A-level Biology OCR [New Spec] - Natural Selection & Evolution | A-level Biology | OCR, AQA, Edexcel

The key points covered of this video include: 1. Evolution by Natural Selection 2. The Process of Evolution Evolution by Natural Selection Variation exists within and between all species because of differences in their genetics and their environment. Despite variations, most organisms within a species are suited to their way of life. Genetic mutations are random and environmental conditions can vary dramatically, so why are organisms suited to their environment? Species have evolved to survive in the face of life-threatening conditions by the process of natural selection. Natural selection is the mechanism of evolution which explains how certain features of the environment can apply a selective force on the reproduction of individuals within a population. The Process of Natural Selection The process of natural selection works in six steps: Genetic mutations create multiple alleles of genes within a population, Genetic variation within a population creates intraspecific competition, Individuals with particular alleles are better able to face challenges imposed by the environment, Individuals with the advantageous characteristics will be more likely to survive than individuals without the characteristics, Individuals that survive are able to reproduce and pass on their advantageous genes to the next generation, The next generation has a higher proportion of individuals with the advantageous characteristic Summary Species must compete to survive Some individuals within a species may be better suited to survive than others Individuals that are better able to survive are more likely to reproduce and pass their genetics on to the next generation This has the effect of increasing the proportion of individuals with beneficial genes within a population