How Climate Shaped the Human Ribcage

Study by José M. López-Rey et al., Communications Biology, July 10, 2025

What if the shape of your chest told the story of where your ancestors lived — in freezing tundras or under blazing desert suns?
That’s exactly what new research has uncovered about our early human relatives.

Fossils That Whisper Across Time

Scientists studied three ancient human skeletons:

1. Nazlet Khater 2 – 30,000 years old, found in Egypt.

2. Ohalo II H2 – 19,000 years old, from Israel.

3. Dolní Věstonice 13 – 30,000 years old, from the Czech Republic.

Each fossil carried a silent message about how humans adapted their bodies to different climates.

What the Bones Tell Us

All three shared the same rounded, globular ribcage we see in modern humans — proof that this shape has deep evolutionary roots.
But there were differences too:

• People living in warm or moderate climates, like those in Egypt and Israel, had smaller, narrower ribcages — efficient for releasing body heat.

• Those in colder regions, like central Europe, had broader, larger chests — better for retaining warmth.

Even the shape of our lungs evolved to help us survive the weather.

A Twist in the Evolution Story

One finding truly surprised scientists.
The Czech fossil, Dolní Věstonice 13, had a ribcage almost as big as a Neanderthal’s — and even wider, like Homo erectus.
That challenges the old idea that Homo sapiens were always slimmer and lighter-built.
Instead, early humans were far more flexible and adaptable than we once thought.

Why It Matters

This isn’t just about bones — it’s about how life adjusts, thrives, and endures.
The study reminds us that climate has always shaped who we are — from our skin and body proportions to the very ribs that help us breathe.

Our skeletons, it turns out, carry the memory of the world we came from.

Relevant questions include:

• “Do Allen’s Rule and Bergmann’s Rule hold for human populations? Explain with examples.” (15 Marks, 2018)

• “Elaborate upon major human adaptations to heat and cold.” (15 Marks, 2013)

• “Critically examine the physiological responses and acclimatization to cold climate in man.” (15 Marks, 2015)

• “Describe the biocultural responses to extreme climatic events.” (15 Marks, 2020)

• “Human adaptations are always bio-cultural in nature. Discuss with reference to human adaptation to high-altitude climate.” (20 Marks, 2019)