1. Evolution:

• Definition: Evolution is the process by which living organisms gradually change over time through genetic changes, leading to the diversity of life on Earth.

• Key Concepts:

  • Natural Selection: Charles Darwin’s theory of natural selection explains how species evolve over generations. It involves the differential survival and reproduction of individuals with advantageous traits.

  • Genetic Variation: Genetic diversity within a population is essential for evolution. Mutations, gene flow, and sexual reproduction contribute to genetic variation.

  • Fossil Record: Fossils provide evidence of past life forms and transitional species, documenting the history of evolution.

  • Homologous Structures: Similarities in structure among different species due to shared ancestry.

  • Vestigial Organs: Structures that have lost their original function but are remnants of evolutionary history.

  • Biogeography: The study of the geographic distribution of species and how it relates to their evolutionary history.

  • Significance: Understanding evolution is crucial in biology as it explains the relationships between species and their adaptations from common ancestors.