Genetic Variability. What does the first born inherit from mom and what from dad? and the second born is a whole new mixture of mom & dad (this occurs during "cross-over") This is what leaves some siblings being weaker and others being stronger. And since "only the fittest survive", natural selection chooses the best and allows the weakest to die, improving the new "gene-pool" overall!
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.
It has not reached carrying Capacity
Genetic variation. If there were no variation in the genes/phenotype then natural selection would have nothing to select from.
Without genetic diversity, natural selection cannot occur
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.
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.
Without variation it would not be selecting, just random death of identical units.
Artificial selection demonstrated that desirable traits could be purposefully selected and passed down in domesticated plants and animals. This helped Darwin understand that similar processes could occur in nature through natural selection, where organisms with advantageous traits are more likely to survive and reproduce. This supported his theory of evolution by natural selection.
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.