Each extinction was followed by a re-colonisation of genetically different
lemmings, according to the study. It investigated how Europe's small mammals fared during the era when large numbers of land animals became extinct.When researches went to research they found that not the same gentically lemmings were present possibly from populations in eastern Europe or Russia. The team focused on lemmings as indicators of what may have happened to other
land mammal populations during the last Ice Age.
Because of human activities causes changes in environment animal become extinct. Researches should research as to what happen to the land animal during ice age and how are they going to prevent animal from being extinct.