A team of researchers made an important discovery after identifying the oldest DNA on record, dated around two million years old. The ancient environmental DNA (eDNA) used in the study was collected from sediments preserved in ice and permafrost at the Kap København formation, located in North Greenland.
Despite typical DNA degradation, the team was able to extract small fragments of DNA that survived, likely by adsorption on mineral deposits. Once the extractions were completed, the DNA was converted into Illumina libraries, and several were enriched using a targeted sequencing method (Arctic PaleoChip 1.0) before both library sets were run on the HiSeq 4000 and NovaSeq 6000.
The resulting metagenomic data led to reads assigned to a large array of genera, showing an expansive ecosystem that once inhabited the area. Some notable identified organisms include reindeer, mastodons, caribou, hares, lemmings, and a wide range of plants. Identifying DNA from mastodons is particularly remarkable because it increases the range in which researchers have believed they roam. In addition, many plants that require higher temperatures and are no longer present in Greenland were also identified, suggesting a warmer climate in Greenland than current conditions.
The success and discoveries of this study opens the possibilities of utilizing these techniques with eDNA and metagenomics to learn more about the ecology and evolution of ancient ecosystems.
Read the original journal article here.
Despite typical DNA degradation, the team was able to extract small fragments of DNA that survived, likely by adsorption on mineral deposits. Once the extractions were completed, the DNA was converted into Illumina libraries, and several were enriched using a targeted sequencing method (Arctic PaleoChip 1.0) before both library sets were run on the HiSeq 4000 and NovaSeq 6000.
The resulting metagenomic data led to reads assigned to a large array of genera, showing an expansive ecosystem that once inhabited the area. Some notable identified organisms include reindeer, mastodons, caribou, hares, lemmings, and a wide range of plants. Identifying DNA from mastodons is particularly remarkable because it increases the range in which researchers have believed they roam. In addition, many plants that require higher temperatures and are no longer present in Greenland were also identified, suggesting a warmer climate in Greenland than current conditions.
The success and discoveries of this study opens the possibilities of utilizing these techniques with eDNA and metagenomics to learn more about the ecology and evolution of ancient ecosystems.
Read the original journal article here.