How Scientists Identify Doomed Arctic Explorer Remains Using Descendant DNA

Introduction

The Franklin expedition, a tragic 1845 voyage to find the Northwest Passage, ended with all 129 crew members perishing in the Canadian Arctic. For over 170 years, the identities of many sailors remained a mystery, their bones scattered across frozen landscapes. But modern DNA technology has changed that: by collecting DNA samples from living descendants of the expedition's crew, scientists have successfully identified four more members. This step-by-step guide explains how researchers use genetic genealogy to match historical remains to their rightful names, revealing crucial clues about the survivors' final attempts to find safety.

What You Need

Before diving into the process, here are the essential materials and prerequisites typically required for this type of historical DNA identification:

• Historical remains – Bones or teeth from the expedition site (e.g., King William Island, Nunavut).
• Living descendant DNA samples – Cheek swabs or blood samples from known relatives of Franklin crew members.
• Genetic database – A lab with facilities for DNA extraction, amplification (PCR), and sequencing (e.g., mitochondrial DNA, Y-chromosome, or autosomal markers).
• Genealogical records – Ship manifests, birth/death certificates, family trees, and historical documents linking crew to living individuals.
• Specialized software – For comparing DNA profiles and calculating likelihood ratios.
• Ethical clearance – Approval from relevant Indigenous communities and descendant groups (e.g., Inuit heritage organizations).

Step-by-Step Guide

Step 1: Locate and Excavate Well-Preserved Remains

Archaeologists first identify burial sites or scattered bone deposits from the Franklin expedition. These are often found on King William Island or near the abandoned ships HMS Erebus and HMS Terror. Excavation must be done carefully to avoid contaminating the DNA. Bones are collected, cleaned, and stored in sterile containers to prevent modern DNA from interfering.

Step 2: Extract and Amplify Ancient DNA

In a controlled lab, scientists drill into the dense part of a bone (e.g., femur) or tooth to extract powdered samples. They use specialized kits to isolate mitochondrial DNA (mtDNA), which is inherited matrilineally and survives well in old remains. For stronger identification, they also target Y-chromosome DNA (from male lineages) or autosomal short tandem repeats (STRs). The DNA is then amplified via polymerase chain reaction (PCR) to create millions of copies for analysis.

Step 3: Recruit Living Descendants Through Genealogical Research

Historians comb through 19th-century records—like the muster roll of HMS Erebus and HMS Terror—to trace family lines of the 129 officers and men. They build family trees using census data, parish registers, and obituaries. Then they contact living relatives, often via genealogy websites or local historical societies, and request a simple cheek swab or blood sample. Key is finding descendants who share a direct maternal line (for mtDNA) or paternal line (for Y-chromosome) with the deceased crew members.

Step 4: Generate DNA Profiles from Descendants

DNA from living relatives is extracted, amplified, and sequenced in the same lab using identical markers. For mtDNA, researchers look at the hypervariable regions (HV1 and HV2) to create a haplotype. For Y-chromosome, they examine short tandem repeats (STRs) or single nucleotide polymorphisms (SNPs). Autosomal DNA is also scanned for shared segments that indicate a familial relationship.

Step 5: Compare Ancient and Modern DNA Profiles

Using software like Family Tree DNA's mtDNA match or custom algorithms, scientists align the ancient DNA sequence with that of each descendant. A perfect match in mtDNA (or a near-perfect match in Y-STRs) suggests a common maternal (or paternal) ancestor. For autosomal DNA, they look for statistically significant allele sharing, adjusting for degradation. Probability calculations determine whether the match is genuine, considering the rarity of the haplotype in the general population.

Step 6: Corroborate with Historical and Isotopic Evidence

DNA alone may not be enough; researchers cross-reference results with physical clues like bone isotopes (e.g., strontium, oxygen) that reveal diet and birthplace. For example, a sailor from the Orkney Islands might have a different isotopic signature than one from London. Also, historical records (e.g., a crewman's rank or health issues) are matched against skeletal injuries or pathologies. This multi-pronged approach strengthens the identification.

Step 7: Announce Findings and Rebury with Honor

Once a positive DNA match is confirmed (often with a 99%+ confidence), the identity is published in peer-reviewed journals, such as the Journal of Archaeological Science. Descendants are notified, and the remains are given a dignified burial—sometimes in a marked grave at the original site or repatriated to the UK. The identifications also help historians understand the crew's desperate attempts to reach safety, by linking certain remains to specific officers or groups.

Tips and Considerations

• Preservation is key: Cold Arctic conditions help preserve DNA, but contamination from modern humans or animals is a constant risk. Always work in a cleanroom.
• Mitochondrial DNA has limits: MtDNA only traces the maternal line, so it can't distinguish between siblings. Combine with Y-chromosome or autosomal markers for granularity.
• Ethics come first: Always obtain informed consent from living descendants. Respect wishes of Indigenous communities whose land holds the remains.
• Network with genealogists: Amateur family historians often have detailed trees that professional researchers miss. Websites like Wikitree or Ancestry can be goldmines.
• Be patient: DNA from old bones is often degraded. Multiple extraction attempts may be needed. Budget for extra time and resources.
• Share data responsibly: Publish de-identified haplotype data to benefit future research, but protect descendant privacy under GDPR or equivalent laws.

By following these steps, scientists have already identified four more Franklin expedition sailors, including officers and crew. Each new name adds a chapter to the tragic story, showing how the men split up, resorted to cannibalism, and tried to march south—failures that ultimately doomed them. DNA is not just a tool for identification; it's a bridge to the past, giving voice to the silent skeletons of the Arctic.