Posts Tagged ‘biology’
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.
Animals have evolved a variety of defensive techniques– camouflage, tough skins, fierce looks. But as National Geographic explains, olfactory defenses are among the most effective. Consider the hoatzin…
Hold your nose and meet the hoatzin, a bird with a number of distinctions, not the least of which is that it smells like fresh cow manure. The animal mostly eats leaves, which it digests in its crop, a pouch some birds have high up in their alimentary canal. It’s the only bird known to digest by fermentation, like a cow. This process is what causes its odor and has earned it the nickname the “stink bird.”
Don’t knock it, though. That stink means that even people don’t want to eat the hoatzin…
More on feral fragrance at “5 Animals With Stinky Defenses.”
* Friedrich Nietzsche
As we hold our noses, we might spare a thought for Hannah Wilkinson Slater; she died on this date in 1812. The daughter and the wife of mill owners, Ms. Slater was the first woman to be issued a patent in the United States (1793)– for a process using spinning wheels to twist fine Surinam cotton yarn, that created a No. 20 two-ply thread that was an improvement on the linen thread previously in use for sewing cloth.
Researchers at the Weizmann Institute of Science have discovered “olfactory white,” the nasal equivalent of white noise, Live Science reports:
Almost any given smell in the real world comes from a mixture of compounds. Humans are good at telling these mixtures apart (it’s hard to mix up the smell of coffee with the smell of roses, for example), but we’re bad at picking individual components out of those mixtures…
Mixing multiple wavelegths that span the human visual range equally makes white light; mixing multiple frequencies that span the range of human hearing equally makes the whooshing hum of white noise. Neurobiologist Noam Sobel from the Weizmann Institute of Science in Israel and his colleagues wanted to find out whether a similar phenomenon happens with smelling…
Spoiler alert: it does. Find out how– and learn more about the most mysterious of our senses at Live Science. (And download the paper from the journal Proceedings of the National Academy of Sciences.)
As we reach for our hankies, we might recall that it was on this date in 1858 that Philadelphia tinsmith John Landis Mason received the patent for Mason Jars. With it’s threaded mouth, metal lid, rubber gasket ring– and the hermetic seal that they can form– the Mason Jar quickly became a staple for food preservation (usually, and ironically, called “canning”). While they are still used to that end, they have more lately flourished as collectables.
If you’re going to be responsible for determining scientific classification, you may as well have fun with it. From BuzzFeed, some of the strangest and most amusing binomial names (Genus species) in all of taxonomy…
Fifteen more humorous handles at “17 Awesome, Nerdy Examples Of Taxonomy Humor.”
As we wonder what’s in a name, we might spare a taxonomical thought for Sir D’Arcy Wentworth Thompson CB FRS FRSE; he died on this date in 1948. The Scottish biologist, mathematician, and classics scholar was the father of mathematical biologist. Starting from the simple premise that “everything is the way it is because it got that way,” Thompson wrote On Growth and Form (1917)– a profound meditation the shapes of living things that has been called by Nobel Laureate Peter Medawar “the finest work of literature in all the annals of science that have been recorded in the English tongue.”
Each year, on May 23 (the birthday of Carl Linnaeus), Arizona State University releases its annual list of the top 10 new species found in the last 12 months. As PopSci reports,
The father of classification would no doubt be pleased with some of the names on this list — they include a mushroom named for a cartoon character, a worm named for the Devil and a jellyfish named “Oh Boy,” because that’s what people should exclaim when they behold it. The list also includes a terrifyingly skull-looking sneezing monkey; a blue tarantula; a sausage-sized millipede; a night-blooming orchid; and much more…
The rest of the story, and photos of each winner, here.
As we delight in diversity, we might spare oa thought for Charles Atwood Kofoid; he died on this date in 1947. Kofoid, a founding staff member at the Scripps Institution of Oceanography, classified many new species of marine protozoans– and in the process, helped establish systematic marine biology.
Reproductive biologist David Bainbridge writes that with the onset of wrinkles, love handles, and failing eyesight we are used to dismissing our fifth and sixth decades as a negative chapter in our lives. However recent scientific findings show just how crucial middle age has been to the success of our species and that with the probable existence of lots of prehistoric middle-aged people, natural selection had plenty to work on. “We lead an energy-intensive, communication-driven, information-rich way of life, and it was the evolution of middle age that supported this,” writes Bainbridge, adding that middle age is a controlled and preprogrammed process, not of decline, but of development. “When we think of human development, we usually think of the growth of a fetus or the maturation of a child into an adult. Yet the tightly choreographed transition into middle age is a later but equally important stage in which we are each recast into yet another novel form” — resilient, healthy, energy-efficient and productive. “The middle aged may not have been able to outrun the prey, but they were really good at working out where it might be hiding and dividing up the spoils afterwards.” Although some critics say that middle age is a construct of the middle aged, Bainbridge asserts that one key role of middle age is the propagation of information. “All animals inherit a great deal of information in their genes; some also learn more as they grow up. Humans have taken this second form of information transfer to a new level. We are born knowing and being able to do almost nothing. Each of us depends on a continuous infusion of skills, knowledge and customs, collectively known as culture, if we are to survive. And the main route by which culture is transferred is by middle-aged people showing and telling their children — as well as the young adults with whom they hunt and gather — what to do.”
As we feel our self-esteem ascend, we might spare a thought for St. Zita of Lucca, whose feast day this is (as she died on this date in 1272). She is invoked against losing keys (or to find lost keys); she is also the patron saint of bakers, butlers, domestic servants, homemakers, housemaids, maids, people ridiculed for their piety, rape victims, servants, single laywomen, waiters, and waitresses.
Virus (source: Flickr/Razza Mathadsa)
The definition of life is as enormous a problem as the phenomenon of life itself. One could easily collect from the literature more than 100 different definitions, none satisfactory enough to be broadly accepted. What should the definition contain, to be suitable for all varieties of observable life? Humans, animals, plants, microorganisms. Do viruses also belong to life?
There are two tendencies in the attempts to define life. One is to formulate an all-inclusive definition, accommodating life’s attributes and manifestations from all levels of complexity. Another tendency is to reduce the attributes to only those which are common to all forms of life. But we do not know what would be the “simplissimus” from which everything, probably, started…
Spoiler alert! In “What is Life?” he presses down and further down the hierarchy of scale and process to suggest that “The border between life and nonlife may, actually, be placed anywhere within the realm of the abiotic processes.” (For those distant from their biology classes: “abiotic.”) Trifonov’s conclusion is fascinating– at once, inspiring and humbling:
… life never stopped emerging, starting some 4 billion years ago with replicating RNA, and continuing to this day within the genomes of every living organism.
As we revisit Walt Whitman, we might send germinating birthday greetings to botanist Charles Joseph Chamberlain; he was born on this date in 1863. Chamberlain was a specialist in the cycad genera (palmlike, cone-bearing plants). His work laid the foundation for understanding the life histories, distribution, ecology, and diversity of cycads (and other primitive seed plants), postulated a course of evolutionary development for the spermatophyte (seed plant) ovule and embryo, and led to speculation about a cycad origin for angiosperms (flowering plants).