The size of the brain is frequently associated with intellect. A new study has revealed a surprising correlation between climate change and the size of the human brain.
As PsyPost reports, this study delves into the hypothesis that the environmental strain induced by climate change is responsible for the observed decline in brain size.
These discoveries provide insights into the evolutionary challenges encountered by contemporary humans over the last 15,000 years and raise concerns regarding the potential consequences of ongoing global warming on our cognitive capacities.
A Closer Look at the Study
The study, led by Jeff Morgan Stibel, a cognitive scientist, represents a notable advancement in our comprehension of the evolution of the human brain.
Stibel believes, "While we acknowledge the brain's growth throughout various species over the preceding million years, our knowledge regarding other large-scale evolutionary patterns remains limited."
Stibel's prior investigations into the decrease in brain size served as the driving force for this research, as he aimed to uncover the underlying causes of these transformations.
To explore the correlation between climate change and brain size, Stibel and his research team examined 298 ancient human remains spanning 50,000 years.
They utilized estimates of body size adjusted for geographical location and gender to account for variations in encephalization. The fossils were categorized into distinct time intervals, such as 100-year, 5000-year, 10,000-year, and 15,000-year groups.
This meticulous approach enabled a comprehensive investigation into brain size evolution amidst notable climatic changes.
The scientists gathered information about skull sizes from different published sources. They obtained a total of 373 measurements of cranial capacity from 298 skulls.
These measurements helped estimate the size of the brain. The researchers then compared these estimates with four climate records, including temperature data from EPICA Dome C, which goes back around 810,000 years.
Surprising Link Between Brain Size Evolution and Climate Change
The research results demonstrated a strong link between climate change and brain size. In the era known as the Holocene warming period, humans witnessed a significant decrease in brain size, amounting to more than 10%.
This evolutionary pattern occurred within a relatively short span of 5,000 to 17,000 years. Stibel cautioned that should global temperatures keep rising, it would intensify the evolutionary pressures on the human brain.
Interestingly, the study also found that humidity and precipitation levels impact brain size.
Although the temperature has a more significant influence, periods of low or no rainfall were moderately associated with larger brain sizes. Stibel stressed the importance of these factors but noted that they had a lesser effect on predicting brain size.
Stibel emphasized the necessity for further investigation, stating, "There is evidence suggesting that both brain and body size undergo natural selection in response to climate change. A pertinent question is whether one phenotype is directly selected while the other merely responds to an evolutionary correlation."
Stay posted here at Tech Times.
