Final

• homology


  similarity resulting from common ancestry
• Homoplasy


  A similar (analogous) structure or molecular sequence that has evolved independently in two species.
• Monophyletic group


  includes a single common ancestor and all of its descendants

  
• Paraphyletic group


  composed of some but not all members descending from a common ancestor (more correct than monophyletic)

  
• Polyphyletic group (clade)


  composite groups consisting of linear species that evolved independently (least resolved)

  
• Porifera


  sponges
• Cnidaria


  jellyfish, corals
• Ctenophora


  comb jellies
• Placozoa


  enigmatic group (mysterious)
• Invertebrates are


  animals without a backbone
• sea urchins


  bilateral or pentaradial symmetry
• Protostomia


  Spiralia and Ecdysozoa
• Spiralia


  Embryos develop using spiral cleavage

  Most live in water

  Move using cilia or contractions of the body musculature
• Ecdysozoans


  A major lineage of protostomes (Ecdysozoam) that grow by shedding their external skeletons (molting) and expanding their bodies. Includes arthropods, insects, crustaceans, nematodes, and centipedes.
• Deutorostomia


  ambulacraria and chordates
• Ambulacraria


  echinoderms and hemichordates
• Chordates


  an animal phylum that has a notochord, a dorsal hollow nerve cord, and gill slits at some time in its life cycle

  
• Cambrian explosion


  A burst of evolutionary origins when most of the major body plans of animals appeared in a relatively brief time in geologic history; recorded in the fossil record about 545 to 525 million years ago. (metazoan diversity in late precambrian era)

  - major climate changes

  
• Ediacaran Period


  geological period (630-542 million years ago) when the oldest definite multicellular organisms with tissues evolved

  - Oldest animal (541 mya)

  - Origin of animal (around 875-650 mya)

  
• Oldest animal fossils


  635-541 mya
• Evolution by Natural Selection A logical outcome of 5 conditions:

  1. Variation within population

  2. Variation is heritable

  3. Overproduction of offspring

  4. Differential survival and reproduction, determined by the environment

  5. Results in gene frequencies that correlates with a change in morphological traits, behaviour, physiology, etc...
• industrial melanism


  darkening of populations of organisms over time in response to industrial pollution

  
• Systematics/Phylogeny


  study of biological diversity and it's traits: past and present; ties in evolutionary history
• Character states


  binary or multi state
• Apomorphy


  places where character state appears for the first time
• Plesiomorphy


  ancestral character state for a particular clade
• homologous features


  character states occur in all descendants of ancestor
• Presence of wings are an __ for __

  apomorphy, Pterygota
• Wings are___ in _____

  homologous, Pterygota
• Wings are __ for __

  plesiomorphic, beetles and butterflies
• Plesiomorphic characters


  Shared ancestral characters. Distant common ancestor.
• convergence


  joining of parts

  
• radiation homoplasy


  more than two lineages
• Adaptive Radiation of Molluscs

  • Diversification of shells and shell plates and muscles

  • Muscle morphology highly modified
• ____ retained single-shell condition (ancestral)

  Conchifera
• Stem group of molluscs

  Aculiferans
• Convergence and Parallelism in Arthropods


  • Similarity in stinging devices/organs

  • Beetles and scorpions

  • Have different developmental origins - antenna and tail
• Arthropods


  A group of organisms that have jointed appendages, an exoskeleton, bilateral symmetry, and reproduce sexually; insects, arachnids, millipedes and cenitpedes, and crustaceans
• Convergent characters of arthropods

  Raptorial forelegs and triangular head
• first prokaryotes


  3 bya