Paleoanthropologists Reveal Impacts Climate Change Had on Ancient Humans

Our forefathers had close contact with their surroundings hundreds of thousands of years ago, which influenced where and how they lived.

But how did ancient humans react when the environment changed; when the river dried up or local pastures and herds dwindled?

Bones, stone tools, and other relics can reveal how ancient humans appeared and behaved across time.

However, as difficult as it is to uncover a 300,000-year-old skull, it can be much more difficult to find physical evidence of what these individuals' surroundings were like, especially because climate change has significantly altered them many times.

Climate change in ancient humans

(Photo : CESAR MANSO/AFP via Getty Images)

Now, scientists have constructed a two-million-year-old supercomputer model of the global climate and its fluctuations.

Researchers used this paleoclimate simulation in conjunction with real-world data, such as hundreds of ancient human bones and stone artifacts, to determine what circumstances occurred where ancient humans lived.

They then used where and when ideal environments existed to map the likely distribution and migrations of five key hominid species, including our own, Homo sapiens.

Surprisingly, the model results showed that key evolutionary shifts, such as the beginning of our own species, were influenced by drastic environmental changes.

Over the last 25 years, researchers studying human origins have been increasingly interested in how climate change and changeable ecological circumstances, such as droughts and cold temperatures, influenced evolution, as per the Smithsonian Magazine.

The theory is that individuals with genetic alterations that made them more adaptable and capable of surviving in a wide range of settings would benefit from the necessity to live in changing surroundings.

Exploring this notion can be difficult since there is frequently little evidence of what the climate, or a specific localized environment, was like during the times and places where big evolutionary changes took place.

Climate records may be extracted from ice cores and ocean sediments, but such data is particularly scarce at fossil sites where scientists have discovered concrete evidence of phases in our evolutionary path.

In Africa, for example, there are only a few two-million-year-old terrestrial records.

Also Read: Unearthed 1.5 Million-Year-Old Human Vertebra Proof of Ancient Humans in Israel

Fluctuating on climate

Paleoanthropologists, or scientists who study human evolution, have presented a number of theories on how environmental factors may have influenced significant changes in human beginnings.

Over the course of human evolution, a variety of species have emerged, each with its own set of adaptations, such as upright walking, the ability to make tools, brain enlargement, prolonged maturation, the emergence of complex mental and social behavior, and reliance on technology to alter the environment.

Here's how these researchers portray the narrative of humanity, which dates back around 2 million years.

Homo erectus had already begun to spread outside of Africa at that time, but an East African species known as H. ergaster stayed close to home.

Between 850,000 and 600,000 years ago, H. ergaster developed into the disputed East African species H. heidelbergensis, which separated into southern and northern branches, as per ScienceNews.

These migrations corresponded with warmer, more conducive to survival climatic fluctuations that occur every 20,000 to 100,000 years as a result of differences in Earth's orbit and tilt, which alter the amount of sunlight reaching the planet.

The researchers believe that H. heidelbergensis gave rise to Denisovans about 430,000 years ago after moving north to Eurasia.

Between 400,000 and 300,000 years ago, harsh environments generated by repeated ice ages aided the development of H. heidelbergensis into Neandertals in central Europe.

Finally, in Southern Africa between 310,000 and 200,000 years ago, more severe climatic circumstances followed a shift from H. heidelbergensis to H. sapiens, who later traveled out of Africa.

Tags climate change, ancient humans