The answer lies in the tiny mitochondrial genome.
Researchers announced today that they have sequenced the mitochondrial genome of an ancient polar bear.
They sequenced the mitochondrial genome of a single human finger from a Siberian cave.
The bear's mitochondrial genome is the oldest one yet reported from a mammal-nearly twice as old as the mammoth genome.
Do it for the tiny mitochondrial genome and the cost is easily affordable, as shown in the Nature paper.
