Origin of Life -- Outer Space + Deep Ocean


When and how did the first life start? The origin of life is another BIG question, as big as the origin of the Universe. The solar system was formed 4.6 billion years ago, that much is well known. The oldest fossil on the earth is telling us that the first life emerged as early as 4 billion years ago, probably deep in the ocean. But let's take a moment. Even before the first life started, key building blocks of life, complex organic molecules such as amid acid, must have been there. Recent studies indicate that these molecules might have been produced in outer space, not on the Earth.

Green_Mist

The picture above is an image from the Spitzer Space Telescope's "GLIMPSE360" survey. Two extremely bright stars illuminate a greenish mist comprised of hydrogen and carbon compounds called Polycyclic Aromatic Hydrocarbons (PAHs), indicating a possible origin of the organic molecules in outer space. Somehow these kinds of molecules were bombarded in the earliest stage of the Earth. As least this is a leading story so far.

ht_white_smokers_nt_110928_wg

Deep under the primitive ocean some 4 billion years ago, for life to emerge, a miracle must have happened at some particular location. A leading candidate of the birth place is Deep See Hydrothermal Vents, like the one shown above.

Deep_sea_vent_chemistry_diagram

Such a place could accelerate the formation of more complex molecules, more and more, perhaps as complex as RNA. And once made, they could be cooled down immediately before they got destroyed back to their starting point. Here is another example of symmetry breaking in nature; creation of more complex states starting from simpler states at molecular level.

life_evolution

Then the rest is the history. A series of symmetry breaking has continued for the next 4 billion years, which are well described by Darwin's Theory of Evolution. And here we are. The above picture shows how various lives were branched out to the diversity today in Biosphere. At Arisaka Lab, we are trying to investigate the mechanism of symmetry breaking of life's origin and evolutional process, taking an advantage of the advanced photon detectors and high-speed optical microscopes.

Some Examples of Symmetry Breaking

During the evolutional process, life on the earth has gone through the numerical stages of symmetry breaking which eventually created the diversity of life today. One of the critical steps at the early stage of life is to split functions between the structure of life (= proteins) and the information of life (= DNA) as shown below.

Eukarotye_DNA

Another critical step was deviation between plants and Animals shown below. Plants produce oxygen for animals via photosynthesis, while animals consume oxygen and produce carbon-dioxide by breathing. We help each others. Without plants, no oxygen, no animals, so we were not here today.

Pasted Graphic

Arisaka Lab is trying to investigate the underlining physics principles of such symmetry breaking, by taking high-speed bio-imaging looking into individual molecules inside of the cells.

Researches at Arisaka Lab


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