Posts tagged life
Articles and news from the latest research reports.
Scientists Offer New Way To Look At The Origins Of Life
People have been trying to understand the origins of life on Earth through scientific means since the concept of science began and a pair of Arizona State University researchers suggests in a new report that we’ve been approaching the question incorrectly, almost from the beginning.
In a paper titled, “The algorithmic origins of life,” Paul Davies and Sara Walker proposed that understanding the correct chemical makeup for the origin of life only tells part of the story and scientists should also be focused on how chemical information is organized into life-creating processes.
They equate the shift in perspective to understanding how a computer works. To function, a computer not only needs hardware, akin to life’s chemical makeup, it also needs software, or chemical information.
“When we describe biological processes we typically use informational narratives – cells send out signals, developmental programs are run, coded instructions are read, genomic data are transmitted between generations and so forth,” Walker said. “So identifying life’s origin in the way information is processed and managed can open up new avenues for research.”
“We propose that the transition from non-life to life is unique and definable,” added Davies. “We suggest that life may be characterized by its distinctive and active use of information, thus providing a roadmap to identify rigorous criteria for the emergence of life. This is in sharp contrast to a century of thought in which the transition to life has been cast as a problem of chemistry, with the goal of identifying a plausible reaction pathway from chemical mixtures to a living entity.”
Walker and Davies argue that their approach skirts many issues that have confounded previous efforts to define the origin of life.
Death: A special report on the inevitable
The only certain thing in life is that it will one day end. That knowledge is perhaps the defining feature of the human condition. And, as far as we know, we alone are capable of contemplating the prospect of our demise. In these articles we explore the implications: the shifting definition of death, how knowing that we will die gave birth to civilisation, the grim reality of decomposition and whether it makes sense to fear death. But first, when did we become aware of our own mortality?
Is the afterlife full of fluffy clouds and angels?
What does the neuroscientist Colin Blakemore make of an American neurosurgeon’s account of the afterlife?
Have you ever noticed that more people come back from Heaven than from Hell? We have all read those astonishing reports of near-death experiences (NDEs, as the aficionados call them) – the things that people say have happened to them when they almost, but don’t quite, shuffle off the coil.
They are nearly always pleasant and deeply reassuring in a saccharin-soaked way. Lots of spinning down warm, dark tunnels to the sound of celestial music; lots of trips along country lanes lined with hedges, towards the light of a welcoming cottage at the end of the road; lots of tumbling down Alice-in-Wonderland rabbit holes, but without the damaging effects of gravity.
True, Dr Maurice S Rawlings Jr, MD, heart surgeon in Chattanooga, Tennessee, and author of To Hell and Back, did have patients who reported very nasty NDEs after they came back on his operating table. Booming noises; licking flames and all that Mephistophelian stuff. But perhaps that tells us more about the challenges of living in Chattanooga, Tennessee, than about the metaphysics of life after death.
Predictably, the amazingly consistent, remarkably heaven-like experiences recounted by the majority of NDE-ers (yes, that really is what the experts call them) have been summarily dismissed by materialist sceptics – like me. Of course the brain does funny things when it’s running out of oxygen. The odd perceptions are just the consequences of confused activity in the temporal lobes.
But NDEs have taken on a new cloak of respectability with a book by a Harvard doctor. Proof of Heaven, by Eben Alexander, will make your toes wiggle or curl, depending on your prejudices. What’s special about his account of being dead is that he’s a neurosurgeon. At least that’s what the publicity is telling us. It’s a cover story in Newsweek magazine, with a screaming headline: “Heaven is Real: a doctor’s account of the afterlife”.
DNA could have existed long before life itself
24 August 2012 by Michael Marshall
THE latest twist in the origin-of-life tale is double helical. Chemists are close to demonstrating that the building blocks of DNA can form spontaneously from chemicals thought to be present on the primordial Earth. If they succeed, their work would suggest that DNA could have predated the birth of life.
Lurking at the dawn of time (Image: Snorri Gunnarsson/Flickr/Getty)
DNA is essential to almost all life on Earth, yet most biologists think that life began with RNA. Just like DNA, it stores genetic information. What’s more, RNA can fold into complex shapes that can clamp onto other molecules and speed up chemical reactions, just like a protein, and it is structurally simpler than DNA, so might be easier to make.
After decades of trying, in 2009 researchers finally managed to generate RNA using chemicals that probably existed on the early Earth. Matthew Powner, now at University College London, and his colleagues synthesised two of the four nucleotides that make up RNA. Their achievement suggested that RNA may have formed spontaneously - powerful support for the idea that life began in an “RNA world”.
Artificial Beginnings: Understanding the Origin of Life by Recreating It
The Origin of Life on Earth was certainly, in retrospect, and from the human vantage point, the most fateful event in the history of the Universe. On a young, tepid Earth chemistry sprung into biology and set course on a four billion year journey that would eventually lead to us. However, all traces of the first, primitive organisms have vanished. They were outcompeted and devoured by their evolutionary descendents, leaving nothing to form fossils. Though we will never be able to set eyes on the first Earthlings, the first pioneers, we can understand what they must have been like through more subtle, indirect approaches. Comparative biochemistry across the whole of life takes us back quite a ways, though not to the first cells. The most recent common ancestor shared by all living organisms—bacteria, plants, animals, fungi, archaea, and unicellular eukaryotes like amoebae—was born long after the first cell ceased to exist. The only way we can truly understand what life must have been like in its earliest days is to create it ourselves.