If a scientist found very high concentrations of organic biomarkers deep inside a 3.9 billion year old meteorite, how would this effect the explanation of the origins of life on Earth?

Question

A.  This would prove the extra-terrestrial origin of life.
B.  This would provide evidence for the extra-terrestrial origin of life.
C.  This would disprove the terrestrial origin of life.
D.  This would provide evidence for the uniqueness of life on earth.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
 
Gather Content
· What do you already know about the role of meteorites in the origin of life?
 
Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?


Answer 1

B.  This would provide evidence for the extra-terrestrial origin of life.

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses the role of meteorites in the origin of life.
· What type of thinking is required?
        o This question is asking you to weigh and judge, or evaluate, evidence to choose the best of the possible answers.
 
Gather Content
· What do you already know about the role of meteorites in the origin of life?
        o The very earliest life-forms may have originated on earth, or they may have come to the earth on a meteorite. (It is also possible that nonliving organic molecules, but not life-forms, traveled to earth on meteorites.)
        o Hundreds of thousands of meteorites and comets are known to have slammed into the early Earth, and recent findings suggest that at least some may have carried organic materials.
        o One way to look for evidence of ancient life is to look for organic molecules, which are clearly of biological origin; such molecules are called biomarkers.
        o The search for definitive chemical markers for living systems in the oldest rocks and in meteorites is an area of intense interest.
 
Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o If biomarkers were found within a meteorite, it would not prove that life began on earth after being “seeded” from space.
        o However, that would be compelling evidence for such a hypothesis, and might demonstrate that it was possible.
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o The question required you to weigh and judge, or evaluate, evidence to choose the best of the possible answers.
        o Did you recognize that biomarkers are signs of the past presence of life?
        o Did you realize that those might indicate that living organisms traveled to earth on a meteorite?