200
Describe the difference between homology and analogy
Homology: •structures are present in 2 different species due to descent from a common ancestor
•structures may or may not be similar in form and function
•e.g., wing of bat vs. leg of horse
•shared common ancestor = ancestral vertebrate species
Analogy: •structures in 2 species are similar, but not due to shared common ancestor
•similarity is due to presence of similar selection pressures (convergent evolution)
•e.g., wing of bee vs. wing of bat
•common selection pressure = what is the best structure for flying?