The warm and humid climate of tropical regions presents exceptional challenges for DNA preservation. The accelerated decay of DNA molecules leads to very short fragment lengths and high rates of chemical damage on the molecules withing a short time. Only by combining several methods such as NGS sequencing, targeted enrichment of human DNA and sampling of elements with high rates of DNA preservation can we reconstruct the genomes of the ancient inhabitants of these regions.
Additionally, tropical regions have been and continue to be severely impacted by the European invasions in the modern era. With European invasion came diseases, massacres, and forced labor, diminishing the numbers among the Indigenous populations. Forced displacement both on a global and regional scale, such as the transatlantic slave trade or the practice of blackbirding (enslaved by deception) in the Pacific Ocean, has changed the geographic distribution of Indigenous populations. As a result, the linguistic, cultural, and genetic landscape has changed dramatically. Furthermore, written accounts of the people inhabiting the islands at European contact are available solely from the colonizers, biased by the “European gaze” and individual agendas. These circumstances make it difficult to impossible to reconstruct population histories from present-day populations.