27 May 2025 The Future is the Product of the Past

Climate has influenced the growth of our bodies and our brain

Over 300 fossils from the genus Homo have been measured for body and brain size by an interdisciplinary team of academics led by the Universities of Cambridge and Tübingen. They determined the exact environment experienced by each fossil while it was a live person by integrating this data with a reconstruction of the world’s regional climates during the last million years.

The findings show that human body size has changed dramatically over the last million years, with bigger bodies developing in colder climates. Larger bodies are considered to function as a buffer against cooler temperatures: when a body’s mass is enormous compared to its surface area, less heat is lost. The findings were just published in the journal Nature Communications.

Our species, Homo sapiens, first appeared in Africa approximately 300,000 years ago. The Neanderthals and other extinct, related species such as Homo habilis and Homo erectus belong to the genus Homo, which has been around for considerably longer.

The tendency of a growing body and brain size has been a distinguishing feature of our genus’ development; compared to previous species such as Homo habilis, we are 50% heavier and our brains are three times bigger. However, the reasons for such shifts are still hotly disputed.

“Our study indicates that climate — particularly temperature — has been the main driver of changes in body size for the past million years,” Professor Andrea Manica, from Cambridge University’s Department of Zoology, told Science Daily.

He added: “We can see from people living today that those in warmer climates tend to be smaller, and those living in colder climates tend to be bigger. We now know that the same climatic influences have been at work for the last million years.”

The researchers also investigated the influence of environmental variables on brain size in the Homo genus, although correlations were typically modest. When Homo lived in environments with less vegetation, such as open steppes and grasslands, but also in ecologically more stable places, brain size tended to be greater.

The findings, when combined with archaeological evidence, imply that humans living in these settings hunted huge animals for sustenance, a complex task that may have fueled the evolution of larger brains.

“We found that different factors determine brain size and body size — they’re not under the same evolutionary pressures. The environment has a much greater influence on our body size than our brain size,” said Dr. Manuel Will at the University of Tubingen, Germany, the first author of the study.

He added: “There is an indirect environmental influence on brain size in more stable and open areas: the amount of nutrients gained from the environment had to be sufficient to allow for the maintenance and growth of our large and particularly energy-demanding brains.”

Non-environmental variables, rather than climate, appear to be more significant in promoting larger brains, with the increased cognitive difficulties of increasingly complicated social lives, more diversified meals, and more sophisticated technologies being prominent possibilities.

According to the experts, there is strong evidence that the human body and brain are still evolving. The human body is still adjusting to various temperatures, with larger-bodied people living in colder locations on average nowadays. Since the beginning of the Holocene, our species’ brain size appears to have shrunk (around 11,650 years ago).

Over the next several thousand years, growing reliance on technology, such as outsourcing complicated work to computers, may lead brains to shrink even more.

“It’s fun to speculate about what will happen to body and brain sizes in the future, but we should be careful not to extrapolate too much based on the last million years because so many factors can change,” said Manica.

Related Articles

In Peru, Archaeologists Discovered an Ancient Dance Floor that can Imitate Rumbling of Thunder

21 July 2023

21 July 2023

Archaeologists have discovered an ancient “sounding” dance floor in Peru that was designed to create a drum-like sound when stepped...

2,200-year-old Greek sling bullet may have been used against Jews

9 December 2022

9 December 2022

A 2,200-year-old lead sling bullet was discovered by the Israel Antiquities Authority (IAA) in the central Israeli city of Yavne,...

New insight into the history of human presence in Paveh county, Kermanshah province, which is located in western Iran

22 August 2021

22 August 2021

Stone tools and animal bones unearthed recently have thrown new insight into the history of human presence in Paveh county,...

Spanish Stonehenge re-emerges from the ‘Valdecañas reservoir’

19 August 2022

19 August 2022

Submerged by the Valdecañas reservoir for decades, the Guadalperal dolmen has been fully exposed as it was two summers ago....

Archaeologists find sunken ancient Egyptian warship under Abu Qir Bay

26 July 2021

26 July 2021

According to a press release by the Egyptian Ministry of Tourism and Antiquities, the Egyptian French archaeological mission of the...

Unexpected Origins of Mysterious Mummies Buried in Boats in a Chinese Desert

17 February 2024

17 February 2024

In 1990, hundreds of mummified bodies were found buried in boats in an inhospitable desert area in the Xinjiang Uyghur...

The World’s Largest Pyramid Is Hidden Within a Hill in Mexico

8 October 2022

8 October 2022

The largest and tallest pyramids in the world are incredible feats of design, engineering, and construction. The Great Pyramid of...

Declassified CIA Satellite Spy Program Reveals Lost Ancient Roman Forts

26 October 2023

26 October 2023

Archaeologists have discovered “massive” ancient Roman forts that redraw the borders of the ancient empire using images from a declassified...

5000-year-old fingerprint found in Orkney pottery

23 April 2021

23 April 2021

Fingerprints were found on a pottery dating back 5,000 years in the Orkney archipelago, located in the northern region of...

The excavation, which started in a cave in Turkey’s Mardin, turned into a huge underground city

19 April 2022

19 April 2022

In an underground city known used as a settlement in the early Christian era, in the Midyat district of Mardin,...

Britain’s Hidden Treasures: The Pieces of Rare Iron Age Helmet Found at Snettisham

19 January 2025

19 January 2025

Thanks to advanced scientific testing, the copper alloy fragments unearthed at Snettisham, Norfolk, at one of Britain’s most significant archaeological...

South Ockendon’s Belhus Park Golf Course: A Tudor Garden Discovered

15 July 2021

15 July 2021

Under a golf course, the ruins of Tudor and Jacobean gardens were unearthed. Aerial images of Belhus Park Golf Course...

What If Ancient Statues Smelled Wonderful? The Surprising Secrets of Greco-Roman Sculptures

16 March 2025

16 March 2025

A new study published in the Oxford Journal of Archaeology has shed light on an often-overlooked aspect of ancient Greek...

Extraordinary discovery for the Western Baltic Sea region: a 400-year-old shipwreck Found at Bottom of German River

3 August 2022

3 August 2022

During a routine measurement at Trave, near Lübeck, in the northern part of Germany,  Kiel-Holtenau Waterways and Shipping Authority (Wasserstraßen-...

Unusual Iron Age Female Grave Found in Pryssgården, Sweden

3 November 2024

3 November 2024

In an Iron Age cemetery in Sweden, archaeologists found a woman’s grave buried with a small needle and an iron...