Table of contents

1. Introduction to Biology2h 42m
2. Chemistry3h 37m
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
14. DNA Synthesis2h 27m
15. Gene Expression3h 6m
16. Regulation of Expression3h 31m
17. Viruses37m
- Viruses
  37m
18. Biotechnology2h 58m
19. Genomics17m
- Genomes
  17m
20. Development1h 5m
21. Evolution3h 1m
22. Evolution of Populations3h 53m
23. Speciation1h 37m
24. History of Life on Earth2h 6m
25. Phylogeny2h 31m
26. Prokaryotes4h 59m
27. Protists1h 12m
28. Plants1h 22m
29. Fungi36m
- Fungi
  19m
- Fungi Reproduction
  17m
30. Overview of Animals34m
- Overview of Animals
  34m
31. Invertebrates1h 2m
32. Vertebrates50m
33. Plant Anatomy1h 3m
34. Vascular Plant Transport1h 2m
- Water Potential
  1h 2m
35. Soil37m
- Soil and Nutrients
  20m
- Nitrogen Fixation
  16m
36. Plant Reproduction47m
- Flowers
  33m
- Seeds
  14m
37. Plant Sensation and Response1h 9m
38. Animal Form and Function1h 19m
39. Digestive System1h 10m
- Digestion
  1h 3m
- Blood Sugar Homeostasis
  7m
40. Circulatory System1h 49m
41. Immune System1h 12m
42. Osmoregulation and Excretion50m
- Osmoregulation and Excretion
  50m
43. Endocrine System1h 4m
- Endocrine System
  1h 4m
44. Animal Reproduction1h 2m
- Animal Reproduction
  1h 2m
45. Nervous System1h 55m
- Neurons and Action Potentials
  1h 8m
- Central and Peripheral Nervous System
  46m
46. Sensory Systems46m
- Sensory System
  46m
47. Muscle Systems23m
- Musculoskeletal System
  23m
48. Ecology3h 11m
49. Animal Behavior28m
- Animal Behavior
  28m
50. Population Ecology3h 41m
51. Community Ecology2h 46m
52. Ecosystems2h 36m
53. Conservation Biology24m
- Conservation Biology
  24m

23. Speciation

Introduction to Speciation

General Biology

23. Speciation

Introduction to Speciation

Previous problemNext problem

2:27 minutes

Problem 3

Textbook Question

According to the punctuated equilibria model:
a. Given enough time, most existing species will branch gradually into new species.
b. Most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species.
c. Most evolution occurs in sympatric populations.
d. Speciation is usually due to a single mutation.

Verified step by step guidance

Understand the concept of punctuated equilibria: This model suggests that species experience long periods of stability (equilibria) interrupted by brief periods of rapid change (punctuation).

Identify the key characteristics of punctuated equilibria: Rapid changes occur during speciation events, followed by long periods where species remain relatively unchanged.

Analyze option a: This describes gradualism, where species slowly evolve over time, which contrasts with the punctuated equilibria model.

Evaluate option b: This aligns with the punctuated equilibria model, as it describes rapid changes followed by stability.

Consider options c and d: Sympatric evolution and single mutations are not central to the punctuated equilibria model, which focuses on rapid changes during speciation events.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Punctuated Equilibria Model

The punctuated equilibria model, proposed by paleontologists Niles Eldredge and Stephen Jay Gould, suggests that species experience long periods of stasis, where little evolutionary change occurs, punctuated by brief, rapid events of speciation. This contrasts with the gradualism model, where species evolve continuously over time. Understanding this model is crucial for interpreting patterns of evolutionary change in the fossil record.

Speciation

Speciation is the process by which new species arise from existing ones. It can occur through various mechanisms, such as allopatric, sympatric, or parapatric speciation, often involving genetic divergence and reproductive isolation. In the context of punctuated equilibria, speciation is seen as a rapid event that contributes to the distinct features of new species, followed by periods of little change.

Sympatric Populations

Sympatric populations refer to groups of organisms that live in the same geographic area and have the potential to interbreed. Sympatric speciation occurs when new species evolve from a single ancestral species while inhabiting the same region, often through mechanisms like polyploidy or disruptive selection. This concept is important for understanding how speciation can occur without geographic isolation, as mentioned in the question.