I am not thinking of things like a platypus for example. I am thinking more of examples of attributes or features that a plant or animal might have that are completely unique and baffle scientists as to how or why something like this may have occurred. I have no examples to start with,
Unnecessary things which exist only in the human body but serve no purpose:
the appendix
the hymen
The longevity of the Greenland Shark is pretty crazy:
Today’s Times has an article about the anglerfish:
https://www.nytimes.com/2024/05/30/science/anglerfish-evolution-sex.html?u2g=i&unlocked_article_code=1.xU0.Ke2V.OG6JvaM1iiaB&smid=url-share.
The much smaller males attach and eventually fuse to the female and gradually all of its non-sex organs atrophy and it is reduced to a gonad. A female may support several such males.
The bacterial flagellum:
It is a true rotating biological motor with a driveshaft and bearing assembly and other components.
It and the archaeal flagellum are as far as I know the only true rotating systems in nature. There are hinges and various things that can move in a circle, but nothing else that can simply rotate in place indefinitely.
There are ideas as to how it evolved, but it’s a very difficult problem.
Bio-wheels were addressed by Cecil a few years ago
People do not give scientists enough credit. They are rarely “baffled”. Oddities evolve. It would be more baffling if they didn’t, similar to people winning huge lotteries twice.
The baculum, i.e., the “penis bone”. His or miss presence in placental mammals but quite common in primates. The exceptions are " lorises, humans, spider monkeys, or woolly monkeys".
And I do mean hit or miss. “Evidence suggests that the baculum was independently evolved 9 times and lost in 10 separate lineages.”
So, why did it evolve in so many types if was so useful but then get lost so many times?
Thats a very interesting question, maybe for some reason the males were not getting " Turned on" due to female behaviors. The only ones that could breed had a perpetual hard on.
In 2007, researchers at Duke University proposed that the appendix serves as a reservoir for gut bacteria. Subsequent research suggests they were correct. Other research shows that the appendix is an important part of the immune system.
This could’ve been an interesting thread.
This post makes me not want to read anymore.
The chestnuts on equids. Conventional thinking is that they’re the remains of lost digits. Alternative theories cite that if they are, they’ve migrated pretty far away from the other toes, and possibly they’re vestigial scent glands. I once read an article in which the author posited that they’re the remains of what would have been the sole/palm of the foot when they had more toes.
The bearing assembly is what is so fascinating, Do the nutrients and senses somehow pass through the bearing?
I don’t think much passes through the bearings since it is a tight fit (like most real bearings). But there is a “stator” assembly, similar to the stator in an electric motor, that transports protons through the cell in order to power it. Either hydrogen or sodium atoms for bacteria. The ions pass down an electrochemical gradient and those electrical forces power the rotor.
The bearings themselves are just simple protein assemblies and don’t need nutrients. It’s not like, say, a human joint that’s itself made from cells that need nutrients. The bacterial cell already has pores and other mechanisms for passing molecules across the cell wall.
IIRC, horses have hymens, too. And is there any evidence that it doesn’t serve the obvious purpose?
what obvious purpose…from a biological viewpoint?
A million years of evolution doesn’t care about weird human social and marriage customs which only developed during the past 3 thousand years.
(And I didn’t know about horses.)
Who said anything about social customs? It’s like those protective films on new products, that you’re supposed to remove before using. It helps prevent dirt and other sources of bacteria getting into the reproductive tract. You can’t keep the covering on forever, or the system wouldn’t work, but you can at least keep it protected for the first decade or two before it’s being used.