15 Questions
What are vestigial structures?
Structures that have lost their original function but still persist in the organism's body
What best describes analogous structures?
Structures that have the same function but are not derived from a common ancestor
How have emu wings changed over time?
They have regressed and become vestigial due to natural selection favoring traits for survival on the ground
What is the purpose of wisdom teeth in evolutionary terms?
To adapt to a more upright posture and larger jaws for chewing tough plant materials
What happened to the tails of our primate ancestors over time?
They regressed, leaving behind vestigial coccyx
Why have wisdom teeth become vestigial in humans?
Due to the change in diet and jaw size over evolutionary time
What is the primary reason for emu wings to become vestigial?
Natural selection favored traits enhancing survival on the ground rather than in the air
Why are analogous structures not necessarily evidence of a common ancestor?
Because analogous structures evolve independently in different species and do not indicate a common ancestry
What are vestigial structures?
Features or organs in a living organism that have lost their original function through evolution
How do vestigial structures differ from homologous structures?
Homologous structures are inherited from a common ancestor, while vestigial structures have lost their original function through evolution
Why do vestigial structures no longer serve their original function?
The environment no longer requires these structures to be functional
Why have emu wings become vestigial over time?
Due to the terrestrial lifestyle of emus and natural selection favoring traits that enhance survival on the ground.
What is the function of emu wings in their current vestigial state?
The wings have lost all function and are purely remnants of their flying ancestors.
How do emu wings demonstrate the concept of vestigial structures?
By losing their original function and persisting in the organism's body despite being unnecessary.
What is the evolutionary significance of emu wings becoming vestigial?
It highlights natural selection favoring traits that enhance survival on the ground rather than in the air.
Study Notes
Comparative Anatomy
- Comparative anatomy is the study of similarities and differences in structures between different species.
- Success criteria:
- Recognize comparative anatomy
- Differentiate between types of structures
- Identify each structure and its meaning
Homologous Structures
- Definition: Anatomical structures inherited from a common ancestor.
- Example: Forelimbs of vertebrates (e.g., humans, birds, whales) – similar bones, but adapted for different uses.
- Origin of the term "homologous": Greek words "homos" (same) and "logos" (relation).
- Evolution predicts that body parts are more likely to be modified from ancestral parts than entirely new features.
Vestigial Structures
- Definition: Anatomical features or organs that have lost their original function through evolution.
- Characteristics:
- Had a purpose in the organism's ancestors
- Became unnecessary or redundant over time as the species evolved
- Examples: not specified in the provided text, but common examples include the human appendix, wisdom teeth, and whale pelvis bones.
Test your knowledge of comparative anatomy with this quiz. Learn to recognize, differentiate, and identify different types of structures such as homologous, vestigial, and analogous structures. Challenge yourself with the success criteria and expand your vocabulary in the field.
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