Jan 1, 2026 03:54 PM
(This post was last modified: Jan 1, 2026 03:57 PM by Mohsen Ezz El-Din Al-Bakri.
Edit Reason: https://upload.wikimedia.org/wikipedia/commons/1/14/Male_anatomy_1.png
)
Biological Evidence of Evolution: The Looping of the Vas Deferens
We brought it from where you love it
One piece of evidence for evolution in the human body is the path of the vas deferens (the tube that carries sperm).
Instead of taking a direct route, it makes a complicated detour around the ureter.
Why all this twisting and turning? Even though it could take a much shorter path — it literally passes right next to a perfectly suitable junction!
But instead of going through it, it keeps looping — as clearly shown in blue in the image.
Even the prostate would still release its fluids into the urethra just fine when needed, just as it currently does through the ejaculatory duct. The sperm meets the prostate fluids downstream anyway.
And in cold-blooded animals, the vas deferens takes a straight route.
So please don’t try to get philosophical and say, “Maybe there’s a smart, intelligent design behind this.”
Because cold-blooded creatures reproduce just fine without all this anatomical gymnastics.
The answer? Evolution.
In fish and reptiles (cold-blooded animals), the testicles stay inside the body cavity, because the internal temperature is low enough to protect sperm.
But with the emergence of warm-blooded animals like mammals, the higher internal body heat became harmful to sperm health.
So the evolutionary solution was to move the testicles outside the body, into a flexible pouch (the scrotum) that can regulate temperature depending on the environment.
However, during that transition, the body retained its old anatomical blueprint — so the vas deferens still loops around the ureter, just like in our distant ancestors.
It’s like living on the ground floor, but instead of using a short stairway to go down, you first climb all the way up to the third floor — or even higher — and then come back down…
Just because you used to live upstairs and still insist on using the same old route.
Logically, it’s absurd.
But from the perspective of evolutionary history, it makes perfect sense.
Even in the human embryo, the testicles begin developing near the kidneys — high up in the abdomen — and slowly descend outward during fetal development, silently reenacting our evolutionary journey.
And in four-legged animals, this setup doesn’t cause much trouble — because the weight of the internal organs is evenly spread along the belly.
But when humans evolved to walk upright, all that weight began pressing downward onto the weak wall between the abdomen and the scrotum — which is why inguinal hernias became so common, especially in human males.
Cheers to the lovers of old staircases
.....
...
— Always giving
Mohsen Ezz El-Din Al-Bakri
We brought it from where you love it
One piece of evidence for evolution in the human body is the path of the vas deferens (the tube that carries sperm).
Instead of taking a direct route, it makes a complicated detour around the ureter.
Why all this twisting and turning? Even though it could take a much shorter path — it literally passes right next to a perfectly suitable junction!
But instead of going through it, it keeps looping — as clearly shown in blue in the image.
Even the prostate would still release its fluids into the urethra just fine when needed, just as it currently does through the ejaculatory duct. The sperm meets the prostate fluids downstream anyway.
And in cold-blooded animals, the vas deferens takes a straight route.
So please don’t try to get philosophical and say, “Maybe there’s a smart, intelligent design behind this.”
Because cold-blooded creatures reproduce just fine without all this anatomical gymnastics.
The answer? Evolution.
In fish and reptiles (cold-blooded animals), the testicles stay inside the body cavity, because the internal temperature is low enough to protect sperm.
But with the emergence of warm-blooded animals like mammals, the higher internal body heat became harmful to sperm health.
So the evolutionary solution was to move the testicles outside the body, into a flexible pouch (the scrotum) that can regulate temperature depending on the environment.
However, during that transition, the body retained its old anatomical blueprint — so the vas deferens still loops around the ureter, just like in our distant ancestors.
It’s like living on the ground floor, but instead of using a short stairway to go down, you first climb all the way up to the third floor — or even higher — and then come back down…
Just because you used to live upstairs and still insist on using the same old route.
Logically, it’s absurd.
But from the perspective of evolutionary history, it makes perfect sense.
Even in the human embryo, the testicles begin developing near the kidneys — high up in the abdomen — and slowly descend outward during fetal development, silently reenacting our evolutionary journey.
And in four-legged animals, this setup doesn’t cause much trouble — because the weight of the internal organs is evenly spread along the belly.
But when humans evolved to walk upright, all that weight began pressing downward onto the weak wall between the abdomen and the scrotum — which is why inguinal hernias became so common, especially in human males.
Cheers to the lovers of old staircases
.....
...
— Always giving
Mohsen Ezz El-Din Al-Bakri