I believe that paleomagnetism was a key to determining that the seafloors were spreading since the paleomagnetism changes at certain geological intervals so that stripes of new rock with the youngest paleomagnetism would be right at the mid-ocean trenches and successively would be older the further they are from the trench, ie on either side of it, symmetrically.
Answer:
If a whole specie of organisms has to survive, they should must possess the ability to reproduce and adopt to environmental conditions in better way.
For example: If a disaster occurs or a condition of unfavorable weather occurs, the specie will survive even if only few members remain alive. Because those members will reproduce and regrow the community.
The reason is this that reproduction is not important for the survival of one organism, like organism will still survive even if he do not reproduce, but if a whole specie has to survive and continue, reproduction is most important trait.
Hope it help!
Friedrich Miescher in 1869
Corynebacterium is the answer I believe