Showing posts sorted by relevance for query astrobiology. Sort by date Show all posts
Showing posts sorted by relevance for query astrobiology. Sort by date Show all posts

Sunday, June 05, 2016

NASA, Jesus, and Templeton...,


HuffPo |  More of NASA’s astrobiology strategy for the next decade can be found in its latest roadmap: Astrobiology Strategy 2015. Lindsay Hays of California Institute of Technology’s Jet Propulsion Laboratory is editor-in-chief. 

Microbes are given some attention in a section titled: “How Does Our Ignorance About Microbial Life on Earth Hinder Our Understanding of the Limits to Life?” Curiously, however, there’s not a word in the entire 256-page document (including the glossary) about the existence of viruses — the biggest part of the biosphere — let alone their consortial and persistent nature, when the new thinking in science is “virus first“ and that persistence may be just as crucial to life as replication.
Templeton last year also awarded $5.4 M for origin of life investigations to the Foundation for Applied Molecular Evolution, with funds being administered by FAME synthetic biologist Steve Benner (who once quipped, “If you don’t have a theory of life, you can’t find aliens — unless they shoot you in the leg with a ray gun.”) AND $5.6M to ELSI — the Japanese government’s earth science institute in Tokyo - for its ELSI Origins Network, headed by astrophysicist Piet Hut also of the Institute for Advanced Study in Princeton.
Steve Benner is listed as a reviewer on NASA’s latest roadmap and is on the editorial board of Astrobiology Journal whose senior editors include NAI’s new chief Penny Boston as well as ISSOL (International Society for the Study of Origin of Life) president Dave Deamer.

Astrobiology Journal is put together in the Kennewick, Washington home of Sherry Cady, a geologist who serves as editor in chief, and her husband Lawrence P. Cady, a fiction writer who serves as the journal’s managing editor and copy editor — according to LP Cady. The magazine is one of 80 of Mary Ann Liebert Inc.’s “authoritative” journals and has close ties to other NASA-funded scientists who serve as reviewers.
If anything substantive is likely to happen as a result of (or in spite of) Templeton funding on origin of life, I would expect it to come from Steve Benner’s project, which includes people like George E. Fox who collaborated early on with Carl Woese on Archaea, and Harry Lonsdale origin of life research funds recipient, Niles Lehman — plus Benner himself and eight others.
On the other hand, I have serious reservations about the NASA award of $1.1M of public funds to CTI. What ever happened to the separation of church and state?

Friday, December 03, 2010

the shadow biosphere


Video - Felisa Simon Wolf discusses her work at Mono Lake.

WaPo | the discovery opens the door to that possibility and to the related existence of a theorized "shadow biosphere" on Earth - life evolved from a different common ancestor from all we've known so far.

"Our findings are a reminder that life-as-we-know-it could be much more flexible than we generally assume or can imagine," said Felisa Wolfe-Simon, 33, the biochemist who led the effort.

Prompted by debate about the possible existence of a shadow biosphere, Wolfe-Simon set out specifically to see whether microbes that lived in California's briny, arsenic-filled Mono Lake naturally used arsenic instead of phosphorus for basic cellular functions, or were able to replace the phosphorus with arsenic.

She took mud from the lake into the lab and began growing bacteria in Petri dishes. She fed them sugars and vitamins but replaced phosphate salt with arsenic until the surviving bacteria could grow without needing the phosphates at all.

Her research found that some of the bacteria had arsenic embedded into their DNA, RNA and other basic underpinnings.

"If something here on Earth can do something so unexpected - that breaks the unity of biochemistry - what else can life do that we haven't seen yet?" said Wolfe-Simon, a NASA Astrobiology Research Fellow and member of the National Astrobiology Institute team at Arizona State University.

"This is different from anything we've seen before," said Mary Voytek, senior scientist for NASA's program in astrobiology, the arm of the agency involved specifically in the search for life beyond Earth and for how life began here.

"These bugs haven't just replaced one useful element with another; they have the arsenic in the basic building blocks of their makeup," she said. "We don't know if the arsenic replaced phosphorus or if it was there from the very beginning - in which case it would strongly suggest the existence of a shadow biosphere."

Theoretical physicist and cosmologist Paul Davies, director of the Beyond Center at Arizona State and a prolific writer, is a co-author on the new Science paper. He had been thinking about the idea of a shadow biosphere for a decade and had written a paper on it in 2005. Two years later University of Colorado at Boulder philosopher and astrobiologist Carol Cleland also published on the subject. Both asked why nobody was looking for life with different origins on Earth, and Cleland coined the phrase "shadow biosphere."

At a Beyond Center conference four years ago, Wolfe-Simon, then in her late 20s, proposed a way to search for a possible shadow biosphere, and it involved Mono Lake and its arsenic.

"We were kicking vague ideas around, but she had a very specific proposal and then went out and executed it," Davies said. "It defies logic to think she found the only example of this kind of unusual life. Quite clearly, this is the tip of a huge iceberg."

Sunday, March 07, 2010

microbial planet



Astrobiology | AM: This year marks the twentieth anniversary of the publication of Microcosmos, which you co-authored with your son Dorion Sagan. You expressed some ideas that at the time were considered pretty maverick. How much controversy did the book generate?

Lynn Margulis: Well it depends on which aspects. The idea that the Precambrian, that is from 4600 million years ago to 541 million years ago, 7/8ths of the entire fossil record, was empty, that nothing happened for all that time, that the fossils were so scarce that you couldn't trace lineages - that idea prevailed such that Stephen Jay Gould said it relatively recently before he died. It was overturned almost exclusively by the science supported by this guy Dick Young. He started as an embryologist, and he started funding non-human NASA biology.

Young had a great deal of insight. He funded people like Elso Barghorn, the professor at Harvard who in 1954 published a paper describing two billion year old plants from the Gunflint chert. They weren't plants, of course, they were bacteria, but at the time the world was divided into plants and animals and there wasn't any choice. Young funded the whole activity that started as exobiology - today it's more astrobiology than exobiology - that completely turned around that idea. And I was privileged to be involved with those people as these data were coming in on the evidence for early life.

Our book is very microbe-centric. The world is very anthropocentric. What we did was sort of turn it around, put the people on the bottom and the microbes on the top as far as their importance in running the ecological system of the Earth. We said people are totally late, typical animals, and are really very unimportant in the workings of the system, whereas the microbes are much earlier, they do all the major gas transformations, they created all the major things we think are important, like sex. Today we might say that this turnaround - people down and microbes up in a world that has always had people up and microbes down -is a strategic perceptual shift. As humans, you can't escape your human perspective. We have a more nuanced view than we had in Microcosmos. On the other hand, at the time it was absolutely necessary to make that shift toward microbial perception because of the skewed anthropocentrism that was driving everything.

we are all microbes

Astrobiology | AM: In Microcosmos, you detailed four specific microorganisms that you thought were involved, through symbiogenesis, in the creation of various eukaryotic cells, the type of cells that animals and plants are made of. At the time, those ideas were not well accepted. Has that changed?

Lynn Margulis: Well, we've won three out of four.

Nobody today doubts that chloroplasts began as cyanobacteria. Chloroplasts are the little green dots in the cells of plants and algae, in which all photosynthesis occurs. Photosynthesis, the conversion of sunlight as energy to food and cell material, is fundamentally a bacterial virtuosity. It began in a specific group of oxygen-producing photosynthetic bacteria that, by definition, are cyanobacteria. If they're green, they're photosynthetic. They make food only in the sunlight, because they require sunlight for their source of energy. They take carbon dioxide out of the atmosphere, and fix it, that is, chemically change it to food and body, and they produce oxygen as waste. That series of changes is done by cyanobacteria exclusively. They're the only organisms that can make the oxygen and make the food that everything else needs.

Well, you say, can't plants do that? And the answer is yes, but plants are something that hold up cyanobacteria. That's all plants are. It's the cyanobacteria in the plants that do that transformation. You say, well, can't algae in the water, green water scum, can't they do it? And the answer is, yes, but the algae are something that brings the little green things inside the scum to the light. So the answer is: nothing but cyanobacteria can make our food and produce our oxygen.

We like to call them the greater bacteria, or the greatest bacteria, because they are. And they're in only three forms: they're in cyanobacteria (what used to be called blue-green algae) all by themselves; or they're in algae; or they're in plants. But fundamentally, if you cut them out of the plant cell, and throw away the rest of the plant cell, the little green dot is the only thing that can do that oxygen production. That is the greatest achievement of life on Earth, and it occurred extremely early in the history of life. Who knows whether it's 3 billion years ago, or 2.7 billion, or 3.5 billion, but it's that kind of time. And the idea that those little organelles, those little bodies inside of cells, started as free-living cyanobacteria is completely accepted by everybody who even thinks about these problems.

So that's one out of four.

bacterial intelligence

Astrobiology | AM: Can you explain how you view bacteria as being intelligent?

LM: If you look up consciousness in the dictionary, it says, "awareness of the world around you," and that's because you lose it somehow when you become unconscious, right? Well, you can show that microorganisms, or bacteria, are certainly conscious. They will orient themselves, they will work together to make structures. They'll do a lot of things. This ability to respond specifically to the environment and to act creatively, in the sense that that precise action has never been taken before, is a property of life. Of course, it has to be moving life, or you can't tell. You can't tell if a plant is thinking, but in organisms that move, you can tell their intelligence.

For example, take Foraminifera - they're single-celled sea creatures, protoctists. The Egyptian pyramids are built of their shells. A colleague of mine put one of these forams in a dish with a small crustacean animal, like a water flea. He was going to watch the crustacean eat the foram. The foram's a single cell, and smaller, right? And he saw the foram kill, trap, and completely destroy and eat the animal. He's got beautiful movies of it. So that group of organisms not only can eat animals, but they can make hunting towers, and they can hunt from the top of the towers.

There's a group of them, called agglutinating forams, these have offspring that look exactly like the parent, with multi colors. But every generation they construct their coloration from pebbles. This single-celled blob - it would look to you like a blob of snot, probably - can pick up pebbles of the different colors. You have to have some red ones and some white ones and some black ones in order to get an offspring that looks like a parent. They will make appropriate choices such that when you see the offspring next to the parent, it looks like they just came about by dividing in half. You can't believe that the newer one, the offspring one, was naked, and then it spent a lot of time plastering and remolding and rearranging pebbles on the surface of itself, so that it now looks indistinguishable from its parent. Those kinds of activities are rampant.

Are humans the master of tools? No, enter the chimp. Are humans the master of language? Ask the dolphin...or a dog. Rico, a dog with an approximately 200-word "vocabulary," can learn the names of unfamiliar toys after just one exposure to the new word-toy combination.

People think that if you can't talk, you can't be intelligent. But you know that's not true if you have a dog. You can communicate with them without talking. If you define intelligence as speaking American English, well maybe they're not. But if you define it in the much more broad sense of behaviors that are modified on the individual level, that involve choice and change and response to the environment, there's every bit of evidence that intelligence is a property of life from the very beginning. It's been modified, of course, and changed and amplified, even, but it's an intrinsic property of cells.

Monday, January 19, 2015

policy-makers know that climate disaster is inevitable


NYTimes |  OUR galaxy, the Milky Way, is home to almost 300 billion stars, and over the last decade, astronomers have made a startling discovery — almost all those stars have planets. The fact that nearly every pinprick of light you see in the night sky hosts a family of worlds raises a powerful but simple question: “Where is everybody?” Hundreds of billions of planets translate into a lot of chances for evolving intelligent, technologically sophisticated species. So why don’t we see evidence for E.T.s everywhere?

The physicist Enrico Fermi first formulated this question, now called the Fermi paradox, in 1950. But in the intervening decades, humanity has recognized that our own climb up the ladder of technological sophistication comes with a heavy price. From climate change to resource depletion, our evolution into a globe-spanning industrial culture is forcing us through the narrow bottleneck of a sustainability crisis. In the wake of this realization, new and sobering answers to Fermi’s question now seem possible.

Maybe we’re not the only ones to hit a sustainability bottleneck. Maybe not everyone — maybe no one — makes it to the other side.

Since Fermi’s day, scientists have gained a new perspective on life in its planetary context. From the vantage point of this relatively new field, astrobiology, our current sustainability crisis may be neither politically contingent nor unique, but a natural consequence of laws governing how planets and life of any kind, anywhere, must interact.

The defining feature of a technological civilization is the capacity to intensively “harvest” energy. But the basic physics of energy, heat and work known as thermodynamics tell us that waste, or what we physicists call entropy, must be generated and dumped back into the environment in the process. Human civilization currently harvests around 100 billion megawatt hours of energy each year and dumps 36 billion tons of carbon dioxide into the planetary system, which is why the atmosphere is holding more heat and the oceans are acidifying. As hard as it is for some to believe, we humans are now steering the planet, however poorly.

Can we generalize this kind of planetary hijacking to other worlds? The long history of Earth provides a clue. The oxygen you are breathing right now was not part of our original atmosphere. It was the so-called Great Oxidation Event, two billion years after the formation of the planet, that drove Earth’s atmospheric content of oxygen up by a factor of 10,000. What cosmic force could so drastically change an entire planet’s atmosphere? Nothing more than the respiratory excretions of anaerobic bacteria then dominating our world. The one gas we most need to survive originated as deadly pollution to our planet’s then-leading species: a simple bacterium.

The Great Oxidation Event alone shows that when life (intelligent or otherwise) becomes highly successful, it can dramatically change its host planet. And what is true here is likely to be true on other planets as well.
But can we predict how an alien industrial civilization might alter its world? From a half-century of exploring our own solar system we’ve learned a lot about planets and how they work. We know that Mars was once a habitable world with water rushing across its surface. And Venus, a planet that might have been much like Earth, was instead transformed by a runaway greenhouse effect into a hellish world of 800-degree days.

By studying these nearby planets, we’ve discovered general rules for both climate and climate change. These rules, based in physics and chemistry, must apply to any species, anywhere, taking up energy-harvesting and civilization-building in a big way. For example, any species climbing up the technological ladder by harvesting energy through combustion must alter the chemical makeup of its atmosphere to some degree. Combustion always produces chemical byproducts, and those byproducts can’t just disappear. As astronomers at Penn State recently discovered, if planetary conditions are right (like the size of a planet’s orbit), even relatively small changes in atmospheric chemistry can have significant climate effects. That means that for some civilization-building species, the sustainability crises can hit earlier rather than later.

Sunday, March 07, 2010

bacteria don't have species

Astrobiology | AM: You have argued that bacteria don't have species. I wonder if you could explain that idea.

Lynn Margulis: Bacteria are much more of a continuum. They drop their genes all the time. Like we say in What is Life?, it's like going swimming in a swimming pool, going in blue-eyed and coming out brown-eyed, just because you've gulped the water. Obviously, animals don't do that. But that's what bacteria do, all the time. They just pick up genes, they throw away genes, and they are very flexible about that.

Say you have a bacterium like Azotobacter. This is a nitrogen-fixing bacterium. It takes nitrogen out of the air and puts it into useable food. Nitrogen fixing is a big deal. It takes a lot of genes. If you put a little something like arsenium bromide in a test tube with these organisms, and put it in a refrigerator overnight, lo and behold, the next day the cells can't do this anymore, they can't fix nitrogen. So by definition you have to change them from one genus to another.

I'll give you another example: E. coli. It's a normal inhabitant of the human gut. If you put a particular plasmid into E. coli, all of a sudden you have Klebsiella and not E. coli. You've changed not only the species, but the genus. It's like changing a person to a chimpanzee. Can you imagine doing that, putting a chimpanzee in the refrigerator, and getting him out the next morning, and now he's a person?

Sorin Sonea, who was the chair of the microbiology department at the Université de Montreal, in Canada, has been saying for 25 or 30 years that you either have to consider all the bacteria on Earth as one species, or you have to consider them as no species at all. The criteria we use for species, which are good ones for animals and plants and fungi, do not apply, because bacteria can change overnight. You have all sorts of gradations, where adding or removing a few genes will change an organism's name, because those genes are what define the organism.