Variations within a population. Variations mean traits that only certain individuals have that give the individual a greater or lesser chance of reproducing.
Without genetic diversity, natural selection cannot occur
There are really no steps in natural selection - just conditions required for it to occur.
What population? Perhaps you mean if there were no variation for natural selection to select from.
Genetic variation. If there were no variation in the genes/phenotype then natural selection would have nothing to select from.
Everything from available food to climate will cause the changes we see in natural selection. Random mutations occur constantly and when those mutations are beneficial for life, the genetic code is more likely to be passed on to future generations.
Without genetic diversity, natural selection cannot occur
Natural selection requires variation in traits within a population, heritability of those traits, and differential reproductive success based on those traits. Without these components, natural selection cannot act on a population.
no there is no genetic variation for natural selection to act upon
Genetic variation is necessary for natural selection to occur. This variation provides the raw material for differential survival and reproduction, which drives the process of natural selection. Without genetic variation, there would be no differences for natural selection to act upon.
Without variation there is nothing to select from.
There are really no steps in natural selection - just conditions required for it to occur.
What population? Perhaps you mean if there were no variation for natural selection to select from.
Without variation it would not be selecting, just random death of identical units.
the presence of predators
Natural selection
Variations in a species are needed for natural selection to occur because they provide the raw material for evolutionary change. Without variation, there would be no differences for natural selection to act upon, and individuals within a species would be identical. Variations allow some individuals to be better adapted to their environment, giving them a higher chance of survival and reproduction, thus driving the process of natural selection.
Genetic variation is necessary for natural selection to occur because it provides different traits and characteristics within a population. These variations create diversity, allowing some individuals to have traits that are more advantageous for survival and reproduction in certain environments. Without genetic variation, there would be no differences in traits to be selected for or against, and natural selection would not be possible.