This new discovery goes against everything we believe in life as we know it by not only thriving on poisonous arsenic, but also having arsenic and phosphorous as DNA ingredients.
All life as we know it depends on six key ingredients — carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus. This bacteria can switch from phosphorus to arsenic — usually a deadly toxin — and not only survive, but thrive. It can swap arsenic for phosphorus so completely that arsenic is incorporated into its DNA and other biomolecules like ATP, according to the study. This is a first, and it upends our assumptions about how life works.
What this means for astrobiology is pretty speculative, however. When looking for life in other worlds, especially promising places like Saturn’s moon Titan or in the Martian soil, scientists look for telltale signs of life That means carbon-based life, respiration with oxygen and carbon dioxide, amino acids, and so on.
What does this mean for the search for Extra-Terrestrial life...? Well, it throws everything we know out the window of relying on just finding water on other worlds that may support life.