Comparative Vertebrate Anatomy, BIOL 021, 3 September 2012

Comparative Vertebrate Anatomy

• What is gained by a comparative approach to vertebrate anatomy?

Morphology: the study of shape

• Morphology is not strictly dictated by evolutionary processes. What interferes? In other words, why aren’t morphological possibilities endless?

Homology and homoplasy: shared morphology

• Homology is a concept to which we will return throughout the semester so get very comfortable with it early. There are three tests of homology: similarity, conjunction, and congruence. What are the benefits and problems with each test of homology? When is each test most effective? least effective?

• What is homoplasy? Homoplasy does not require shared function. What are some other factors that can lead to homoplasy?

• Know your directional terminology (listed below). It will prove crucial to your success in lab.

Phylogeny and cladistics

• What is the difference between phylogeny and cladistics? What are the three major types of phylogenetic characters? Which of these is useful in building cladograms and why is this so?

• Of monophylies, paraphylies, and polyphylies, why do we only name monophylies?

Vocubulary for lecture 1 phylogeny transverse plane apical morphology frontal plane cladistics extant phylogenetic bracket cranial synapomorphy homology rostral symplesiomorphy similarity (test of homology) caudal autapomorphy conjunction (test of lateral node homology) medial monophyly congruence (test of internal paraphyly homology) external polyphyly homoplasy proximal ingroup stylopod distal outgroup zeugopod mesial crown group autopod lingual stem group directional terminology labial sagittal plane (mid-, para-) coronal