight and volume, its stem reaches 1.5 meters or more (five feet) wide and a height of 30 metres, with a crown up to nine meters across.
Darwin, camped near the peak of La Campana, noted that:
“The evening was fine, and the atmosphere so clear, that the masts of the vessels at anchor in the bay of Valparaiso, although no less than 26 geographical miles distant, could be distinguished clearly, as little black streaks. A ship doubling the point under sail appeared as a bright white speck… The setting of the sun was glorious; the valleys being black, whilst the snow peaks of the Andes yet retained a ruby tint. When it was dark, we made a fire beneath a little arbour of bamboos, fried our charqui (or dried strips of beef), took our maté, and were quite comfortable. There is an inexpressible charm in thus living in the open air. The evening was calm and still; the shrill noise of the mountain bizcacha, and the faint cry of the goatsucker, were only occasionally to be heard.”
We saw and heard the Mountain Viscacha, too. In his Origin of Species, Darwin used the distributions of the various species of these rodents in the Chinchilla family as an example of natural selection for different habitats.
Darwin, a keen observer of local customs, compared the Huasos, Chilean horsemen, with the gauchos of Argentina. In cattle country around La Campaña, I’ve often encountered them, always in their traditional broad-brimmed straw hats, knee-length leather boots, and colourful scarves. In the village of Batuco, we had to pull the car into a driveway so they could drive the herd through town. In Omué, as picturesque a town as one can imagine at the base of La Campaña, at night we saw horses tied to a cantina’s hitching rack; in the morning we met the fathers riding to the school with one or two children astride, or driving the whole family into town in a one-horse buggy.
Leaving Quillota, Darwin made the first of several excursions into and ultimately across the Andes. In one(April 1835), he went southward to the capital, Santiago, up the now-famous wine region of the Maipo Valley, up the Maipo River to a hotsprings resort, across a high pass and down to Mendoza, Argentina, and back to Chile by a more northerly pass. Afterwards, he remarked, “My excursion only cost me twenty-four days, and never did I more deeply enjoy an equal space of time.” I felt the same after each of my trips. Both of these passes, where Darwin struggled on horseback leading laden mules, I drove on a good highways past ski resorts.
Before mooring at Valparaiso, Darwin had already worked out how repeated earthquakes had caused some areas to sink and others to rise, throwing marine sediments laden with sea shells far above sea level. He had already theorized that the islands of Tierra del Fuego had been formed by the sinking of a mountain range. Now, he considered his finding thick layers of marine sediments with shells of extinct species at elevations up to 4,270 metres (14,000 feet), and other geological evidence, as proof that the Andes were formed by a slow and gradual rise of land over uncounted eons. Moreover, his finding along the coast of masses of marine shells of currently living species, elevated in sediments 120–150 metres (400–500 feet) above sea level, proved that this part of the coast of South America is still rising.
Darwin recalled, looking back at La Campana early one morning from the Andes:
“These basins or plains, together with the transverse flat valleys (like that of Quillota) which connect them with the coast, I have little doubt, are the bottoms of ancient inlets and deep bays, such as at the present day intersect every part of Tierra del Fuego, and the west coast of Patagonia. Chile must formerly have resembled the latter country, in the configuration of its land and water. This resemblance was…seen with great force, when a level fog-bank covered, as with a mantle, all the lower parts of the country: the white vapour curling into the ravines, beautifully represented little coves and bays; and here and there a solitary hillock peeping up, showed that it had formerly stood there as an islet.”
I was fortunate to see almost the exact same view as I crossed a ridge above the low-lying clouds, the Bell of Quillota rising above as if an island in the sea. These ideas were central to his theory that natural selection enabled individuals with some slight variation that gave it an advantage in a new environment to persist and its progeny to procreate more than those lacking the variation; and that over many generations, repeated selection for that characteristic could, in the time scale of the formation of mountains, evolve into new species.
Travel Notes
Hotel Hispano Restaurant, Plaza Parroquia 391, Viña del Mar. Tel: (56) (32) 268-5860, Fax (56) (32) 247-7096; a single for one night was $45.00 CAD.
My favourite hotel when not on business was Hotel Presidente, at Eliodoro Yanez 867, in the Presidente district of Santiago. A single was $145 USD in 2006. Tel: +(56) (2) 235-8015, email: infohp@presidente.
Nearby is the excellent restaurant, El Otro Sitio (“The Other Place”) at Antonia Lopez de Bello 53, is consistently rated as one of the top Peruvian restaurants in Santiago. Tel: 777-3059
In Olmué, a delightful hotel with a fine restaurant is the Hosteria Aire Puro (“Hotel of Pure Air”), Av. Granizo 7672, Tel: (56) (33) 441381, email: infor@hosteriaairepuro.cl, www.hosteriaairepuro.cl. The price for a chalet for three for one night was $94.00 CAD.
A nice restaurant in Valparaiso was the Café Journal, Cochrane 81, Tel: (56) (32) 259 6760. Lunch for four was $45.00 CAD. It has a sister restaurant in Viña del Mar.
“When morning came, every thing appeared delightful. After Tierra del Fuego, the climate felt quite delicious—the atmosphere so dry, and the heavens so clear and blue, with the sun shining brightly, that all nature seemed sparkling with life. The view from the anchorage is very pretty. The town is built at the very foot of a a range of hills, about 1,600 feet high and rather steep…In a north-easterly direction there are some fine glimpses of the Andes.”
On the 150th anniversary of his publication of Charles Darwin’s On the Origin of Species in 1859 (24 November 2009), it is well to remember that he didn’t go just to the Galapagos. Some of his greatest insights into the mechanisms of evolution were in Chile and retracing his journey there makes for a fascinating vacation. Following Darwin through the exciting city of Santiago and the wine region of the Maipo Valley adds additional delights.
Darwin spent two and a half years in Chile (December 17, 1832 to June 29, 1835), fully half of his round-the-world voyage, and one whole year in just in the Valparaiso-Santiago area (July 23, 1834 to June 29, 1835). From the Beagle’s base in Valparaiso, he made numerous trips around central Chile and seems to have thoroughly enjoyed every minute—as do visitors today.
Darwin described Valparaiso as a “picturesque” town consisting of “one long, straggling street… parallel to the beach [with] low, whitewashed houses with tile roofs.” Today it has grown into a sprawling city and bustling seaport, but just across the bay, the village of Viña del Mar, long a resort favourite of Chileans, retains the small town charm that Darwin appreciated. On my last visit I found a quaint, clean hotel, conveniently a few steps from an empanada stand on the main street.
From nearby hills, Darwin got a better view of the Andes and the highest mountain outside of the Himalayas at 6962 metres (22,841 ft). We begin to realize that, besides becoming the world’s first and foremost evolutionary biologist, he had the soul of a poet:
"…the volcano of Aconcagua is particularly magnificent... the Cordillera [range of mountains] owe the greater part of their beauty to the atmosphere through which they are seen. When the sun was setting in the Pacific, it was admirable to watch how clearly their rugged outlines could be distinguished, yet how varied and how delicate were the shades of their colour.”
The “range of hills” Darwin saw beyond Valparaiso is topped by pyramidal form of La Campana, the “Bell of Quillota.” After so long at sea, Darwin couldn’t wait to stretch his legs and within days of his arrival he was riding to Quillota to climb La Campana.
Of all the areas he saw in Chile, he seemed to like the town of Quillota and its fertile valley the most:
“…The valley of Quillota…was exceedingly pleasant, just such as poets would call pastoral: green open lawns [actually, alfalfa fields], separated by small valleys with rivulets, and the cottages, we will suppose of the shepherds, scattered on the hill-sides… Any person who had seen only the country near Valparaiso, would never have imagined that there had been such picturesque spots in Chile… The little square gardens are crowded with orange and olive trees, and every sort of vegetable. On each side huge bare mountains rise, and this from the contrast renders the patchwork valley the more pleasing. Whoever called Valparaiso ‘the Valley of Paradise’ must have been thinking of Quillota.”
Quillota today is just as pretty. A city of 75,000, it retains its Spanish colonial character with continuous, low buildings surrounding the Church of St. Martin and the Convent of Santo Domingo. An archaeological museum contributes to the community’s culture by sponsoring poetry recitals. It nestles against La Campana National Park.
Following Darwin’s route, my companions and I took a trail to a high waterfall, “la cascada” on the maps. The photo of La Compana at the head of the blog was taken on this trail. Climbing up gradually through semi-desert, it passes a forest of giant palm trees, the endemic Chilean Wine Palm. It intrigued Darwin because “its stem is very large, and of a curious form, being thicker in the middle than at the base or top”—and because its sap can be made into wine, sugar, or a sweet, sticky desert that he called “treacle.” Its edible fruit and tastes like coconut. The world’s largest palm by weight and volume, its stem reaches 1.5 meters or more (five feet) wide and a height of 30 metres, with a crown up to nine meters across.
Darwin, camped near the peak of La Campana, noted that:
“The evening was fine, and the atmosphere so clear, that the masts of the vessels at anchor in the bay of Valparaiso, although no less than 26 geographical miles distant, could be distinguished clearly, as little black streaks. A ship doubling the point under sail appeared as a bright white speck… The setting of the sun was glorious; the valleys being black, whilst the snow peaks of the Andes yet retained a ruby tint. When it was dark, we made a fire beneath a little arbour of bamboos, fried our charqui (or dried strips of beef), took our maté, and were quite comfortable. There is an inexpressible charm in thus living in the open air. The evening was calm and still; the shrill noise of the mountain bizcacha, and the faint cry of the goatsucker, were only occasionally to be heard.”
We saw and heard the Mountain Viscacha, too. In his Origin of Species, Darwin used the distributions of the various species of these rodents in the Chinchilla family as an example of natural selection for different habitats.
Darwin, a keen observer of local customs, compared the Huasos, Chilean horsemen, with the gauchos of Argentina. In cattle country around La Campaña, I’ve often encountered them, always in their traditional broad-brimmed straw hats, knee-length leather boots, and colourful scarves. In the village of Batuco, we had to pull the car into a driveway so they could drive the herd through town. In Omué, as picturesque a town as one can imagine at the base of La Campaña, at night we saw horses tied to a cantina’s hitching rack; in the morning we met the fathers riding to the school with one or two children astride, or driving the whole family into town in a one-horse buggy.
Leaving Quillota, Darwin made the first of several excursions into and ultimately across the Andes. In one(April 1835), he went southward to the capital, Santiago, up the now-famous wine region of the Maipo Valley, up the Maipo River to a hotsprings resort, across a high pass and down to Mendoza, Argentina, and back to Chile by a more northerly pass. Afterwards, he remarked, “My excursion only cost me twenty-four days, and never did I more deeply enjoy an equal space of time.” I felt the same after each of my trips. Both of these passes, where Darwin struggled on horseback leading laden mules, I drove on a good highways past ski resorts.
Before mooring at Valparaiso, Darwin had already worked out how repeated earthquakes had caused some areas to sink and others to rise, throwing marine sediments laden with sea shells far above sea level. He had already theorized that the islands of Tierra del Fuego had been formed by the sinking of a mountain range. Now, he considered his finding thick layers of marine sediments with shells of extinct species at elevations up to 4,270 metres (14,000 feet), and other geological evidence, as proof that the Andes were formed by a slow and gradual rise of land over uncounted eons. Moreover, his finding along the coast of masses of marine shells of currently living species, elevated in sediments 120–150 metres (400–500 feet) above sea level, proved that this part of the coast of South America is still rising.
Darwin recalled, looking back at La Campana early one morning from the Andes:
“These basins or plains, together with the transverse flat valleys (like that of Quillota) which connect them with the coast, I have little doubt, are the bottoms of ancient inlets and deep bays, such as at the present day intersect every part of Tierra del Fuego, and the west coast of Patagonia. Chile must formerly have resembled the latter country, in the configuration of its land and water. This resemblance was…seen with great force, when a level fog-bank covered, as with a mantle, all the lower parts of the country: the white vapour curling into the ravines, beautifully represented little coves and bays; and here and there a solitary hillock peeping up, showed that it had formerly stood there as an islet.”
I was fortunate to see almost the exact same view as I crossed a ridge above the low-lying clouds, the Bell of Quillota rising above as if an island in the sea. These ideas were central to his theory that natural selection enabled individuals with some slight variation that gave it an advantage in a new environment to persist and its progeny to procreate more than those lacking the variation; and that over many generations, repeated selection for that characteristic could, in the time scale of the formation of mountains, evolve into new species.
Travel Notes
Hotel Hispano Restaurant, Plaza Parroquia 391, Viña del Mar. Tel: (56) (32) 268-5860, Fax (56) (32) 247-7096; a single for one night was $45.00 CAD.
My favourite hotel when not on business was Hotel Presidente, at Eliodoro Yanez 867, in the Presidente district of Santiago. A single was $145 USD in 2006. Tel: +(56) (2) 235-8015, email: infohp@presidente.
Nearby is the excellent restaurant, El Otro Sitio (“The Other Place”) at Antonia Lopez de Bello 53, is consistently rated as one of the top Peruvian restaurants in Santiago. Tel: 777-3059
In Olmué, a delightful hotel with a fine restaurant is the Hosteria Aire Puro (“Hotel of Pure Air”), Av. Granizo 7672, Tel: (56) (33) 441381, email: infor@hosteriaairepuro.cl, www.hosteriaairepuro.cl. The price for a chalet for three for one night was $94.00 CAD.
A nice restaurant in Valparaiso was the Café Journal, Cochrane 81, Tel: (56) (32) 259 6760. Lunch for four was $45.00 CAD. It has a sister restaurant in Viña del Mar.
Thursday, December 3, 2009
The other Darwin: Alfred Russel Wallace, co-discoverer of natural selection
Alfred Russel Wallace, co-discoverer of natural selection as the driving force of evolution
On the 150th anniversary (November, 24 2009) of Charles Darwin’s publication of On the Origin of Species in 1859, it is worth remembering that Alfred Russel Wallace made the discovery independently from Darwin. His essay, On the Tendency of Varieties to Depart Indefinitely from the Original Type, which he mailed to Darwin and other notable scientists from an island in southeast Asia, was read to the Linnean Society of London on July 1, 1858. It was read together with an extract of an unpublished 1844 essay by Darwin, whom Wallace considered something of a mentor, titled On the Perpetuation of Varieties and Species by Natural Means of Selection; and an abstract of a private October 1857 letter from Darwin to Professor Asa Gray, of Boston, U.S. These were published in the Linnaean Society’s journal on August 20 as one paper by Darwin and Wallace, but in fact they were separately authored and read separately at the July 1 meeting. The reading of these two papers prompted Darwin to rush to complete his book.
Wallace (January 8, 1823 – November 7, 1913) was born in Llanbadoc, Wales. A prolific author, he wrote on both scientific and social issues; the account of adventures and observations during his explorations in Indonesia and Malaysia, The Malay Archipelago, was one of the most popular and influential journals of scientific exploration published during the 19th century.
Although from a respectable, middle-class family, a deterioration of the family's finances forced young Alfred to withdraw from grammar school at age 13. He apprenticed as a surveyor with his brother William and worked at various surveying jobs, culminating in a position at the Collegiate School in Leicester to teach drawing, mapmaking, and surveying.
It was already more than a century since Carolus Linnaeus had published his Systema naturae in 1735, demonstrating the relatedness of species living close to one another, the relationships becoming more distant with increasing geographic distance. Scientists were already aware of the vast periods “geologic time” during which the various kinds of rock had been created. They knew that sedimentary layers had been build up over uncounted eons, occasionally interrupted with igneous layers indicating ancient lava flows. They knew that metamorphic rock was older, created from sedimentary or igneous layers by immense pressure and time. They could see that some layers were made of sediments eroded from mountains and volcanoes no longer there, and that some of these, containing shells of extinct sea animals, were found on mountain tops too far from any sea to be explained by cataclysm. They also knew, from the discoveries of fossils in different layers, that species of animals and plants evolved or “transmuted” over time, ancestral species giving way to similar, modern ones. Extinct fossil species most similar to extant ones were in the most recent layers at the top, while deeper, older layers held species that were increasingly different, indicating some process of gradual change. What they didn’t know was how.
In the Leicester library, Wallace, then about 21, met Henry Bates, at 19 already an accomplished zoologist. The two friends took beetle-collecting field trips together and discussed and corresponded about the important ideas of the day regarding human population and evolution. These included An Essay on the Principle of Population by Thomas Malthus (1798), the anonymous evolutionary treatise Vestiges of the Natural History of Creation (1844), Charles Darwin's Journal (1839), and Charles Lyell's three-volume Principles of Geology (1830–1833).
Because of these insights, and the thirst for knowledge of foreign places that accompanied the colonial period, museums throughout Europe had an unquenchable thirst for exotic animal specimens. The public was also hungry for travel books. Supplying the specimens and writing the books became profitable businesses for adventurers and ways to subsidise expeditions for explorers. In 1848, Wallace and Bates left for Brazil to collect insects and other animal specimens in the Amazon rainforest and sell them to collectors back in the United Kingdom. They also hoped to gather further evidence of the transmutation of species.
After about a year collecting together in the Amazon jungle, Wallace and Bates seem to have had some sort of falling out. Neither of their journals explains why, but anyone who has ever taken a long trip with a friend knows how the exigencies of travel can strain relationships. They separated and continued collecting separately for three more years, occasionally meeting to exchange notes and news. Then Wallace packed his collections and meticulous notes and illustrations and went home, while Bates stayed for seven more years. When Bates finally arrived home in 1859, he had sent back over 14,000 species (mostly of insects) of which 8,000 were new to science.
Meanwhile, en route home in 1852, Wallace's ship caught fire and the crew abandoned ship. All of his specimens, the vast majority of those he had collected during his entire trip, were lost. He could only save part of his diary and a few sketches. Although this was obviously a financial and scientific loss and a personal blow, the insurance payment for his lost collection plus the sale of a few specimens that he had previously shipped back to Britain allowed Wallace to spend eighteen months living in London. During this period, he wrote six academic papers (for example, On the Monkeys of the Amazon) and two books; Palm Trees of the Amazon and Their Uses and Travels on the Amazon. He also met and corresponded with a number of other British naturalists — most significantly, Charles Darwin.
The city could not hold his attention long, however. In 1854 at age 31 he embarked on an eight-year expedition through the Malay Archipelago to collect specimens for sale and to study nature. Among other discoveries, he noticed a sharp zoological divide across the strait between Java and the Seychelles. Unlike the islands of Sumatra, Java and Borneo, and the southeast Asian mainland to the northwest, which have many closely-related species, the Seychelles, Philippines and other islands to the south and east have mainly unrelated taxa, many of which are endemic. But neither are they related closely to species in Australia to the south, or to those on Papua New Guinea to the east. It has since been discovered that shallow ocean shelves connecting Java, Sumatra and Borneo with the mainland were occasionally exposed when glacial maxima in the late Pliocene and Pleistocene lowered sea levels, allowing species to move among these islands; however, the islands to the south and east had arrived there by plate tectonic movements and were always separated by deep water, so that no land connections were ever possible. Their species therefore evolved independently.
This biological realm is known today as Wallacia, and the line encompassing it, the Wallace Line. Wallace collected more than 125,000 specimens in the Malay Archipelago (more than 80,000 beetles alone). More than a thousand were new to science.
Because he was collecting for sale, Wallace collected many specimens of each species, allowing him to study the variations within each species throughout its range, and among related species. This allowed him to see how varieties with seemingly minor differences could prosper in different environments. His insight, in parallel with Darwin’s, was that even minor differences in an individual that conferred a survival or reproductive advantage would be passed on to its progeny in a higher proportion than from individuals without the advantage. In time, the differences in a variety from it parent type could become so great as to constitute a new species.
Neither Darwin nor Wallace discovered evolution or created a theory of it. Evolution is a fact that had been known long before. What they discovered was the theory of how it worked, a theory that has stood the test of time, has been strengthened and elaborated, and has become one of the foundations of biology.
On the 150th anniversary (November, 24 2009) of Charles Darwin’s publication of On the Origin of Species in 1859, it is worth remembering that Alfred Russel Wallace made the discovery independently from Darwin. His essay, On the Tendency of Varieties to Depart Indefinitely from the Original Type, which he mailed to Darwin and other notable scientists from an island in southeast Asia, was read to the Linnean Society of London on July 1, 1858. It was read together with an extract of an unpublished 1844 essay by Darwin, whom Wallace considered something of a mentor, titled On the Perpetuation of Varieties and Species by Natural Means of Selection; and an abstract of a private October 1857 letter from Darwin to Professor Asa Gray, of Boston, U.S. These were published in the Linnaean Society’s journal on August 20 as one paper by Darwin and Wallace, but in fact they were separately authored and read separately at the July 1 meeting. The reading of these two papers prompted Darwin to rush to complete his book.
Wallace (January 8, 1823 – November 7, 1913) was born in Llanbadoc, Wales. A prolific author, he wrote on both scientific and social issues; the account of adventures and observations during his explorations in Indonesia and Malaysia, The Malay Archipelago, was one of the most popular and influential journals of scientific exploration published during the 19th century.
Although from a respectable, middle-class family, a deterioration of the family's finances forced young Alfred to withdraw from grammar school at age 13. He apprenticed as a surveyor with his brother William and worked at various surveying jobs, culminating in a position at the Collegiate School in Leicester to teach drawing, mapmaking, and surveying.
It was already more than a century since Carolus Linnaeus had published his Systema naturae in 1735, demonstrating the relatedness of species living close to one another, the relationships becoming more distant with increasing geographic distance. Scientists were already aware of the vast periods “geologic time” during which the various kinds of rock had been created. They knew that sedimentary layers had been build up over uncounted eons, occasionally interrupted with igneous layers indicating ancient lava flows. They knew that metamorphic rock was older, created from sedimentary or igneous layers by immense pressure and time. They could see that some layers were made of sediments eroded from mountains and volcanoes no longer there, and that some of these, containing shells of extinct sea animals, were found on mountain tops too far from any sea to be explained by cataclysm. They also knew, from the discoveries of fossils in different layers, that species of animals and plants evolved or “transmuted” over time, ancestral species giving way to similar, modern ones. Extinct fossil species most similar to extant ones were in the most recent layers at the top, while deeper, older layers held species that were increasingly different, indicating some process of gradual change. What they didn’t know was how.
In the Leicester library, Wallace, then about 21, met Henry Bates, at 19 already an accomplished zoologist. The two friends took beetle-collecting field trips together and discussed and corresponded about the important ideas of the day regarding human population and evolution. These included An Essay on the Principle of Population by Thomas Malthus (1798), the anonymous evolutionary treatise Vestiges of the Natural History of Creation (1844), Charles Darwin's Journal (1839), and Charles Lyell's three-volume Principles of Geology (1830–1833).
Because of these insights, and the thirst for knowledge of foreign places that accompanied the colonial period, museums throughout Europe had an unquenchable thirst for exotic animal specimens. The public was also hungry for travel books. Supplying the specimens and writing the books became profitable businesses for adventurers and ways to subsidise expeditions for explorers. In 1848, Wallace and Bates left for Brazil to collect insects and other animal specimens in the Amazon rainforest and sell them to collectors back in the United Kingdom. They also hoped to gather further evidence of the transmutation of species.
After about a year collecting together in the Amazon jungle, Wallace and Bates seem to have had some sort of falling out. Neither of their journals explains why, but anyone who has ever taken a long trip with a friend knows how the exigencies of travel can strain relationships. They separated and continued collecting separately for three more years, occasionally meeting to exchange notes and news. Then Wallace packed his collections and meticulous notes and illustrations and went home, while Bates stayed for seven more years. When Bates finally arrived home in 1859, he had sent back over 14,000 species (mostly of insects) of which 8,000 were new to science.
Meanwhile, en route home in 1852, Wallace's ship caught fire and the crew abandoned ship. All of his specimens, the vast majority of those he had collected during his entire trip, were lost. He could only save part of his diary and a few sketches. Although this was obviously a financial and scientific loss and a personal blow, the insurance payment for his lost collection plus the sale of a few specimens that he had previously shipped back to Britain allowed Wallace to spend eighteen months living in London. During this period, he wrote six academic papers (for example, On the Monkeys of the Amazon) and two books; Palm Trees of the Amazon and Their Uses and Travels on the Amazon. He also met and corresponded with a number of other British naturalists — most significantly, Charles Darwin.
The city could not hold his attention long, however. In 1854 at age 31 he embarked on an eight-year expedition through the Malay Archipelago to collect specimens for sale and to study nature. Among other discoveries, he noticed a sharp zoological divide across the strait between Java and the Seychelles. Unlike the islands of Sumatra, Java and Borneo, and the southeast Asian mainland to the northwest, which have many closely-related species, the Seychelles, Philippines and other islands to the south and east have mainly unrelated taxa, many of which are endemic. But neither are they related closely to species in Australia to the south, or to those on Papua New Guinea to the east. It has since been discovered that shallow ocean shelves connecting Java, Sumatra and Borneo with the mainland were occasionally exposed when glacial maxima in the late Pliocene and Pleistocene lowered sea levels, allowing species to move among these islands; however, the islands to the south and east had arrived there by plate tectonic movements and were always separated by deep water, so that no land connections were ever possible. Their species therefore evolved independently.
This biological realm is known today as Wallacia, and the line encompassing it, the Wallace Line. Wallace collected more than 125,000 specimens in the Malay Archipelago (more than 80,000 beetles alone). More than a thousand were new to science.
Because he was collecting for sale, Wallace collected many specimens of each species, allowing him to study the variations within each species throughout its range, and among related species. This allowed him to see how varieties with seemingly minor differences could prosper in different environments. His insight, in parallel with Darwin’s, was that even minor differences in an individual that conferred a survival or reproductive advantage would be passed on to its progeny in a higher proportion than from individuals without the advantage. In time, the differences in a variety from it parent type could become so great as to constitute a new species.
Neither Darwin nor Wallace discovered evolution or created a theory of it. Evolution is a fact that had been known long before. What they discovered was the theory of how it worked, a theory that has stood the test of time, has been strengthened and elaborated, and has become one of the foundations of biology.
Wednesday, December 2, 2009
Charles Darwin, Geologist
Charles Darwin, Geologist
On the 150th anniversary of his publication of Charles Darwin’s On the Origin of Species in 1859 (24 November 2009), we can appreciate his impact more if we remember that he was as much a geologist as a zoologist. His first paper, read to the Geological Society in May, 1837, was about the geological formation of coral atolls. After leaving South America and the Galapagos Islands, the HMS Beagle had travelled to many Pacific islands built of coral. There he worked out how the islands form by the slow growth and death of corals over many millennia, and are given life by the transport of plant seeds and landing of birds and insects.
Darwin himself did not even write the zoology of the Beagle’s 1831–1936 British Admiralty expedition. Its volumes, published from 1838 to 1843, were authored by Richard Owen (fossil mammals), George Robert Waterhouse (living mammals), John Gould (birds), Leonard Jenyns (fish) and Thomas Bell (reptiles). But Darwin, as the editor, wrote a geological introduction to the Fossil Mammalia and a geographical introduction to the Mammalia.
Before the voyage, scientists already knew that the Earth’s surface had formed by slow geological processes over countless eons contrary to the Biblical (Noachian) flood. They had been studying fossils of extinct plants and animals that were known, by the geological layers in which they were found, to have predated modern forms. They knew that the fossils that were most dissimilar to modern ones were in deeper, older layers and that those most like modern species were in the newer layers. They generally (though not universally) recognized that some sort of “transmutation” of species occurred, and had proposed various theories about the forces driving it and the mechanisms by which it occurred. In 1830, Charles Lyell had brought these ideas together in his widely acclaimed volume 1 of Principles of Geology.
Darwin was not the official naturalist on the voyage: that post was filled by naval officers who made the official biological collections. Darwin was merely a paying passenger, although a highly placed one who became close friends with the captain, Robert Fitzroy, himself a trained scientist and biological specimen collector. A condition of Darwin’s passage was that he was given facilities for a private collection of fossils and animals. Before the voyage, Lyell had asked Fitzroy to make specific geological observations—the enthusiasm for which he shared with his passenger, the young Charles Darwin.
It was Fitzroy who had given Darwin his own copy of Lyell’s first volume before they sailed. Darwin eagerly obtained Lyell’s volumes 2 and 3 during the voyage, as soon as they were published. Darwin’s Narrative (1839) is filled with geological musings of how what he saw had come to be, largely by fitting his observations to Lyell’s framework, but also relying on the journals of previous expeditions such as Humboldt’s and Kotzebue’s. Thus, along the Argentine coast, Darwin used fossil mammal bones underlying fossil marine shells to theorize about geology: that they had been swept down a Tertiary river into the sea, covered with sediments, subsequently raised by geological uplift above the sea surface and later eroded to become the cliff face on a high point of land where he found them. Rounding Cape Horn, he surmised that the archipelago might be a row of mountains that had become submerged. Further up the coast of Chile, he confirmed his guess by noting the age and location of strata where he found marine fossils of various ages, from the seashore high up into the Andes. He worked out how crustal uplifting and earthquakes (one of which he experienced in Valdivia) and volcanoes had combined to raise the Andes from below sea level to the 7,000 meter high Mount Aconcagua, which he climbed (not to the top, but high enough). He realized that the forces that raised the Andes were the opposing forces to those that had submerged Tierra del Fuego. It was geology, also that led him to challenge previous assumptions, including Lyell’s, that species were “immutable” (i.e., fixed, not changing) because that would mean that either they had been created at different times in different places, or had crossed geological barriers such as salt water or solid rock, both of which geology had shown to be impossible. Geology, not finches, proved that species were not immutable: they evolved.
On the 150th anniversary of his publication of Charles Darwin’s On the Origin of Species in 1859 (24 November 2009), we can appreciate his impact more if we remember that he was as much a geologist as a zoologist. His first paper, read to the Geological Society in May, 1837, was about the geological formation of coral atolls. After leaving South America and the Galapagos Islands, the HMS Beagle had travelled to many Pacific islands built of coral. There he worked out how the islands form by the slow growth and death of corals over many millennia, and are given life by the transport of plant seeds and landing of birds and insects.
Darwin himself did not even write the zoology of the Beagle’s 1831–1936 British Admiralty expedition. Its volumes, published from 1838 to 1843, were authored by Richard Owen (fossil mammals), George Robert Waterhouse (living mammals), John Gould (birds), Leonard Jenyns (fish) and Thomas Bell (reptiles). But Darwin, as the editor, wrote a geological introduction to the Fossil Mammalia and a geographical introduction to the Mammalia.
Before the voyage, scientists already knew that the Earth’s surface had formed by slow geological processes over countless eons contrary to the Biblical (Noachian) flood. They had been studying fossils of extinct plants and animals that were known, by the geological layers in which they were found, to have predated modern forms. They knew that the fossils that were most dissimilar to modern ones were in deeper, older layers and that those most like modern species were in the newer layers. They generally (though not universally) recognized that some sort of “transmutation” of species occurred, and had proposed various theories about the forces driving it and the mechanisms by which it occurred. In 1830, Charles Lyell had brought these ideas together in his widely acclaimed volume 1 of Principles of Geology.
Darwin was not the official naturalist on the voyage: that post was filled by naval officers who made the official biological collections. Darwin was merely a paying passenger, although a highly placed one who became close friends with the captain, Robert Fitzroy, himself a trained scientist and biological specimen collector. A condition of Darwin’s passage was that he was given facilities for a private collection of fossils and animals. Before the voyage, Lyell had asked Fitzroy to make specific geological observations—the enthusiasm for which he shared with his passenger, the young Charles Darwin.
It was Fitzroy who had given Darwin his own copy of Lyell’s first volume before they sailed. Darwin eagerly obtained Lyell’s volumes 2 and 3 during the voyage, as soon as they were published. Darwin’s Narrative (1839) is filled with geological musings of how what he saw had come to be, largely by fitting his observations to Lyell’s framework, but also relying on the journals of previous expeditions such as Humboldt’s and Kotzebue’s. Thus, along the Argentine coast, Darwin used fossil mammal bones underlying fossil marine shells to theorize about geology: that they had been swept down a Tertiary river into the sea, covered with sediments, subsequently raised by geological uplift above the sea surface and later eroded to become the cliff face on a high point of land where he found them. Rounding Cape Horn, he surmised that the archipelago might be a row of mountains that had become submerged. Further up the coast of Chile, he confirmed his guess by noting the age and location of strata where he found marine fossils of various ages, from the seashore high up into the Andes. He worked out how crustal uplifting and earthquakes (one of which he experienced in Valdivia) and volcanoes had combined to raise the Andes from below sea level to the 7,000 meter high Mount Aconcagua, which he climbed (not to the top, but high enough). He realized that the forces that raised the Andes were the opposing forces to those that had submerged Tierra del Fuego. It was geology, also that led him to challenge previous assumptions, including Lyell’s, that species were “immutable” (i.e., fixed, not changing) because that would mean that either they had been created at different times in different places, or had crossed geological barriers such as salt water or solid rock, both of which geology had shown to be impossible. Geology, not finches, proved that species were not immutable: they evolved.
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