A Japanese study has discovered that deer in Nara Park possess unique genotypes, distinguishing them from other deer populations in the Kii Peninsula.

This genetic separation results from the extinction of deer in surrounding areas over 1,000 years ago, while the deer in Nara Park have thrived under human protection.

The purpose of the study was to understand the impact of human activities on sika deer populations, as stated in a joint press release issued on January 31 by Fukushima University, Yamagata University, and Nara University of Education. Researchers collected samples from 294 sika deer across the Kii Peninsula, including Nara Park, and extracted genetic material from these samples. They analyzed the partial alignment of the D-loop region in the mitochondrial DNA and measured the length of the repetitive sequences using a "microsatellite sequence" marker.

The study's results revealed that the deer of the Kii Peninsula could be roughly divided into three distinct groups: those from Nara Park, the western part of the peninsula, and the eastern part of the peninsula. About 1,000 years ago, the Nara Park group separated from the common ancestor of the three groups. Approximately 500 years ago, the western and eastern groups diverged from each other.

Mitochondrial DNA analysis identified 18 haplotype genotypes of sika deer within the Kii Peninsula. Notably, all sika deer in Nara Park belong to only one of these haplotype genotypes, designated as S4. This genotype has not been found in any other deer population in the region, indicating that the Nara Park herd has a unique haplotype distinct from other deer herds. The findings suggest that the Nara Park herd, the most genetically independent, has been isolated from other deer populations for over 1,000 years. While deer in neighboring areas became extinct due to human hunting and exploitation, the Nara Park sika deer survived thanks to human protection. This prolonged isolation has resulted in their distinct genetic makeup.

The research has significant implications for wildlife conservation, highlighting the importance of human intervention in preserving certain species and maintaining genetic diversity within animal populations. The Nara Park sika deer are a prime example of how human protection can enable a species to survive and thrive despite external threats. The study's methodology involved collecting and analyzing genetic samples to understand the genetic diversity and relationships among sika deer populations.

The researchers focused on the D-loop region of mitochondrial DNA, commonly used in genetic studies due to its high mutation rate and variability. The use of microsatellite markers further allowed the researchers to measure genetic variation within and between the different deer populations. These findings underscore the role of Nara Park as a critical sanctuary for sika deer, providing them with a safe environment to live and reproduce. The park's historical significance and cultural value have contributed to the protection and preservation of these deer, ensuring their continued existence for centuries.

The study conducted by Fukushima University, Yamagata University, and Nara University of Education has provided valuable insights into the genetic distinctiveness of Nara Park's sika deer. The isolation of these deer for over a millennium has led to a unique haplotype, distinguishing them from other deer populations in the Kii Peninsula. This research emphasizes the impact of human activities on wildlife and the crucial role of conservation efforts in protecting endangered species.

The findings serve as a reminder of the delicate balance between human intervention and natural preservation, highlighting the need for continued efforts to conserve and protect wildlife around the world.