What is the difference between analogous and homologous?

Answer 1

Analogous means that the structures have different origins, but they do the same things. Homologous means the opposite: that they have the same origins but are adapted to do different functions.

Answer 2

Homologous structures have the same basic plan but are adapted for different function.

For example, the pentadactyl limb of vertebrates has the same arrangement of bones in a bat's wing, a human arm, a dolphins flipper and a mole's claw. Although the basic plan is the same (single bone, two parallel bones, a block of bones and five digits) the plan has been adapted for a range of purposes.

Analogous structures do the same job but have different origins, for example a moth's wing and an eagle's wing, or an ant's leg and a dog's leg.

John H in Yahoo

Answer 3

Analogous structures are similar in function but not in evolutionary origin, while homologous structures are similar in structure and evolutionary origin but may perform different functions. Analogous structures result from convergent evolution, where organisms adapt to similar environmental pressures. Homologous structures indicate common ancestry and evolutionary relationships between species.