Anatomical Homology

Anatomical Homolgy

Mandibular Arch (ventral)

Mandibular Arch (dorsal)

Hyoid Arch (dorsal)

Shark Meckel's cartilage

Palatoquadrate cartilage

Hyomandibular cartilage

Amphibian Articular (bone) Quadrate (bone)

Stapes

Mammal Malleus Incus Stapes

Embryonic Arches

Hyoid Arch

Mandibular Arch

Otic pit

Fish Amphibian BirdReptile Pig Cow Rabbit Human

Von Baer - Comparative Embryology

Anatomical Homology/Analogy

wild-type Antennapediamutant

Fly heads

Hoxb-4 knockoutwildtypemouse

Gene/Gene Expression Homology

Gene/Gene Expression Homology

Signaling pathways

Drosophila (invertebrate) Xenopus (vertebrate)

dpp BMP-4(dorsalization) (ventralization)

SOG chordin(blocks dpp, ventralization) (blocks BMP-4, dorsalization)

tolloid (TLD) xolloid(cleaves SOG, dorsalization) (cleaves chordin, ventralization)