Unit 7 · 7.1 — Introduction to Natural Selection [cite: 10, 28, 44]

Everything to learn here

• Concept: True evolutionary fitness is measured mathematically by an organism's reproductive success and its quantifiable contribution to the gene pool of subsequent generations [cite: 14, 45].
• Concept: Natural selection acts exclusively on directly expressed phenotypic variations within a population, never directly on underlying genotypes [cite: 21, 45].
• Concept: Natural selection occurs when limited resources cause individuals with advantageous traits to survive and reproduce more effectively.
• Concept: Competition for finite resources leads to differential survival, where those with beneficial phenotypes pass traits to the next generation.

Practice problems for this topic are coming — generated and validated by our AI pipeline, aligned to these exact items.