Which conditions are necessary for natural selection? Check all that apply. Populations do not have genetic variation.
Populations have genetic variation.
The environment changes.
The environment stays the same.
Organisms must have specific traits in order to survive and reproduce.
Organisms with any traits will survive and reproduce.

Populations have genetic variation.

The environment changes.

Organisms must have specific traits in order to survive and reproduce.

Explanation:

Natural selection provides an advantage during an adverse condition for organisms that have a rich genetic variation in their population.

Also, environmental changes induced natural selection whereby organisms must adapt to changes around them.

For organisms to survive, they must have specific traits that gives them a competitive reproductive advantage.

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.