Humans can thank Neanderthals for the size and shape of our noses

A recent study led by researchers from University College London (UCL) has revealed that humans inherited genetic material from Neanderthals, which affects the shape of our noses. 

This discovery sheds light on the role of natural selection in shaping our facial features and provides further evidence of the interbreeding between ancient human ancestors and Neanderthals.

Published in the journal Communications Biology, the study suggests that a specific gene responsible for a taller nose (measured from top to bottom) may have evolved as ancient humans adapted to colder climates after leaving Africa. 

Dr. Kaustubh Adhikari, co-corresponding author from UCL Genetics, Evolution & Environment, and The Open University, stated, “In the last 15 years, since the Neanderthal genome has been sequenced, we have been able to learn that our own ancestors apparently interbred with Neanderthals, leaving us with little bits of their DNA.”

The researchers found that some DNA inherited from Neanderthals affects the shape of our faces, potentially offering an evolutionary advantage that has been passed down for thousands of generations. 

How the study was done

The scientists analyzed data from more than 6,000 volunteers across Latin America, who were part of the UCL-led CANDELA study. These participants had mixed European, Native American, and African ancestry and were recruited from Brazil, Colombia, Chile, Mexico, and Peru.

By comparing genetic information from the participants with photographs of their faces, the researchers were able to identify associations between various facial traits and the presence of specific genetic markers. 

They newly identified 33 genome regions related to face shape, 26 of which were replicated in comparisons with data from other ethnicities, including participants from East Asia, Europe, and Africa.

What the researchers learned

The researchers discovered that many individuals in their study with Native American ancestry (as well as others with East Asian ancestry from another cohort) had inherited genetic material from Neanderthals in a gene region called ATF3. 

This genetic material contributed to increased nasal height, and the researchers found signs of natural selection in this gene region, suggesting it offered an advantage to those carrying the genetic material.

“It has long been speculated that the shape of our noses is determined by natural selection; as our noses can help us to regulate the temperature and humidity of the air we breathe in, different shaped noses may be better suited to different climates that our ancestors lived in. The gene we have identified here may have been inherited from Neanderthals to help humans adapt to colder climates as our ancestors moved out of Africa,” explained study first author Dr. Qing Li of Fudan University.

Co-corresponding author Professor Andres Ruiz-Linares from Fudan University, UCL Genetics, Evolution & Environment, and Aix-Marseille University, highlighted the significance of their diverse sample. “Most genetic studies of human diversity have investigated the genes of Europeans; our study’s diverse sample of Latin American participants broadens the reach of genetic study findings, helping us to better understand the genetics of all humans.”

This research marks the second discovery of DNA from archaic humans, distinct from Homo sapiens, influencing our face shape. The same team had previously identified a gene affecting lip shape, which was inherited from the ancient Denisovans, in a 2021 paper. The study involved researchers based in the UK, China, France, Argentina, Chile, Peru, Colombia, Mexico, Germany, and Brazil.

More about Neanderthals

Neanderthals, or Homo neanderthalensis, were a species of hominids that lived in Europe and parts of western and central Asia from around 400,000 to 40,000 years ago. They are the closest extinct relatives of modern humans, Homo sapiens, and the two species share a common ancestor from approximately 600,000 to 800,000 years ago.

Physical Characteristics

Neanderthals were shorter and stockier than modern humans, with a more robust build. They had a distinct facial structure with a prominent brow ridge, a forward-projecting midface, and a receding chin. 

Their cranial capacity was slightly larger than that of modern humans, indicating a similar brain size. Neanderthals were well-adapted to cold climates, with their short limbs and barrel-shaped chest helping to conserve body heat.

Culture and Behavior

Neanderthals were capable of creating and using tools, including stone tools made using the Levallois technique. They hunted large mammals such as woolly mammoths, rhinoceros, and deer, and evidence suggests they also consumed plant-based foods. They used fire for cooking, warmth, and protection.

Neanderthals likely lived in small groups and had complex social structures. They cared for their injured or sick members, and there is evidence of intentional burials, suggesting they had some form of cultural or religious beliefs.

Interaction with Homo sapiens

The exact relationship between Neanderthals and Homo sapiens is still a subject of debate among scientists. However, genetic evidence shows that there was interbreeding between the two species. As a result, non-African modern human populations have approximately 1-2% Neanderthal DNA.

Extinction

The reasons for Neanderthal extinction are still not entirely clear. It is believed that several factors, including competition with modern humans for resources, climate change, and the spread of diseases, could have contributed to their decline. Some researchers also suggest that assimilation through interbreeding with Homo sapiens may have played a role in their eventual disappearance.

Recent Discoveries

Advancements in genetic research and paleoanthropology have led to a better understanding of Neanderthals. The Neanderthal genome was sequenced in 2010, revealing their genetic similarities and differences with modern humans. Additionally, recent studies have identified Neanderthal genes that still influence the appearance, health, and behavior of some modern human populations.

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