Homology

Question 1

Homology

Answer 1

a similar character inherited from the same ancestor

genealogical inheritance

Question 2

Homoplasy

Answer 2

A similar character that evolved independently

Question 3

Criteria of homology after Remane

Answer 3

1. Position (extremities)
2. continuity
3. Specific quality

Question 4

Criteria of position & example

Answer 4

Structures are homologous if they obtain an
identical position in the organism

• Ex. vertebrate extremities

Question 5

Criteria of continuity & example

Answer 5

If their position doesn’t
match, but intermediate forms are recognizable

intermediates only visible during ontogenesis or in
extinct forms.

Ex. lungs tetrapods

Question 6

Criteria of specific quality & example

Answer 6

Complex structures are also
homologous if they match in many
details even if they cannot match by
position or continuity

Ex. Tetrapodd teeth or scales of a shark

Question 7

Analogy

Answer 7

Functional similarity, not based on genealogy, but
on adaptation to different habitats.

Question 8

Convergence

Answer 8

Parallel development of traits in two not directly
related animals due to adaptation to similar
habitats (Kind of homoplasy)

Ex. Wings of Birds and Insects
•Torpedo shape of dolphins and penguins
•Eyes in octopus and vertebrates