What is lek ?
A gathering of males of a spieces, to compete for mating by extravagant visual or aural
displays ( such as mating dances, plumage displays or vocal challenges )
o Befre and during the breeding season
o Take up/guards the same individual position/territory on a leg mating area ()
territory or court) –personal spaces
o The most desiable male ( top ranking male) (alpha male ) occupies the most
prestigious central territory
o Females come to the arena when the heirachy is established, and prefertially
mate with the dominants in the centre of the arena
Why do females prefer elaborate male sexual characteristics, when it provides no direct benefit to her
or her offspring? ---what’s the reason of such strategy of sexual selection ?
Under this system, what are the sexual characteristics attractive to female ?
o no resources to females; no parental care to offspring
o Hence the female gain /benefit is indirect in the form of ‘good gene’
The female should choose the apha male who can confer good gene s
that can increase the survivial and reproductive fitness for the offspring,
but is this really implied by elabotrate disoplay??
So the question is : do these elaborate male sexual characteristics
convey ‘useful’ information to females /good genes to offspring that can
increase their SR fitness?
Zahavi: yes, only if the traits confer a handicap on the male
o Because if it’s handicap on the survivial of the male, then it’s deleterious to the
males’ survivial, and ehnce
increased risk under predation
more time and energy expenditure in maintaining it
ie, they have already withstood the costs to having thise traits
o hence it becomes a test that by which female can assess the male quality
The lek paradox
Miller, Christine and Allen Moore. (2007). "A potential resolution to the lek paradox through indirect
genetic effects." Proceedings of the Royal Society B: Biological Sciences 274:1279-1286
leads to persistent female choice for one male trait values
o hence decrease genetic variance in male population this may remove the benefits of choice ( to eliminate the less fit, and keep the
more fit alleles) , so this type of sexual selection should be eradicated through
evolution, since it doesn’t benefit the speices variance
but this type of sexual selectrion ( female choice) still persist!!!!
o The mistery of why genetic variation persist among male population in the face of persistent
/consistent female preference towards a particular trait ---is called ‘lek paradox’
o Hwo to explain the existence of such mistrery?
The existence of genetic variation may be due to the ocrrence of mutation ,
which inctroduce potential differences
Also because , the elaborate trait may convey recessive alleles, which may not
show in the phenotype, but inherited in the recessive form and later in the