animal evolution Flashcards
what 2 features determine animal clades?
- adult body plan, 2. embryonic patterns
What is the differentiating body plan features between land and water animals?
4 limbs
The Cambrian explosion 540 million years ago refers to what happening?
Lots of fossils popping up ( but really there many living creatures before - they were just softer and didn’t fossilize)
The earliest animals that didn’t fossilize were in what form?
single celled prokaryotic
Were there also multicellular organisms before the Cambrian explosion?
yes, eggs, embryos
Does a cladogram indicate a hypothesis of evolutionary patterns?
yes, shows an ORDER of evolution and specialization
what are the 8 clades for invertebrates in order of evolution?
- sponges (first), 2. cnids (radial and with tenticles), 3. arthopods, 4. round worm (mouth and anus), 5. tape worm, 6. Annelids segmented! 7. mollusks (organs)8. echinoderms (radial symmetry)
Name 5 important adaptation in the evolution of invertebrates?
- multi cellular, 2. complex tissues, 3. bilateral symmetry, 4. anus and mouth
Modern chordate consist of how many groups and what are they?
6 groups (1 of which is an invertebrate group). 1. Invertebrates, 2. fish, 3. amphibians, 4. reptiles, 5. birds, 6. mammals.
Most chordates are in which of the 6 groups?
fish
what are 6 important evolutionary features in the chordate cladogram?
- vertebrae, 2. jaws, 3. lungs, 4. bones, 5. amniotic egg, 6. 4 limbs
Tunicates and lancelets have what evolutionary feature (or lack of this feature) in common?
their chordates with no back bone
lampreys and hagfish have what in common?
Although these chordates have a back bone, they lack a jaw
What do Chondrichthyes have in common from an evolutionary stand point?
Sharks. have jaws. but no bones (only cartilage)
whats a tetrapod?
type of bony fish that would evolve into a creature with 4 limbs
