Tagged with “biology” (55)

  1. Carolyn Porco: Searching for Life in the Solar System - The Long Now

    Life nearby

    If we find, anywhere in the universe, one more instance of life besides what evolved on Earth, then we are bound to conclude that life is common throughout the vastness of this galaxy and the 200 billion other galaxies.

    The discovery would change how we think about everything.

    Most of the search for life beyond Earth, Porco explained, is the search for habitats.

    They don’t have to look comfy, since we know that our own extremophile organisms can survive temperatures up to 250°F, total desiccation, and fiercely high radiation, high pressure, high acidity, high alkalinity, and high salinity.

    In our own Solar System there are four promising candidate habitats—Mars, Europa (a moon of Jupiter), Titan (a moon of Saturn), and Enceladus (“en-SELL-ah-duss,” another moon of Saturn).

    They are the best nearby candidates because they have or have had liquids, they have bio-usable energy (solar or chemical), they have existed long enough to sustain evolution, and they are accessible for gathering samples.

    On Mars water once flowed copiously.

    It still makes frost and ice, but present conditions on Mars are so hostile to life that most of the search there now is focussed on finding signs of life far in the past.

    Europa, about the size of Earth’s Moon, has a salty ocean below an icy surface, but it is subject to intense radiation.

    Photos from the Hubble Space Telescope revealed that occasional plumes of material are ejected through Europa’s ice, so future missions to Jupiter will attempt to fly by and analyze them for possible chemical signatures of life.

    The two interesting moons of Saturn are Titan, somewhat larger and much denser than our Moon, and tiny Enceladus, one-seventh the diameter of our Moon.

    Both have been closely studied by the Cassini Mission since

    2004.

    Titan’s hazy atmosphere is full of organic methane, and its surface has features like dunes and liquid-methane lakes “that look like the coast of Maine.”

    But it is so cold, at 300°F below zero, that the chemical reactions needed for life may be too difficult.

    Enceladus looks the most promising.

    Cassini has sampled the plumes of material that keep geysering out of the south pole.

    The material apparently comes from an interior water ocean about as salty as our ocean, and silica particles may indicate hydrothermal vents like ours.

    “I hope you’re gettin excited now,” Porco told the audience, “because we were.”

    The hydrothermal vents in Earth’s oceans are rich with life.

    Enceladus has all the ingredients of a habitat for life—liquid water, organics, chemical energy, salts, and nitrogen-bearing compounds.

    We need to look closer.

    A future mission (arriving perhaps by the 2030’s) could orbit Enceladus and continually sample the plumes with instruments designed to detect signs of life such as complexity in the molecules and abundance patterns of carbon in amino acids that could indicate no biology, or Earth-like biology, or quite different biology.

    You could even look for intact organisms.

    Nearly all of the material in the plumes falls back to the surface.

    Suppose you had a lander there.

    “It’s always snowing at the south pole of Enceladus,” Porco said.

    “Could it be snowing microbes?”

    (A by-the-way from the Q&A:

    Voyager, which was launched 40 years ago in 1977, led the way to the outer planets and moons of our Solar System, and five years ago, Porco pointed out, “It went beyond the magnetic bubble of the Sun and redefined us as an interstellar species.”)

    —Stewart Brand

    http://longnow.org/seminars/02017/jul/24/searching-life-solar-system/

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  2. BBC Radio 4 - In Our Time, Darwin: In Our Time, Darwin: The Voyage of the Beagle

    How Darwin’s work during the Beagle expedition influenced his theories.

    http://www.bbc.co.uk/programmes/b00gbf2g

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  3. Donald Hoffman: Do we see reality as it is? | TED Talk | TED.com

    Cognitive scientist Donald Hoffman is trying to answer a big question: Do we experience the world as it really is … or as we need it to be? In this ever so slightly mind-blowing talk, he ponders how our minds construct reality for us.

    http://www.ted.com/talks/donald_hoffman_do_we_see_reality_as_it_is

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  4. A Brief History of Everyone Who Ever Lived | Jesse Mulligan, 1–4pm, 3:08 pm on 20 September 2016 | Radio New Zealand

    Each of us carries an epic poem in our cells. DNA tells the story of our murky origins, shaped by evolution, to our current obsession with tracing our ancestry.

    That nucleic acid has the genetic information needed to make all living things. But it’s not the whole story, not even close according to former geneticist, now host of the BBC’s Inside Science.

    Adam Rutherford says the human genome should not be read as instruction manuals, but as epic poems.

    His new book A Brief History of Everyone Who Ever Lived separates the myths about what DNA can and can’t tell us about ourselves, where we came from and where the human race is going.

    He uses a metaphor to help people get their head around what DNA is – that of sheet music and an orchestra.

    “More often than not people have referred to DNA as a blueprint or an instruction manual.

    “Sometimes that can be quite misleading because if something’s a blueprint it implies that all the plans are laid out and it has this association with biological determinism – what your genes are is what you will be.”

    And he says we now know that’s not true.

    “The sheet music for a piece of music is the same whether you buy it in 1906 or 2006 but the interpretation of that is down to the conductor and the orchestra and all of the annotations, the layering and the performance.

    “This feels like a better way of describing nature and nurture which results in the symphony which is us.”

    As to forking out hard earned money to find out your ancestry, through DNA profiling don’t bother, he says.

    “We now know about ancestry that we’re all incredibly inbred, the last common ancestor of all Europeans was only about four or five hundred years ago.

    "If you pay them to tell you your ancestors were vikings, it’s true, but only because everyone is. The truth is all of us have ancestors who were vikings and Jews and Indians."

    http://www.radionz.co.nz/national/programmes/afternoons/audio/201816861/a-brief-history-of-everyone-who-ever-lived

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  5. The Economist asks: How has DNA shaped the human race?

    Jason Palmer, editor of the Espresso daily-briefing app, is joined by geneticist and broadcaster Adam Rutherford to get to the bottom of the stories told by human DNA. They discuss the genetics of sprinters, the misguided nature v nurture debate and how promiscuous humans’ forebears were.

    ===
    Original video: https://soundcloud.com/theeconomist/the-economist-asks-how-has-dna-shaped-the-human-race
    Downloaded by http://huffduff-video.snarfed.org/ on Sat, 20 Aug 2016 09:36:21 GMT Available for 30 days after download

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  6. Sara Seager: Other Earths. Other Life. - The Long Now

    We are one tool away from learning which distant planets already have life on them and which might be welcoming to life.

    MIT Planetary Scientist Sara Seager is working on the tool. She is chair of the NASA team developing a “Starshade” that would allow a relatively rudimentary space telescope to observe Earth-size planets directly, which would yield atmospheric analysis, which would determine a planet’s life-worthiness.

    Despite 1,000-plus exoplanet discoveries by the Kepler spacecraft and the hundreds more expected from the Transiting Exoplanet Survey Satellite after 2017, neither instrument can make detailed observation of the atmosphere of small rocky planets, because each star’s brilliance overwhelms direct study of the rocky motes that might harbor life. A Starshade cures that.

    A former MacArthur Fellow, Seager is author of Exoplanet Atmospheres (02010) and an astrophysics professor at MIT. Her maxim: “For exoplanets, anything is possible under the laws of physics and chemistry.”

    http://longnow.org/seminars/02015/aug/10/other-earths-other-life/

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  7. BBC Radio 4 - The Life Scientific, EO Wilson

    E O Wilson has been described as the "world’s most evolved biologist" and even as "the heir to Darwin". He’s a passionate naturalist and an absolute world authority on ants. Over his long career he’s described 450 new species of ants.

    Known to many as the founding father of socio-biology, E O Wilson is a big hitter in the world of evolutionary theory. But, recently he’s criticised what’s popularly known as The Selfish Gene theory of evolution that he once worked so hard to promote (and that now underpins the mainstream view on evolution).

    A twice Pulitzer prize winning author of more than 20 books, he’s also an extremely active campaigner for the preservation of the planet’s bio-diversity: he says, "destroying rainforest for economic gain is like burning a Renaissance painting to cook a meal".

    E O Wilson talks to Jim al-Khalili about his life scientific.

    http://www.bbc.co.uk/programmes/b0639kzv

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  8. Big Picture Science: Long Live Longevity

    Here’s to a long life – which, on average, is longer today than it was a century ago. How much farther can we extend that ultimate finish line? Scientists are in hot pursuit of the secret to longer life.

    The latest in aging studies and why there’s a silver lining for the silver-haired set: older people are happier. Also, what longevity means if you’re a tree. Plus, why civilizations need to stick around if we’re to make contact with E.T.

    And, how our perception of time shifts as we age, and other tricks that clocks play on the mind.

    http://radio.seti.org/episodes/Long_Live_Longevity

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  9. Smashing Physics: how we discovered the Higgs boson - podcast | Science | theguardian.com

    This week Guardian science editor Ian Sample meets particle physicist Professor Jonathan Butterworth from University College London to talk about his new book Smashing Physics. It’s an insider’s account of one of the most momentous scientific breakthroughs of our times: the discovery of the Higgs boson announced in July 2012.

    Jon discusses what it’s like to work on the largest science experiment in history and why such ambitious – and costly – endeavours benefit us all.

    Next up, British Association media fellow Nishad Karim reports from the UCL Symposium on the Origins of Life. Be it life on Earth or life elsewhere in the universe, this symposium covered it all with a range of experts from cosmology and biology to meteorology, discussing some very big questions. Where did we come from? Did life begin on Earth or elsewhere? Are we alone?

    Nishad spoke to several of the presenters including Dr Zita Matins, an astrobiologist from Imperial College London, and Dr Dominic Papineau, a geochemist from UCL. Dr Martins is a specialist in finding organic material essential for life in meteorites, and Dr Papineau looks for old organic life a little closer to home, analysing Earth rocks.

    Other speakers included Dr Francisco Diego, a UCL cosmologist, who discussed the life of the universe itself from beginning to now, 13.8bn years later.

    And finally, Ian asks Guardian environment writer Karl Mathiesen whether 2014 will be the hottest year on record.

    http://www.theguardian.com/science/audio/2014/jul/28/smashing-physics-higgs-boson-jon-butterworth-podcast

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  10. Craig Venter: Life at the Speed of Light : NPR

    In his new book Life at the Speed of Light: From the Double Helix to the Dawn of Digital Life, Craig Venter writes of the brave new world synthetic biology may some day deliver: from consumer devices that print out the latest flu vaccine to instruments on Mars landers that analyze Martian DNA and teleport it back to Earth to be studied or recreated.

    http://www.npr.org/2013/10/25/240751591/craig-venter-life-at-the-speed-of-light

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