FreeNotes
Evolution: The gradual change in species over time due to genetic variation and natural selection. Homologous organs: Structures that have a similar basic design but different functions, indicating a common ancestry. Speciation: The process by which new species evolve from existing ones due to genetic differences and reproductive isolation. Natural selection: A process where organisms … Read more
a. Which variety was more common when there was more air pollution? Give a reason. The dark-colored (melanic) variety was more common when air pollution increased because soot-covered trees made it easier for dark moths to camouflage and avoid predators. b. Which variety is more common in England nowadays? Give a reason. The light-colored variety … Read more
Comparative embryology shows that embryos of different species share common developmental stages, suggesting a common ancestor. For example, human and fish embryos have gill slits in early development, indicating shared ancestry. Related Questions: Explain the homologous structures in plants. Why was the theory of evolution attributed to Darwin? What is meant by descent with modification? … Read more
Convergent evolution occurs when unrelated species develop similar traits due to adapting to similar environments. An example is the streamlined body shape of sharks (fish) and dolphins (mammals), which evolved separately for efficient swimming. Related Questions: Explain the homologous structures in plants. Why was the theory of evolution attributed to Darwin? What is meant by … Read more
Fossils provide a historical record of life on Earth, showing how species have changed over time. They help scientists identify transitional forms, such as Archaeopteryx, which links reptiles and birds. Related Questions: Explain the homologous structures in plants. Why was the theory of evolution attributed to Darwin? What is meant by descent with modification? Differentiate … Read more
Industrial melanism refers to the evolutionary process in which darker-colored organisms become more common in industrial areas due to pollution. A classic example is the peppered moth, which evolved darker coloration to blend with soot-covered trees. Related Questions: Explain the homologous structures in plants. Why was the theory of evolution attributed to Darwin? What is … Read more
Vestigial organs are remnants of structures that were functional in an organism’s ancestors but have lost their original function due to evolutionary changes. Examples include the human appendix and whale pelvic bones. These structures provide evidence that species have evolved over time. Related Questions: Explain the homologous structures in plants. Why was the theory of … Read more
Natural selection occurs in nature when organisms with favorable traits survive and reproduce, while artificial selection is controlled by humans to breed organisms with specific characteristics. Natural selection leads to adaptation and evolution, whereas artificial selection focuses on traits useful to humans. Related Questions: Explain the homologous structures in plants. Why was the theory of … Read more
Descent with modification refers to the concept that new species arise from pre-existing species over generations. As organisms reproduce, genetic changes accumulate, leading to variations and adaptations, which eventually result in the emergence of new species. Related Questions: Explain the homologous structures in plants. Why was the theory of evolution attributed to Darwin? Differentiate between … Read more
The theory of evolution is attributed to Charles Darwin because he provided extensive evidence for the process of natural selection, explaining how species change over time. His book On the Origin of Species (1859) introduced the idea that organisms with beneficial traits survive and reproduce, passing those traits to the next generation. Related Questions: Explain … Read more