Human Facial Diversity is Influenced by Evolution

http://news.nationalgeographic.com/news/2014/09/140916-faces-evolution-cognition-social-recognition-genetics/

Have you ever wondered why it seems easy to tell the difference between different people, but you can’t differentiate between two penguins? Evolution may have a reason.  A new study conducted at the University of California, Berkeley suggests that humans may have evolved to have a genetic facial diversity, giving other humans the ability to recognize each other visually much more easily.

While other animals are able to differentiate between each other using different methods, like pheromones or special audible calls (Hughes mentions Polistes fuscatus, a species that is “phenomenally diverse in their color patterning”) humans are primarily visual learners. As Hughes suggests, this may have been influenced by a specific benefit in survival for early humans, as these humans could have committed unwarranted acts upon each other if and when they confused one individual with another.

The National Geographic displays this reality effectively; Martin Schoeller shows readers the wildly ranging facial traits that humans possess, from different hair color and structure to different eye colors to differently shaped noses. He highlights that even in areas where different races of humans came about, they still manage to range in facial features.

Interestingly enough, this study has broken ground in the scientific community as different experts agree with or criticize aspects of the study. Along with an account from the lead researcher of the study, Hughes includes in her article quotes from  Biologist T. Ryan Gregory at the University of Guelph in Ontario and Barnaby Dixson at University of New South Wales in Sydney, Australia, both of whom have comments of criticism concerning the study. They pose an adjacent hypothesis that there could have been additional influences on the diverse facial makeups of humans – ranging environments causing different facial features to develop in different groups, for example.

Regardless of the circumstances that led to humans’ unique facial diversity compared to other animals, the reality of our genetic uniqueness is hard to ignore. Still, additional studies are already underway to analyze samples and their locations in order to determine the future of the theory.  Will this theory hold ground or will it be disproven?

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26 Responses to Human Facial Diversity is Influenced by Evolution

  1. gatorade15 says:

    This was a very cool article macnplease! It presented evolution in a different light than, at least I, have seen in the past. Generally, when thinking about “natural selection”, the changes that create a more successful organism include changes that increase mobility, stealth, intellect, etc. But seeing the diversity of human faces as a product of natural selection is pretty cool. I would have never thought having “ID tags”, distinguishable faces, would make us humans so much better suited to survive and succeed. It makes sense though: us humans exhibit such a diversity in facial structure and features (eyes, ears, nose, mouth, etc.). Do you guys think that we will continue to create children with even more diverse faces, or will our children become more similar in the connected world that we live in today?

    • macnplease says:

      Indeed, the implications of his study are quite significant since it suggests an entirely different explanation for the development of human facial features; that it may not have entirely been determined by natural environment but also by human interaction. By definition, I would guess that we will continue to become more and more diverse, although this will be hard to measure at this point since we are already quite diverse in our facial features. Only time will tell.

    • thinkbrush says:

      I agree that this article effectively highlights how this aspect of human evolution does not necessarily fit the adage “survival of the fittest” but rather survival of those best adapted to their environment. In the case of early human ancestors, it was beneficial to easily distinguish between faces as a way of establishing and maintaining social hierarchy. We don’t see such unique physical features in many other animals and I think this emphasizes that this evolutionary development ultimately only aided humans and thus developed in those species.

  2. Thanks macnplease for the great post! When I first read this I was a little skeptical to this idea because I’ve always seen human diversity as an aspect of race and how humans have evolved with different skin colors or facial features due to evolving in different climate and locations. But when compared to other animals, we are far more sophisticated in that we can distinguish faces from one another. Facial diversity is human’s way of differentiating compared to other animals’ ways through pheromones or special audible calls. I’ve never really have thought about how such a complex trait is such an innate feature of human life now. In response to gatorade15’s question, are we becoming more diversified now or are we becoming more similar because we are so connected globally? I believe the latter because modernization has brought about globalization and every race is accessible to another. In the past location and environment aided in diversifying humans evolving over time. Now, despite living across the globe, humans can easily access one another, reproduce, and create a human race that is essentially race-less. This idea of a race-less world has been brought up mainly because of an increase in acceptance of interracial relationships and families. A race-less world could yield a lack of facial diversity in future human generations.

    • macnplease says:

      Your hypothesis is really interesting, I admit I hadn’t thought about modern globalization as a factor for our ongoing evolutionary process. However, it may not be as simple as increasingly similar features due to globalization, but rather new and different mixes of genes that result in new facial features. I’m not saying a new part of the face, but rather new, subtle changes to the shape of the nose or ears or eyes as a result of unprecedented intercontinental breeding of our modern age.

      • When I say the racial diversity affects facial diversity, I was trying to convey more of what pigfish1116 clarified. That the actual facial features typical with races are getting mixed and facial features are not as distinct in the racial aspect. However, I can see what you mean in the distinction between faces and as I mentioned before, human’s ability to recognize these differences is incomparable to most other animals. I don’t believe that the globalization will ever go far enough to affect that distinctive ability that we innately have with facial diversity.

    • pigfish1116 says:

      slowdownyourmind brought up a good point when saying that many people have thought of our diversity of faces being classified by race. We associate white people with generally small noses and mouths, Asians with small facial features, and black people with big facial features. However, these classifications are usually thwarted when we see someone who does not look like their racial classification. Although I agree that we are heading towards a raceless world, slowdownyourmind, I don’t think it will change the uniqueness of faces.

      • macnplease says:

        I would agree. The main theme of this article is FACIAL diversity, not RACIAL diversity. Already we can think of people who are, at first glance, racially ambiguous. They may come from lines of several original races that mixed. This does not mean that they are suddenly indistinguishable from another person; they still have a unique facial structure and features that allow us to identify him/her.

  3. collegeblogger19 says:

    I really enjoyed reading this article, macnplease! I think it was definitely very interesting, and opens your eyes to the recent effects of evolution. When we learn about evolution, it is hard to imagine it happening right before our eyes–but this new finding allows us to wrap our minds around the recent process of evolution. Thinking about all of the different kinds of people we have all met in life, our facial features are exceptionally diverse–and since it is due to our DNA I think evolution/natural selection definitely plays a part in the diversity. The findings presented in the National Geographic article will require further research and development, but are beneficial to the theory of evolution.

    In response to gatorade15, I think your question is very interesting to think about it. More recently, it has been more common for different ethnic backgrounds/races to intermarry. So in the future, younger generations might look completely different from what people look like now due to the mixing of DNA and diverse facial features.

  4. pigfish1116 says:

    The article that macncheese presented was surprising because first, I didn’t see the end coming. The National Geographic used Harris’ tactic of forwarding by coming to terms with UC Berkeley’s idea that variety of faces have evolved then stating other academics counter perspective.
    From examples of evolution that I’ve heard, cheetahs becoming faster, etc., they all seem more survival heavy than the changing of faces. Cheetahs became faster in order to catch their prey or other reasons that would help them to “survive” but it seems odd to say that humans have unique faces so that we can tell the difference between each other. It’s definitely helpful to be able to tell the difference between my two sisters but I don’t see how accidentally killing your neighbor can be a catalyst for face mutations so that I don’t kill my neighbor instead of the real culprit.
    This article by Business Insider (I’m surprised they are talking about evolution) interprets UC Berkeley’s findings as social interactions influencing the evolution of faces. http://www.businessinsider.com/why-are-human-faces-so-complex-and-unique-2014-9
    In response to gatorade15, macncheese’s article stated, our faces and children’s faces will just become more unique since interracial relationships are becoming more common.

    • macnplease says:

      pigfish1116, I would suggest not looking too heavily into the “neighbor” example from the article – it is a minor example that is used to provide some clarity to a relatively complex point. Rather, the reality of human facial diversity comes from multiple factors (according to this study), including survival conditions (i.e. bushier eyebrows to keep the face warm in cold conditions) and the natural need of humans to differentiate each other visually. It is affected primarily by our memory (as the article you posted from Business Insider points out), since we have few other ways of recognizing each other, save voice and body recognition.

      • pigfish1116 says:

        Thank you for the bushy eyebrow example macnplease(i got your name right this time,sorry about that)!!! I was very focused on the social interactions aspect of it rather than the environmental adaptations that could make evolution possible.

  5. Interesting Post macnplease. I had never given the idea that much though before but now that it is brought up there is a clear distinction between human faces that doesnt appear in other species. It is interesting to see that facial structure has become our “ID tag.” While ultimately human “races” are scientifically non- existent it is interesting to see how the diversity that exists because of the original geographic area of development have generate created such drastic differences. It seems equitable to the development of different species in the animal kingdom. If we understand it in that sense then I believe that the answer to Gatorade15’s question would be that we are becoming more diverse. If we are “cross breeding” in todays global system then we might be less diverse in that there wont be such drastic differences between the apparent races but more diverse as far as the individual is concerned. As interracial marriages occur all sorts of new colors, facial structures, and general possibilities begin to occur. Essentially developing a more diversified human race as a whole.

    • macnplease says:

      It’s interesting to see how the two sides being drawn concerning Gatorade15’s question are becoming more distinct; I would agree with you and guess that diversity will continue to increase, following the pattern of all of human development, but now that we live in a global age where transportation is so much more practical, we may start to see significant changes in human development from interracial and intercontinental breeding in the next couple of thousands of years.

  6. greyelephant1 says:

    Going off of what gatorade15 mentioned in the beginning of the blog, I really noticed and liked the talk about how there are so many facial features because of natural selection. If, as the article says, long noses were a disadvantage, we would not see them as much. But, because facial features are just features and not as much advantages, all are passed down through genes. Going off of that, I do not see as much though the connection between being able to recognize features and evolution itself. I believe that there will need to be more information and research for that to become a well-supported theory. That being said, I really liked this idea Macnplease! I had never thought of this and I thought it was very interesting. So, thank you!

    • macnplease says:

      I would say that being able to recognize each other is not directly connected to our evolution, but it certainly played a large role. Our preference (and often need) to be able to tell one individual from another influenced our development to diversify facial structure and features – we know this for a fact because these differences are clearly defined by our genes. Thanks for your comment!

  7. serrobert says:

    I think that we would have a hard time realizing the particular advantages or disadvantages of facial features. In the modern world they play little part in any sort of natural selection, and we have been out of the bush for so long that we have become disconnected with the reasons for some of our developed traits. I can think of no other thing other than sexual selection playing a part in facial traits, but my point is that I don’t know because our culture is so different than it was hundreds of thousands of years ago. So my point is that I would not no the reasons for all human evolution through intuition.

    • macnplease says:

      You may be forgetting the fact that the article addresses nothing about modern evolution, or what micro-changes we are experiencing now. Just like the vast majority of the field of Human Origins and evolution, we are looking at evidence from thousands upon thousands of years ago. It also speaks very little about culture, as the ability to recognize individuals through facial features is not a matter of culture but a matter of survival and communication. And we, just like you, do not know “the reason for all human evolution through intuition”. We are trying to discover more; not through intuition but through scientific deduction.

  8. sunny2018 says:

    I think that is article is very fascinating, however I am having trouble seeing the connection between evolutionary advantages and diverse facial features. Perhaps it’s similar to sexual selection and nonrandom mating? I understand the advantages that the article brings up in having a ‘unique face,’ but I’m just not sure that they are necessarily evolutionary advantages.

    • macnplease says:

      I appreciate your skepticism, and the potential lack of connection is a problem that some skeptics have with the study, too. It is another reason why this hypothesis will flesh out more over time. The main question here is whether or not human facial diversity (which we can all accept as reality) comes from natural selection, convenience, or a subtle need to identify each other visually (since we lack other effective means of doing so).

      • sunny2018 says:

        I understand; are you aware of ways in which it’s possible to test this hypothesis? I think it’s an interesting one for sure, I just want to further understand how it fits into human development as a whole.

      • moneytrees3001 says:

        Sunny2018, this may not be a firm test of this article’s hypothesis, but I think it would be interesting to supplement this information with a study of facial diversity in animals. Certain animals have had millions more years to establish themselves than humans, and so offer more data. Perhaps we could study the fossil record to compare the facial diversity of similar extinct and non-extinct species to see if a lack of diversity correlates with becoming less fit and going extinct.

  9. I love this article! I think its a really interesting to look at something within the human body more specific than just evolution of “humans”–because as straightforward as the theory of evolution is, the evolution of one part or the other of humans–anatomical or personal–is not all the same.

  10. pianokid123 says:

    Thanks for the article! It reminded me of a common Creationist argument demanding how such diverse organisms could have been derived from one ancestral prokaryotic cell 4 billion years ago, but just look at the diversity humans exhibit! We are 99.9% similar and we have such a wide range of body heights, facial structures, eye colors, etc. It is not hard to imagine how the diversity found in one population can be molded into a wide array of other species if under environmental pressure!

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