Common examples of this would be if you place your hand in extremely warm or cold water, and an immediate response of pulling out of the water or any fluid, is an example of this extreme response, other responses are what is done in everyday, like being thirsty or hungry etc.
These behaviours are shared by all organisms even the most simple ones.
Atmosphere of the early earth + lighting = paleolightning
Other reasons are
Not finishing the antibiotics.
Or
Taking antibiotics too often
Based on that scenario, a faulty reasoning that the student's research advisor most likely point out is : The rock that makes up the fossils replaced the organisms tissue and genetic material,
Because of this , their genomes can't be extracted.
hope this helps
