Lecture 7: Animals III Flashcards
What are the shared derived characters of deuterostome
- radial, and indeterminate cleavages
- coelom forms from archenteron
- blastopore becomes anus
- ( other organisms do this bc of convergent evolution
phylum Echinodermata
- non-chordate deuterostome
what does Echinodermata s mean
- spiny skin
what type of symmetry does Echinodermata
- larva ( bilateral symmetry)
- adults - often have 5 part symmetry
what are Echinodermata categorized by
- endoskeleton: internal, calcium carbonate
- spine projects through the epidermis
what is the shared derived traits of Echinodermata
- water vascular system
- network of fluid- filled canals
- feeding, gas exchange
Phylum Chordata
- only phylum that included vertebrates
- also includes invertebrates
Phylum Chordata shared derived traits
- notochord
- dorsal hollow nerve cord
- pharyngeal ( throat) gill slits
- post-anal tail
notochord
- firm but flexible longitudinal supporting rod between gut and nerve cord
- functions as internal skeleton as all chordate embryos & in adults of some
- fore runner of backbone
dorsal ( towards back), hollow nerve cord
- devlops into central nervous system
- other animals have solid nerve chords ( usually ventral)
pharyngeal ( throat) gill slits
- ancestors probably suspension feeders
Muscular, post anal tail
- extends posterior beyond anus
basal chordates
- invertabrates
cephalochordate aka lancelets ( basal chordates)
- most basal chordate group
- marine suspension feeders
- 1 set of HOX genes
urochordate aka (tunicates (basal chordates)
- maries suspesion feeders
- all 4 chordate characters only as a larvae
- 1 set Hox genes
vertebrates shared dervied traits
- backbone or cartilige vertebre that replaces notochord
- 2 + set of hox genes
- increase genetic complexity -> more complex body plan
basal vertabrate
- jawless fish
- hagfish, lampreys
- composed of cartildge not bones
gnathostomes
- jaw mouth
- hinged law, grasp and hold prey
- bony skelaton
- 4 hox clusters - more complexity
- basal clade - chondrichtyes ( most bone lost)
osteichtyes
- 1st group with lungs
- bone-fish
- derived: lungs/swim bladder
- named for bony skeleton - calcium phosphate
- basal clade - Actinopterygii - ray- finned fish
lobe- fins
- derived traits: muscular fins/ limbs for locomotion
- all terrestial vetebrates found in this clade
- basal clades
- actinistia (coelacanths)
- dipnoi (lungfish) - lungs and gills ( sister group to tetrapods)
tetra pods
- 4 linbs with digits
- have a neck
- fused pelvic girdle
- effciently transmits forces through body - needed for living on land
- early example - tiktaalik
amphibia - basal tetrapods
- terrestrial but require most environment
- eggs laid in water
- aquatic larvae
- thin, moist skin
- ex: frogs toads, salamanders
amniotes
- amnotic egg
- amnion: membrane that forms fluid- filled sac around embryo
- allows for completly terrestrial lofe
- rib cage ventilation
- more efficient than through skin
- reptilia
- turtles, lizards, snakes, alligators, birds
- shelled eggs laid on land
derived traits of mammals
- mammary glads
- give birth to live young
- hair, fat layer under skin -> retains heat
monotremes
- lay eggs
- have hair, produce milk, but no nipples
- platypus & echindas - only in austrialia and new guinea
marsupials
- give birth to live young
- have nipples
- have a placenta: structure for nutrient exchange from mother to embryo
- born early, complete development while nursing
- often in pouch
- opossums, kangaroos, kaola
euthrians
- placental mammals - have complex placenta
- longer pregnancy than marsupials
- complete embryonic development in uterus
derived traits of primates
- large brain
- hangs and feet for grasping
- forward facing eyes
- high parental care
- complex social behavior
- monkey’s , apes ( fully opposable thumb)
- order contains: lemurs, tarsiers, monkeys, apes
human evolution derived traits
- bigger brains
- upright posture & bipedal locomotion
- language and symbolic thought
- manufature and use complex tools
- shorter jaw
- shorter digestive tract
human evolution
- closest living relative: chimpanzzess
- share common ancestor with simps, DID NOT EVOLVE FROM THEM
- derived 8-10 mya
homoninis
- 20 psecies
- more closely related to humans then to chimps
- orginated oin africa
shared some of derived characters of humans - homo sapiens is only living hominin
homo genus
- genus apperead 2.4 mya
- homo sapiens only living member
human migration
- eastern central africa -> everywhere else -> out of africa
- 3rd “ out of africa” migration- interbred with other hominins
homo habilis
- handy man
- oldest evidence of tool use
homo eretus
- 1st out of africa
homo neanderthalensis
- europe and near east
- 200,000 to 28,000 years ago
- thick bines with a larger brain
- buried their dead
- made hunting tools
homo sapiens
- 200,00 years old
- changes in cognition -> rapid geograpic expansion
