Others’ Shoes

by James Morris

At a time of increasing political division, it’s worth asking ourselves – can we put ourselves in someone else’s shoes?

In Free Solo, Alex Honnold impossibly scales the vertical face of El Capitan in Yosemite National Park without ropes or harnesses, scampering up the wall like a gecko or ibex. He is a member of the same human species as all of us, but his abilities, focus, and fearlessness are so far outside of what most of us can even imagine that it encourages us to ask – how similar and different are we?

We can answer this question genetically. We are 99.9% identical at the level of our DNA. Put another way, the DNA sequences of any two of us differ by only 0.1% – whether we are a Democrat or Republican, and regardless of our hair color, eye color, skin color, sexual orientation, or gender identity.

This difference is very small. Looked at from a genetic perspective, then, we are much more similar than we are different. There are differences, to be sure, but they are only a very small fraction of the total – a single base change here, a small deletion or insertion there – tiny islands of difference in the same genetic sea.

The small genetic differences can, in some cases, affect the way we look – our eye color or hair color or skin color or height or weight. They can affect how we respond to medicines. They can increase or decrease the likelihood that we will develop high blood pressure, cancer, or dementia.

And a precious few can even affect how we perceive the world around us. A recent study revealed that a small genetic change influences whether we are able to detect the scent of lilies of the valley, beets, and whiskey. It’s also well known that, for some of us, cilantro has a soapy taste. These and other differences in smells and tastes have been linked to small changes in individual genes.

If differences in our genes can affect our scent-scape, can they also influence the way we perceive other aspects of our environment? Is my green the same as your green? My blue the same as your blue? Do we all see things very similarly or very differently?

These and other genetic differences among us are few. We have much more in common than we don’t, with language, creativity, imagination, and intelligence all part of our shared genetic heritage.

The fact that we are so similar genetically reflects our recent ancestry. The modern human family, of which we are all a part, originated about 200,000 years ago. This is a blink of the eye in the 4 billion years during which life has been evolving on Earth. A small amount of time corresponds to a small amount of genetic difference – there just hasn’t been very much time for mutations to occur and spread through the human population.

We evolved in Africa. So, in an evolutionary sense, we are all Africans. Perhaps 60,000 years ago, some of our ancestors left Africa and traveled around the world, while others stayed in Africa. But, by then, the traits that make us human were already in place.

It’s hard to imagine, but 60,000 years ago there wasn’t just one human species – Homo sapiens – as there is today. Instead, there were several, including the Neanderthals and Denisovans. As our ancestors migrated out of Africa, they came across and interbred with these other groups. As a result, some of us carry small amounts of DNA from these ancestral encounters.

Furthermore, as we spread around the world, we adapted to different environments and evolved in different ways. These changes make us look more different from one another than our underlying genetics reveals.

Our lived experiences also shape us. We begin life with so much in common, but our experiences can be vastly different and these differences can influence how we understand and navigate the world around us. I experience the world as a white male living in the 21st century in the US. What is it like to be a woman? Or a trans-woman? What is it like to be a person of color? What is it like to be brought up in poverty or with extreme wealth? What is it like to grow up in Ecuador, China, or Kenya?

Little, daily incidents can imprint on the mind as well. How does a kind, supportive word at key junctions affect our confidence and outlook over the long term? Or a passing phrase or look that hurts and festers? And does our genetic architecture make us more or less resilient to these kinds of experiences?

To what extent can we put ourselves in someone else’s shoes? Do we have enough shared genes, history, and experiences to be able to fully empathize with others? Or is the chasm too great? Can we place ourselves next to Alex Honnold on El Capitan? What about relating to other athletes, like Simone Biles, who has won the most awards of any gymnast, or Eliud Kipchoge, who recently completed a marathon under 2 hours for the first time? What about a concert pianist? Or, for that matter, can we feel what it’s like to be any of us?

The best we can do is take the time to listen to others’ stories. I don’t know the answer to the question of how similar or different we are – there may be no definite answers to such big questions – but we can only begin to answer the question by taking the time to listen, learn, and ask questions. And, by listening to others, we will also inevitably learn a little bit more about ourselves.

© James Morris and Science Whys, 2019

2 thoughts on “Others’ Shoes

  1. Andy Extance

    I’m fascinated by this 99.1% number. If we get 50% of our DNA from our mum and 50% from our dad, how is this possible? Is it that the 50% only capture half of the 0.9% variation between people? Are you saying that I’m 99.55% similar to my parents? Also, I’m curious how 99.1% is arrived at. Is that just at the gene level, or are we talking about literal base-to-base similarity? Because I believe that there are potentially several functional versions of the same genes with different sequences.

    Reply
    1. James Morris Post author

      Good questions. When scientists say that we are 99.9% identical to one another genetically, it’s a base-by-base comparison. In other words, if I sequence my genome (all of my DNA) and sequence your genome, and line the sequences up side-by-side, they will be 99.9% exactly the same – not similar, but identical. Or, put another way, only 1 base in every 1000 bases will be different; the other 999 will be the same. These numbers are across the entire genome, not just in the regions where there are genes (which encode proteins).
      Note that we are not talking about where we get our genes from. The fact that half of our DNA comes from our mother and half from our father doesn’t change the 99.9% number. In fact, the DNA sequences of your mother and father are also 99.9% identical.

      Reply

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