Continental Drift Theory

**Continental drift:** The movement of continents over millions of years has led to changes in the distribution of landmasses, altering habitats and creating opportunities for species to migrate, adapt, and diversify. It has influenced speciation events by creating barriers to gene flow and promoting allopatric speciation. **Glacial cycles:** Fluctuations in global climate associated with glacial-interglacial cycles have had profound effects on ecosystems and species distributions. Periods of glaciation have resulted in the expansion and contraction of ice sheets, leading to changes in sea levels, habitats, and the distribution of flora and fauna. These environmental changes have driven evolutionary processes such as adaptation, migration, and extinction. Therefore, both continental drift and glacial cycles have played significant roles in shaping the evolution of organisms.

Statement I is correct: Geological matching (Jigsaw Fit) shows that the 2,000-million-year-old belt of ancient rocks from the Brazilian coast matches those from Western Africa. This suggests the two continents were once joined. Statement II is correct: This refers to "Placer Deposits." Ghana possesses rich placer deposits of gold despite having no known source rock (mother lode) in the region. The gold-bearing veins are actually located in Brazil, proving the continents were once side-by-side. Statement III is correct: The Gondwana system of glacial tillite sediments found in India has identical counterparts in six different landmasses: Africa, the Falkland Islands, Madagascar, Antarctica, Australia, and South America. This provides powerful evidence of a shared climatic and geological history. Correct Answer: All three statements are correct.