This deep dive covers Natural Selection — Step by Step within Evolution for GCSE Biology. Theory of evolution, natural selection, and evidence for evolution It is section 2 of 13 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 2 of 13
Practice
26 questions
Recall
25 flashcards
Natural Selection — Step by Step
- Individuals within a population show variation
- There is competition for resources (food, mates, space)
- Individuals with advantageous characteristics are more likely to survive
- These individuals are more likely to reproduce
- They pass on the alleles for advantageous characteristics
- Over time, the proportion of the population with these characteristics increases
- Eventually, this may lead to new species (speciation)
Natural selection is like a survival competition. Those with the best "skills" (adaptations) survive and have kids. Those kids inherit the winning traits. Over many generations, the population becomes better suited to its environment.
Mutations are random — they don't happen "because" an organism needs them. But selection is NOT random — the environment consistently favours certain traits. That's why evolution has direction!