Complex sentence: These were the descendants of Tahitians and the HMS "Bounty" mutineers, along with Fletcher Christian that had resettled from the Pitcairn Islands, which had become too small for their growing population.
Split into simpler sentences: These were the descendants of Tahitians and the HMS "Bounty" mutineers, along with Fletcher Christian. They resettled from the Pitcairn Islands, which had become too small for their growing population.