But Seriously, Why The F*ck Do Giraffes Have Long Necks?
Their genes know more than you think...
Insight Axis explores ideas in science, technology and philosophy. I’m Zan - follow me on Substack.
Why do giraffes have long necks?
This is old chestnut is usually sprung on high-school biology students who are expected to regurgitate a dull answer that hits the buzzwords evolution and survival of the fittest and Darwin.
But the standard answer isn’t completely true1.
Stories in science shouldn't favour simplicity over truth. The truth is always more interesting, useful and compelling because it's, well... true. I want to share the real story of how these lanky beasts with long eyelashes came to walk the earth.
So seriously, why the f*ck do giraffes have such long necks?
In the simple high-school answer, the giraffe is the protagonist.
When we look at any group of giraffes, we'll see a natural range of neck lengths. Those with longer necks can reach food on taller trees, leading to better odds at surviving. These giraffes have more chance to pass on their genes to their offspring.
Over time, nature will favour giraffes with longer and longer necks until they reach the height of trees. This is where the standard high-school story ends. In this version of the story, genes are just a blueprint for building giraffes with long necks. They're merely a supporting character.
But in the deeper answer, genes are the protagonist.
The natural variation we see in giraffes’ heights actually comes from variation in their genes. If a particular gene variant builds a taller giraffe, then that variant is more likely to proliferate through the baby giraffes that are endowed with it. It's important to remember a distinction here: giraffes reproduce to make babies that are not identical to either parent, but the genes themselves are identically copied, half from each parent2.
These genes have a single motive - to self-replicate. They just happen to do this by building giraffes around themselves. Through passive trial and error, the different variants of a giraffe’s genes are testing to see if they can align better with the environment, because this would let them replicate more often. In this version of the story, the knowledge contained in genes only exists to help them replicate. It's just a supporting character.
But in the real answer, it turns out that knowledge is the star of the show.
True knowledge has a single characteristic - it sticks around by self-replicating. In this version of the story, the gene is nothing more than nature's chosen molecule to hold knowledge. The truer the knowledge contained in the gene, the better it can replicate across a wider range of environments, and across time too.
When we give knowledge the starring role, we uncover something far more interesting; a giraffe's genome explicitly has the knowledge to build a giraffe, but also implicitly has knowledge about the giraffe's environment. In other words, a giraffe's genes know the height of trees. If that sounds wacky, let's do a quick and morbid thought experiment to show you what I mean: what would happen if we dropped a few giraffes on the North Pole? Sadly they would probably die. But this wouldn’t because they are poorly designed giraffes, rather it’s because their genes didn't contain the right knowledge about the environment.
So now we can arrive at the true answer: a giraffe - along with its long neck - is simply a solution which gives the knowledge contained in its genes the best chance at self-replicating in a particular environment - the African savannah3.
Epilogue - Humans
I wanted to stop the story here, but the implications of this story are too exciting to keep to myself! Because when we understand the true story of genes, we understand what makes humans unique.
Unlike giraffes, humans can survive in the African savannah, on the North Pole, and even in space. This is because we aren't limited to using the knowledge contained in our genes like they are.
We can use our minds to create our own knowledge.
When we use this knowledge to build technology, we can harness fire to warm us through arctic blizzards, sharpen spears to fend off lions, and build spacesuits to resist the cold, harsh and unforgiving vacuum of space. And just like genes, the truer the knowledge humans create, the more likely we are to thrive.
Our knowledge and ability to survive are no longer confined our genes. We are only limited by our (infinite) creativity.
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This is no fault of Darwin’s - he remains the bedrock for everything that came after him. Darwin wasn’t wrong, he just couldn’t give the full story because he didn’t know about DNA, genes and patterns of inheritance.
Roughly 50% of the genes are maternal, and 50% are paternal - but remember it’s whole genes from either parent that are replicated, with very high (but not perfect) fidelity.
A giraffe is not the only viable solution to the African savannah - lions are another solution, as are the trees themselves, and all the other creatures. Also note that every organism is part of the “environment” for every other organism (the lion is technically a part of the giraffe’s environment and vice versa). There is complete interdependence. I’ve just picked the perspective of a giraffe to make my point. And I like giraffes.
Thanks to
for reviewing early drafts of this essay.
Giraffes are God’s natural “tree trimmers”!
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Thanks Zan, excellent post!
That was a cool explanation.