Signals from Appearance

Question 1

What are signals?

Answer 1

• Signals are traits that change another organisms behaviour
• Signals benefit the sender and have evolved for this function
• Signals are effective through the evolved response of the receiver
• The receiver need not have a desirable payoff from attending to the signal, but some kind of benefit does occur
• A signal must be useful enough for a receiver to attend to it
• This can create the pressure for occasional deceptive signals
• Signals can allow other animals to be used as tools

Question 2

Signal systems: Spangled drongo

Answer 2

• Gives occasional deceptive calls for multiple species, eats food as meerkats run off

Question 3

What keeps a signal system working?

Answer 3

• Costs
• Signals have an associated cost that depends on the conflicting interest between sender and receiver
• Can be described as an evolutionary arms race

Question 4

What are signals in mate choice?

Answer 4

• Conflict of interests
• Exaggerating fitness
• Detecting exaggeration
• If the signal is not costly then the system collapses

Question 5

What are the signals in parental investment

Answer 5

• Conflict of interests
• Chicks exaggerate need for self benefit (feeding)
• Inflict cost on siblings and parent’s fitness
• Manipulation of parents

Question 6

What kind of costs are associated with signals?

Answer 6

• Costs can be direct (via signal production) or indirect (via consequences of false signal/production)

Question 7

Distilling signals method

Answer 7

• Facial photographs of large number of people with neutral expressions
• Profiles of each person:
  1. Personality (Big 5)
  2. Health in daily life
  3. Sociosexual orientation

Question 8

What are signals from human skin?

Answer 8

• Skin can change over short term periods, accurately reflecting current condition
• Cannot maintain good skin condition unless in a good condition
• Skin condition is an honest signal of health

Question 9

Source of skin health signal: Texture

Answer 9

• Homogenous texture signals absence of parasites or disease

Question 10

Source of skin health signal: Colour

Answer 10

• Facial redness associated with oxygenated blood –> observers prefer oxygenated colouring