The ravages of World War II — particularly the destruction of Manila in 1945 — continue to haunt the Philippines even almost a century after they happened, as evidenced through the difficulty in the search for native Manileños.

Since 1996, researchers from the University of the Philippines – Diliman College of Science (UPD-CS) Natural Sciences Research Institute’s (NSRI’s) DNA Analysis Laboratory have been surveying the genetic ancestry of Filipinos across the country. More recently, the laboratory’s ambitious Filipino Genomes Research Program (FGRP) has aimed to document and understand the rich diversity of Filipinos’ genetic heritage. The study’s findings, when completed and made available, will have far-reaching implications on many fields, from forensics and medicine to history and anthropology.

But despite the program’s urgency and lofty goals, there is at least one place in the country where genetics and local ancestry have proven to be difficult to document for the most poignant of reasons.

Searching for native Manileños

Partnering and volunteering for the FGRP seems simple enough: to become a representative of a particular Filipino group from a particular Filipino region, you as well as your parents and grandparents on both sides should also be from the same place. Meeting these criteria outside of the National Capital Region (NCR) would be no problem — especially in largely homogeneous ethnic groups, such as those in the Cordilleras and in Mindanao. However, the researchers have found it next to impossible to obtain samples from Metro Manila, despite repeated efforts. 

“Nahihirapan talaga kami hanapin silang mga at least third generation na born in Metro Manila, kahit na ikinalat na namin ang aming recruitment sa iba’t-ibang LGUs, universities, at maging sa Facebook at Twitter,” said FGRP researcher Noriel Esteban. “Kaya we are now relaxing our inclusion criteria to at least having both parents born in Metro Manila.” Yet even despite these adjustments to the eligibility criteria, Esteban said that out of over 40  potential partner-volunteers from the NCR, only 17 were able to be accepted into the study. 

This present dearth likely hints at an ominous past, according to evolutionary geneticist and FGRP Program Leader Frederick Delfin. 

Genetic ghosts of lost people

“Such a massive loss of native populations can be due to a natural event, such as a volcanic eruption, or as is most likely in this case, a man-made event such as war,” Delfin explained.

More than one in ten civilians were killed out of a population of just 1 million people in the Battle of Manila towards the end of the Second World War in 1945, based on historical accounts and census data. This decimated the local population, which never completely recovered and is the likely reason for the near absence of native Manileños today. 

“Catastrophic events can severely reduce the population size, with locals either killed or forced to leave. This can result in the reduction of genetic diversity in an area. It takes a very long time for local populations to recover, if at all,” Delfin lamented. “In a way, we can think of the lost genetic variation as the ghosts of the people we lost.”

FGRP seeks partner-volunteers

The FGRP is a comprehensive study that emphasizes the informed consent of its participants, especially indigenous peoples. A similar earlier study, published by the University of Uppsala in 2021, was plagued by ethical issues.

With COVID-19 pandemic restrictions easing up, the FGRP’s nationwide sampling is proceeding at a steady pace as the team is focused on acquiring permission from, as well as explaining the project’s objectives and potential impact to, the country’s various indigenous peoples.

To learn more about the FGRP and to inquire about becoming a partner-volunteer, please contact Frederick Delfin at fcdelfin@up.edu.ph. You may also visit their Facebook page for ongoing and future recruitment postings at https://www.facebook.com/DNAForensicAndEthnicity/. 

For other requests and media inquiries, please contact media@science.upd.edu.ph.