Data from: Direct and indirect genetic effects in life history traits of flour beetles (Tribolium castaneum)

Indirect genetic effects (IGEs) are the basis of social interactions among
conspecifics, and can affect genetic variation of non-social as well as
social traits. We used flour beetles (Tribolium castaneum) of two
phenotypically distinguishable populations to estimate genetic
(co)variances and the effect of IGEs on three life-history traits:
development time (DT), growth rate (GR), and pupal body mass (BM). We
found that GR was strongly affected by social environment with IGEs
accounting for 18% of the heritable variation. We also discovered a
sex-specific social effect: male ratio in a group significantly affected
both GR and BM. That is, beetles grew larger and faster in male-biased
social environments. Such sex-specific IGEs have not previously been
demonstrated in a non-social insect. Our results show that beetles that
achieve a higher BM do so via a slower GR in response to social
environment. Existing models of evolution in age-structured or
stage-structured populations do not account for IGEs of social cohorts. It
is likely that such IGEs have played a key role in the evolution of
developmental plasticity shown by Tenebrionid larvae in response to
density. Our results document an important source of genetic variation for
GR, often overlooked in life-history theory.