| Figure 1 -Insects showing different degrees of parental care. |
Parental care is a classic example an early developmental stage of altruistic traits, which
evolved to enhance the fitness of the recipients of care at the expense of the donor, in this case being the offspring and parents respectively (Royle et al 2012).
Although the vast majority of insect parents have no connection to their children beyond depositing the eggs, all eusocial insects have very thorough systems for defending and nurturing offspring (Wong et al 2013).
The initial evolutionary stage in parental care is mass provisioning (Wong et al 2013), where the female builds a nest, deposits an egg along with enough food to rear a single offspring, seals the nest and moves on to construct another. This already shows a large shift in energy spent per offspring compared with simply choosing a safe spot to lay an egg then abandoning it.
From there the next stage is progressive provisioning (Wong et al 2013), where the female builds a nest, lays an egg in it, then feeds or at least guards the hatching larva repeatedly until it matures. For species that lay larger broods this is the stage where group behavioural dynamics may start to be expressed and further develop.
The initial evolutionary stage in parental care is mass provisioning (Wong et al 2013), where the female builds a nest, deposits an egg along with enough food to rear a single offspring, seals the nest and moves on to construct another. This already shows a large shift in energy spent per offspring compared with simply choosing a safe spot to lay an egg then abandoning it.
From there the next stage is progressive provisioning (Wong et al 2013), where the female builds a nest, lays an egg in it, then feeds or at least guards the hatching larva repeatedly until it matures. For species that lay larger broods this is the stage where group behavioural dynamics may start to be expressed and further develop.
Continuing towards eusociality requires then that a female and her adult offspring do not disperse to start new, individual nests but instead remain together at the old nest (Toth et al 2012). At this point, group living dynamics become an increasingly important selection pressure, as more organised, cohesive groups will out-compete the others.
References:
References:
Royale, N.J, Smiseth, P.T., Kolliker M., The Evolution of Parental Care., 2012, Oxford University Press, Oxford, U.K.
Toth, A. L.et al. Wasp gene expression supports an evolutionary link between maternal behavior and eusociality, 2015, Science318,441–444
Wong, J.W.Y., Muenier, J. and Kolliker, M., The evolution of
parental care in insects: the roles of ecology, life history and the
social environment, 2013, Ecol Entomol, 38: 123-137. doi:10.1111/een.12000
Figure:
Figure:
Examples of different forms of parental care in insects, https://www.researchgate.net/figure/examples-of-different-forms-of-parental-care-in-insects-a-nest-building-in-the-wasp_fig1_291969783, 23/05/2020
This seems to be quite a crucial step. In what circumstances/conditions do you think the benefits of staying and investing in the current brood would be greater than the benefits of just producing more offspring?
ReplyDeleteThis is probably the most perplexing step to be honest. Even mass provisioning is a huge leap in parental energy so it's hard to think that it would be done out of any other reason than necessity. Perhaps environmental pressures changed such that leaving an egg with sufficient food became necessary?
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