A To Z Challenge: Xenobiology And XNA

Xenobiology, also known as astrobiology and exobiology, is the study of alien life, including how life may have originated on Earth. It encompasses physics, astronomy, chemistry, geology, and biology. Technically, xenobiology has nothing to study other than Earth itself--planets are continually being discovered, but they're very far away. However, research into the history of development of life on this planet has begun to yield possibilities for how it may have formed on others.

A new development in the field of xenobiology is XNA. DNA is the fundamental building block of life on Earth, so messing with it is obviously an idea with some risks involved. XNA, a synthetic material that stands for xeno nucleic acids, could be an interesting solution toward designing new life and preventing damage to existing DNA. It can store information the same way DNA can, and has the potential for being the basis of new life--but if two organisms, one with DNA and the other XNA, interacted, they could come into contact without affecting the other's genetic material, acting as a so-called "genetic firewall".

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Sources:
http://www.xenology.info/Papers/Xenobiology.htm
http://www.redorbit.com/education/reference_library/space_1/space_sciences/2574862/xenobiology_exobiology/
http://education-portal.com/articles/Xenobiology_Education_Requirements_and_Career_Information.html
https://astrobiology.nasa.gov/exobiology/about/
https://astrobiology.nasa.gov/about-astrobiology/
http://www.universetoday.com/46851/exobiology/
http://www.chem.duke.edu/~jds/cruise_chem/Exobiology/
http://www.accessexcellence.org/WN/NM/miller.php
http://www.newscientist.com/article/dn9941-instant-expert-astrobiology.html
http://scienceblogs.com/oscillator/2010/04/07/xenobiology/
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2909387/
http://io9.com/5903221/meet-xna-the-first-synthetic-dna-that-evolves-like-the-real-thing

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Would you be comfortable with synthetic organisms existing alongside natural ones? Do you think humanity will ever come into contact with alien life?


-----The Golden Eagle

A-Z Blogging Challenge: Exobiology

Public domain image. SOURCE.

Exobiology, also known as astrobiology, space biology, or xenobiology, is the study and search for life on other planets. The phrase was coined by microbiologist Joshua Lederberg.

Despite its name, a good part of exobiology is concerned with the origins of life on Earth itself. Earth is currently thought to be around 4.55 billion years old, with the first evidence of life occurring on the record at 3.5 billion years; however, the state of life up until relatively recently in the planet's history is unknown. Harold Urey (famous for the Miller-Urey Experiment) proposed that Earth had an atmosphere containing methane, ammonia, hydrogen, and water--a "reducing" atmosphere--which would be the right conditions for organic chemistry to exist. Another theory is panspermia, or that life arrived from another planet via an object such as an asteroid.

An asteroid. Public domain image. SOURCE.

Some ongoing research in the field of exobiology focuses on prebiotic evolution (what kind of chemical system would be required to facilitate metabolism and replication, and alternative systems to DNA/RNA protein-based life), the evolution of early life (there are two major sources for this research: living organisms and geological records), the biosphere (such as how it might have responded to extraterrestrial events), and advanced life (biological and chemical factors which allowed it to develop). Studies also look at planetary conditions necessary for all that evolution (the formation of habitable planets, the formation of organic molecules, environments where chemical synthesis could happen, and the range in which life could exist).

Notable Exobiologist/Astrobiologist:

David Harry Grinspoon

David Grinspoon is the current Curator of Astrobiology at the Denver Museum of Nature and Science's Department of Space Science; he is also Adjunct Professor of Astrophysical and Planetary Science at the University of Colorado. He is an advisor to NASA on space exploration, an Interdisciplinary Scientist on Venus Express (a satellite studying the atmosphere of Venus led by the European Space Agency), and has published books including Venus Revealed and Lonely Planets: The Natural History of Alien Life. He was awarded the Carl Sagan Medal for public communication of planetary science in 2006.

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Sources:
http://www.accessexcellence.org/WN/NM/miller.php
http://astrobiology.nasa.gov/exobiology/about/
http://cafescicolorado.org/Grinspoon.htm 
http://www.chem.duke.edu/~jds/cruise_chem/Exobiology/index.html
http://www.funkyscience.net/bio.html
http://www.merriam-webster.com/dictionary/exobiology
http://sci.esa.int/science-e/www/area/index.cfm?fareaid=64
http://www.thefreedictionary.com/exobiology

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What do you think the chances are that significant signs of life will be found on another, non-Earth planet? And if you think it's possible, how advanced do you think it could be?


-----The Golden Eagle