Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Welcome to CVA Fall 2004

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Introduction Syllabus Schedule

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Comparative Vertebrate Anatomy What is it? –Vertebrate Descriptive Morphology –Vertebrate Functional Morphology Ontogenetic change Phylogenetic change

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 It incorporates: Genetics –mechanisms of heredity –effects on variation –control of development Embryology (study of development) Molecular Biology Biochem Physiology: form and function at many levels

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Paleontology –Historical record of past anatomy –How many species have existed on Earth? –How many are extinct? Ecology –Interactions between species and their environment Physics? (Handout)

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Area of coverage Kingdom Animalia –Phylum Chordata Subphylum Urochordata (=Tunicata) –Sea squirts, larvaceans, thaliaceans Subphylum Cephalochordata – Amphioxus (lancelet) Subphylum Craniata (=Vertebrata of Haeckel) –Hagfish (Mixini) –Vertebrata

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Protostome Invertebrates Crinoids, Sea stars, etc Pterobranchia Enteropneusta (Acorn worms) Tunicates (Tunicata) Amphioxus (Cephalochordata) Craniates Deuterostomata Pharyngotremata ChordataHemichordata Echinodermata Somitichordata

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Protostome inverts Deuterostome inverts

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04

Hemichordata ( incertae sedis ) (=Enteropneusta) Pterobranch Acorn Worm

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Acorn worm ( Sarcoglossa )

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Pharyngeal (“gill”) slits Opening from the gill chamber –Can include associated tissues P. pouch – outpocketing of the gut P. arch – tissues lying between P. slits

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Urochordata (=Tunicata) Corella parallelograma Notochord – cordlike skeleton of the back

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04

Ascidian tunicate

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 P. Chordata, Sp. Cephalochordata Amphioxus Somites – rectangular shaped pairs of mesoderm on sides of notochord – gives rise to axial skeleton, muscles and dermis

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Sp. Craniata

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Some Concept Review Ideas of Darwin and Wallace Evolutionary Developmental Concepts –Ontogeny: the history of an individual from initiation of cell division to death –Phylogeny: the evolutionary history of independent lineages or species

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 “Ontogeny recapitulates phylogeny” Ernst Haeckel ( ) German anatomist Embryonic stages of an animal reflect its evolutionary history 1874

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Better explained by: –Von Baer’s “Law” (1828): General (primitive) features develop earlier in ontogeny than do special features (derived) that distinguish groups –Biogenetic “Law”: features that develop earliest in ontogeny are the oldest phylogenetically and features developing later in ontogeny are of more recent phylogenetic origin

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 A few notes on Patterns and Process in Evolution Homology: Analogy: Homoplasy:

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Cladistic Classification / Phylogenetic systematics The science of evolutionary grouping based on shared derived characteristics The naming of organisms based on these groups –Plesiomorphy: –Synapomorphy: –Autapomorphy: –Monophyly: –Paraphyly: –Polyphyly:

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 ABCNM Cladogram Branch Node Internode Root OTU Ingroup Outgroup Autapomorphy Plesiomorphy Synapomorphy

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04 Next Time… Characters that define the Vertebrates

Comparative Vertebrate Anatomy – Bloomsburg University Fall 04