Saturday, October 31, 2015

Atacama Bloom

Atacama Desert
Perched on a plateau west of the Andes on the Pacific coast is the driest non-polar desert on Earth. The Atacama Desert is a 600 mile long strip of otherworldly terrain of rocky hillsides, salt lakes, sand, and ancient felsic lava flows.

The hyperaridity of the Atacama has existed for at least 3 million years. It's the oldest continuously arid land on Earth. A few weather stations in the Atacama have never recorded precipitation.

Mean rainfall ranges from 0.04 to 0.12 inches per year in the coastal towns of Arica and Iquique to 0.6 inches per year in the abandoned mining town Yungay.
"Don't think about what you've left behind" The alchemist said to the boy as they began to ride across the sands of the desert. "If what one finds is made of pure matter, it will never spoil. And one can always come back. If what you had found was only a moment of light, like the explosion of a star, you would find nothing on your return.
Paulo Coelho, The Alchemist
This year the Atacama is experiencing a rare springtime bloom. The Garra de León or Lion's Claw is a stunning red flower that's blooming in the Atacama. The Garra de León is a plant species exclusive to the Atacama Desert.

Garra de León in bloom
by Tomás Cuadra Ordenes

Historically a significant Atacama Desert bloom occurs every 5-7 years, but unusual March and August rains this year have produced cumulative precipitation not seen in nearly 20 years.

"At the moment it is gently raining. Imagine these flowers tomorrow."
by Tomás Cuadra Ordenes

Uncharacteristic rains have spawned a profusion of flowers. Seeds have germinated that have lain dormant for many years.
Long before I ever saw the desert I was aware of the mystical overtones which the observation of nature made audible to me. But I have never been more frequently or more vividly aware of them than in connection with the desert phenomena.
— Joseph Wood Krutch (1893-1970)

REFERENCES

Saturday, October 24, 2015

One in the Sunbeam

From a creed steeped in sin and submission, grew an expansive creed of wonderment and awe. Naturalist and preservationist John Muir abandoned an evangelical upbringing to discover a god of nature.
That Muir was thus reborn, not from a life of sin to submission to the God of the Bible, but from a life of repression to revelation of the God of Nature, has left us the rich and inspiring legacy of his wilderness gospel.
Mark R. Stoll
Inspired by the transcendence of the High Sierras, Muir wrote:

Mountains holy as Sinai. No mountains I know of are so alluring. None so hospitable, kindly, tenderly inspiring. It seems strange that everybody does not come at their call. They are given, like the Gospel, without money and without price. 'Tis heaven alone that is given away'.

Alpine meadow, boulders, and mountains in Humphries Basin
John Muir Wilderness, Sierra Nevada

For Muir the Sierras were a source of infinite well-being, awe, and wonderment. He described the deep calm and connection with a keen presence and awareness:

Here is calm so deep, grasses cease waving... Wonderful how completely everything in wild nature fits into us, as if truly part and parent of us. The sun shines not on us but in us. The rivers flow not past, but through us, thrilling, tingling, vibrating every fiber and cell of the substance of our bodies, making them glide and sing. The trees wave and the flowers bloom in our bodies as well as our souls, and every bird song, wind song, and; tremendous storm song of the rocks in the heart of the mountains is our song, our very own, and sings our love.

Folded rocks of Sevehah Cliff on the trail up Convict Canyon
John Muir Wilderness, Sierra Nevada

Of the resonance and oneness one experiences in the transcendence of nature, Muir wrote:

The Song of God, sounding on forever. So pure and sure and universal is the harmony, it matters not where we are, where we strike in on the wild lowland plains. We care not to go to the mountains, and on the mountains we care not to go to the plains. But as soon as we are absorbed in the harmony, plain, mountain, calm, storm, lilies and sequoias, forests and meads are only different strands of many-colored Light-are one in the sunbeam!


REFERENCES

Saturday, October 17, 2015

Tongue of the Hummingbird

Exposed tongue of a
black-throated mango
photo: Dr. Kristiina Hurme
A hummingbird's feeding mechanism is a rapier-like bill protecting a tongue that has adapted to extend deep into flowers to drink pools of sugar-rich nectar.

Conventional wisdom among ornithologists held that the hummingbird's tongue used capillary action to draw in nectar. Capillary action describes liquid flowing into narrow spaces due to intermolecular forces, rather than some external forces like gravity.

This past summer, while hummingbirds in North America were gathering nectar in preparation for their migratory journey to equatorial locales, evolutionary biologist and functional morphologist Alejandro Rico-Guevara published the results of a study that suggests the hummingbird's tongue acts like an elastic micro-pump.

Rico-Guevara observed that hummingbirds can draw nectar from a flower in less than a second which, he reasoned, was much too quick to be attributed to the wicking action of intermolecular forces.



Rico-Guevara's slow-motion video posted on YouTube by Science News (above) shows a hummingbird repeatedly extending its tongue into a red drink.
The hummingbird's tongue acts like an elastic micropump.
Rico-Guevara's study suggest that the hummingbird's tongue is compressed as it approaches the nectar, then becomes plump as the nectar rapidly hydrates grooves in the tongue.

And the humming-bird that hung
Like a jewel up among
The tilted honeysuckle horns
They mesmerized and swung
In the palpitating air,
Drowsed with odors strange and rare.
And, with whispered laughter, slipped away
And left him hanging there.

James Whitcomb Riley

REFERENCES

Saturday, October 10, 2015

Autumnal

As Earth orbits the Sun, it rotates on an axis tilted at 23.5 degrees. Accordingly, on its yearly journey, parts of Earth receive proportionally fewer hours of sunlight.
"Autumn seemed to arrive suddenly that year. The morning of the first September was crisp and golden as an apple."
J.K. Rowling, Harry Potter and the Deathly Hallows
Earth's tilt relative to the Sun creates our seasons. As we move around the sun, the position of each hemisphere in relation to the Sun changes. Today we in the northern hemisphere are well underway tilting away from the sun, shortening the days and lengthening nights.

Northern Hemisphere Southern Hemisphere
June SolsticeTilted towards the Sun → SummerTilted away from the Sun → Winter
December SolsticeTilted away from the Sun → WinterTilted towards the Sun → Summer

As parts of Earth are illuminated by fewer hours of sunlight, days are shorter and nights are longer. The temperature drops. Autumn arrives, then in time, winter follows.

Trees respond to fewer hours of sunlight by generating less and less chlorophyll.

Intercity Bridge / Ford Parkway Bridge / 46th St Bridge over the Mississippi River

Chlorophyll in leaves enables trees to absorb and convert sunlight energy into sustenance via photosynthesis.

When chlorophyll (green) production stops, carotenoid (yellow, orange, brown) in the leaves become visible. Carotenoids are pigments synthesized by plant life. Reddish leaves are determined by temperature and cloud cover. Many consecutive warm autumn days and cool non-freezing nights produce anthocyanin (red) causing a reddish colors in leaves because of the sugar produced.

AUTUMNAL

Pale amber sunlight falls across
The reddening October trees,
That hardly sway before a breeze
As soft as summer: summer's loss
Seems little, dear! on days like these.

Let misty autumn be our part!
The twilight of the year is sweet:
Where shadow and the darkness meet
Our love, a twilight of the heart
Eludes a little time's deceit.

Are we not better and at home
In dreamful Autumn, we who deem
No harvest joy is worth a dream?
A little while and night shall come,
A little while, then, let us dream.

Beyond the pearled horizons lie
Winter and night: awaiting these
We garner this poor hour of ease,
Until love turn from us and die
Beneath the drear November trees.

Ernest Dowson, The Poems and Prose of Ernest Dowson

REFERENCES

Saturday, October 3, 2015

Platypus to Puffball

Family tree of Earth's lifeforms
A family tree of Earth's lifeforms, some 2.3 million named species thus far, was recently published in draft form on opentreeoflife.org.

The circular tree of life compiled on opentreeoflife.org traces back 3.5 billion years ago to the beginning of life on Earth.

A tree of life, or phylogenetic tree, is typically a branching diagram that resembles a tree found in nature.

The lines or branches on a phylogenetic tree represent evolutionary relationships ― from platypus to puffball.
The affinities of all the beings of the same class have sometimes been represented by a great tree. I believe this simile largely speaks the truth.
Charles Darwin, Origin of Species, Chapter IV
Branching relationships are derived from an organism's physical or genetic characteristics. Microbiologist Carl Woese proposed the tree of life shown below based on RNA data.

Phylogenetic tree scientific names
source: Eric Gaba, NASA Astrobiology Institute

The human species falls under the kingdom of animalia (shown in brown lines above) in the eucarya branch (cf. Human Classification in Know thy Tribe).

Charles Darwin found the tree to be a suitable metaphor to represent evolutionary relationships:
"The green and budding twigs may represent existing species; and those produced during former years may represent the long succession of extinct species. At each period of growth all the growing twigs have tried to branch out on all sides, and to overtop and kill the surrounding twigs and branches, in the same manner as species and groups of species have at all times overmastered other species in the great battle for life. The limbs divided into great branches, and these into lesser and lesser branches, were themselves once, when the tree was young, budding twigs; and this connexion of the former and present buds by ramifying branches may well represent the classification of all extinct and living species in groups subordinate to groups. Of the many twigs which flourished when the tree was a mere bush, only two or three, now grown into great branches, yet survive and bear the other branches; so with the species which lived during long-past geological periods, very few have left living and modified descendants. From the first growth of the tree, many a limb and branch has decayed and dropped off; and these fallen branches of various sizes may represent those whole orders, families, and genera which have now no living representatives, and which are known to us only in a fossil state. As we here and there see a thin, straggling branch springing from a fork low down in a tree, and which by some chance has been favoured and is still alive on its summit, so we occasionally see an animal like the Ornithorhynchus or Lepidosiren, which in some small degree connects by its affinities two large branches of life, and which has apparently been saved from fatal competition by having inhabited a protected station. As buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever-branching and beautiful ramifications."
― Origin of Species, Chapter IV
Intelligent Life

Asked in a NOVA episode about the prospect of finding intelligent life somewhere beyond Earth's biosphere, cosmologist Neil deGrasse Tyson speculates that finding intelligent extraterrestrial life seems unlikely. Tyson draws a distinction between human intelligence ― characterized by perception, consciousness, self-awareness, and volition ― and the mechanisms needed to survive and proliferate.
I think that intelligence is such a narrow branch of the tree of life—this branch of primates we call humans. No other animal, by our definition, can be considered intelligent. So intelligence can't be all that important for survival, because there are so many animals that don't have what we call intelligence, and they're surviving just fine.
Neil deGrasse Tyson
Life might exist beyond our life-raft in the biosphere. Tyson muses that the search for extant life is more likely to turn up "anything that falls between single-celled bacteria and life that has some kind of interesting purpose or function to perform", rather than life with the intellectual capacity of humans.


REFERENCES

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