In some of my previous posts I was discussing about the origin of matriliny. Some of the points I made during the argument based on the findings of other anthropologists;
- Whereas patrilarchy is about exclusive male rights; matriliny is about equal rights (except in the case of politics where it was a male privilege)
- Only tribes in food abundant regions could develop equal rights society because division of labour wasn't there and both men and women participated in hunting
- All civilizations were created in regions where male was the primary warrior. Thus original civilizations were naturally patriarchal
- It's possible for matrilineal civilizations to come up if the tribes in food abundant regions come into contact with sedentary civilizations people who aren't part of ruling classes
- Tulu tribes (tribes part of present day Kerala and Tulu regions) became matrilineal as they were part of food abundant regions and met mostly merchants-artisans from the sedentary civilzation of the north
I think I need to make a drastic change in this theory.
I am proposing Kerala and Tulu regions became matrilineal because there was a huge male migrant population to these coastal regions which resulted in imbalance in male-female ratio and thus polyandry was the only option left. Thus the children became part of mother's family as that was the only sensible thing for civilized migrants.
Of course, this theory has precedence in another theory with a opposite scenario. According to one theory about matriliny in Kerala, it had been argued that during hundred years of Chera-Chola war, Nayars lost a lot of men and there were excess of Nayar women. Thus a new type of familial relationship was created (called Sambandham) where men and women had relationship only for sex. Anyway, this has been discredited since hundred year Chola-Chera war itself has been considered a mere legend. I would say there are too many other reasons to reject it.
Even if Chola-Chera war was indeed the case then Central and South Kerala regions should have shown very strong matrilineal traditions but only Malabar (north Kerala) one could find matriliny across majority of the castes and tribes. Also, Matrilineal traditions were common in Tulu region too without the caste and tribe divisions(with exceptions everywhere). In Tulu region many castes share the same lineages.
Now coming to my new theory, let's discuss what would have happenend if Kerala and Tulu regions received a greater number of male migrants than there were tribes pre-existing in that region. We should note that these two regions had active trading relationship with Greeks, Romans and Semites. There was every reason for merchants and their workers to stay back build a life there. But how would they find females for procreation. Probably, if the number of migrants isn't very large as compared to the native population, speculating the longest male wait and earliest female readiness every person could have found a bride. But if the scenario is beyond such adjustments then I would suppose only polyandry could have helped them.
I believe once the polyandry gave rise to equilibrium in sex-ratio after few generations depending upon the rate of migration, the most people would have gone back to monogamous life (or polygynous). But I suppose if it takes many generations to reach the equilibrium then the aspects of polyandry become ritualized. This plausibly the reason behind matrlineal civilzation of Tulu and Malayali regions. It should be noted that even polyandry has become ritualized for certain castes and tribes even after an equilibrium had been reached in the sex ratio.