Intro continued

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

Deuterostomata Pharyngotremata Hemichordata Chordata Somitichordata Echinodermata Hemichordata Chordata Somitichordata (Cephalochordata) Amphioxus Protostome Invertebrates Crinoids, Sea stars, etc Enteropneusta (Acorn worms) Tunicates (Tunicata) Pterobranchia Craniates Mouth second upon development, pharyingeal gill slits, notochord, somites, braincase

Protostome inverts Deuterostome inverts

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

Acorn worm (Sarcoglossa)

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

Urochordata (=Tunicata) Corella parallelograma Notochord – cordlike skeleton of the back

Ascidian tunicate

P. Chordata, Sp. Cephalochordata Amphioxus Somites – rectangular shaped pairs of mesoderm on sides of notochord – gives rise to axial skeleton, muscles and dermis

Sp. Craniata

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

“Ontogeny recapitulates phylogeny” Ernst Haeckel (1834-1919) German anatomist Embryonic stages of an animal reflect its evolutionary history 1874

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

A few notes on Patterns and Process in Evolution Homology: Analogy: Homoplasy:

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:

M N A B C Cladogram Branch Node Internode Root OTU Ingroup Outgroup Autapomorphy Plesiomorphy Synapomorphy