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By: Adhityo WIcaksono

INTRODUCTION TO

XENOBIOLOGY

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WHAT ARE WE GOING TO LEARN TODAY• The Definition: Difference from Space Biology, Astrobiology, and Xenobiology

• Barriers of Our Knowledge

• Carbon Chauvinism

• Anthropocentric

• Alien Life Forms: Biomechanics to The State of Arts

• Shadow Biosphere Hypothesis

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THE DEFINITION: SPACE BIOLOGY, ASTROBIOLOGY, AND XENOBIOLOGY• Space Biology is a part of biological sciences which involves of study and observation by

taking a living organism into a space environment (either directly exposed, inside a space station, or simulated ground-based experiment)

• Astrobiology is a study to find a possibility of life existence beyond the earth including the research of searching it (such as Search for Extra Terrestrial Inteligent, or SETI project) and all of this research procedures are using of perception of “Life as we know it”

• Xenobiology is a speculative study of an alien life form, done by using the state of art and science of comparing the existing life on earth on the view of creature’s anatomy, physiology, and further on the aspect of evolution

Aster: starBios: lifeXeno: strangeLogos: logic

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THE DIFFERENCES BY THE LEARNING METHODOLOGY

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• Direct Exposition To Space Environment

• Experiment on Space Module

• Ground-Based Experiment

• On the lab

• Aerial or sub orbit tests

SPACE BIOLOGY

(Clément & Slenzka, 2006)

Minicentrifuge to observe the rootings ofLentil seeds in microgravity (S/MM-05 SpaceHab Mission). Image courtesy of: Brinckmann, (2007)

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• Study on “Building Block” of Life

• Study on Planetary Environment Aspect

• Search For Exoplanet

• The Origin of Life (on Earth)

• SETI Project

• Drake’s Equation

• Fermi’s paradox & Rare Earth Hypothesis

ASTROBIOLOGY

Artist’s rendition of Kepler-22b, the proposed Earth-like exoplanet

(Benett & Shostak, 2006)

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• Study on Extremophilles

• Study of the process of evolution and natural selection

• The Existing Alien Life: Shadow Biosphere Hypothesis

• Speculative Science of:

• Alternative Biochemistry

• Effect of Environmental Condition on Living Organism

• Evolution of Alien Life

XENOBIOLOGY

Sound-feeding creature, harvesting energy by using the vibration on its thin membrane. Image courtesy of Andrew Hou (http://njoo.deviantart.com)

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THE BARRIERS OF OUR KNOWLEDGE

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Most of our experiments to find life look for "life as we know it" (an exception is SETI, which is only looking for signals). Everyone recognizes that this is probably too narrow-minded, but it's hard to think of good experiments for finding microbes

that are NOT like the ones we know on Earth. Many people have thought about this, and several types of experiment have been proposed, but it's still a difficult

problem.-Dr. Seth Shostak, Senior Astronomer of SETI Institute-

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CARBON CHAUVINISM

• Carbon chauvinism is a assumption that biochemistry base of the predicted life forms of extraterrestrial life must be consisted of carbon

• Opposite to this assumption, scientists have the proposed theory of alternative biochemistry of life that might be possible to the not-yet-found alien life

"Life exists in the universe only because the carbon atom possesses certain exceptional properties." – James Jeans, The Mysterious Universe

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Proposed Biochemistry of LifeThis table is courtesy of Thomas Duffy (http://thomastapir.deviantart.com)

PS: More from this table can be explained on the next lecture

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ANTHROPOCENTRISM

• This idealism considers that the only superior and sapience being is only human

• This thought has impact on many prediction of intelligent alien life as depicted on humanoid form which described as:

• Bipedal

• Bilateral symmetry

• Human-like organs

• etc

Anthropocentric (adj): Considering human beings as the most significant entity of the universe (definition from Merriam-Webster dictionary)

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Human brain Insect “brain”

Dolphin brain Octopus brain

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REDEFINING LIFE

• Characteristic of life

• Metabolism

• Nutrition absorption

• Reproduction

• Adaptation to environment

• Type

• Cellular life (normal life like on Earth)

• Non cellular life (virus, crystal (?))

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SHADOW BIOSPHERE HYPOTHESIS

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• Hypothesize the existence of microbial biosphere here on Earth with a totally different biochemical and molecular processes than the known life on Earth (Cleland & Copley, 2005)

• Until now, the scientists had found an extremophile called GFAJ-1 which reported to use arsenic on their nucleotide (even later this statement is still a controversy)

SHADOW BIOSPHERE HYPOTHESIS

GFAJ-1

EXPLAINING: EXTREMOPHILLES• Extreme Temperature Membrane cell adaptation and enzyme adaptation (in low

temperature)

• Extreme pH Condition Membrane cell ion channel adaptation and pH buffer accumulation

• Extreme Low Hydration Osmoprotectant chemical accumulation (i.e: Trehalose)

• Extreme Pressure Membrane cell adaptation

• Extreme Radiation Exposure Rapid DNA repairing

• Extreme Scarcity of Nutrients and Chemical Extreme Vacuole and physiology adaptation

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SO THE MAIN CONCERN OF XENOBIOLOGY IS:

TO DECRYPT OR SPECULATE LIFE ON THE UNIVERSE AS WE DON’T KNOW IT

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REFERENCESAnonim (2012). The Transit of Synthetic Astrobiology. http://2012.igem.org/Team:Stanford-Brown, access date January 20th 2013

Benett, J.O. and S. Shostak (2006). Life in The Universe (2nd Edition). New York: Pearson Addison-Wesley. ISBN-13: 978-0805347531

Cleland, E.C. and S.D. Copley (2005). The possibility of alternative microbial life on Earth. International Journal of Astrobiology 4 (3 & 4): 165–173 (2005). DOI: 10.1017/S147355040500279X

Brinckmann, E. (2007). Biology in Space and Life on Earth: Effects of Spaceflights on Biological Systems. Weinheinm: WILEY-VCH Verlag GmbH & Co. KGaA. ISBN: 978-3-527-40668-5

Clément, G. and K. Slenzka (2006). Fundamental of Space Biology: Research on Cells, Animals, and Plants in Space. California: Springer. ISBN-13: 978-0387-33113-3

Downloaded Image: GFAJ-1: http://tikalon.com/blog/2011/GFAJ_1_Halomon.jpgHuman brainhttp://www.brainhealthandpuzzles.com/images/labeled_diagram_human_brain_sagittal.jpg Insext brain: http://a3.ec-images.myspacecdn.com/images01/59/8642e58527ee01a17537f5174b8a4851/l.gif Dolphin brain: http://www.starfiretor.com/TheWhaleAndDolphinPeopleProject/jpgs/DolphinBrainGraphic.jpg Octopus brain: http://4.bp.blogspot.com/_6FXhb-SM0NA/TBAImVaY0uI/AAAAAAAAAEU/9NhCri-H9vw/s1600/Young+Figure+1-6.jpg