Why have female animals evolved such wild genitals?
smithsonianmag.com
smithsonianmag.com
git format-patch --stdout | mail
... | git am
These creatures are aware of more modern practices and yet they choose to remain in their own evolutionary niche, in part, because they lament the way in which Developa intercourse has been cheapened and corrupted by an unmentionable website named “something”hub.com.
And there's a reason there is no company worth its salt, no matter the scale, that still works by sending patches by email.
It's pre-commit. A way to work out if it gets into git, or what not.
But of course, if something has worked well for decades, and continues to work well, that's meaningless.
Linux kernel development works perfectly well using mailing lists. The fact that it discourages people who can't bother spending 15 minutes to learn how to send a patch is a feature, not a bug.
"donation and acceptance of information carrying material" = a high-enough abstraction to cover both sex and development of the Linux Kernel.
"git format-patch --stdout | mail" = creates a patch (a series of commits wrapped neatly) in std-out and then pipes that into the computer's mail client
"... | git am" = the receiver pipes that information into git which then applies the commits
It is different for birds that don’t fly. Water fowl especially have a different reproductive system. Because they don’t fly. This is true for all flightless birds. Even for birds like geese that only fly for seasonal migration. They get their food from the water. Ground dwellers have plenty of food and don’t have spend as much energy foraging for food as a bird that flies. Very few of them mate for life.
Further: Galus Galus has different design than geese and ducks. Castrated roosters are called ‘capons’(French)…produces a nice soft fat capon for Sunday lunch. It’s genitalia is less developed than say..geese.
As a chef, I knew how to sex identify geese/duck. water fowl genitalia is different than fowl. Most farmers know this as sex determination is key to raising animals for profit. With the exception of Pilgrim/Emden/White Italian and some Chinese geese where the autosexing is straightforward with feather colouring and down colour, most have to be identified while they are still goslings.
Goslings can be gender identified as early as the first week and also when they are adults. Male adult penis is invaginated and like a corkscrew. Female organs has genital eminence. The breeding ratio is 1:3 or max 1:5. So it’s important to separate them as early as possible.
Mammals are different..example: feline penii is barbed and most copulation results in kittens. A female cat can have a single litter with multiple tomcats. Male cats will kill kittens ..probably those that aren’t their own..because a lactating mother cat won’t go into heat.
With insects like bees and mantii, the male often meets his end after sex. It comes down to energy needs and availability of resources.
P.S: [..] Birds, she thought at the time, didn’t have penises. In her two years studying them at Cornell University, a world leader in avian research, she’d never once heard her colleagues mention a bird penis.[..] Huh! Really? Cornell university scientists don’t know what a farm child picks up during one farming season? The article is full of red flags for clickbait lies.
I don't really see how machine learning would improve this process
Crap, I can't tell a human baby's gender just from the face. The secondary sex characteristics show up closer to puberty pretty much by definition.
I'm aware that the rest of this is automated. I guess I just haven't kept up to date with the last 5 years of chicken sexing technology.
Your comment has a lot of interesting info, but could’ve easily done without this opening. I don’t see the need to reductively frame your experience against this entire scientific exploration.
Uh, here in Germany we took until February 2022 to have the first anatomically correct drawing of a human clitoris in a schoolbook [1]. I'm pretty sure the US hasn't reached even that state, given that university textbooks aren't accurate either [2].
And when we can't even manage to have anatomically correct drawings in university textbooks for our own species, how on earth can we assume that the situation is different in veterinary science?!
Farm kids obviously know the difference because they have first-hand experience. But most farm kids don't go and become veterinary scientists or scientists at all!
[1] https://kurier.at/leben/gesellschaft/keine-scham-klitoris-er...
[2]: https://www.vice.com/en/article/nejny8/fear-of-the-clit-a-br...
What the?! Where is your data on this?
Do you think the offspring of farmers are stupid? This seems incredibly biased.
This statement lives or dies by your definition of 'scientist', but if we're talking about research scientists, it seems trivially obvious that a group constituting a small minority of the population would be quite unlikely to be a majority of 'farm kids'.
Having gotten that out of the way,I agree that it read as deliberately derogatory. Grandparent also draws the specious connection between knowledge and something being present in elementary textbooks, which I found more misleading. Clearly the body of knowledge of a society extends infinitely beyond the contents of their elementary textbooks; even the knowledge of the grade-school user of said book does so.
Also, why would not becoming scientists equal to being stupid? Kind of biased, hmm?
See for example here: https://academic.oup.com/joeg/article/21/5/683/5998980
> Do you think the offspring of farmers are stupid?
No, rather that the education opportunities in rural areas are rather scarce and underfunded (because school funding depends on the number of citizens, which is lower in rural areas), and as a result the education outcomes are worse (see above).
I think the more accurate complaint is most farm kids don't grow up on farms with ducks.
Ducks are pretty niche in the US. If it's not on the menu at McDonald's or Taco Bell, it's not on 95% of US farms.
I don't know exactly when I first learned about duck penises and labyrinthine duck vaginas, it's not precisely a 9/11 memory, but it was certainly after I left the farm in 2001 and could be entirely due to news reports about this researcher's research trickling out to the pop sci blogosphere.
Either the author have never seen one. Or they are scared of Disney. Hints for the latter might be that there no mice either. For visual completeness there are rats, which is close enough to not need mice.
I know a decent number of people that duckhunt and I've tripped over domestic breeds on friends' acreages often enough. They're easy birdwatching too if you bundle up, so if you hang out with that sort of crowd, you'll hear plenty of discussion. It might just depend on how much time you spend out of the city or staring at ponds.
Oh, for shame. Back in the '70s a whole bunch of pictures of human (oh, and animal) clitorinks were hidden in a box under my friends dads bed.
As far a why a Cornell scientist didn't know about bird penises, it's because the vast majority of bird species don't have them. If she didn't do much work with Anserids, it wouldn't be surprising at all that she hadn't encountered them.
This was about fowl and water fowl penii. That a male duck has a penis is rather well know farmers and chefs and scientists who study about their subjects.
The bird mentioned is a ground dwelling bird (possibly flightless) and every scientist is required to ask WHY. The answer to The Why of fowl and waterfowl having penii is simply because they are ground foragers or aquatic.
I used to cook at an offal restaurant and I have pulled enough pluck to know that human beings will eat anything when they are starving if poor.. or when rich enough to seek culinary adventures.
I still don't see how penises have anything to do with being flightless. You've decided that since tinamous are fairly terrestrial birds that it must be a terrestrial bird thing, so you've found a way to convince yourself that waterfowl don't fly enough to be considered flying birds and then you shoehorned some theory in there about that causing them to have penises.
Chickens, even the Red Junglefowl that the domestic chicken presumably descended from, are much more terrestrial than ducks and geese. You've worked in restaurants. What kind of penis does a chicken have? You know what else is aquatic and doesn't fly? Penguins! What kind of penis does a penguin have? Loons? They're basically wonky ducks. Pheasants, turkeys, kakapos? They've all got penises, right?
We can go over entire lists of all the birds found in nature but the way it actually works is we classify them into broad categories and generalize.
Yes, we classify them into categories. I'm trying to figure out how you've managed to convince yourself that ducks and tinamous fall into this special category of terrestrial birds which the experts should obviously know have penises for obvious reasons, but these other birds with the same life history don't fall into this magical category and thus don't have them. What about tinamous and anatids place them in this group which excludes penguins, turkeys, loons, and all of the other birds which are either aquatic or terrestrial and do not have penises?
Edit: I'm also waiting here for you to bring the Rattites into this. I'm a little disappointed honestly. There's some arguments for you to make from that family and I don't know why you haven't brought them up.
Birds copulating in flight are not resisting and simply cannot due to their dynamics.
Where did you get information about loon, penguin and turkeys and their respective penii? They are not adjacent classes as chicken and geese(which was what I was talking about..).
1. Do the birds have easy access to food resources?
2. Do they have to take flight to look for food?
3. Do they migrate?
4. Do they have predators in the wild?
5. Are they aggressive or docile?
6. Are they domesticated?
7. Are they monogamous or promiscuous?
Take all the bird examples you can think of + chicken/eggs.
Make a table and let me know how my ‘shoehorned’ theory fails. Unlike you, I am not an expert. Or a scientist. I farm and have been a chef. I haven’t had an opportunity to check for ostrich penis, but I have cooked them for breakfast.
ETA: I am not interested in an never ending ‘what about’ or gotcha games. However, if you are willing, I will walk you through critical thinking process using logic and multi modal approach to answering questions that confound us.
I will present you with a set of questions you can answer as a biologist/expert or you can google. At the end of it, you will arrive at the answer you want. It will be fun.
Raptors have a slower heartbeat than hummingbirds. That is true. What does that have to do with any of this?
[..] In birds, apoptosis of the genital tubercle is triggered by a gene called Bone morphogenetic protein 4, or Bmp4, a protein involved in bone, muscle, cartilage, and limb development. In the majority of birds, Bmp4 gets switched on and blocks the genital tubercle from developing into a penis so they either lack one altogether or it’s so small as to be rendered useless.
In ducks and other birds which grow penises, Bmp4 remains switched off and the genital tubercle develops into a functioning penis.
But although this explains how most birds end up penis-less, it doesn’t explain why. And scientists are still not sure of the answer to that conundrum.
There are several plausible explanations. It could be that the loss of the penis was an unfortunate side-effect of Bmp4 triggering other changes to body parts such as the development of feathers, or the variations in beak size. A bird without a penis carries less weight and therefore would be able to fly more easily, although this theory is unlikely when you consider that fact that ducks make some of the longest migrations of all species of birds. And most flightless birds or birds who fly very little, other than the ratites, have non-existent penises.[..]
Hope this helps.
This is incorrect.
This is quite misleading without further context.
My understanding is that a majority of birds are observed to be "socially monogamous"; that is they form a pair lasting a single breeding season, and the pair works together to raise that season's brood. It's only a minority of species in which the same pairs reform across multiple seasons. I don't know how well understood this is; at least for sea birds, which are general among those to form long-term relationships, I've heard a theory that it might be related to the fact that fishing is an aquired skill that should improve with age; finding enough fish to feed both parents and chicks is difficult, and therefore there's a bigger risk if you change partners. The difficulty of finding food, and long time after birth before the offspring become self-sufficient, means these birds can typically only raise one or at most two young per year, so again the cost of failure is high.
Even though in general the rate of social monogamy among bird species is high, this doesn't mean that birds are always parenting their own offspring. In some species (kittiwakes, terns) parenting others' chicks is really rare, but in other species there can be high rates of sexual infidelity e.g. some studies suggest that ~20% of chicks in flycatchers and ~30% in cardinals are unrelated to one (or, less commonly, both) parents. The latter may seem surprising, but of course brood parasitism (e.g. cuckoos) is well known, and there's a same-species variant of that in some species where a female will intentionally lay some eggs in the nest of another pair.
Of course, there are exceptions here too..there are brood parasites too. Long migrations, short nesting periods .. long incubation time and of course anything that requires courting displays (like the peacock..swans etc) make monogamy a necessary evolutionary strategy.
Some migratory birds return every year to the same spot they roost every year and such memorized cooperative efforts make them staunchly monogamous. I have had the good fortune to witness a pair of nesting ospreys for the past five something years. Nature is wicked smart.
Why has biological gendering evolved to lead to this dynamic? Is it to enable one sex to vary wildly evolutionarily to respond to wildly changing conditions, while the other maintains the stability of the species? Is it because of what we’ve seen in human governments where division of power keeps one dominant bad leader from sinking the whole species? We saw GANs lead to tremendous boosts in creativity in machine learning algorithms. What if we apply these two-role algorithms (competing side and curating side) into machine learning and see where it takes us with agent systems for example? It’s already applied in business [Founders (competing), investors (curating)] and education [students and universities].
If I know anything about nature, it's that it's a brute-force optimizer for biological fitness. Every possible combination of traits could feasibly be tested on these scales.
> [...] and there are - or used to be, sadly - enough species for every linear combination of both possibilities.
Extinction is sad, but there's still plenty enough species to make this statement true.
> If I know anything about nature, it's that it's a brute-force optimizer for biological fitness. Every possible combination of traits could feasibly be tested on these scales.
Not quite. Eg there's basically no wheel in nature, despite the structure itself being quite simple. That's mostly because it's hard to evolve in small steps.
Fair enough. I do find it interesting that even in plants that have N different sexes, their life cycles are still often dimorphic.
Maybe the most fundamental abstraction really is the difference between a 1 and a 0.
Nature and nurture. Gattica-level eugenics, at the end of the day, only affect the DNA. And eugenics will never save someone from the adage "Hard times make strong men. Strong men make good times. Good times make weak men. Weak men make hard times."
Eg western militaries don't seem to be worse at fighting than militaries from poor countries?
> In plant biology, Vavilovian mimicry (also crop mimicry or weed mimicry[1][a]) is a form of mimicry in plants where a weed evolves to share one or more characteristics with a domesticated plant through generations of artificial selection.[2] It is named after Nikolai Vavilov, a prominent Russian plant geneticist.[2] Selection against the weed may occur by killing a young or adult weed, separating its seeds from those of the crop (winnowing), or both. This has been done manually since Neolithic times, and in more recent years by agricultural machinery.
> Vavilovian mimicry is a good illustration of unintentional selection by humans. Although the human selective agents might be conscious of their impact on the local weed gene pool, such effects go against the goals of those growing crops. Weeders do not want to select for weeds that are increasingly similar to the cultivated plant, yet the only other option is to let the weeds grow and compete with crops for sunlight and nutrients. Similar situations include antibiotic resistance and, also in agricultural crops, herbicide resistance. Having acquired many desirable qualities by being subjected to similar selective pressures, Vavilovian mimics may eventually be domesticated themselves. Vavilov called these weeds-become-crops secondary crops.
Agreed, but V-ATPase is worth mentioning as it has a rotor and is very highly conserved. I guess it all depends on scale.
It works in the other direction as well, especially if competition involves expending many resources on a single female. Only attractive females attract many competitors.
> It’s already applied in business [Founders (competing), investors (curating)] [...]
Wouldn't the even more basic dynamic in business been between company and customers? (And of course also between company and suppliers including workers who supply labour (or investors who supply capital, as you mention)?)
I know many people, male and female, who would be considered prime mating material opting out of having children because they do not want to spend the resources they would have to to raise children.
Now a population of mixed male-type and hermaphoditic-type individuals by definition can only skew male-type (in the sense that the average individual over the entire population somewhat prefers fathering over mothering). But each offspring has one male and one female parent; i.e. the population of parents does not skew in either direction. Run the math and you'll find that, counting hermaphodites as 1/2 in each category, there are more offspring per female-type than per male-type: those hermaphodites who prefer mothering are now the sexually fittest individuals in the group. And much like in the case with males above, a genetic preference towards mothering will catch on among the hermaphoditic population and begin skewing a subpopulation ever more female-like.
Eventually the male-type and female-type sexes fully diverge from each other, and the initial population of hermaphodites get out competed by the sexual specialists and fall solely into the fossil record.
If there's a evo geneticist around, one thing I'm wondering is whether some of these traits might have evolved as a heck from the male side. E.g., if I have mutations that increase selectivness of the females against everyone but me, passing those mutations would bias later generations to select for my gene line. I'm not sure whether this is feasible or likely, but it's an example of evolutionary benefit without any real benefit if possible
This is fairly intuitive result when you consider gestation time - imagine a scenario where there are more male than female in a given moment for a given species. At most each female got fertilized once, so the number of distinct male parents is less than or equal to the number of females. If there are more females than males, the you get the same situation (less distinct male parents). This result is simply because a male parent can fertilize multiple females quickly, while gestation period limit the females.
This dynamic has led to sexual selection mostly affecting the males of the species, which means that this is where the competition happens. The move from polygamy to monogamy in human culture has allowed more males to reproduce and reduced this effect (although it still exists, and is significant).
1. https://en.wikipedia.org/wiki/Bateman%27s_principle
2. https://en.wikipedia.org/wiki/Reproductive_success#Humans
> Although Bateman's principle served as a cornerstone for the study of sexual selection for many decades, it has recently been subject to criticism. Attempts to reproduce Bateman's experiments in 2012 and 2013 were unable to support his conclusions. Some scientists have criticized Bateman's experimental and statistical methods, or pointed out conflicting evidence, while others have defended the veracity of the principle and cited evidence in support of it.
Seems like a very convincing conjecture otherwise, though.
I'm having trouble to understand how this can be true. It seems like every human should have equal numbers of male and female ancestors, e.g. by induction on how many generations back you look.
Taking an average human generation time of 25 years, you would theoretically have 2^30 = roughly a billion ancestors 30 generations back, or 750 years ago. But the population of the Earth in 1300 was... maybe 400 million. (e.g. https://www.census.gov/data/tables/time-series/demo/internat... for world population estimates)
And your ancestors in 1300 aren't drawn from the entire population of the world; they're drawn from a tightly restricted subset of that.
And if you think that's ridiculous, imagine how many ancestors you'd have thirty-one generations back!
Females are super careful about picking a mate because they spend months making an egg. They have a sunk cost. And females are relatively more caring about young because it is cheaper than making a new egg.
This access control forces males to evolve to be pleasing and provide some proof of quality. And this proof of quality can create more of a sunk cost for the male. They stick around and protect the young because it is easier to do that than find another female, impress them, build a nest etc.
Also, sex is very very obvious in terms of primary sexual characteristics. We have literally evolved to focus on those things. But outside of reproduction it is far less obvious in biology. On an individual level it is better to think of sex as an output rather than an input. Things don't happen because of the sex variables state, rather sexual characteristics are a consequence of other processes.
>Females are super careful about picking a mate because they spend months making an egg.
The prevailing science was that females - assuming we are talking about humans - don’t make eggs rather are born with a finite number that reduces over their life time.
Only in the last couple years has the science begun to be questioned with the possibility that women do in fact make new eggs during adulthood. However, as far as I know that is still an open ended question being studied, whereas you offer some very specific facts about the required energy to produce eggs, which would suggest that in fact studies have not only confirmed women do actually make new eggs during their lifetime but there is further understanding about that process.
Could you link any studies about women producing new eggs “every couple months” and the energy required that you reference?
Humans are social animals with a wide variety of cultural values, in most cultures throughout history it won’t be a viable option for a man to go around impregnating multiple women every year and likely result in becoming a social outcast in civilized societies or outright killed in others.
Most cultures tend to be monogamous, courting and marriage being fairly common and also dowries were and are real thing -where a man pays a cost for each daughter to be married - not to mention co-evolution of societal norms that have also resulted in laws in some societies requiring child support until a child is 18. Whatever the natural biological costs, humans seem to have created different social norms and laws that have there own costs tending to curb the behavior you describe.
The same is true of humans. If a males want their kids to survive to reproductive age then looking after their mum and the kids during infancy is the best strategy. And the best strategy for the mum is to use what power she has to encourage that. That may not be entirely a reflection of biology now, but it certainly was in the past. And it is no accident that humans find certain traits attractive in a mate.
But the difference in cost absolutely does still exist. Single parent households where the mum is left holding the baby are not exactly unusual. And the health burden of carrying a child and birthing is 100% on the women.
Of all things we know and think we know, we still don't know this? That's a miracle.
[0] https://thehighbook.netlify.app/muller's-ratchet (first half)
But if we don't observe that complete control (at least not in most species), and instead it's more of an "arms race"; then it makes me think complete control is an evolutionary disadvantage. Is that true?
That is to say, sexual evolution increasingly approximates a globally optimal process, as an aggregate system of autonomous agents.
The Internet is also not actually a global network. It's just lots of local connections between two computers. Yet the effect approaches a global network.
It seems obvious to me (from logic and observation) that most animals don’t have global connectivity (despite your comparison to internet meshes), and obviously evolve differently across the world.
Virii, for example, transfer genes between species. Bacteria have plasmids, rings of genes they can literally just give to other bacteria.
As for an example where you know the global optima: real life hill climbing rather than the blindfolded version used to explain the algorithm of the same name?
If a female duck had complete control, genetic variety would likely decrease quickly as fewer, genetically similar males fathered all the children. This group of ducks would be more susceptible to disease, genetic defects, etc.
It could also be the case that if male ducks can’t be certain who the father is, they are more likely to help protect/not kill the young.
Have you considered that every specie approaches this differently for their own situations? That doesn’t mean it’s a conceptual failure.
Would you care to name a few?
I don’t immediately see it, unless we assume that the male genitalia stops adapting to whatever the female has.
The strategy is not fundamentally stable; female bedbugs have no genitalia at all but that doesn't give them any control.
Ducks are savage. York University where I studied, in the 70s had a huge shallow lake and it had a regrettable sexual population imbalance which caused fatalities. Randy drakes drowned the decreasing number of ducks. I think they had to do culling to fix it. You think nature would right itself, but in human time for small local populations sometimes it doesn't do a good job.
Why think this? Populations and their environments constitute complex systems, not magical ones. They can self-correct, or not, just like how humans don't always manage to not develop cancer.
Or at least that's how I imagine it would go.
Follow this train of thought, we can imagine that reproductive morphology is there for it's own sake. The genes that create it, are successful if they create creatures that propagate those genes. Never mind how onerous it is to the creature. Sure, they can't cause the creature to actually expire in the effort. But short of that, they can get as strange as galapagos birds and so on, purely for their own sake.
“Insect genitalia have been the focus of much attention since the middle of the 19th century, when their taxonomic value to diagnose species with otherwise very similar [shapes] was recognised.”, “The structure of the female genitalia of Limnebius is poorly known, mostly due to the lack of sclerotized parts”. https://peerj.com/articles/1882/
https://en.wikipedia.org/wiki/Drone_(bee)#Mating_and_the_dro...
"Mating between a single drone and the queen lasts less than 5 seconds, and it is often completed within 1–2 seconds. Mating occurs mid-flight, and 10–40 m above ground. Since the queen mates with 5– 19 drones, and drones die after mating, each drone must make the most of his single shot. The drone makes first contact from above the queen, his thorax above her abdomen, straddling her. He then grasps her with all six legs, and everts the endophallus into her opened sting chamber. If the queen’s sting chamber is not fully opened, mating is unsuccessful, so some males that mount the queen do not transfer semen. Once the endophallus has been everted, the drone is paralyzed, flipping backwards as he ejaculates. The process of ejaculation is explosive—semen is blasted through the queen’s sting chamber and into the oviduct. The process is sometimes audible to the human ear, akin to a "popping" sound. The ejaculation is so powerful that it ruptures the endophallus, disconnecting the drone from the queen."
I'm not sure I fully appreciate the evolutionary pressure in the bird's "arms" race, in that the female duck chooses mate despite violent competing males. Up to 40% die in the violence -- would that not put evolutionary selection in favor of females that lack resistance?
I think this is what they mean. Not offspring dying per se, but still an evolutionary pressure
There is no indication of the rate of drowning, but it would be a constant risk across all females, so no real evolutionary pressure would be evident (aside from a risk to the species as a whole). That is to say: the rate of drowning for females would have to be very low, otherwise the species would fail. If the rate was too high, you’d expect to see a counter pressure to have a higher rate of females born versus males.
The point here is that as reproductive structures evolved, the female developed equally complex structures. She might not a choice in if mating occurs, but she does have a choice in whether a particular male fertilizes her eggs. That is the evolutionary pressure… not in response to death from forced mating.
> Whatever the females were doing, they were succeeding. In ducks, only 2 to 5 percent of offspring are the result of forced encounters.
So regardless of if the mating was forced or not, female ducks are quite successful in choosing who fertilizes her eggs.
There would be quite a lot of pressure to not die from forced mating. Can't reproduce when you are dead after all.
A male that kills his mate has fewer offspring than a mate that manages to keep the female alive, doesn't he?
The risk of drowning during mating is the same for both groups. So, neither group gets a natural selection advantage from being less likely to drown, because it is a constant risk for both groups.
The key here is that the males don’t know if the successfully mated with the female (passed on their genes) or not. Only the female knows.
Seems to be the strongest evolutionary signal would be where the female has lots of offspring, whether desired or not.
So you get multidimensional optimization of a single quantity - become too aggressive and your sperm won't pass, but if you're not aggressive enough you might not eat.
What are we to infer about cultures that forcibly remove erogenous tissue (clitoris/clitoral hood/vulva on females and foreskin/frenulum/ridged band on males) from their children?
> "...there is a huge gaping hole in our knowledge of this very fundamental part of bird biology"
> Brennan’s husband is used to these kind of excursions: “He brings me roadkill as a nuptial gift,” she says.
"..they both did a double-take. He had never seen anything like it. "
and, so on...
Interesting she did not ask the farmers where she purchased the ducks to get their insight...
I am rather more troubled by the idea of someone “enjoying” these dead examples in that way. But I have the same trouble with leather fetishism for exactly the same reasons, and most do not share my negative reaction to the latter.
I wonder how that works, and why? Stream of consciousness here, but specifically about leather: could it be that the uncanny valley effect happens when the visual processing in our brains detect most of the signals to positively recognise an object, but missing a certain number of core features or possessing anti-features, and that my brain is trying to match again an unusual set of features such that leather induces this reaction in me — i.e. that it’s a person wearing someone else’s skin — whereas more normal people learned a substantially different set of feature detectors and just see leather as nothing more than a durable fabric?
> That’s when she began thinking about conflict. Duck sex, she knew, could be notoriously violent. Ducks tended to mate for at least a season. However, extra males lurked in the wings, ready to harass and mount any paired female they could get their hands on.
I never knew ducks had hands! I thought that was only in cartoons! This is big news, even bigger than reverse-threaded vaginas.
> Today, he admits that perhaps the reason he hadn’t considered looking at the female side of things was a result of his own male bias.
Honestly, the male scientists really disappointed me. Do they not have any curiosity or sense of professionalism? This guy dissected multiple penises and never once thought to dissect a vagina? Wow, just, wow.
The two sentences immediately after your quote can be read this way:
> ...a result of his own male bias. “It was fitting that a woman followed this up,” he says. “We didn’t need a man to do it.”
https://en.wikipedia.org/wiki/Barnacle#Sexual_reproduction
>Sexual reproduction
>Most barnacles are hermaphroditic, although a few species are gonochoric or androdioecious. The ovaries are located in the base or stalk, and may extend into the mantle, while the testes are towards the back of the head, often extending into the thorax. Typically, recently moulted hermaphroditic individuals are receptive as females. Self-fertilization, although theoretically possible, has been experimentally shown to be rare in barnacles.
>The sessile lifestyle of barnacles makes sexual reproduction difficult, as the organisms cannot leave their shells to mate. To facilitate genetic transfer between isolated individuals, barnacles have extraordinarily long penises . Barnacles probably have the largest penis to body size ratio of the animal kingdom, up to eight times their body length.
>Barnacles can also reproduce through a method called spermcasting, in which the male barnacle releases his sperm into the water and females pick it up and fertilise their eggs.
>The Rhizocephala superorder used to be considered hermaphroditic, but it turned out that its males inject themselves into the female's body, degrading to the condition of nothing more than sperm-producing cells.
https://en.wikipedia.org/wiki/Rhizocephala#Description_and_l...
>Description and lifecycle
>Sacculina carcini (adult female) parasiting a crab (Carcinus maenas). Haeckel's drawing also shows the internal network of filaments from the parasite.
>As adults they lack appendages, segmentation, and all internal organs except gonads, a few muscles, and the remains of the nervous system. Females also have a cuticle, which is never shed. Other than the minute larval stages, there is nothing identifying them as crustaceans or even arthropods in general. The only distinguishable portion of a rhizocephalan body is the externa; the reproductive portion of adult females.
>Nauplii released from adult females swim in water for several days without taking food (the larva has no mouth and no intestine) and transform into cypris larvae (cyprids) after several moults. Like the nauplii, the cyprids are lecithotrophic (non-feeding). The female cypris in Kentrogonida settles on a host and metamorphoses into a specialized juvenile form called a kentrogon, which has no visible segmentation and has no appendages except the antennules that are used to attach itself to the host, and whose only purpose is to inject a cell mass named the vermigon into the host's hemolymph through a retractive hollow stylet on its head. The kentrogon stage seems to have been lost in all of the Akentrogonida, where the cypris injects the vermigon through one of its antennules. The vermigon grows into root-like threads through the host's tissue, centering on the digestive system and especially the hepatopancreas, and absorb nutrients from the hemolymph. This network of threads is called the interna. The female then grows a sac-like externa, which consists of a mantle, a mantle cavity, an ovary and a pair of passageways known as cell receptacles, extruding from the abdomen of the host.
>In the order Kentrogonida, the virgin externa contains no openings at first. But it soon molts to a second stage that contains an orifice known as the mantle departure, and which leads into the two receptacle passageways — once assumed to be the testes in hermaphroditic parasites before the realization that they were actually two separate sexes — and starts releasing pheromones to attract male cyprids. From inside the body of the male cypris that succeeds in entering the departure, a unique and very short lived male stage called the trichogen emerges through the antennule opening. It is the homologue of the female kentrogon, but is reduced to an amoeboid unsegmented cuticle-covered mass of cells consisting of three to four cell-types: the dorsolateral, the ventral epidermis, the inclusion cells, and the postganglion. The externa have room for two males, one for each of the receptacles, which increase the heterozygosity of the offspring. Once inside, the trichogen will shed its cuticle before reaching the end of the passageway.
>In the order Akentrogonida, which form a monophyletic group nested within the paraphyletic Kentrogonida, the male does not develop into a trichogon, and the cypris injects its cell mass through its antennule and directly into the body of the immature externa. The offspring also hatch directly into fully developed cyprids instead of nauplius larvae (except for a few species of kentrogonid rhizocephalans, which hatch into cyprids like the akentrogonids, the kentrogonids have kept their nauplius stage). In species like Clistosaccus paguri, the male injects its cluster of cells which migrates through the connective tissue of the mantle and into the receptacle. But in forms like Sylon hippolytes the receptacle is absent, and the males cells implant in the ovary instead. While only a single male can settle in each receptacle, which is the rule in Kentrogonida, the number of implanted males in Akentrogonida can range from just one to more than ten.
>The small cluster of cells injected by the male cypris will, once it reaches its destination inside the female, differentiate into a loosely connected mass of sperm-producing germ cells. Being nothing more but sperm-forming cells, these adult male rhizocephalans represents the simplest form of male in the entire animal kingdom. Mature female externa releases eggs into its mantle cavity where eggs are fertilised by sperm from the hyper-parasitic male(s). Due to the larval sexual dimorphism in the Kentrogonida, the females produce two different egg sizes; small female eggs and larger male eggs. It appears the sex determination in Akentrogonida is environmental.
>In Peltogasterella gracilis, the externa produces several batches of larvae before it drops off the host, taking the male(s) inside with it. After the original externa disappear, the host moults and the interna grows buds that each develops into a new virgin externa. The females commonly has two cypris cell receptacles. With more than one externa, and new ones replacing the old ones, each female Peltogasterella can receive sperm from numerous males during its lifetime.
>The externa is where the host's egg sac would be, and the host's behaviour is chemically altered: it is castrated and does not moult until aged externa(e) drop(s) off. The host treats the externa as if it were its own egg sac. This behaviour even extends to male hosts, which would never have carried eggs, but care for the externa in the same way as females.
I’m not up to speed on topology but generally turning things inside out changes the “handedness” (cf. a glove).
Instead picture one of those cabinets with the built-in gloves that are used for sandblasting or handing hazardous materials, and focus on the glove on the right side.
Normally a person's right hand would fit inside the glove (which as before is just a continuation of the outside surface of the cabinet).
Now pressurize the cabinet so that the glove pops out and inflates. The glove would now be in the shape of a left hand, and if you were to try and put a right-handed glove on it, it wouldn't fit.
There isn't really a profound takeaway here, other than maybe they're crediting a a genital arms race for something that is just an accident of related reproductive organs (there's a long list of these types of structures: https://en.wikipedia.org/wiki/List_of_related_male_and_femal...).
Evolution by natural selection has been witnessed in modern times. Is there some reason to doubt the fossil record evidence that life has repeatedly developed from simpler forms toward more complex? (Albeit repeatedly as changing conditions caused some mass extinctions.)
From the perspective of "evolution", there is no difference between a strand of RNA mutating into a different strand of RNA and a cluster of vaguely RNA-like chemicals mutating into a strand of RNA. Those are both things that are outside the scope of evolutionary theory.
The origin of life - that is, how the very first ancestor in the chain came to be from simpler chemical processes - remains an active open area of research.
This isn't some faith based, moving the goal posts etc argument - its simple scientific fact: we don't yet know the chemical processes that can start with inorganic compounds and lead to a living cell. We will, some day, but we don't now.
Although it is complicated, we know a bit about the chemistry of self-replicating molecules. Things like prions and viruses also show that the boundary between alive and not-alive could be much more blurry than what most people have in mind when discussing such things.
Stone does so in a temperature gradient in the environment (atoms crystallizing as they precipitate out of solution) while Life is able to store enough energy in itself to impose structure (trading energy for entropy) on surrounding atoms even when the environment would otherwise dissolve it. The threshold for 'life' is replicating even when conditions are not perfect, that's survival.
(on another note, we would never have discovered DNA if not for the same x-ray techniques being used to analyze the symmetries of stone)
We're missing a tiny blip of specificity in the history of life, but there's not anything particularly mysterious about it anymore. It's chemistry and time and probably vast scale and chaotic processes, but fundamentally and simply, it's a matter of chemistry and probability. There's no reason to ascribe to life life any special mystery over any other dynamic processes, like tides or orbits. We won the existence lottery, nothing more or less.
I'm just saying the answer is sufficiently bounded that it's not very mysterious - there's not a lot of room for anything radically weird. We're not going to find out that the great spaghetti monster visits planets every hundred million years and deposits special life building nanobots. Panspermia, weird multiplanet exotic chemical exchange from massive impacts, etc are all possible contributors to the origin of life. Whatever the answer ends up being, modern science is 100% capable of replicating any chemical or physical occurrence that played a part.
It might require impractical scales of energy or mass - I personally suspect you need an ocean sized laboratory to achieve the variety of chemicals and sequences of processes to get the right mix of molecules that combine into replicators, and you need a lot of replicators before you get dynamic life that starts evolving. Complex amino acids have been found in asteroids and space debris, so maybe the spark was space junk?
It's a neat question but we're not looking for elan vital or anything fundamental anymore. We know what the mechanics of life are at a subatomic level, so the particular occurrence of life on earth is now a mystery similar to the interstellar origin story of matter in the solar system - we lack specifics but have a great general handle on how and why things are the way they are.
Now, there must have been specific conditions that lead to the production of some specific molecules, and we do not know all the details. These conditions are probably quite different from what we have on earth today, which does not help. There certainly is room for progress. But we do have a decent understanding of basic biochemistry.
The relevant study is the field of abiogenesis:
A female duck’s vaginal barriers cannot shield her from physical harm. On an evolutionary level, though, they protect her in another way—by allowing her to choose the father of her offspring.
By using her vaginal barriers, she is able to maintain her sexual autonomy in the face of sexual violence.
Our observations also revealed that when a female duck solicits sex with a chosen mate, her cloacal muscles dilate to allow uninhibited entry.
The result is that, even for species in which nearly forty per cent of all copulations are violently coerced, only between two and five per cent of ducklings come from extra-pair matings. As a method of contraception, ducks’ vaginal barriers can be ninety-eight-per-cent effective...
Is there an equivalent mechanism in human females? Why yes, there is. As one would expect, it's framed as a 'disorder': https://en.wikipedia.org/wiki/Vaginismus
No one has seriously examined this as a natural defense against coerced sex, but maybe it's time...
Further, if this is supposed to be an argument against legal abortion (I heard before from the anti-abortion crowd, that the body has defenses against unwanted pregnamcy), then the question becomes if this really can be willfully controlled and if we really want to limit the choice making of women to that short period of time, when they are being violated.
I think the disorder comes in, when women complain about it to their doctors, i.e. they are unable to control it. So I don't see a reason why it should be considered anything else in such circumstances.
Most notably the GOP Rep[0] Todd Akin:
https://en.wikipedia.org/wiki/Todd_Akin#Comments_on_%22legit...
[0] short for "reprehensible" in this case
> Is there an equivalent mechanism in human females? Why yes, there is. As one would expect, it's framed as a 'disorder': https://en.wikipedia.org/wiki/Vaginismus
Hve you tried putting these two pieces of the puzzle together? They are pretty clear I think: Vaginismus is a disorder because it affects women who are trying to have consensual sexual relations. If it were only happening when someone was trying to coerce sexual relations, it would NOT have been labeled a disorder.
Simple as that.
So not necessarily a disorder, but a reaction; and if that's the case, it deserves more investigation, particularly given how widespread rape is.
Then women might not need something like Rape-aXe (https://rape-axe.com/)
Is there widespread evidence of rape victims experiencing vaginismus as a protective reaction at the moment of attack (as opposed to them experiencing it as a disorder in a post-rape-trauma context?)
>Then women might not need something like Rape-aXe (https://rape-axe.com/)
The spasms by themselves are ineffective at preventing forceful penetration. If they were effective there would be no rape, or at least no penetrative vaginal rape. The reason such a device is desired is precisely because it's ineffective.
> He suggested that perhaps the male was responding to female preference—wink-wink, nudge-nudge—but hadn’t bothered to actually examine the female.
I think "wink-wink nudge-nudge" is an unfair characterisation of someone's motivation to dissect duck genitals. It's a statement about evolutionary pressure, not a bawdy joke.
Brennan really love science. And genitals. And vivisections.