Bibliography (5):

1. Genome-scale sequencing and analysis of human, wolf and bison DNA from 25,000 year-old sediment

2. Million-year-old DNA sheds light on the genomic history of mammoths

3. Genomics reveals the origins of ancient specimens

4. Excess of genomic defects in a woolly mammoth on Wrangel island

5. Wikipedia Bibliography:

   1. https://en.wikipedia.org/wiki/Eurasian_hedgehog  :

      https://en.wikipedia.org/wiki/Eurasian_hedgehog