Abstract
As a preliminary study for analysing human biology data, recently collected from Cook Islanders, the reliability of the data in representing the indigenous population of the pre-European period has been assessed in three islands of the Cook group, Rarotonga, Mangaia, and Pukapuka, in terms of the population changes since European contacts and the ongoing process of mixture with foreign strains and of inter-island crossbreeding among the residents. All the islands surveyed suffered a decline in population after European contacts to a moderate extent, but the degree was far slighter than many islands in Eastern Polynesia, suggesting that random genetic drift did not so seriously affect these island populations as to change the genetic compositions significantly. Concerning gene flow from outside through European admixtre and inter-island crossbreeding, the effect appeared to have advanced profoundly on Rarotonga, slightly on Mangaia, but rather negligibly on Pukapuka. It has been concluded that the present-day populations of Pukapuka and probably of Mangaia are still qualified enough to represent the prehistoric indigenous populations, but that on Rarotonga, even living pure-blood Polynesians cannot be considered as representative of the pre-European Rarotongan population.
