Answer:
some traits become more common, others less. ... The traits that become more common are the ones that are “adaptive” or “increase fitness” (that is, a creature's chances of living longer and producing more offspring).
Answer: Bacteria gain resistance to drugs because of mutations (permanent and random changes to their DNA) which means they have changed DNA coding, giving them the ability to resist the drug fighting them off. As a result, they survive and reproduce. Over time, more and more bacteria are generated as the DNA code for resistance is passed on over generations. This results in bacteria having the ability to resist drugs. This is particularly prevalent with antibiotics.
The answer should be 2. Skin fossilization is rare due to decomposition and scavengers.