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Anthro > Natural Selection (2) > Flashcards

Natural Selection (2) Flashcards

1
Q

What will we be reviewing: 5

A

1) Parental Investment (PI)
2) Different level of PI for males/females
3) Differences in potential reproductive output in XX & XY
4) The difference in Variances in fitness XX & XY
5) Difference factors limiting fitness for XX & XY

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2
Q

Note) Kin selection and reciprocal altruism explain

A

Altruism

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3
Q

Parental Investment explains?

A

Sex differences in behaviour (Morphology)

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4
Q

Parental Investment is NOT a reformation of Darwins Theory of Sexual Selection T or F?

A

FALSE - Parental Investment IS a reformation of Darwins Theory of Sexual Selection

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5
Q

Sexual Selection (3)

A

1) Proposed by Darwin
2) Explain Secondary Sexual Characteristics
3) Sexual Dimorphism

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6
Q

Sexual Selection - Darwin - Attributes secondary sexual characteristics to …..

A

sexual selection

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7
Q

What are secondary sexual characteristics? (2)

A
  1. Male / Female distinctions that appear at puberty.
  2. The distinction between men and female that go beyond reproductive differences
  3. ex) larger teeth, difference size, coloration
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8
Q

Why was another mechanism needed to explain these features - Secondary Sexual Characteristics

A

ARE NOT easily explained by NATURAL SELECTION

1) Not beneficial to survival
2) Are sometimes detrimental to the survival
3) Don’t appear until puberty - can’t be part of the competition for survival to adulthood

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9
Q

According to Darwin, Secondary Sexual Characteristics evolved due to (3)

A

1) Male- Male Competition (intracompetition)
2) Female Choice (Introcompetition)
3) Fall under the umbrella of sexual selection

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10
Q

According to Darwin, Secondary Sexual Characteristics evolved due to …. Male - Male Competition (3)

A

1) Intra - On the inside (within)
2) Members of ones sex (usually males) compete with other members in a process called intrasexual competition
3) Secondary sexual characteristics give males fitness advantage via intra competition

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11
Q

According to Darwin, Secondary Sexual Characteristics evolved due to …. Male - Male Competition should lead to the appearance of..

A

1) Traits associated with winning battles
2) Traits for advertising a male’s competitive ability
3) Think about the GELADA’S LONG CANINES

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12
Q

What is so special about the Geladas (2)

A

1) Long canine

2) Eat grass and teeth are not for hunting!

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13
Q

According to Darwin, Secondary Sexual Characteristics evolved due to …. Female Choice ( intersexual Selection_

A

1) Darwin hypotheisized that some traits (women mainly) evolved not for survival but BECAUSE women preferred them
2) Make females more attracted to males (male secondary sexual characteristics)

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14
Q

Sexually Selected Traits due to Female Choice Examples (4)

A

1) Skin colouration
2) Ornaments
3) Behaviour / Acoustic courtship
4) Pelage (fur)

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15
Q

Sexually Selected Traits due to Female Choice Examples -Why might a female be attracted to these traits?

A

Wasting energy shows possession of energy

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16
Q

Sexually Selected Traits due to Female Choice Examples of wasting energy to show possession of energy

A

Indian Peafowl

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17
Q

Sexually Selected Traits due to Female Choice Examples of wasting energy to show possession of energy - Indian Peafowl (2)

A

1) Longtails require energy

2) Long tells shows you have expendable energy therefore expensive trait / sexy

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18
Q

Natural Selection & Sexual Selection - What’s the bottom line?

A

Biological fitness

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19
Q

Natural Selection & Sexual Selection - What’s the difference? ***** (4)

A

1) NS operates on survival, SS operates on fitness
2) NS emphasizes getting to adulthood and staying alive as long as possible
3) Once an adult - SS kicks in whereas NS kicks in since day one
4) SS operates more on men
5) SS is a social environment rather than the traditional environment of survival of the fitess

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20
Q

Who is Triver? (2)

A
  • Applied the principles of sexual selection to male-female behaviour as well as morphology
  • That parental investment is a key variable controlling Sexual Selection
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21
Q

What is Parental Investment?

A

Any investment by the parent in an individual offspring increases the offspring chances of survival ( and hence fitness) at the cost of the parent investing time in another offspring

22
Q

Parental Investment (3)

A

1) Investment by the parent in an individual offspring
2) hence increases offspring fitness
3) Cost = investment to other offspring
- Limited investment budget

23
Q

What are the three conflicts in parental investment? (3)

A

1) Successive offspring issue - limited budgets
2) Parents and new offspring balance
3) Different parental roles and cost

24
Q

What are the three conflicts in parental investment? - Different parental roles and cost - What is the difference between males and female cost

A

Females have high-cost whereas males have low cost

25
Q

What are the three conflicts in parental investment? - Different parental roles and cost - Name four parental investment cost to females (4)

A

1) (Anisogamy) Large nutrient eggs
2) A limited number of eggs
3) Gestation cost is high
4) Lactation (Lactational Amenorrhea)

26
Q

What are the three conflicts in parental investment? - Different parental roles and cost - Name four parental investment cost to males (4)

A

1) Tiny sperm eggs
2) An infinite number of sperm eggs
3) No Gestation
4) No Lactation

27
Q

What are the three conflicts in parental investment? - Different parental roles and cost - Name four parental investment costs to females - What is Anisogamy?

A

Sexual reproduction by the fusion of dissimilar gametes (conception) Female Gamete is BIG and contains cytoplasm organelles needed for reproduction. Very expensive

28
Q

What are the three conflicts in parental investment? - Different parental roles and cost - Name four parental investment costs to females - What is Gestation?

A

The period where the mother is pregnant very high in time / energy

29
Q

What are the three conflicts in parental investment? - Different parental roles and cost - Name four parental investment costs to females - What is Lactation?

A

Secretion of milk from mammary gland (titties) provides nutrients to the infant. VERY expensive

30
Q

What are the three conflicts in parental investment? - Different parental roles and cost - Name four parental investment costs to females - What is Lactational Amenorrhea

A

Temporary fertility that occurs after a female gives birth when she is BREASTFEEDING (hormones)

31
Q

What are the consequences of sex differences in parental investment? Females

A

Sexually mature females spend most of their times either pregnant or lactation period

32
Q

do most females reach menopause?

A

No, menopause is when your period stops = not sexually viable

33
Q

What are the consequences of sex differences in parental investment? Males 3

A

1) Very competitive and rare because
2) Sexual mature women spend most of their time either pregnant or in a state of lactational amenorrhea
3) Cost to reproduce is trivial for men

34
Q

Sex and Optimal Strategies for each party - Trivers MAIN claim - Males strategy

A

Go for as many fertilization as possible and move on - little or nothing to lose energy-wise - Be a playa / dead beat

35
Q

Sex and Optimal Strategies for each party - Trivers MAIN claim - Female strategy

A

Be very choosy

-Males must provide assistance, territory, good genes

36
Q

Sex and Optimal Strategies for each party - Trivers MAIN claim - Female strategy - What must male provide (30

A

1) Assistance
2) Territory
3) Genes

37
Q

Important point - it not about being __ & __ per say, but about the level of Pi this is what determines ____ & ____

A

Male & Female

Sex differences!

38
Q

The more similar the level of parental investment between the sexes, the more similar the sexes will be in (2)

A

1) Behaviour

2) Morphology

39
Q

The Different level of parental investment corresponds with many

A

behaviour and morphology

40
Q

Three VERY important parental investment between male * females (3)

A

1) Potential Reproductive Output
2) Variation in reproductive success
3) Limiting factors

41
Q

Three VERY important parental investment between male * females - Potential Reproductive Output - Total reproductive output for females primates is limited (3)

A

1) Have a reproductive lifespan
2) Their interbirth interval
- gestation
- Lactation
- Lactational Amenorrhea
3) Low reproductive potential relative to males

42
Q

Three VERY important parental investment between male * females - Potential Reproductive Output - Total reproductive output for males primates is high (3)

A

1) Males reproductive output is correlated with their ability to find conceptive females
2) If he has high access to conceptive females - he can have high reproductive success
3) Males have higher reproductive success

43
Q

Females have a higher reproductive output than males - t or f

A

FALSE

44
Q

Three VERY important parental investment between male * females - Variance in reproductive success - Females

A

1) Females tend to have the same variance in the number of babies they have. Even in hierarchies structures. = Low variance
2) Females compete but not over males USUALLY

45
Q

Three VERY important parental investment between male * females - Variance in reproductive success - Males (2)

A

1) Males high levels of reproductive variance. Some dudes ball while other flops
2) Higher competition for females

46
Q

Three VERY important parental investment between male * females - Limiting factors - Females

A

Limited by access to energetic resources

47
Q

Three VERY important parental investment between male * females - Limiting factors - Males

A

Limited by access to reproductive opportunities

48
Q

Summary: Parental Investment - Men Vs women

A

Low vs high

49
Q

Summary: Potential Reproductive Output - Men VS women

A

High vs low

50
Q

Summary: Variance in reproductive success - Men VS women

A

HIgh vs low

51
Q

Summary: actor Limiting reproductive success - Men VS women

A

Access to fertile females - Access to energetic food

Anthro (12 decks)

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