From Mandarin to Italian, How Language Shapes Genetics

Can you differentiate Mandarin from French or Italian?

Of course, you can. 

The sounds of each of these languages are very different, from hard or soft consonants to long or short vowels.

Due to the dynamic sounds of each mother tongue, you can see the adaptation of different vocal tracts across cultures.

These adaptations have developed across generations according to the languages spoken in countries around the world.

We discussed gene-culture coevolution last week in relation to the human species and speech.

Now, let’s talk about how speech and language have evolved our genetics across cultures.

Physiological Traits Adapt to Language

Speech-related physiological adaptations vary across the human species according to the language spoken.

Some languages, like German or Arabic, require deep guttural sounds due to the harsh consonants.

Others, like Spanish, require speakers to roll their r’s.

One of the ways in which this presents in our physiology was reported by Discover Magazine.

Researchers found that the roof of the mouth differs across cultures, according to how vowel sounds are pronounced. 

Furthermore, these anatomical variations evolve upon each generation, creating an evolution in the language itself and the sounds of speech.

The study’s author, Linguistics Expert Dan Dediu, says, 

“Even small variations in the shape of our vocal tract may affect the way we speak, and this may even be amplified — across generations — to the level of differences between dialects and languages.”

The Study

How did researchers discern this change?

The study looked at over 100 people from several ethnolinguistic groups in Europe, North America, China, and across India.

MRI scans were taken of the hard palate of each participant.

Using the scans and machine learning, computer models formed a picture into the future of the hard palate and the sounds it might produce. 

Five commonly used vowel sounds – the “uh” in sofa,” the “ah” in “hot,” the “oo” in “boot,” the “a” in “bat,” and the long “e” in “feet” – were plugged into the computer model. 

A second generation, mimicking the sounds from the first, showed the amplified pronunciation of each sound – as did 50 generational models after it.

Though the change in the shape of the hard palate over time only impacted pronunciation slightly each generation, the change in the vowel sounds after 50 generations was much more pronounced.

The researchers write that,

“besides culture and environment, quantitative biological variation can be amplified, also influencing language.”

This research begs the question: what will our languages sound like in 50 generations…and how did they sound 50 generations ago?

Does Culture Drive Human Behavior More Than Genetics?

Biologists say that behavior is ultimately determined by natural selection.

This is because genetic structures are constructed according to the mental processes and learned patterns and responses to different environments.

As Richerson and Boyd, authors of Not By Genes Alone: How Culture Transformed Human Evolution, note: physiological changes that shape behavior are evolutionary.

Take bird migration, for instance.

Instead of passing winter in harsh environments, birds have acquired their migratory behavior according to evolutionary physiological reactions.

The brain has formed evolutionary strategies across time to send hormonal signals that trigger annual migration to warmer climates.

So, while genes may determine the traits and behaviors best suited to the environment, the environment has helped shape these genes. 

Where does culture come into play?

Culture is part of the environment, especially where humans are concerned.

Culture Drives Human Evolution

Taking the environment’s impact on evolution a step further, in a study by the University of Maine, culture was found to drive human evolution even more so than genetics.

According to the 2021 study by researchers, Tim Waring and Zach Wood, humans adapt to their environment and challenges in their environment via culture – in the form of learned knowledge, skills, and practices –more effectively and at a faster pace than through genetics.

One reason for this “special evolutionary transition” is that the cultural transfer of knowledge is flexible and fast when compared to genetic transfer.

Waring notes that:

“Gene transfer is rigid and limited to the genetic information of two parents, while cultural transmission is based on flexible human learning and effectively unlimited with the ability to make use of information from peers and experts far beyond parents.”

This results in a stronger adaptation via cultural evolution than genetic evolution allows.

The researchers also argue that culture’s group-oriented nature produces more group-oriented evolution as well.

Ways in Which Humans Have Evolved

How have humans evolved via culture?

Humans have adapted in several key ways over the millennia.

These include:

  • Capacity for social learning
  • Predisposition to be cooperative
  • Capacity to collaborate
  • Diminishing aggression

Genetics and culture work together to adapt behaviors, but as Waring and Wood’s research suggests, culture is becoming even more influential on the evolution of human behavior.

As Waring concludes:

“This research explains why humans are such a unique species…We are slowly becoming ever more cultural and ever less genetic.”