Posts Tagged ‘bacteria’
For about a billion years, life on earth was a relatively simple proposition: it was composed entirely of single-celled organisms (prokaryotes) in either the bacteria or archaea families. Then, about 2.1 billion years ago, one of those single-celled critters crawled inside another; the two merged, and a new kind of life– multi-cellular (eukaryotic) life– was born…
This inner cell—a bacterium—abandoned its free-living existence and eventually transformed into mitochondria. These internal power plants provided the host cell with a bonanza of energy, allowing it to evolve in new directions that other prokaryotes could never reach.
If this story is true, and there are still those who doubt it, then all eukaryotes—every flower and fungus, spider and sparrow, man and woman—descended from a sudden and breathtakingly improbable merger between two microbes. They were our great-great-great-great-…-great-grandparents, and by becoming one, they laid the groundwork for the life forms that seem to make our planet so special. The world as we see it (and the fact that we see it at all; eyes are a eukaryotic invention) was irrevocably changed by that fateful union—a union so unlikely that it very well might not have happened at all, leaving our world forever dominated by microbes, never to welcome sophisticated and amazing life like trees, mushrooms, caterpillars, and us.
Read the extraordinary story of how one freakish event may well account for all sophisticated life on earth in “The unique merger that made You (and Ewe, and Yew).”
* Lao Tzu
As we fill out our family trees, we might send microscopic birthday greetings to Carl Woese; he was born on this date in 1928. A microbiologist, Woese recognized and defined (in 1977) the existence of archaea as a third domain of life, distinct from the two previously-recognized domains, bacteria and “life other than bacteria” (eukaryotes). The discovery revolutionized the understanding of the “family tree” of life. And the technique he used to make it– phylogenetic taxonomy of 16S ribosomal RNA– revolutionized the practice of microbiology.
“The fact is that no species has ever had such wholesale control over everything on earth, living or dead, as we now have”*…
From the always-amazing Randall Munroe, who reminds us that bacteria still outweigh us thousands to one– and that’s not counting the pounds of them in each of our bodies…
* “The fact is that no species has ever had such wholesale control over everything on earth, living or dead, as we now have. That lays upon us, whether we like it or not, an awesome responsibility. In our hands now lies not only our own future, but that of all other living creatures with whom we share the earth.”
― David Attenborough, Life on Earth
As we watch our weight, we might send carefully-calculated birthday greetings to John Graunt; he was born on this date in 1620. A London haberdasher by trade, Graunt was fascinated the human tide that swelled around him– a fascination that led him to create the first statistically-based estimation of the population of London in his book Natural and Political Observations Made upon the Bills of Mortality, undertaken as Charles II and other officials were trying to create a system to warn of the onset and spread of bubonic plague in the city. Profiled as one of Aubrey’s Brief Lives, Graunt has been called the first statistician, the first demographer, and was in any case the first statistician to become a fellow of the Royal Society of London.
In news likely to unsettle “young earthers”– the plurality of Americans who believe that the earth, and life on it, were created by God all at once about 10,000 years ago– scientists have discovered 34,000-year-old organisms…
It’s a tale that has all the trappings of a cult 1960s sci-fi movie: Scientists bring back ancient salt crystals, dug up from deep below Death Valley for climate research. The sparkling crystals are carefully packed away until, years later, a young, unknown researcher takes a second look at the 34,000-year-old crystals and discovers, trapped inside, something strange. Something … alive.
Thankfully this story doesn’t end with the destruction of the human race, but with a satisfied scientist finishing his Ph.D.
“It was actually a very big surprise to me,” said Brian Schubert, who discovered ancient bacteria living within tiny, fluid-filled chambers inside the salt crystals.
Salt crystals grow very quickly, imprisoning whatever happens to be floating — or living — nearby inside tiny bubbles just a few microns across, akin to naturally made, miniature snow-globes.
“It’s permanently sealed inside the salt, like little time capsules,” said Tim Lowenstein, a professor in the geology department at Binghamton University and Schubert’s advisor at the time…
The key to the microbes’ millennia-long survival may be their fellow captives — algae, of a group called Dunaliella.
“The most exciting part to me was when we were able to identify the Dunaliella cells in there,” Schubert said, “because there were hints that could be a food source.”
With the discovery of a potential energy source trapped alongside the bacteria, it has begun to emerge that, like an outlandish Dr. Seuss invention (hello, Who-ville), these tiny chambers could house entire, microscopic ecosystems…
As we ponder the prospect of seasoning our popcorn, we might recall that it was on this date in 1809 that the first U.S. geology book of importance was read by William MacLure, a Scot who’d immigrated to the U.S. ten years earlier, before the American Philosophical Society at Philadelphia, Pa. Observations on the Geology of the United States, which was published in revised form in 1817 and contained the first chart of United States territory that divided the land into rock types, was the first true geological map of any part of North America and one of the world’s earliest geological maps. (MacLure’s reading predated William Smith’s first geological map of England by six years.)