Let’s Celebrate the Diversity (and Similarity) in Homo sapiens!

Telma G. Laurentino
sci five | University of Basel
8 min readAug 7, 2017
“Migration is beautiful” — street art on Feldbergstrasse in Basel. We’re all descendants from migrants, if not in our recent past, in our ancient past as a species. There are currently around 244 million people that live outside their country of birth. (Image: Telma G. Laurentino)

We’re currently around 7,5 billion of opposite-thumb-possessing-primates and one of the most adaptable species on planet earth. As fascinating as we are, intolerance and ignorance towards human diversity are still widespread. I think that we should put ethnocentrism aside and celebrate what evolution gave us. It is more what we share than what makes us different! Anthropology, population genetics, and development knowledge show that, and I want to share some with you.

Adaption is key

The human biological and cultural diversity arises from our remarkable adaptability, and it’s nothing but beautiful — both poetically and scientifically speaking.

Over time, we have evolved more than 6000 languages, which can vary radically in sound, meaning, and syntax. We display a beautiful myriad of phenotypes (observable characteristics), from the fascinating amount of colors and tones that the human skin can adopt, to the more than 520 dances we dance. Despite all this diversity, we share a significant part of our human existence. Here are some examples:

We all share a four letter genetic code, and we all descend from the same 1000 migrants that left Africa some 50,000 years ago.

Four letters spell our entire history

Like all other eukaryotic organisms, we are composed of cells that have a nucleus which contains our genome: the DNA helix. This helix is made of specific pairs of four nucleotides: adenine, thymine, guanine, and cytosine — ATGC. These four letters make up sequences, and the variation in those sequences (which we read in population genetics) is where diversity resides.

Studying these sequences from humans from different populations and ethnic backgrounds allows us to understand the past and the present, and the similarity and divergence within our species. In other words: with these four letters alone, we tell our entire history.

Leaving Africa and some other evolutionary shenanigans

Here’s a (very) rough and (very) short part of our history, starting 50,000 years ago: the migrants that came out of Africa and gave rise to our modern human population had a really small effective population size. We hypothesize that there were merely 1000 breeding individuals, who carried the genetic variation that we inherited from our African ancestors.

After leaving Africa, we met other folks in Eurasia. The study of the ancient genomes of Neanderthal and Denisovan hominids revealed that Homo sapiens hybridized with Neanderthals (more than once) and that contemporary human populations can carry up to six percent of Denisovan genome. This means that we mingled a lot with other hominids and then a multitude of other evolutionary beautiful shenanigans happened.

The result of all this: up to one-third of human diversity (common haplotypes) may be contained within a single modern human. Studies show that most genetic diversity is found within individuals, rather than between populations of different continents. This means that I can be more different from my Portuguese neighbor than both of us are from someone from, let’s say, Australia.

Diversity is mainly inside each one of us, not between! We are all Neanderthal, Denisovan and a lot of other events and peoples mixed.

It’s all about division

We all started as a zygote (a fertilized egg). When a sperm enters the egg, several molecular mechanisms make sure no further penetration occurs. If more than one sperm fertilizes an egg, the zygote ends up having more than 46 chromosomes, and cells cannot divide properly. And for the rest of our development this is basically what happens — division.

In this famous photo by Lennart Nilsson you see how we all looked liked at 5 weeks-old and 9mm long. At this stage, eyes, nostrils, and mouth already have their designated place — charming, right?

The zygote then becomes a blastula, a gastrula, and so on. At day 18 the nervous system starts to “fold” and develop. It is only finished almost 34 weeks later. All of our development is driven by a genetic toolbox that we all share. This toolbox is calibrated to activate and inactivate certain master genes, at specific times, in the most impressively fine tuned genetic symphony.

No matter what nationality, hair color, or cinematic taste we have, we all started as a zygote, a blastula, a gastrula and we all looked a bit weird (but still cute) when we were five weeks old.

We are then born as the mammal with the highest brain-to-body size ratio. This is one of the primary drivers of our adaptive advantages: our amazing brain. It is the center for our capacity of learning, language and tool usage, and symbolic thinking. These human features evolved for millions of years, allowing us to survive and develop what we call culture.

Cultural behavior is fluid

Culture shapes our personality: we learn what is proper or inadmissible, we are guided to certain activities or traits that are cool and desirable, and we learn standards of beauty and attractiveness. Since, locally, we all go through a similar learning process, some behavioral congruence emerges that becomes typical of the people from a particular social group.

Cultural differences are often used as the basis for hate-speech. However, anthropology and history show us that culture is not inert, it can be as fluid and dynamic as genetics, changing through diffusion and acculturation.

For example, this blog is part of the information technology evolution that allows for communication and culture diffusion. I’m writing in English as a result of what’s called culture generality (something that became common to different human cultures). English was brought to several countries by settlers, or through colonialism, but it’s nowadays mainly spread by diffusion, becoming the leading business and scientific language.

Diverse acculturation stories from the University of Basel

There are also cultural particularities, such as local dialects. I’ve recently learned from Christian, a Mexican PhD student, that even if you speak fluent German (as he does) understanding Swiss German might be quite the challenge. You’d be amazed at how many different dialects this tiny country has come up with!

Since more than 3% of all humans are migrants, this got me wondering how other migrants felt when moving to Basel. So I asked other international students at the University of Basel. Here are some of their struggles and experiences:

The University of Basel has an international student body. Here you see the origins of all the 3047 international students and PhD candidates (numbers from fall semester 2016). (Image: Telma Laurentino)

Maridel, a PhD candidate from the USA, struggled with organizing her daily life around the Swiss schedules. “As someone who is absent-minded and not good at planning” not having grocery stores available 24/7, do laundry on a specific weekday, and having to carry her own reusable shopping bags caused some initial nuisance, she says. However, she points out that the more sustainable lifestyle is a very positive thing.

Suvitha, a PhD student from Singapour, agrees and she admires “the effort that is put towards recycling” hoping that this can serve as an example to other countries.

Alexa’s favorite thing about Basel is that you can ride your bike everywhere (and you see very few cars!). She is a postdoc from the Swiss canton of Lausanne. If you haven’t been there, let me tell you that the topography does not favor bike riding.

Nature is also highly appreciated by all of us. Whenever you feel like immersing yourself in it, it’s right around the corner. This is something that Jelena, a PhD candidate from Serbia, really enjoys. “You can take a train anywhere into real nature,” she says.

As for myself, I thought people were crazy when I was first told to swim in the Rhine (the river flowing directly through Basel). In Portugal, I was taught that rivers are dangerous, but swimming in Atlantic waves is fine. A fact that Jelena, who learned how to swim in the Danube, considered crazy. Well, I acculturated: I swim in the Rhine whenever I can.

People in Basel use these bags to keep their belongings safe and dry while floating down the river. On a hot day, the Rhine is doted with hundreds of colorful bags. (Image: University of Basel)

So does Niko, a PhD from Germany, who says that the “Rhine culture” is his favorite thing about Basel. He loves the fact that people just chill with friends by the river, with a beer and a portable barbecue.

However, when relaxing with friends, you need to arrange meeting-time. This is where things can get complicated. Usually, Niko is the first to arrive. Some of us tend to arrive “fashionably late,” in Maridel’s words, which we soon learned is not fashionable at all, here. Others, really appreciate the precise Swiss timekeeping. Priya, a postdoc from India, says she does not miss the general lack of commitment to punctuality back home and she’s happy with the Swiss punctuality.

Celebrating the diversity and similarity within and between us. (M)aridel, (C)hristian, (N)icolas, (T)elma, (A)lexa, (N)iko, (L)illa, (J)elena, (P)riya and (S)uvitha shared their acculturation stories. (Image: Telma G. Laurentino)

How a simple hello can result in extreme awkwardness

But nothing put me in more socially graceless situations than the Swiss greetings. These can range from a handshake to three cheek kisses, to one cheek kiss, to a hug. I was lost, several times, between the three kisses (we give two back home), the awkward hug (when people went for the handshake) or the handshake (when people went for the kisses)… But it’s all right, because Raclette makes up for all awkwardness, by making life happier!

While many of us are very happy with the Swiss gastronomy, Nicolas, a PhD student from Colombia, suffers a little from the “lack of fruit variety” and misses the flavor of Colombian fruit. Others are just not biologically adapted to the local food. Remember that lactase allele that the Europeans got from their pastoralist ancestors?! Yeah, Christian doesn’t have it. So naturally, he isn’t the biggest Raclette or Fondue fan. Lilla, a Hungarian PhD student, says that “the food is a cultural shock.” She remembers a particular episode where she was mistaken for a drug dealer, all because of cake. She’ll “never forget the suspicious smiles” she got when offering poppy seed cake. “I only understood much later: people thought I was inviting them to a psychotropic journey.” She now makes sure to explain that opium comes from the sap of the poppy, not from the seeds. Here we have it: sharing culture and knowledge!

All together under the same roof ❤ You can find this street art work near R. São Bento, in Lisbon, Portugal. This is one of the Lisbon’s streets where a free-entry festival called “TODOS” (ALL) takes place. There, the Asian, African, Brazilian, Portuguese and Latin American 7 arts fuse, in a city proudly known for its multiculturalism. (Image: Telma G. Laurentino)

As you can see, close or far born, everyone finds differences when changing cultural context. However, this does not change how much we share as Homo sapiens, and it’s not a barrier to mingle and frolic! Certainly not here: 53% of marriages in Switzerland are between partners of different nationalities. So here’s my message: our evolution shapes our culture and vice versa. When you look at it from a biological perspective, we’ll always share more than what might divide us.

Being part of the University of Basel gives you the chance to meet people from all continents. Enjoy it and celebrate both the similarities and differences! Ultimately, we’re all under the same (atmospheric) roof.

For fascinating readings on culture and anthropology, I suggest the work of Conrad Phillip Kottak.

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Telma G. Laurentino
sci five | University of Basel

I’m a Portuguese Nature lover and I dedicated my life to the study of evolution