Biology 3 Lecture: Intro to Animal Diversity (CR7: Ch 32)
©2005
copyright Marta D. de Jesus
I. Overview: what makes an animal, an animal?
A. General characteristics
1.
2.
3.
4. glycogen
5.
6.
7.
8. developmental process
9.
B. early groups & relationships
1. hypotheses about origins
a. all plants, animals & fungi from green algae
b. colonial protists ancestral to animals: choanoflagellates
c. monophyletic vs. polyphyletic origins?
1) Parazoa
2) Eumetazoa
2. when did animals appear?
a. long defined Pre-Cambrian/Cambrian boundary
“Cambrian explosion”
b. now known to be older -> Ediacaran fauna
c. DNA molecular clocks
d. why all the phyla in Cambrian?
C. Evolutionary trends in bodies
1. symmetry
a. asymmetry
b. radial symmetry
biradial symmetry
d. bilateral symmetry
cephalization
1) directional terms
(i) dorsal vs. ventral
(ii) anterior vs. posterior/caudal
(iii) superior/cephalic vs. inferior
2. development of true tissues
a. gastrulation
1) diploblastic
2) triploblastic
b. in triploblastic embryos
1) acoelomate
2) pseudocoelomate
3) true coelom
3. coelomate differences
a. protostome:
1) cleavage of blastula
2) blastopore
3) coelom formation: schizocoelous
b. deuterostome:
1) cleavage of blastula
2) blastopore
3) coelom formation: enterocoelous
4. skeletons
a. hydrostatic
b. exoskeleton vs. endoskeleton
c. invertebrate vs. vertebrate
5. eventual terrestrial adaptations
6. larvae
7. 2 major hypotheses of the family tree
8. “God must have loved worms, he made so many”