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Animal Diversity Yr 2 > Vertebrates 3 > Flashcards

Vertebrates 3 Flashcards

1
Q

What may the dimetrodon sail have been used for?

A
  • maybe sexual selection, maybe to gain heat
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2
Q

The pelycosaurs gave rise to the …, which gave rise to the …, which gave rise to the mammals

A

therapsids, cynodonts

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3
Q

In the mammals, the tail has become …, the vertebrae are more …, the anterior pelvic region is …, the … are reduced, the limbs are … the body rather than…

A

smaller, flexible, reduced, ribs, below, out to the side (allowing faster movement)

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4
Q

The reduction in ribs is thought to coincide with the development of the …

A

diaphragm

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5
Q

The non-mammalian synapsids are often referred to as the…

A

mammal-like reptiles

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6
Q

The non-mammalian synapsids are …, meaning all their … are the same

A

Homodont, teeth

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7
Q

The movement towards mammals changed the articulation of the …, and some of the previously large bones of the jaw have become incorporated into the … …. The teeth became …

A

dentary, middle ear, heterodont

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8
Q

Mammals have limbs below their body. This means that their movement is less … and their … stays still as they run. Their movement can help … their lungs with changes in volume as they run - making ventilation more efficient

A

undulatory, thorax, ventilate

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9
Q

It is believed that early mammals were small and …, … laying, … and solitary, with large … bulbs and a strong infant-mother bond

A

insectivorous, egg, nocturnal, olfactory

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10
Q

The movement of mammals towards a more active lifestyle also suggests a movement towards …

A

endothermy

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11
Q

What are the key unique features of mammals?

A
  • lactation and suckling

- hairs (may have originally started as a sensory structure, then became insulatory structure)

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12
Q

Most mammals are … (in terms of their teeth) and have precise …

A

diphyodont (two same sets of teeth), occlusion (teeth fit together)

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13
Q

In mammals the lower jaw is …, allowing sideways movement to process food

A

narrower

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14
Q

Precise occlusion is not possible in … (found in reptiles, non-mammal synapsids)

A

polyphyodonty

  • therefore diphyodonty preceded precise occlusion
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15
Q

How could diphyodonty have evolved?

A
  • adult didn’t require teeth until later in life once jaw fully formed - fed milk early in life
  • -> must have evolved lactation first
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16
Q

How did lactation evolve?

A
  • Mammary glands related to apocrine glands (related to hairs - think monotremes) - originally secreted aggregating pheromones - milk may have been produced to protect eggs from desiccation and microbes - then evolved as nutritious secretion
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17
Q

Males also have mammary glands (except …) - some bats actually …

A

marsupials, lactate

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18
Q

What is the evolutionary advantage of lactation?

A
  • production of offspring separated from seasonal food supply
  • Mother not dependent on paternal care (more potential for male reproduction
  • Young can be born at small body size
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19
Q

Lactation helps mammals cope with…

A

patchy food supplies

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20
Q

Suckling has evolved by the production of … … in the pharynx which prevent fluids from entering the lungs and stomach in an uncontrolled way

A

tight seals

  • because have secondary palate that separates
  • can breath and feed at same time
  • allows baleen whales to feed in the way that they do
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21
Q

Mammals also have more development of … muscles

A

facial

  • more manipulation of food before it is swallowed
  • homologous with neck constrictor muscles in reptiles, which swallow larger bits of prey)
  • has meant that mammals can display facial expressions (now used in communication)
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22
Q 
Prototheria
   - ...
Theria
  - ...
  - ...
A

monotremes, metatheria (marsupials), eutheria (placentals)

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23
Q

Monotremes have a single …

A

cloaca

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24
Q

The platypus is rich in … and … receptors

A

mechanical, electrical

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25
Q

There are … orders of marsupials, four of which occur in …, the others ocurring in the Americas

A

7, Australasia

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26
Q

What are the unique characteristics of the metatherian mammals when compared to the eutheria?

A
  • usually possess an opposable digit on the hind foot
  • generally more incisors and molars but fewer pre-molars
  • bifurcated reproductive tract - penis, vagina
  • (pouch/marsupium present in 50% of species)
  • young more altricial (1% body mass)
  • lower body temp and basal metabolic rate
  • smaller relative brain size
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27
Q

What does diprotodont mean?

A

2 procumbent lower incisors

- biggest metatheria order is diprodontia

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28
Q

The marsupial mole is a fantastic example of…

A

convergence

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29
Q

The marsupials split from the eutherian mammals around … in …

A

100MYA, Gondwanaland

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30
Q

At the KT extinction, approximately … of all genera became extinct

A

50%

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31
Q

Australia-Antarctica split occured approx …

A

45MYA

32
Q

There is a deep trench in the sea between PNG+Australia and Asia, called the … …, which represents the biogeographical division of the placental and marsupial mammals - the two land masses have never met

A

Wallace line

33
Q

Marsupial females:

A
  • 50% have marsupium (pouch)
  • Sperm is transferred via paired vaginae
  • Birth occurs via a pseudovaginal canal
  • Two Uteri
  • Few have simple placenta
  • Highly altricial young with short gestation
  • Flexible reproduction - can have new born attached to nipple, fertilised blastocyst in uterus and young at foot
  • Similar oestrus cycle to eutherians (controlled by same hormones
34
Q

Marsupial males:

A
  • Combined urogenital track - cloaca (both males and females)
  • Scrotum in front of split penis (bipartite)
35
Q

What are the costs of placental mammals?

A
  • can’t offload embryo (long gestation)
  • Female structure (and fitness) has to be altered for birth (pelvic girdle)
  • Placentals had to develop trophoblast to protect embryo
36
Q

What are the costs of marsupial mammals?

A
  • Restriction of forelimb development

- Reduced brain size - opportunity to learn by observation rather than work things out

37
Q

Over … species of marsupial are listed as having some level of concern in Australasia

A

200

  • massive extinctions that may be result of colonisation by aboriginal humans
  • accelerated when Europeans reached Australia and South America
  • And extinctions during Pliocene when North American Eutherians invaded

+ 2/3 of marsupials are endangered

38
Q

How has Australia tried to conserve marsupials?

A
  • Introduced herbivores - BAD
  • Introduced predators (but more successful hunting marsupials as introduced herbivores had coevolved with predator)
  • Changed fire regimes
  • Burrowing Boodie now in 4 islands when used to be over majority of Australia
39
Q

How many primate species are there?

A

around 250

- restricted to tropical regions for the most part, mostly arboreal

40
Q

Most primates are general …, whereas some are specialist … eaters with … fermentation

A

omnivores, leaf, cellulose

41
Q

How long ago did the earliest true primate exist?

A

55MYA

42
Q

What are the four main groups of primates?

A
  • Prosimians (Simoidea) - basal primates - lemurs and bushbabies
  • New World Monkeys (Ceboidea) - marmosets, tamarins, spider monkeys
  • Old World Monkeys (Cercopithecoidea)- macaques, baboons, langurs
  • Apes (Hominoidea) - lesser apes (gibbons and siamang), great apes and humans
43
Q

What are the characteristics of the primates?

A
  • Opposable thumbs
  • 4 Pentadactyl limbs (exceptions)
  • Nails on fingers
  • Large brain
  • Shoulder joint permits movement in all directions + elbow joint permits rotation of forearms
  • Reduced snout + reduced no of teeth
  • Usually one young per pregnancy
  • Retention of clavicle
  • Most features are attributed to arboreal lifestyle and large body size
44
Q

The Strepsirrhini are the “… …”, the tarsiers and prosimians and the Haplorhini are the “… …”, all other primates

A

wet noses, dry noses

45
Q

What are the characteristics of the Strepsirrhini?

A
  • Usually small
  • Nocturnal
  • Long snouted
  • Less fusion in skull bones, lack of postorbital closure
  • Africa + SE Asia
  • Lemurs native to Madagascar, more diverse with large species (cf. apes) in the past
46
Q

What are the catarrhini?

A

Narrow nosed primates - old world monkeys and apes

47
Q

The old world monkeys are more … and …-rich than apes

A

specialised, species

48
Q

The catarrhini have two …

A

premolars in each quarter

49
Q

What are the old world monkey groups?

A
  • Colobines (fruit eaters, complex fore-stomach, arboreal, stub thumbs, back limbs longer)
  • Cercopithecines (omnivorous, increasingly terrestrial - short tail, limbs equal length)
50
Q

What are the Platyrrhini?

A

Broad nosed monkeys - a group of new world monkeys - 3 premolars

51
Q

What are key characteristics of the Hominidea?

A
  • broad thorax and dorsal position of scapula - assist balance in a bipedal pose, centre of gravity near vertebrate column
  • Caudal vertebrae reduced (usually no tail)
  • Front skull characterised by sinuses
  • Five cusps on molars (only for on OWM)
  • Critically endangered
52
Q

Give e.g.s of monogomous primates

A

gibbons, tamarins, lemurs

53
Q

Give e.g.s of solitary primates

A

Bushbabies, orangutans

54
Q

Give e.g.s of species that show male transfer social systems

A

Most cercopithecines (male hierarchy system)

55
Q

Give e.g.s of species that show female transfer social systems

A

Chimp, gorilla, baboons, colobus (territorial male behaviour, sometimes kinship groups)

56
Q

Downward nostrils evolved in the..

A

old world monkeys onwards

57
Q

The tail is lost in the…

A

apes (+ some old world such as barbary macaque)

58
Q

Spider monkeys have a … tail

A

prehensile

59
Q

All primates have …-… eyes

A

forward-facing

60
Q

Callosities are present in the…

A

old world monkeys and apes (except humans)

61
Q

Colobus and spider monkeys only have thumbs…

A

on their feet

62
Q

Gibbons are sexually dimorphic in their …. Great apes are sexually dimorphic in their …

A

colour, size

63
Q

Lemurs have a … claw

A

grooming

64
Q

Orangutans can walk ….

A

bipedally

65
Q

Most mammals are …, and along the lineage they improved their night vision by…

A

nocturnal, losing some colour vision that had evolved before (lost 2 different colour cones and mostly became dichromatic, when ancestral vertebrates where tetrachromatic)

66
Q

In the primates, colour vision has …

A

re-evolved

67
Q

The more opsin pigments you have the more…

A

colours you can perceive (monochromatic = 1 pigment, dichromatic = 2 pigments etc.)

68
Q

What are the 3 types of colour vision in primates?

A
  • Dichromacy (red/green colour blind)
  • Routine trichromacy (OW + Apes + Howlers) - convergently evolved
  • Allelic trichromacy (NW) - polymorphic
69
Q

Cone cells in the retina contain photopigments called … that “see” colour

A

opsins

70
Q

In primates, each cone cell has its own …. The signals are not “pooled” so genetic mutations CAN lead to new colour signals

A

innovation

71
Q

The genes for short wavelength (blue) opsin are on chromosome …, whereas the genes for medium (green) and long (red) wavelength opsins are on the … chromosome

A

7, X

  • why 1/12 males are red/green colour blind whereas only 1/200 females
72
Q

Most new world monkeys are…

A

dichromatic (red-green colourblind - only have short and long opsins)

73
Q

Dichromats may be better at distinguishing…

A

camouflaged predators/prey

74
Q

Howlers are the most … monkeys in the new world, enforcing their need for routine trichromacy

A

folivorous

75
Q

Dichromatic New world monkeys were more frantic with their foraging, touching, sniffing and biting more fruit. Trichromats make fewer mistakes but forage more slowly and measuredly. This suggest..

A

there may not be an advantage to trichromacy in these polymorphic species

76
Q

Whilst trichromacy is no doubt advantageous for detecting …, dichromacy may be more effective when detecting…

A

fruit, the ages of leaves

Animal Diversity Yr 2 (6 decks)

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