Table of contents
- 1. Introduction to Biology2h 42m
- 2. Chemistry3h 40m
- 3. Water1h 26m
- 4. Biomolecules2h 23m
- 5. Cell Components2h 26m
- 6. The Membrane2h 31m
- 7. Energy and Metabolism2h 0m
- 8. Respiration2h 40m
- 9. Photosynthesis2h 49m
- 10. Cell Signaling59m
- 11. Cell Division2h 47m
- 12. Meiosis2h 0m
- 13. Mendelian Genetics4h 44m
- Introduction to Mendel's Experiments7m
- Genotype vs. Phenotype17m
- Punnett Squares13m
- Mendel's Experiments26m
- Mendel's Laws18m
- Monohybrid Crosses19m
- Test Crosses14m
- Dihybrid Crosses20m
- Punnett Square Probability26m
- Incomplete Dominance vs. Codominance20m
- Epistasis7m
- Non-Mendelian Genetics12m
- Pedigrees6m
- Autosomal Inheritance21m
- Sex-Linked Inheritance43m
- X-Inactivation9m
- 14. DNA Synthesis2h 27m
- 15. Gene Expression3h 20m
- 16. Regulation of Expression3h 31m
- Introduction to Regulation of Gene Expression13m
- Prokaryotic Gene Regulation via Operons27m
- The Lac Operon21m
- Glucose's Impact on Lac Operon25m
- The Trp Operon20m
- Review of the Lac Operon & Trp Operon11m
- Introduction to Eukaryotic Gene Regulation9m
- Eukaryotic Chromatin Modifications16m
- Eukaryotic Transcriptional Control22m
- Eukaryotic Post-Transcriptional Regulation28m
- Eukaryotic Post-Translational Regulation13m
- 17. Viruses37m
- 18. Biotechnology2h 58m
- 19. Genomics17m
- 20. Development1h 5m
- 21. Evolution3h 1m
- 22. Evolution of Populations3h 52m
- 23. Speciation1h 37m
- 24. History of Life on Earth2h 6m
- 25. Phylogeny2h 31m
- 26. Prokaryotes4h 59m
- 27. Protists1h 12m
- 28. Plants1h 22m
- 29. Fungi36m
- 30. Overview of Animals34m
- 31. Invertebrates1h 2m
- 32. Vertebrates50m
- 33. Plant Anatomy1h 3m
- 34. Vascular Plant Transport1h 2m
- 35. Soil37m
- 36. Plant Reproduction47m
- 37. Plant Sensation and Response1h 9m
- 38. Animal Form and Function1h 19m
- 39. Digestive System1h 10m
- 40. Circulatory System1h 57m
- 41. Immune System1h 12m
- 42. Osmoregulation and Excretion50m
- 43. Endocrine System1h 4m
- 44. Animal Reproduction1h 2m
- 45. Nervous System1h 55m
- 46. Sensory Systems46m
- 47. Muscle Systems23m
- 48. Ecology3h 11m
- Introduction to Ecology20m
- Biogeography14m
- Earth's Climate Patterns50m
- Introduction to Terrestrial Biomes10m
- Terrestrial Biomes: Near Equator13m
- Terrestrial Biomes: Temperate Regions10m
- Terrestrial Biomes: Northern Regions15m
- Introduction to Aquatic Biomes27m
- Freshwater Aquatic Biomes14m
- Marine Aquatic Biomes13m
- 49. Animal Behavior28m
- 50. Population Ecology3h 41m
- Introduction to Population Ecology28m
- Population Sampling Methods23m
- Life History12m
- Population Demography17m
- Factors Limiting Population Growth14m
- Introduction to Population Growth Models22m
- Linear Population Growth6m
- Exponential Population Growth29m
- Logistic Population Growth32m
- r/K Selection10m
- The Human Population22m
- 51. Community Ecology2h 46m
- Introduction to Community Ecology2m
- Introduction to Community Interactions9m
- Community Interactions: Competition (-/-)38m
- Community Interactions: Exploitation (+/-)23m
- Community Interactions: Mutualism (+/+) & Commensalism (+/0)9m
- Community Structure35m
- Community Dynamics26m
- Geographic Impact on Communities21m
- 52. Ecosystems2h 36m
- 53. Conservation Biology24m
21. Evolution
Introduction to Evolution and Natural Selection
Problem 2`
Textbook Question
Which of the following observations helped Darwin shape his concept of descent with modification?
a. Species diversity declines farther from the equator.
b. Fewer species live on islands than on the nearest continents.
c. Birds live on islands located farther from the mainland than the birds' maximum nonstop flight distance.
d. South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe.

1
Understand the concept of 'descent with modification': This is a key principle of Darwin's theory of evolution, which suggests that species change over time, giving rise to new species, and share a common ancestor.
Analyze the options provided: Each option represents an observation that could potentially support the idea of descent with modification.
Option a: Consider how species diversity might relate to evolutionary processes and environmental factors at different latitudes.
Option b: Think about how the isolation of islands could lead to fewer species and how this might support the idea of species evolving differently in isolated environments.
Option d: Reflect on how the similarity between South American temperate and tropical plants, compared to European temperate plants, might suggest a common ancestry and adaptation to local environments, supporting descent with modification.

This video solution was recommended by our tutors as helpful for the problem above
Video duration:
1mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Descent with Modification
Descent with modification is a fundamental concept in Darwin's theory of evolution, suggesting that species change over time and give rise to new species, sharing a common ancestor. This process involves gradual changes in traits, influenced by natural selection, leading to adaptations that enhance survival and reproduction in specific environments.
Recommended video:
Guided course
Descent With Modification
Biogeography
Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Observations of species distribution, such as fewer species on islands compared to continents, provide evidence for evolution, as they suggest that isolation and environmental factors influence species diversity and adaptation.
Recommended video:
Guided course
Biogeography
Comparative Anatomy
Comparative anatomy involves comparing the anatomical structures of different species to understand evolutionary relationships. Darwin noted similarities between South American temperate and tropical plants, which supported the idea that species with common ancestry can diverge and adapt to different environments, illustrating descent with modification.
Recommended video:
Guided course
Leaf & Chloroplast Anatomy
Watch next
Master Evolution and Natural Selection with a bite sized video explanation from Jason
Start learningRelated Videos
Related Practice