chapter 34 - origin and evolution of vertebrates Flashcards
1
Q
how many species of vertebrates are there?
A
65,000
2
Q
chordates
A
bilaterian animals that belong to clade Deuterostomia
- all vertebrates and two groups of invertebrates:
- urochordates
- cephalochordates
3
Q
all chordates share a set of these four traits:
A
- notochord
- dorsal, hollow nerve cord
- pharyngeal slits or clefts
- muscular, post-anal tails
4
Q
longitudinal, flexible rod between the digestive tube and nerve cord (spell)
A
notochord
5
Q
dorsal, hollow nerve cord
A
- develops from plate of ectoderm, rolls into a tube dorsal to notochord
- develops into CNS
6
Q
A
7
Q
grooves form along the outer surface of the pharynx in chordate embryos (spell)
A
pharyngeal clefts
8
Q
in most chordates grooves develop into…
A
pharyngeal slits, open to outside of the body
9
Q
functions of pharyngeal slits
A
- suspension-feeding structures in many invertebrate
- gas exchange in vertebrates (except tetrapods)
- develop into parts of the ear, head, and neck in tetrapods
10
Q
muscular post-anal tail
A
- posterior to the anus
- greatly reduced during embryonic development for most
- contains skeletal elements + muscles
- provides propelling force for aquatic species
11
Q
lancelets (cephalochordata)
A
- bladelike shape
- retain characteristics of chordate body as adults
12
Q
tunicates (urochordata)
A
- more related to other chordates than are lancelets
- like chordates during larval stage
- resorption of tail + notochord during metamorphosis
- adult draw in water + filter food
- shoot water through excurrent siphon
13
Q
earliest vertebrates lacked…
A
jaws
14
Q
lineages of jawless vertebrates today
A
- hagfishes and mapreys (myxini and petromyzontida)
- lack a backbone but presense of basic vertebrae - are vertebrates
15
Q
cyclostomes
A
hagfishes and lampreys clade of living jawless vertebrates
16
Q
hagfishes (myxini)
A
- cartilagnious skull
- reduced vertebrae
- flexible rod of cartilage from notochord
- small brain, eyes, ears and nasal opening
- all marine
- slime to repel predators
16
Q
A
17
Q
lampreys (petromyzontida)
A
- SW and FW habitats
- some are parasites
- feed as larvae for several years, die within few days of maturing + reproducing
- have a notochord and cartilaginous skeleton
18
Q
gnathosomes
A
- jawed vertebrates
- sharks, some fish, amphibians, reptiles, birds, mammals
- enlarged forebrain
- lateral line system
19
Q
rows of organs sensitive to vibrations that are located along each side of the body of aquatic gnathosomes (spell)
A
lateral line system
20
Q
earliest gnathosome appeared in fossil record around…
A
440 MYA
20
Q
early gnathosomes had armored vertebrates called… (spell)
A
placoderms
21
Q
chondrichthyans (sharks, rays, etc).
A
- skeleton mostly cartilage
- sharks have streamlined body, fast swimmers
- most carnivores, largest suspension feeder
22
Q
reproductive tract excretory system, and digestive tract empty into the… (spell)
A
cloaca
23
oviparous
- eggs mature and hatch outside mother's body
- embryo recieves all nutrition from egg yolk
- birds, reptiles, amphibians
24
ovoviviparous
- eggs retained within the oviduck; young usually bron after hatching within uterus
- internal fertilization
- embryo recieves all of its nutrition from the yolk content of the egg sacs
- sharks, rays, snakes, aquatic sp.
25
vivparous
- embryo develops within the uterus and is nourished from mother's blood through placenta, young born alive
- internal fertilization
- egg receives all nutrition from mother
- humans and most animals
26
majority of the vertebrates are...
osteichtyans, almost all have bony endoskeleton
- bony fishes and tetrapods
- aquatic ost. informally fish
27
most fish breathe by drawing water over gills protected by an... (spell)
operculum
28
fishes control their buoyancy with air sac known as a... (spell)
swim bladder
29
ray-finned fishes
- Silurian period (444-419 MYA)
- fins supported by long, flexible rays are modified for maneuvering and defense
- harvesting and industry fishery collapse
30
lobe-fins
- Silurian period
- rod shaped bones surrounded by a thick layer of muscle in their pelvic and pectoral fins
31
tetrapods have:
- four limbs and feet w/ digits
- neck
- fusion of pelvic girdle to backbone
- absence of gills (ex some aq. sp.)
- ears
32
tiktaalik "fishapod"
- fins, gills, lungs and scales like fish
- ribs, neck, front fins w/ bone pattern of tetrapod limp, pelvis and rear fin large like tetrapods
- likely walked in water but not land
33
amphibians
- 6,150 species in three clades
- salamanders, frogs, caelilians
- declining in recent decades
34
salamanders
- (urodela, tailed ones)
- some aquatic but others live on land
- paedomorphosis common in aquatic salamanders
35
frogs
- (anura, tailless ones)
- powerful hind legs
- leathery skin? toads
36
caecilians
- (apoda, legless ones)
- nearly blind, like earthworms
37
amniotes
group of tetrapods whose living members are the reptiles including birds, reptiles, mammals
38
what are amniotes named for?
major derived character of clade, the amniotic egg that contains membranes protecting the embryo
39
reptiles
- tuataras, lizards, snakes, turtles, birds, etc.
- scales, waterproof barrier
40
absorbing external heat as the main source of body heat (spell)
ectothermic, most reptiles, regulate temp thru behavioral adaptations
41
maintaining body temp through metabolism
endothermic, birds
42
early reptiles were
diapsids
43
leipidosaurs
tuataras, lizards, snakes, extinct mosasaurs
44
archosaur
turtles, crocodilians, pterosaurs, dinosaurs
45
pterosaurs
- first tetrapod w/ flapping flight
- extinct 66 MYA
46
dinosaurs
- diverse
- herbivores and bipedal carnivores called theropods
- also extinct at end of Cretaceous, 66 MYA
47
lepidosaurs
- two species of lizard-like reptiles called tuataras
- living in islands off of new zealand
- threatened by rats, rat eat their eggs
48
lepidosaurs other lineage
- squamates, lizards, snakes
- squamates can be 16 mm to 3 m long
- snakes are legless lepidosaurs, evolved from lizards w legs
49
snakes have...
- chemical sensors
- heat-detecting organs
- venom
- loose jawbones to dislodge and elastic skin
50
toxic
substance produced within living cells/organisms (virus, protein or peptide)
51
poison
substance that can cause illness or death when absorbed/ingested (mercury, puffer fish, ricin)
52
venom
a substance produced by an animal for self defense & injected into another animal (scorpion, stingers, fangs
53
if it bites you and you die it's...
venomous
54
if you bite it and you die it's...
poisonous
55
turtles
- several distinctive traits including lack of holes in skull behind eye socket
- boxlike shell made of upper and lower shields that fuse to vertebrae, clavicle, and ribs
- some adapted to deserts and others in sea
- many endangered from humans
56
crocodilians
- alligator and crocodiles
- late Triassic lineage
- restricted to warm regions
57
birds
- modified reptiles designed for flight
- wings w/ keratin feathers
- no bladder, 1 ovary, small gonads and no teeth
- escape and fly away wings
- high energy demand from flight
- elborate courtship
58
birds likely evolved from
theropods, group of carnivorous dinosaurs
59
feathers might have evolved earlier than flight for..
insulation, camoflauge, courtship display
60
oldest bird known
- archaeopteryx
- feathered wings, ancestral traits like teeth, claws, and a long tail
61
living birds
- Neornithes
- ratites are flightless birds
- penguines pectoral muscles "fly in water"
- some rails, ducks, pigeons
62
mammals
5,300+ species
63
derived characteristics of mammals
- mammary glands, which produce milk
- hair and a fat layer under the skin for insulation
- kidneys, which conserve water from wastes
- endothermy and a high metabolic rate
- efficient respiratory and circulatory system
- a large brain to body size ratio
- extensive parental care
- differentiated teeth
64
monotremes
- small group of egg-laying mammals
- platypus and echnidas
- baby gets milk from mother's fur
65
marsupials
- opposums, kangaroos, koalas
- embryo develop in uterus + placenta nourishment
- born very early
- nurses in a pouch called marsupium
66
eutherians
- complex placenta comp. to marsupials
- molecular (100 mya) vs morpho (60 mya)
- finish developing within uterus
67
primates
- lemurs, tarsiers, monkeys, apes
- humans part of apes
- hands and feet adapted for grasping, flat nails instead of claws
68
derived characters of primates
- large brain and short jaws
- forward-looking eyes close together on face, depth perception
- opposable thumb
69
groups of living primates
lemurs, tarsiers, anthropoids (monkeys and apes)
70
homo sapiens is about...
200,000 years old
71
characters to distinguish homo sapiens
- upright posture and bipedal locomotion
- larger brains higher learning and language
- reduced jaw bones and muscles
- shorter digestive tract
72
human and chimpanzee
- 99% genetically identical
- differ in expression of 19 genes
73
paleoanthropology
study of human origins
74
extinct species that are more closely related to humans than chimpanzees
- hominins (20 species discovered, 6.5 MYA oldest)
- bipedalism, 1.2 m tall
75
75
australopiths
- paraphyletic assemblage of hominins living between 4 and 2 MYA
- some walked fully erect
- robust had sturdy skulls + powerful jaws
- gracile had slender/lighter jaws
- long distances walking abt 1.9 MYA
- tool use 2.5 MYA
76
homo habilis
- 2.4-1.6 MYA
- "handy man"
77
homo egaster
- fully bipedal
- large brained hominid
- 1.9 and 1.5 MYA
- sexual dimorphism
78
homo erectus
- Africa
- first hominin to migrate out of africa
- 1.8 mya
79
neanderthals
- homo neanderthalensis
- europe and near east 350k-40k and 28k yrs ago
- thick-boned, larger brain than modern humans
- buried dead, hunting tools
80
homo sapiens
- oldest fossils of homo sapiens in Ethiopia, 195k and 160k years old
- all come from African ancestors
- next oldest middle east 115k years
- new world 15k years ago
- new member in 2015 Homo naledi
