An allele that is relatively new to a population and has been subject to positive natural selection is characterized by having .

High frequency and High linkage disequilibrium

Explanation: Natural selection is a process whereby an people with a with a specific genotype are more likely to survive and pass their alleles to their next generation that people with another type of genotype. Natural selection can also influence the frequency of and allele by either causing and increase or decrease of that allele's frequency.

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.

i am going to guess that it is co2.