That is interesting - one of the postulated prerequisites for sociality in insects is haplo-diploidy, where one gender is haploid and the other is diploid, like

That is interesting - one of the postulated prerequisites for sociality in insects is haplo-diploidy, where one gender is haploid and the other is diploid, like it happens in bees and ants. This leads to the curious outcome where sisters are closer related to their sisters than to their daughters: https://en.wikipedia.org/wiki/Haplodiploidy#Relatedness_ratios_in_haplodiploidy https://en.wikipedia.org/wiki/Haplodiploidy#Relatedness_rati... I assume these spiders are all diploid? Wikipedia says that part of the social behaviors in these spiders is that they don't discriminate towards foreign offspring. I'm reminded of Argentine super-colonies, which are ant species which form enormous colonies stretching several hundred kilometers but which may or may not be genetically distinct - one hypothesis as to why they cooperate and not fight is this: >the reason ants in the Mediterranean don't fight is that, although they are genetically diverse, they have lost the diversity in the genes that are involved in recognition and thus don't recognize each other as different. Source, 2004: http://news.stanford.edu/news/2004/april7/antstudies-47.html http://news.stanford.edu/news/2004/april7/antstudies-47.html Wonder whether these spiders have the same thing!