Which of the following best describes the current status of the debate over evidence for life in the Martian meteorite ALH84001?
A) Most scientists now agree that the meteorite shows clear evidence of past life on Mars.
B) Most scientists now agree that the meteorite shows no evidence for past life on Mars.
C) Most scientists agree that the evidence would support life if the meteorite truly comes from Mars, but few scientists accept that the meteorite is from Mars and instead think it is an ordinary Earth rock.
D) Most scientists find the evidence intriguing but suspect that it can be explained without requiring past life on Mars.
Question 2
When we analyze whether a world is a possible home to life, the key thing we look for is
A) the past or present existence of liquid water.
B) evidence of atmospheric oxygen.
C) the presence of organic molecules such as amino acids.
D) surface coloration changes that could indicate vegetative growth.
A web of life
The life cycle of a zygomycete, the black bread mould Rhizopus stolonifer.
Hierarchy of evidence
Evidence for big game hunting by archaic H. sapiens is suggested by the excavations at the Boxgrove
Marine pollution threatens resources and marine life
Food, friends, and football . . . a way of life