Naked Science Forum
General Science => Question of the Week => Topic started by: thedoc on 12/06/2012 17:33:37
-
Hi Chris and other scientists. I listen to your podcast weekly. Love them.
Has there been any progress in creating a living organism from basic elements (CHONPS) and some heat? Seems like with so many advances in human biology, science should be able to produce a simple organism in the lab.
Bob Archibald
Berkeley Ca
Asked by Bob Archibald
Find out more on our podcast page (http://www.thenakedscientists.com/HTML/podcasts/show/2435/)
-
We answered this question on the show...
Hannah - We put this to Professor Lee Cronin from Glasgow University:
Lee - This is a really important question because it allow us to define life beyond the current toolbox that is used in biology on planet Earth. But to answer this question, we need to side step the definition of life and instead ask a different question which is, what is the minimal unit of matter on planet Earth that can exhibit and undergo Darwinian evolution in an autonomous fashion? [img float=right]/forum/copies/RTEmagicC_Destillasjon_av_tre_01.jpg.jpg[/img]And the result is both obvious and startling. It’s a very simple cell – bacterial cell, amoeba and so on. So what we’ve tried to do in my lab is to engineer all inorganic cells to see if we can put these features together. So by using molybdenum or tungsten oxides, we’ve been able to make very large clusters containing many hundreds of units. But not only that. We can have different building blocks templating the clusters. So we almost have an analogy to DNA, RNA and proteins in the clusters built in. So the question now is, can we get this system to boot up to replicate and evolve? And for that, you need to watch the space.
Hannah - So, our version of life uses DNA and protein building blocks. But you can create a different type of building block by making clusters of basic metallic elements that can form structures similar to membranes and enzymes. But, getting these clusters to replicate, mutate, and evolve by themselves has not yet happened. So, we’re not quite there yet.
-
Didn't somebody try doing this years ago with a flask of elements and passing a spark through them? Obtained some organic compounds but not life as I recall. Obviously missing the 'key' ingredient.
-
There are many theories about Abiogenesis, and whether it is a relatively common event, or a relatively rare event.
Current theories indicate that life first was found on Earth within a few hundred million years of the planet first being able to support life. Based on that, some researchers have concluded that life forms quite readily, and for example, Frank Drake (http://en.wikipedia.org/wiki/Drake_equation) theorized that 100% of planets capable of supporting life actually develop life.
Yet, on Earth, all currently living life appears to be highly related. That could indicate that there has been only one Abiogenesis event on Earth despite it being an "ideal" environment for life to evolve. However, once life had evolved, there could be other explanations for the highly interrelated nature of life. Once life had evolved, then the basic set of amino acids, DNA nucleotides. and other biologic compounds became a dominant form of complex carbon compounds, and thus any co-evolving life would use the same building blocks. Bacteria can absorb and swap DNA, and competing forms of life might have convergently evolved, absorbing useful genes from other species.
Many phages and viruses likely evolved independently, but based on proteins, DNA, and RNA formed earlier in biologic organisms.
Nonetheless, the first Abiogenesis event likely took millions, or hundreds of millions of years to occur, and additional millions of years until the life form actually stabilized.
So, forming de-novo life in a petri dish would be difficult in the order of a human lifespan.
There are several things that would support the spontaneous formation of life.
A soap or detergent is a special form of carbon chain with a polar head. These readily form micelles (http://en.wikipedia.org/wiki/Micelle) when mixed with water, or in some senses, a rudimentary form of a cellular membrane with the ability to contain whatever is inside.
As Guthers mentioned, the Miller-Urey experiment (http://en.wikipedia.org/wiki/Miller-Urey_experiment) demonstrated that it is possible to create amino acids, the basic building blocks of proteins, out of water (H2O), methane (CH4), ammonia (NH3), and hydrogen (H2), electricity, and heat.
Several researchers have also found amino acids present in meteorites, presumably formed independently of biological processes, and indicative that amino acids would be present on a primitive earth prior to the evolution of life.
Sidney Fox demonstrated that amino acids will spontaneously form proteinoid polymers (http://en.wikipedia.org/wiki/Sidney_W._Fox#The_creation_of_proteinoids) when heated. Yet, the Fox proteinoids are far short of the very specific complex structures that form proteins in living organisms. Yet, it is possible that a few useful proteins would spontaneously form.
Anyway, many of the individual components of life can spontaneously form. Can they all be found together? Perhaps there a slow build-up of useful proteins.
The process likely took thousands or millions of years, to occur... somewhere on the entire planet.
It is unlikely to find life spontaneously arising in a petri dish.
-
An interesting YouTube video about Abiogenesis.
If only it had voice rather than music. But, good graphics.
-
Probably the closest we have come is Craig Venter's effort in 2010, where they read the DNA of an already-living bacteria, and then used a DNA synthesis machine to generate the same DNA sequence (with a signature in it), and insert this into a closely-related, already-living bacterium. This bacteria survived the DNA transplant, and the "daughter"cells carried the signature in the DNA.
http://www.nytimes.com/2010/05/21/science/21cell.html
DNA has a very regular structure, which makes it relatively easy to generate.
However, a cell is made up of thousands of different proteins, in the right proportions, all intricately folded and actively interacting with each other. Trying to assemble this into a working whole from a protein synthesiser is far beyond our current technology. [Sometimes pharmaceutical companies would be happy to get just one properly folded protein - this is closer to our current capabilities!]
Even with Craig Venter's achievement, the DNA had to be inserted into a closely-related bacterium, as the DNA is very dependent on the set of proteins that are present in the cell, and the signals used to control them (and the proteins in the cell are similarly interdependent on the signals from the DNA).
Conclusion: Although this was hailed in the more sensationalist media as "creating life in the laboratory", there is still a very long way to go!
-
If the question is to intentionally create "life"... rather than just wait around for it to happen.
Perhaps we are not too far from being able to create a self-replicating computer.
"Life" doesn't have to be organic.
-
So, why not shot and heat it at proper temperatures to just mix them randomly with the aspect of gravity and even high impacts to simulate the environment of earth when it formed ?
Take lots of basic and purified elements and shove them in a big ball, make it so strong it can't be busted open without human tools, throw that thing at the planet from space so it simulates impacts, and also make it electrified and very hot in random places, then take the time to sift through all the materials, maybe there will be something to discover.