Table 1 Overview of notation.

From: Coevolution of parental investment and sexually selected traits drives sex-role divergence

Symbol

Meaning

T

Female care duration

n

Number of females per breeding attempt

k

Strength of sexual selection on females (proportion of maturing females qualified to mate)

μ I , μ O

Female mortality during time-in and time-out

x

Female competitiveness

r

Maturation sex ratio (MSR)

M

Mate search coefficient

α

Shape coefficient of brood survival function

γ

Synergy coefficient

τ

Expected care duration per brood provided by a given female (accounting for the possibility that she may die during care)

a

Mating rate of female qualified to mate

p

Probability to survive a given time-in period (for female qualified to mate)

s

Probability to survive a given time-out period (for caring female)

b

Brood size

S

Brood survival

W

Fitness of average female

v

Reproductive value of average female

r O

Operational sex ratio (OSR)

r A

Adult sex ratio (ASR)

  1. Corresponding male symbols are obtained by marking female symbols with a tilde ().