What is represented by the base root of a phylogenetic tree?
the extinction of the species
the origin of the species
evolution of populations over time
where a population splits into two.

Hello~

The answer to your question is C.

Evolution of populations over time

~Hope this Helps!~

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.