wu :: forums
« wu :: forums - Theories of Life »

Welcome, Guest. Please Login or Register.
Jun 22nd, 2018, 2:43am

RIDDLES SITE WRITE MATH! Home Home Help Help Search Search Members Members Login Login Register Register
   wu :: forums
   general
   truth
(Moderators: towr, Eigenray, SMQ, ThudnBlunder, william wu, Grimbal, Icarus)
   Theories of Life
« Previous topic | Next topic »
Pages: 1  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print
   Author  Topic: Theories of Life  (Read 8001 times)
flamingdragon
Uberpuzzler
*****






    flamingdragon532
Email

Gender: male
Posts: 671
Theories of Life  
« on: Nov 28th, 2006, 8:16pm »
Quote Quote Modify Modify

I was searching around for some theories on how life started and some of them are pretty out there.  
Take a look at these real theories:
 
### 1
Revolutionary New Theory For Origins Of Life On Earth
 
A totally new and highly controversial theory on the origin of life on earth, is set to cause a storm in the science world and has implications for the existence of life on other planets. Research* by Professor William Martin of the University of Dusseldorf and Dr Michael Russell of the Scottish Environmental Research Centre in Glasgow, claims that living systems originated from inorganic incubators - small compartments in iron sulphide rocks. The new theory radically departs from existing perceptions of how life developed and it will be published in Philosophical Transactions B, a learned journal produced by the Royal Society. Professor Martin and Dr Russell have long had problems with the existing hypotheses of cell evolution and their theory turns traditional views upside down. They claim that cells came first. The first cells were not living cells but inorganic ones made of iron sulphide and were formed not at the earth's surface but in total darkness at the bottom of the oceans. Life, they say, is a chemical consequence of convection currents through the earth's crust and in principle, this could happen on any wet, rocky planet.
 
Dr Russell says: "As hydrothermal fluid - rich in compounds such as hydrogen, cyanide, sulphides and carbon monoxide - emerged from the earth's crust at the ocean floor, it reacted inside the tiny metal sulphide cavities. They provided the right microenvironment for chemical reactions to take place. That kept the building blocks of life concentrated at the site where they were formed rather than diffusing away into the ocean. The iron sulphide cells, we argue, is where life began."
 
One of the implications of Martin and Russell's theory is that life on our planet, even on other planets or some large moons in our own solar system, might be much more likely than previously assumed.
 
The research by Professor Martin and Dr Russell is backed up by another paper The redox protein construction kit: pre-last universal common+ ancestor evolution of energy-conserving enzymes by F. Baymann, E. Lebrun, M. Brugna, B. Schoepp-Cothenet, M.-T. Giudici-Orticoni & W. Nitschke which will be published in the same edition. *On the origins of cells: a hypothesis for the evolutionary transitions from abiotic geochemistry to chemoautotrophic prokaryotes, and from prokaryotes to nucleated cells by Professor William Martin, Institut fuer Botanik III, University of Dusseldorf and Dr Michael Russell, Scottish Environmental Research Centre, Glasgow.
IP Logged

"The fool doth think he is wise, yet the wise man knoweth himself to be a fool"

"He who commands the past, commands the future. He who commands the future, commands the past."
flamingdragon
Uberpuzzler
*****






    flamingdragon532
Email

Gender: male
Posts: 671
Re: Theories of Life  
« Reply #1 on: Nov 28th, 2006, 8:17pm »
Quote Quote Modify Modify

### 2
 
Did life begin in ice?
 
Aug. 9, 2005
Special to  World Science
 
New findings are backing up a theory that life originated in ice, researchers say. If it’s true, they add, it could boost the chances that life might turn up in places considerably colder than our planet.
Ice might have been an ideal environment for the first self-replicating molecules, some researchers argue. (Photo by Zee Evans/U.S. National Science Foundation)
 
The theory departs from mainstream thinking on the origins of life, which usually assumes a warm, or hot, and wet environment was necessary.
 
“Conditions associated with freezing, rather than ‘warm and wet’ conditions, could have been of key importance” for the chemical reactions that led to life, wrote four researchers in the July 21 advance online issue of the Journal of Molecular Evolution, a research publication.
 
The scientists, including Laura F. Landweber of Princeton University in Princeton, N.J., argue that ice might have been a favorable environment to generate the first self-replicating molecules, a precondition for life.
 
These molecules would be of a type called ribonucleic acids, or RNA—a chemical cousin of DNA, which makes up genes.
 
Many researchers believe the first self-replicating molecule was RNA, not DNA. This is because RNA can do various things in addition to carrying genetic information, which is all that DNA basically does.
 
Some of RNA’s activities seem to be similar to what would be required for self-replication, something that DNA can’t do, strictly speaking. DNA needs the help of other molecules to copy itself. Also, RNA still exists in living cells, where it has various functions—some so basic to life that many scientists think RNA must have been there from the beginning.
 
The theory that RNA started it all, a 20-year-old proposal called the “RNA world hypothesis,” holds that RNA was not only the first self-replicating molecule, but also that it initially carried out most of life’s functions, such as metabolism and cell formation.
 
Most biologists consider the RNA world hypothesis at least plausible, but it has some problems. It’s not easy to explain how the first self-replicating RNA molecules might have arisen.
 
RNA molecules tend to fall apart under warm conditions outside of cells. This would prevent the buildup of the rather long, complex RNA molecules that would probably be needed to conduct life processes, according to Landweber and her colleagues.
 
Various conditions can prevent RNA molecules’ breakdown, the researchers argue. These include various types of water solutions, and freezing. But freezing may have been the one that most likely occurred on the early Earth, they argued.
 
Freezing usually slows down chemical reactions, which is why cold places are generally considered hostile to life. But freezing actually speeds up some of RNA’s key activities, Landweber and colleagues argue.
 
This is because ice contains hard, tiny compartments that hold the molecules in one place, where they can react together. Some of these reactions result in the creation of bigger RNA molecules.
 
In liquid water, by contrast, the molecules don’t come close enough together often enough to react as much. Thus they tend to fall apart faster than they can react to create bigger products.
IP Logged

"The fool doth think he is wise, yet the wise man knoweth himself to be a fool"

"He who commands the past, commands the future. He who commands the future, commands the past."
flamingdragon
Uberpuzzler
*****






    flamingdragon532
Email

Gender: male
Posts: 671
Re: Theories of Life  
« Reply #2 on: Nov 28th, 2006, 8:18pm »
Quote Quote Modify Modify

### 2.5
 
In essence, the small compartments in ice play the role that cells today play in bringing the molecules together to react, Landweber and her colleagues argue. Dehydrated substances—a sort of primordial sludge, for instance—could also have provided a function similar to ice, they added, but ice works better.
 
Landweber’s group conducted an experiment to test the theory. Led by Alexander Vlassov of SomaGenics, a Santa Cruz, Calif.-based biotechnology company, the researchers broke to pieces some RNA molecules found in normal cells. This process yielded more, smaller, RNA molecules.
 
By doing this, the researchers produced RNA molecules of sizes that biologists think might have been available on early Earth. They then experimented to find out what sort of capabilities these smaller RNAs had.
 
Reporting their results in the May 25, 2004 issue of the journal Nucleic Acids Research, the researchers noted that the broken-up RNAs still could carry out some of the same functions as normal RNAs, but only in ice or sometimes other extreme conditions, such as dehydration.
 
These activities included grabbing other pieces of RNA and attaching them together, an activity called “ligation” that is similar to self-replication.
 
To fully self-replicate, a molecule must attach other molecules together in such a way as to match the sequence of chemical pieces that characterize the first molecule. This process is called “template-directed” ligation.
 
But the ligation alone—even without the self-replication—can build up ever larger and more complex RNA molecules, which according to the RNA world hypothesis could eventually develop self-replicating abilities.
 
The theory that an icy environment might have helped jump-start life isn’t new. Researchers proposed in 1994, for example, that repeated cycles of freezing and thawing could help accelerate some of the chemical reactions necessary for life.
 
Such a scenario might have existed on early Earth, where according to some researchers, repeated meteor and comet impacts might have periodically melted an otherwise icy environment.
 
However, Landweber and her team seem to be the first to have provided an account of how the “RNA world” might have fit into this scenario, according to Leslie Orgel, an origins-of-life researcher at the Salk Institute for Biological Studies in San Diego, Calif.
 
The work “has important implications,” said Jeffrey L. Bada, director of the NASA Specialized Center in Research and Training in Exobiology in La Jolla, Calif., one of the original proponents of the freeze-thaw cycle theory.
 
Although Landweber and her colleagues also wrote that freeze-thaw cycles are helpful for the processes they describe, such cycles aren’t strictly necessary in their proposal.
 
Moreover, they wrote in their Journal of Molecular Evolution paper, “It is worth noting that Jupiter’s moon Europa and even Mars are also thought to contain large amounts of liquid water and ice now or at some time in the past.”
 
The possibility of RNA activities in ice, they added, “lends some credibility to claims that the rather extreme environments of these extraterrestrial locations could have provided suitable conditions for the emergence of life.”
 
However, as Sergei Kazakov of Somagenics noted in an email, the origin of life and the RNA world aren’t necessarily the same thing.
 
“The RNA world as complex self-replicating molecular society could appear at multiple places in Universe, but not necessarily result in the appearance of life as we know it,” he explained. This transition may actually be rare, he added.
 
“I also think that Earth is a possible but not necessarily the best place where the RNA world could start. Rather, I would bet on Europa or a giant comet,” he continued. If the transition to life as we know it did occur, he added, “it could spread across many planets through cross-contamination,” carried by comets or meteorites.
 
* * *
 
Send us a comment on this story, or send it to a friend
 
Reference:
A.V. Vlassov, S.A. Kazakov, B.H. Johnston, L.F. Landweber, 2005. The RNA World on Ice: A New Scenario for the Emergence of RNA Information. J Mol Evol. Jul 21 [Epub ahead of print]
IP Logged

"The fool doth think he is wise, yet the wise man knoweth himself to be a fool"

"He who commands the past, commands the future. He who commands the future, commands the past."
goodRiddler
Newbie
*



What is what?

   


Posts: 49
Re: Theories of Life  
« Reply #3 on: Nov 19th, 2013, 8:46pm »
Quote Quote Modify Modify

I'm not really convinced by the first theory at all. They have actually recreated organic material in conditions that would have existed in a prehistoric world.
IP Logged
erica
Junior Member
**





   


Gender: female
Posts: 76
Re: Theories of Life  
« Reply #4 on: Jan 25th, 2014, 3:44am »
Quote Quote Modify Modify

For me the 2nd theory seems to be more convincing...
IP Logged

I am passionate about translation
jordan
Junior Member
**





   


Gender: male
Posts: 60
Re: Theories of Life  
« Reply #5 on: Feb 2nd, 2014, 1:53am »
Quote Quote Modify Modify

I am for the second theory because as I know life originated in water (ice - state of water)
IP Logged

Questions and answers administrator in ask questions online
wakiza33
Junior Member
**



industrial Engineer // Berkeley Alumnus

   
WWW

Posts: 54
Re: Theories of Life  
« Reply #6 on: Oct 28th, 2014, 9:09am »
Quote Quote Modify Modify

The second theory is very interesting. Thanks for posting.
IP Logged

Binder Jetting Engineer
Pages: 1  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print

« Previous topic | Next topic »

Powered by YaBB 1 Gold - SP 1.4!
Forum software copyright © 2000-2004 Yet another Bulletin Board