Comparative Anatomy: Meaning of Comparative Anatomy, Analogous Structures

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Meaning of Comparative Anatomy

  • It is the study of similarities and differences in the anatomy of different species.

  • It has provided evidence of common descent and has assisted in the classification of animals.

  • In simple terms one can say that Comparative anatomy is a comparison of the body structures of two species.

  • It is closely related to evolutionary biology and phylogeny (the evolution of species).

  • The genetic change occurring in a population over time is called evolution.

    • The offspring has a different look than that of the parent.

Homology vertebrates

Comparative Anatomy

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Two Major Concepts

Analogous Structures

  • These structures are similar in different organisms.

  • They evolved in a similar environment in convergent evolution.

    • Rather than were inherited from a recent common ancestor.

  • Usually the same or similar purposes are served.

  • The streamlined torpedo body shape of porpoises and sharks is an example.

  • The evolution is from different ancestors.

Evolutionary Biology

Evolutionary Biology

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Homoplasy

Porpoises and sharks developed analogous structures because of their evolution in the same aquatic environment.

Convergent Evolution

  • It is the independent evolution of similar features in species of different periods or epochs in time.

  • It creates analogous structures that have similar form or function.

  • Independently evolved the useful capacity of flight:

    • Flying insects

    • Birds

    • Pterosaurs

    • Bats

Convergent evolution

Convergent Evolution

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Convergent evolution

Convergent Evolution

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Homologous Structures

  • These are similar in different species because the species have common descent.

  • The evolution is usually divergently, from a shared ancestor.

  • Same function may or may not be performed.

  • The forelimb structure shared by cats and whales is an example.

Uses of Comparative Anatomy

  • It simply indicates that the organism shares a common ancestor.

  • It has long served as an evidence for evolution, now joined in that role by comparative genomics.

  • It further assists scientists in classifying organisms based on similar characteristics of their anatomical structures.

  • The similar bone structures in forelimbs of cats, whales, bats, and humans is one of the best examples.

FAQs

Q 1. Define homologous structure.

Answer:

Homologous structure is an organ or body part that appears in different animals and is similar in structure and location.

Q 2. List out the names of some independently evolved species involving Convergent Evolution.

Answer:

Some of the independently evolved species involving Convergent Evolution are:

i) Flying insects

ii) Birds

iii) Pterosaurs

iv) Bats

Q 3. What are some of the uses of Comparative Anatomy?

Answer:

Some of the uses of Comparative Anatomy are:

i) It simply indicates that the organism shares a common ancestor.

ii) It has long served as an evidence for evolution, now joined in that role by comparative genomics.

iii) It further assists scientists in classifying organisms based on similar characteristics of their anatomical structures.