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| "Onthophagus taurus male and female comparison" by Source (WP:NFCC#4). Licensed under Fair use via Wikipedia. |
This article by Garcia-Gonzalez and Simmons focus on the importance of the good genes model in female mate choice.
One
founding component of sexual selection is the existence of heritable
variation in fitness. The good genes model tells us that this variance
in quality is expressed phenotypically in the males and that females
base their mate choice upon a trait that represent the male's good
genes.
The dung beetle has shown condition dependence of
sexually selected traits and genetic correlations between preference and
trait, thus comes the logical next step to see if the fitness of the
father is inherited to the offspring.
Here they do a
quantitative genetic analysis with a full-sib/half-sib design to compare
the additive genetic effect of father on egg to adult and adult
viability between families (one male mated with three females).
They
found a significant effect of the father for egg to adult viability and
survival of sons but not daughters to adult age and no indication for
sexual antagonism in genetic variation for fitness.
The
authors argue for pre- and post-copulatory choice from females and
competition between males to give the female indirect benefit in terms
of higher offspring fitness in agreement with the good genes model.
Although this is not my current topic of research, I decided to share this article with you for three reasons.
First
of all, I have the possibility to do a similar project with Leigh
Simmons (one of the authors) as my supervisor in the future, second
because it relates with my ongoing project since they investigate
paternally inherited fitness in a quantitative genetic study with a
full-sib/half-sib breeding design and also discuss sexual antagonism
briefly. And last, because it is short and neat (only 4 pages).
See you on Tuesday!
Jessica Åhlén Sandblom
Abstract: Whether species exhibit significant heritable variation in fitness is
central for sexual selection. According to good genes models there must
be genetic variation in males leading to variation in offspring fitness
if females are to obtain genetic benefits from exercising mate
preferences, or by mating multiply. However, sexual selection based on
genetic benefits is controversial, and there is limited unambiguous
support for the notion that choosy or polyandrous females can increase
the chances of producing offspring with high viability. Here we examine
the levels of additive genetic variance in two fitness components in the
dung beetle Onthophagus taurus. We found significant sire
effects on egg-to-adult viability and on son, but not daughter, survival
to sexual maturity, as well as moderate coefficients of additive
variance in these traits. Moreover, we do not find evidence for sexual
antagonism influencing genetic variation for fitness. Our results are
consistent with good genes sexual selection, and suggest that both pre-
and postcopulatory mate choice, and male competition could provide
indirect benefits to females.
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