The Bubble Model

The Bubble Model

The bubble model presents a theory for how cells may have formed from the collection of large molecules in the early stages of life. The bubble model states that gases escaping from hydrothermal vents, fissures at the ocean floor where gases escape from beneath the surface of the Earth, become trapped inside protective bubbles. These gases interact within the enclosed environment to form larger, organic molecules. The bubbles pop at the ocean’s surface, releasing their molecular contents into the atmosphere, where they then react with other such molecules. Fueled by lightning and UV radiation, these molecules may have formed more complex organic compounds. Finally, these molecules, regardless of whether they became more complex or not, fall back into the ocean, potentially to be encased in bubbles again, starting the whole process over.

As the complexity of the bubbles increased, their ability to incorporate more molecules and energy also increased, extending the span of existence for the most complex bubbles. Furthermore, some bubbles may have been able to multiply themselves by cleaving in two in a process similar to cellular reproduction, in which a parent cell produces an identical offspring cell. Although bubbles in this state would not have been considered living, current theory suggests that if molecules with the ability to store and pass on genetic material existed in these bubbles, life may have formed from them.

Although much remains unknown about these early origins, one of the appeals of the bubble method is the protective barrier the bubble provides. A protective boundary the separates the inside of an organism from its environment is one characteristic of all living things. Bubbles may have provided the early membrane for potentially fragile early life forms, until a true cell membrane evolved.

http://www.sparknotes.com/101/index.php/biology/the_origin_of_life/the_early_earth.html

Exra Terrestrial Sources

Panspermia
In the early twentieth century, a Swedish chemist named Svente Arrhenius developed a theory called panspermia. Arrhenius' theory accounted for life's origins by simply stating that life did not originate on the Earth, but originated elsewhere in the universe. He believed that cellular life reached the Earth hiding inside a meteor which hit the Earth long ago. Newly uncovered evidence suggests that this might be possible, since an organism inside a meteor (Picture of impactor) would be safe from the high levels of radiation in space, and would be kept at a relatively low temperature. The odds of an organism surving inside a meteor for thousands of years, however, are not high. It is even less likely that organisms would be able to withstand the high energy impacts of bolides into the Earth or other planetary objects. However, it is considered possible, at least for now, and so is still a candidate for life's origin on earth.

Did Life Begin In Space? New Evidence From Comets

ScienceDaily (Aug. 14, 2007) — Recent probes inside comets show it is overwhelmingly likely that life began in space, according to a new paper by Cardiff University scientists.

Professor Chandra Wickramasinghe and colleagues at the University's Centre for Astrobiology have long argued the case for panspermia - the theory that life began inside comets and then spread to habitable planets across the galaxy. A recent BBC Horizon documentary traced the development of the theory.

Now the team claims that findings from space probes sent to investigate passing comets reveal how the first organisms could have formed.

The 2005 Deep Impact mission to Comet Tempel 1 discovered a mixture of organic and clay particles inside the comet. One theory for the origins of life proposes that clay particles acted as a catalyst, converting simple organic molecules into more complex structures. The 2004 Stardust Mission to Comet Wild 2 found a range of complex hydrocarbon molecules - potential building blocks for life.

The Cardiff team suggests that radioactive elements can keep water in liquid form in comet interiors for millions of years, making them potentially ideal "incubators" for early life. They also point out that the billions of comets in our solar system and across the galaxy contain far more clay than the early Earth did. The researchers calculate the odds of life starting on Earth rather than inside a comet at one trillion trillion (10 to the power of 24) to one against.

Professor Wickramasinghe said: "The findings of the comet missions, which surprised many, strengthen the argument for panspermia. We now have a mechanism for how it could have happened. All the necessary elements - clay, organic molecules and water - are there. The longer time scale and the greater mass of comets make it overwhelmingly more likely that life began in space than on earth."

www.chem.duke.edu/~jds/cruise_chem/Exobiology/sites.html

Thermal Vents

One current theory is that life originated deep beneath the surface of the ocean at deep sea hydrothermal vents. These hydrothermal vents were first discovered in 1979. Soon after, scientists made an exciting discovery. These vents release hot gaseous substances from the center of the earth at temperatures in excess of 572oF. Previously scientists were sure that life could not exist, deep beneath the surface of the ocean. After the discovery of hydrothermal vents, they found ecosystems thriving in the depths of the ocean. These ecosystems contained various types of fish, worms, crabs, bacteria and other organisms which had found a way to survive in a cold, hostile environment without energy input from sunlight. Because life had been found to exist where it previously was thought unable to, many scientists began to ask questions as to whether or not this was where life may have originated on the earth.

On the molecular level, the chances of life originating at deep sea thermal vents is not likely. It is known that organic molecules are unstable at high temperatures, and are destroyed as quickly as they are produced. It has been estimated that life could not have arisen in the ocean unless the temperature was less than 25oC, or 77oF.

Supporters of this theory claim that the organic molecules at the thermal vents are not formed in 300oC temperatures, but rather in a gradient formed between the hydrothermal vent water, and the extremely cold water, 4oC (39.2oF), which surrounds the vent at the bottom of the ocean.

The temperatures at this gradient would be suitable for organic chemistry to occur. Debates still remain, however, as to the gradient's effectiveness in producing organic compounds.

www.chem.duke.edu/~jds/cruise_chem/Exobiology/sites.html

Comparing Darwinism, Creationism/ID and Cosmic Ancestry What'sNEW

Question / Darwinism / Creationism/ID / Cosmic Ancestry
Origin of life? / chance
(1) / God/unspecified
intelligence (1) / undemonstrated (2)
Source of life? / the cosmos
Origin of genetic programs for higher life forms? / chance
(1) / God/unspecified
intelligence (1) / undemonstrated (2)
Source of genetic programs for higher life forms? / the cosmos
Can mutation and natural selection produce microevolution? / yes
(1) / no/yes / yes
Can mutation and natural selection produce macroevolutionary progress? / no / not without HGT (3)
Has life inhabited Earth for more than 3 billion years? / yes / no/yes / yes
Did higher life forms descend from lower ones? / yes / no/maybe / yes with HGT (3)
What existed before the [standard] big bang? / nothing / God / something
Was there life before the [standard] big bang? / no / no / yes
Can miracles be scientifically proved? / no (4) / yes/maybe / no
What caused the cosmos to exist? / the big bang / God / science cannot answer
What caused life to exist? / chance / God/unspecified
intelligence / science cannot answer
(1) The answering philosophy sees these two questions as the same question.
(2) The origins of life and genetic programs are assumed events with weak logical grounding and no firm supporting evidence.
(3) HGT = Horizontal Gene Transfer
(4) But the superastronomical unlikelihoods that darwinian evolution claims to overcome are effectively

http://www.panspermia.org/comparison.htm