Edifying Universe

April 17, 2011

We’ve discussed the formation of the planet Areios, the stellar characteristics of the star it orbits, its interactions with its three moons and the Alkyoneus gas giant. We’ve covered the composition of the crust, and the presence that liquid water plays in plate tectonics, which is the mechanism that regulates the atmosphere’s composition. All of these factors have been leading up to the sole reason why this thought experiment; these factors lead to an environment conducive to the origin of life. A phenomenon so rare that for the majority of human existence we could not even fathom the concept that life could have arisen a second time on some other world, no matter how likely that possibility may be, given what we know about the enormity of the universe. Separated by 14 billion years of cosmic evolution, humans are connected to all living things in the universe by our distant relation to the first stars ever spawned after the Big Bang that spread the chemical means for biology to exist. Our discussion of Areios and the solar system it occupies will forever be changed by the presence of life. Starting with the most basic cells and climaxing with animal life, the many forms of Areia and its evolution through time will dominate this discussion of speculative biology.

The history of our understanding of the origin of life in Western thought begins with the book of Genesis in the Bible; the idea that life on Earth was created in just seven days was the undisputed paradigm for two thousand years. It wasn’t until later in the nineteenth century that the science behind chemical evolution began to arise with Charles Darwin’s writing. He conjectured that all complex life alive today evolved from a simpler form until he reasoned that all life arose from a single common ancestor that was spawned in what he described as a “warm little pond” somewhere. But the greatest breakthroughs on this subject came with the research of J.S. Haldane and Alexander Oparin. These two scientists independently worked on theories of biochemistry that suggested life wasn’t an intrinsically magical property; cells were a very complex set of specific inorganic chemical reactions, all occurring within the boundaries of a cell. In this understanding, cells were bags of chemical machinery that could self-replicate under the right conditions. These scientists believed that the early environment on Earth was conducive for a primitive biological system to spawn. The Urey-Miller experiment in 1948 by Stanford scientists Stanley Miller and Harold Urey experiment went one step further to simulate the conditions of early Earth that would have led to the creation of life.

The basic building blocks of biochemistry like carbon monoxide, water, ammonia, and methane were heated in a glass tube and sent through a battery of shocks before allowed to condense in a test tube on the other end. The results were spectacular; the pair of scientists discovered that given the right ingredients and the right conditions, amino acids, the building blocks of the proteins could form from such simple processes. As this experiment was repeated, some scientists began to question the validity of the assumptions made; some questioned the composition of the atmosphere assumed in the experiment wasn’t realistic. When Miller passed away in 2007, researchers unearthed the apparatus he used and repeated the experiment, this time using more sensitive instruments to detect chemicals and a more accurate understanding of the environment at the hypothesized time of creation; scientists were astounded by the presence of even more amino acids produced. Even more surprising was when researchers located a vial that contained the results of another experiment that Miller kept from the world for over 25 years. He mixed ammonia and cyanide, but immediately froze the chemicals at over -100 Fo. Scientists opened that sealed vial and analyzed the results to find that despite the fact that chemical reactions proceed at a snail‘s pace at those frigid temperatures the air bubbles trapped within the ice made an ideal test tube for amino acids and nucleotides to form.

Astronomers have found complex organic molecules floating out in nebulas or in the icy tails of comets; since then, some researchers believe that the ingredients for life may be delivered ready-made to the Earth by impacts. Others believe that freeze-dried cells might be able to hitch a ride on a meteorite from some other world only to survive the re-entry into the atmosphere where these spores would colonize some barren but habitable world. These processes called panspermia may seed the universe (or at least neighboring planets) with extraterrestrial life. There is some debate among scientists if this process of transferring spores from one world to the next has happened in our solar system or if the idea is even possible. In any case, research points out that even the simplest organic molecules in our body can be created abiotically. This alone suggests that life need not form from some supernatural process directed by an omnipresence god, but that the origin of life could be explained entirely by organic chemistry and eventually biocatalysis.

The Urey-Miller experiment first presents experimental evidence of chemical evolution leading to the creation of life on Earth.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: