Lecture 7: Animals III

Question 1

What are the shared derived characters of deuterostome

Answer 1

• radial, and indeterminate cleavages
• coelom forms from archenteron
• blastopore becomes anus
• ( other organisms do this bc of convergent evolution

Question 2

phylum Echinodermata

Answer 2

• non-chordate deuterostome

Question 3

what does Echinodermata s mean

Answer 3

• spiny skin

Question 4

what type of symmetry does Echinodermata

Answer 4

• larva ( bilateral symmetry)

- adults - often have 5 part symmetry

Question 5

what are Echinodermata categorized by

Answer 5

• endoskeleton: internal, calcium carbonate

- spine projects through the epidermis

Question 6

what is the shared derived traits of Echinodermata

Answer 6

• water vascular system
• network of fluid- filled canals
• feeding, gas exchange

Question 7

Phylum Chordata

Answer 7

• only phylum that included vertebrates

- also includes invertebrates

Question 8

Phylum Chordata shared derived traits

Answer 8

• notochord
• dorsal hollow nerve cord
• pharyngeal ( throat) gill slits
• post-anal tail

Question 9

notochord

Answer 9

• 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

Question 10

dorsal ( towards back), hollow nerve cord

Answer 10

• devlops into central nervous system

- other animals have solid nerve chords ( usually ventral)

Question 11

pharyngeal ( throat) gill slits

Answer 11

• ancestors probably suspension feeders

Question 12

Muscular, post anal tail

Answer 12

• extends posterior beyond anus

Question 13

basal chordates

Answer 13

• invertabrates

Question 14

cephalochordate aka lancelets ( basal chordates)

Answer 14

• most basal chordate group
• marine suspension feeders
• 1 set of HOX genes

Question 15

urochordate aka (tunicates (basal chordates)

Answer 15

• maries suspesion feeders
• all 4 chordate characters only as a larvae
• 1 set Hox genes

Question 16

vertebrates shared dervied traits

Answer 16

• backbone or cartilige vertebre that replaces notochord
• 2 + set of hox genes
  
  • increase genetic complexity -> more complex body plan

Question 17

basal vertabrate

Answer 17

• jawless fish
• hagfish, lampreys
• composed of cartildge not bones

Question 18

gnathostomes

Answer 18

• jaw mouth
• hinged law, grasp and hold prey
• bony skelaton
• 4 hox clusters - more complexity
• basal clade - chondrichtyes ( most bone lost)

Question 19

osteichtyes

Answer 19

• 1st group with lungs
• bone-fish
• derived: lungs/swim bladder
• named for bony skeleton - calcium phosphate
• basal clade - Actinopterygii - ray- finned fish

Question 20

lobe- fins

Answer 20

• 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)

Question 21

tetra pods

Answer 21

• 4 linbs with digits
• have a neck
• fused pelvic girdle
• effciently transmits forces through body - needed for living on land
• early example - tiktaalik

Question 22

amphibia - basal tetrapods

Answer 22

• terrestrial but require most environment
• eggs laid in water
• aquatic larvae
• thin, moist skin
• ex: frogs toads, salamanders

Question 23

amniotes

Answer 23

• 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

Question 24

derived traits of mammals

Answer 24

• mammary glads
• give birth to live young
• hair, fat layer under skin -> retains heat

Question 25

monotremes

Answer 25

• lay eggs
• have hair, produce milk, but no nipples
• platypus & echindas - only in austrialia and new guinea

Question 26

marsupials

Answer 26

• 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

Question 27

euthrians

Answer 27

• placental mammals - have complex placenta
• longer pregnancy than marsupials
• complete embryonic development in uterus

Question 28

derived traits of primates

Answer 28

• 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

Question 29

human evolution derived traits

Answer 29

• bigger brains
• upright posture & bipedal locomotion
• language and symbolic thought
• manufature and use complex tools
• shorter jaw
• shorter digestive tract

Question 30

human evolution

Answer 30

• closest living relative: chimpanzzess
• share common ancestor with simps, DID NOT EVOLVE FROM THEM
• derived 8-10 mya

Question 31

homoninis

Answer 31

• 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

Question 32

homo genus

Answer 32

• genus apperead 2.4 mya

- homo sapiens only living member

Question 33

human migration

Answer 33

• eastern central africa -> everywhere else -> out of africa
• 3rd “ out of africa” migration- interbred with other hominins

Question 34

homo habilis

Answer 34

• handy man

- oldest evidence of tool use

Question 35

homo eretus

Answer 35

• 1st out of africa

Question 36

homo neanderthalensis

Answer 36

• europe and near east
• 200,000 to 28,000 years ago
• thick bines with a larger brain
• buried their dead
• made hunting tools

Question 37

homo sapiens

Answer 37

• 200,00 years old

- changes in cognition -> rapid geograpic expansion