MOST of us do not know. However, there is such a thing as “ancient genomics,” a discipline highly useful in archaeological studies due to its capability to determine human genetic pools in certain geographical areas, and how they dispersed throughout the continents and countries for kiloyears (1,000 years) in the past.
In less than a decade, specifically around five years ago, scientific and technological breakthroughs in this field were astonishing. Around 2008, ancient DNA researchers hopelessly believed that full genome sequencing of extinct species (e.g. Neanderthals or woolly mammoth) were real only in science fiction and humanly impossible to perform.
The best molecular technology at that time, which was polymerase chain reaction (PCR), required large amounts of fossil material, large experimental workload, and high costs. The amplifiable fragments were only up to 150 base pairs, which can generate up to 16.5 kilobases of mitochondrial genomes through bacteria-propagated PCR amplicons. A microliter of DNA extract can yield only one PCR amplicon at 384 sequences per run. Thus, one gram of cave bear bone material can produce only 570 PCR amplicons. To generate a complete draft of the cave bear genome would require 180 kg of materials, more than 103 million amplicons, billions of U.S. dollars in operational costs, and around 48,000 years of experimental work. Thus, ancient genomic researchers were correct to say that such a project was a “Mission Impossible.”
However, using reversible terminator chemistry, by 2010, the Illumina Genome Analyzer II can already generate 180 million sequences per run, 384 grams of material, less than two months to process, and less than a million U.S. dollars in operating costs. It can identify blood types, eye color, earwax dryness, metabolism rate, and body mass index (BMI). For instance, the first ancient human genome that this technology mapped was a paleolithic (Old Stone Age) Eskimo that belonged to the Saqqaq culture, existing along Greenland’s southwestern coast 4,000 years ago. It has a confirmed A+ blood type, most likely brown eyes, dry earwax, and a metabolic rate and BMI adapted to cold environment.
Currently, developers are working to deliver gigabases of genomic sequences at a smaller cost. Studies even have started appearing that tried to determine genomic changes, which helped various species adapt to climate change. Clio Der Sarkissian and 25 other colleagues from Center for GeoGenetics in Copenhagen, Denmark published their review on May 7 in the Philosophical Transactions Royal Society B.
Theodosius Dobzhansky wrote in Mankind Evolving: The Evolution of the Human Species (1962): “Nature’s stern discipline enjoins mutual help at least as often as warfare. The fittest may also be the gentlest.”