Populations of the same species that live in different places often have different genetics to each other. More recently scientists have studied how climate change has altered the distribution of these genetically distinct populations of species
Humans seem to have been adapted to the last ice age in similar ways to wolves and bears, according to our recent study, challenging longstanding theories about how and where our ancestors lived during this glacial period.
Previous studies have supported the view of most archaeologists that modern humans retreated into southern Europe during the height of the last ice age and expanded during the later increase in global temperatures.
But our study is the first to use genetic data to show that at least some humans stayed in central Europe, unlike many other animals and despite our species having evolved in the much warmer climate of Africa.
Scientists have known since the 19th century that the distributions of animals and plants across the world may fluctuate with the climate. But the climate crisis has made it more important than ever to understand these fluctuations.
Populations of the same species that live in different places often have different genetics to each other. More recently scientists have studied how climate change has altered the distribution of these genetically distinct populations of species.
Most of the studies in this field focus on individual species of animal or plant. They have shown that many species, including humans, expanded their geographical ranges since the height of the last ice age, approximately 20,000 years ago.
At this time, European ice sheets reached Denmark and south Wales. Europe was cold but mostly unglaciated, probably much like Alaska or Siberia today.
Our team’s new study, led by Oxala García-Rodríguez at Bournemouth University, took a different approach and reviewed the genetic history of 23 common mammals in Europe. In addition to humans, these included rodents such as bank voles and red squirrels, insectivores like shrews and hedgehogs, ungulates like red deer and wild boar, and carnivores like brown bears and weasels.
An important metric in our study was where the greatest diversity is today across Europe. This is because areas of high genetic variation are likely to be the areas of longest occupation by species.
These areas, known as refugia, are locations where species retreated to survive during periods when environmental conditions were unfavourable elsewhere.
For the mammals we studied, these refugia would have been occupied since the height of the last glaciation, at least. These refugia were probably the warmest areas or places where it was easiest for the animals to find food.