The climate of the Earth has influenced migration of our ancestors and contributed to the emergence of the modern-day human species, revealed a study.

A research team from South Korea's Pusan National University on Wednesday published a paper in the scientific journal Nature showing evidence of a link between human evolution and astronomically-driven climate change.

The team, led by climate physicist Axel Timmermann, used a new supercomputer model simulating 2-million-years history of the Earth's climate and combined it with the data of well-dated fossil remains and archaeological artefacts. Using the data, the team of experts was able to determine the environmental conditions responsible for human evolution.

Timmermann’s team used the supercomputer for six months to run a climate model that would reconstruct how temperature and rainfall may have influenced the resources that were available to humans in the past few million years.

Scientists have tried to study the role of climate in human evolution since 1920s, when it was debated whether drier conditions had prompted early humans to start walking on two feet in a bid to adapt to life on the savannah, Nature reported. However, they have not been able to provide strong evidence of climate playing a major role in shaping human progress.

One of the major challenges for scientists studying climate impact on human evolution is the paucity of climate records near human fossil-bearing sites. To overcome this problem, the Pusan team investigated what the climate in their computer simulation was like at different times and places humans lived. Through this, the team tried to establish the preferred environmental conditions of different groups of hominins. They then looked for all the places and times in which those conditions occurred in the model and created a map over time of potential hominin habitats.

"Even though different groups of archaic humans preferred different climatic environments, their habitats all responded to climate shifts caused by astronomical changes in earth's axis wobble, tilt, and orbital eccentricity with timescales ranging from 21 to 400 thousand years," Science Daily quoted Timmermann as saying.

Timmermann’s team was able to identify a few surprising trends as well. For example, they found that Homo heidelbergensis (suspected to be the progenitors of both Neanderthals and modern humans) had started to expand from their traditional range around 700,000 years ago. This happened because elliptical orbit created a wetter and more habitable climatic condition at that time to support the expansion.

Speaking about the study to Nature, Peter de Menocal, director of the Woods Hole Oceanographic Institution in Falmouth, Massachusetts, said: “This is another brick in the wall to support the role of climate in shaping human ancestry.”

(Edited by : Sudarsanan Mani)