Biological Rhythms Derived from Siberian Mammoths' Hairs

The study analyzed biologic rhythms in the hairs of four Siberian mammoths, aged between 18,000 and 20,000 years, and compared them to modern human hair. The mammoths' hair growth rate was approximately 31 cm/year, while humans' was about 16 cm/year. The study identified annual rhythms of slow and fast growth in mammoth hairs, with cycles ranging from 3.4 to 8.7 weeks for slow periods and 1.2 to 2.2 weeks for fast periods. Mineral analysis showed mammoth hairs had significantly more iron than human hair. Seasonal variations in iron and copper content suggested changes in the mammoths' food intake. The study provided insights into the lifestyle and behavior of extinct mega-fauna through modern analytical methods.