How the COVID variants are like duck penises. (An imperfect but fun analogy.) 🧵...
Certain species of ducks have long, corkscrew-shaped penises. This impressive specimen is a male Argentine Lake Duck nature.com/articles/35093… 
This is weird for…a lot of reasons. But one of them is that most birds don’t have penises at all! They have sex by rubbing together a multipurpose organ used for mating and pooping called a “cloaca.”
But not only do these ducks have corkscrew penises…The females of the species have corkscrew vaginas! (Well, they have corkscrew “lower oviducts” but…you get the idea.)
It turns out that in some species of ducks there’s a lot of forced copulation. And over time, females evolved elaborate vaginas with dead ends, which give them some control over who fathers their babies. (Image found at pattybrennan.com/research)
The twists and turns makes it hard for a rape-y duck to successfully impregnate the females.
These corkscrew genitals are the result of an evolutionary arms race. This all happened over many generations and involved many mutations. Every time the females’ vaginas got twistier it put evolutionary pressure on the males.
And then when males gained the ability to grow longer, twistier penises, it put evolutionary pressure on the females again.
Yes, ducks grow their penises seasonally (!) and the length may be influenced by the presence of other males: bioone.org/journals/the-a…
We know this is a case of coevolution because scientists have compared the penises of waterfowl that do/do not exhibit forced copulation. No forced copulation=short penis. Forced copulation: crazy corkscrew. journals.plos.org/plosone/articl…
Ok ok, what does this have to do with COVID? Well, all these different variants are arising and spreading because of evolutionary pressure. But in this case, it’s an arms race between our immune systems and the virus.
Whether ducks or viruses, evolution happens because of random mutations that arise through reproduction. If those mutations happen to help the next generation survive and reproduce better, they will continue to get passed on.
Ducks and coronaviruses are different in many ways, but a big one is generation time.
COVID replicates FAST. An infected person carries something like 1-100 billion viruses in them at the peak of their COVID infection. pnas.org/content/118/25…
Ducks don’t breed anywhere near that quickly.
Anyway, my point is that every single time COVID replicates, it has the chance to gain mutations. Some of those mutations will allow the virus to evade our immunity.
When we’re exposed to the virus and survive or we get a vaccine, our bodies learn how to make the right weapons to fight COVID.
But with mutations, the viruses can get around those weapons. Which means we have to build new ones… And thus the cycle continues.
That why vaccines are a huge tool to help us limit variants. If you are vaccinated, the chance that COVID has an opportunity to replicate (and thus mutate) within you is smaller.
If we can rapidly vaccine most people in a population, the virus may not have time to mutate in ways that evade our immunity before most people have at least some protection.
I’m not saying that there won’t EVER be new variants if we all get vaccinated. My point is just that we might see far fewer of them.
And by the time they do arise, people might already have some level of protection against them.
In conclusion, getting vaccinated prevents you from evolving a long, corkscrew penis. (Jkjk, but COVID can cause erectile dysfunction, so there’s another reason to get vaccinated.) latimes.com/california/sto…
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