Sexual Selection + Raising Young

Question 1

Secondary Sexual Characteristics

Answer 1

• Not part of reproduction but develops during sexual maturity - results in sexual dysmorphism ⇒ gives selective advantage

Question 2

Direct Secondary Sexual Characteristics

Answer 2

Weapons, size (for physical competition)

Question 3

Indirect Secondary Sexual Characteristics

Answer 3

Ornaments (attracts mates)

Question 4

Conflict between males (Intrasexual)

Answer 4

e.g red deer conflict during breeding season (rut)

• Dominant males compete to take each other harems
• Multiple stages to assess strength ⇒ to minimise actual fighting

Question 5

Cuckoldry

Answer 5

Males who invest parental effort to offspring that isn’t theirs

Question 6

Parental Cuckoldry

Answer 6

Will mate and guard offspring

Question 7

Sneaker Cuckoldry

Answer 7

Will wait until nests are unattended to fertilise eggs in nest

Question 8

Satelite Cuckoldry

Answer 8

Will disguise as female then fertilise

Question 9

Female Choice

Answer 9

• Has more to invest as energy and resources go int gestation
• Have more to lose so chooses carefully (mating with wrong male could be a waste of a year’s supply of eggs)

Question 10

Why females choose a particular mate? - Direct Benefits

Answer 10

• Access to food
• Shelter/protection
• Parental care
• Nuptial gifts (e.g. nutrients in sperm, prey etc.) ⇒ could be manipulation / distraction

Question 11

Why females choose a particular mate? - Good genes

Answer 11

• code for favourable traits depending on environment
• need to be selective to avoid relatives, males may give impression of favourable traits
• selection pressure is for traits that can’t be cheated
• honest indicators e.g. parasite resistance in black birds is seen in an orange beak from caratanoids

Question 12

Runaway sexual selection

Answer 12

Evolution of exaggerated male ornamentation

Question 13

Sensory Exploitation

Answer 13

Preference for a male trait emerges as it elicits neurobio response in females that weren’t initially related to mate preference e.g. red in primates

Question 14

Parent-Offspring Conflict

Answer 14

• have to think how much aid to give current offspring + energy to save on future offspring

Question 15

Example of Parent-Offspring Conflict - Case Study of Primates

Answer 15

• Weaning conflict - rhesus macaques are seasonal breeders - prev. infant has to wean to enable breeding
• carrying conflict
• temper tantrums

Question 16

Is Begging for attention reliable for animal offspring?

Answer 16

Assumptions ⇒ parents respond with increased provision - should be costly + vary to relate to need

• Is it reliable?
  
  • vocal displays most common - cardueline finches gape changes colour
  • parents increase provisioning with signal intensity

Question 17

Sibling Rivarly

Answer 17

• Competing siblings can waste resources ⇒ can increase parent-offspring conflict
• Asynchronous birth e.g. eggs laid a few days apart to form brood hierarchies

Question 18

Insurance-Egg Hypothesis

Answer 18

• 2nd egg laid to ensure against infertility but parents cant raise both
• Surplus removed if older is viable

Question 19

Extended Family

Answer 19

• social learning + cultural transmission e.g. in Japanese macaque
• sweet potato given by researchers ⇒ washed by one individual ⇒ passed on to other in troop (SL) ⇒ new infants learn from mothers (CT)

Question 20

Dugatkin (2014) - Local Enhancement

Answer 20

• Drawn to particular environment by action of another

Question 21

Dugatkin (2014) - Social Facilitation

Answer 21

• Presence of another individual induce behavioural change