====== Cooperative breeding ======

In //Cooperative breeding,// individuals contribute towards the care and upbringing of offspring //which are not their own.// It's found in many species of birds,<sup> </sup>mammals, fish, and insects.*

The behaviour has puzzled evolutionary biologists for many decades, given that individuals apparently sacrifice some of their own breeding prospects in order to increase the potential of the species as a whole.

>A behaviour is cooperative if it provides a benefit to another individual and if it has evolved at least partially because of this benefit]. Such behaviours pose a problem to evolutionary theory because — all else being equal — they would reduce the relative fitness of the performer of that behaviour and hence be selected against.\\ \\ Source : {{:oa_padlock_grn.png?16}}[[https://www.cell.com/current-biology/fulltext/S0960-9822(07)01499-6?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982207014996%3Fshowall%3Dtrue|Current Biology, Volume 17, issue 16, pp. 661-672,]]

Many explanations have been put forward, notably from William Hamilton in 1981 ([[https://www.science.org/doi/10.1126/science.7466396|ref.]] {{:oa_padlock_red.png?16}}<sup>[  paywalled ] </sup>)  - but, to date, there is still no general agreement on any particular theory, or which combinations of factors might contribute to the behaviour.

Further reading : [[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427589/|Life histories and the evolution of cooperative breeding in mammals]] {{:oa_padlock_grn.png?16}}//Proc Biol Sci.//  279(1744): 4065–4070.

//*Note :// There are many examples of human cultures which have (or have had) very co-operative child-rearing strategies.