Why do women – and so few other animals – have periods?


Image credit: Patricia Moraleda via Pixabay

My cmnt: I include this topic because the Left-Lib-democrats have started saying and demanding that men can have periods. This is sooooo ridiculous I want to note again the obvious.

My cmnt: In the article below I changed all the words “human” back to “women” since ONLY women can have periods and that is how the article was originally written before the PC-police got a hold of it.

My cmnt: The entire ridiculous speculating about WHY women have periods from dubious evolutionary perspectives is included for laughs. No one knows “why”, only that women “do”.

My cmnt: Here is my educated hunch about why women have periods. Beautiful women are so beguiling and goddess like creatures as it is that without periods they would be ruling the world more than they already do through the men who covet and adore them.

My cmnt: In a Seinfeld episode Jerry’s girlfriend likes to walk around his apartment nude. At first Jerry thinks this is great, then he sees her trying to take a tight lid off a jar of pickles. He winces. After a short time he wants her to start wearing clothes again. Ignoring hints she just won’t put on clothes. So Jerry starts walking around the apartment nude also. She says that’s disgusting and dresses and leaves. Jerry asks Elaine what gives. Elaine says, “Whoa. Walking around naked? Uh, that is not a good look for a man.” George asks, “Why not, it’s a good look for a woman?” Elaine elaborates, “Well, the female body is a … work of art. The male body is utilitarian. It’s for getting around. It’s like a Jeep.”

My cmnt: Please also read the articles I’ve included below this one.

Opposable thumbs, the power of speech, the capacity to think and reason: there are many reasons to relish being a woman. Regularly bleeding out of your vagina is not one of them. 

We are taught that menstruation is a normal part of the reproductive cycle, a necessary by-product of being a sexually reproducing species. Every cycle, before an egg is released from the ovaries, reproductive hormones like progesterone cause the lining of the uterus – the endometrium – to thicken and fill with blood vessels. If the egg is fertilised, the uterus is ready to receive it so that it can implant and start growing. If not, progesterone levels fall rapidly, and the endometrium begins to shed. Your regularly scheduled underwear-staining, cramp-inducing crimson tide has arrived. 

It turns out, menstruation is quite rare in the animal kingdom, even amongst mammals. Other primates menstruate (though not as heavily as humans do), as do some species of bats and elephant shrews. That’s it. The number of myths, taboos and misconceptions surrounding this phenomenon are a testament to how rare and alarming it is  – the word taboo itself likely derives from the Polynesian word for menstruation, tapua. Pliny the Elder explained that menstrual blood could stop seeds from germinating, wither plants, and make fruit fall from trees. Conveniently, it could also clear a field of pests if the menstruator walked around in it naked. Throughout history, women have been forced to isolate themselves during their periods, for fear they would spoil food or cause men to lose their virility.

Still today, menstruation is poorly understood because periods are widely stigmatised and talking about them openly is uncomfortable.

Menstruation seems like such a wasteful, energy-consuming process. It would be like deep cleaning your spare room every month for a guest who might not arrive, and whom you might not even want in your house. And yet, menstruation evolved independently at least three times, so it must have some evolutionary advantage. 

Pregnancy is often viewed as a magical time in a woman’s life, during which the mother forms an intimate bond with their child. In fact, pregnancy is an all-out evolutionary war. On one side of the battlefield, we have the embryo, and its genes. Its goal is to divert as much nutrition as it can from the parent so that it can grow to propagate its genes; human embryos are amongst the most invasive during pregnancy. On the other side, we have the mother. The parent wants to conserve their energy so that they can have many children to propagate their genes. There is some evidence that the embryo gets some genetic reinforcements from its father, whose genes are pitted against those of the parent in the early stages of embryo development. Natural selection may have acted to advance each belligerent’s goals. 

To understand why menstruation evolved, we have to think of it as a by-product of spontaneous decidualisation. In most mammals, decidualisation – the thickening of the uterine wall – is controlled by the embryo: it occurs in response to fertilisation rather than in preparation for it. In menstruating species like humans, spontaneous decidualisation is one way the parent tries to wrest back dominance of their uterus from an increasingly invasive embryo. The uterine lining now responds only to the woman’s hormones rather than the embryo’s, and the mother controls whether or not they get pregnant. They put their defences up preemptively, by sealing off the main blood supply from the endometrium before the embryo implants there. Not content with this, the embryo evolved to burrow through the endometrium until it reaches the arteries, where it tears through the wall and rewires the blood vessels so that it can bathe directly in the parent’s blood. The (arguably) ungrateful parasite pumps out hormones to make the arteries expand around it, and paralyses them to prevent the parent from cutting off its supply. It produces more hormones, which act directly on the parent to maintain pregnancy and increase the availability of nutrients. The parent defends themselves as best they can: their endometrium fights against the embryo’s invasive proteins, their immune system attacks the invading cells, and their own hormones try to counteract those of the embryo. The tug-of-war rages on. 

Human embryos may be aggressive, but they are also particularly prone to genetic abnormalities. Genetic analysis of morphologically normal, high quality embryos during IVF showed that around 70% of embryos have complex chromosomal abnormalities such as aneuploidies. An aneuploid cell has either too many or too few chromosomes, and most aneuploidies are lethal. It’s unclear why, but the rate of aneuploidy in human embryos is estimated to be 10 times higher than in other mammalian species. Therefore, the second advantage of spontaneous decidualisation is that menstruation gives the parent the opportunity to get rid of defective embryos. As we’ve established, growing a new human takes a considerable toll on the parent. Spontaneous decidualisation gives them the power to select the embryos that have the best chance of prospering. Embryos with lethal aneuploidies are more metabolically active than healthy ones, possibly because they are expending more energy just to stay alive despite their abnormal genotype. When the cells of the endometrium prepare for a possible pregnancy, they gain the ability to sense this metabolic activity. If the endometrium decides that an embryo is unworthy, it actively hinders the migration of the embryo through the endometrium. The uterine lining is then shed, taking the embryo with it. This could explain why, compared to other species, humans are inefficient procreators: it has been estimated that only half of human conceptions progress to a full pregnancy. However, it is also thought that the repeated cycle of regeneration may allow the human endometrium to adapt and improve. In other mammals, this renewal would only occur at the end of a pregnancy, whereas humans have a monthly practice run. This could be why most people who suffer from recurrent miscarriages eventually have a successful pregnancy. 

Perhaps menstruation is particularly bothersome to us nowadays because we have so many periods. For most of human history, having a period would have been rare. Other menstruating mammals and natural fertility human populations (so-called because they don’t use contraception) spend most of their reproductive life either pregnant or breastfeeding, during which time they stop menstruating. In Tanzania, the Hadzabe people have around 6 children on average, which they breastfeed for 4 years. At most, they likely have a few tens of periods. In contrast, people who menstruate in our society can now expect to have 300-500 periods over the course of their lifetime. For such a common occurrence, it’s appalling that we know so little about it, and discuss it so shamefully. 

But now if you’ll excuse me, I have to go deal with the communists taking over my gazebo. 

Written by Helena Cornu and edited by Ailie McWhinnie.

This article was originally published on 9/4/20 and updated on 26/6/20 to use more inclusive language.

There are 5,000 slang terms for periods – but we still can’t talk about them

Naming our periods is all well and good, but it’s reflective of a culture where women are embarrassed to talk about their monthly cycles.

BY VICTORIA CHANDLER – 3 Mar 2016 – for Good Housekeeping

My cmnt: Note that Victoria wrote this in 2016 before the LGBTQwerty crowd made it an offense to state the obvious: ONLY women have periods.

This week, menstruation app Clue and the International Women’s Health Coalition discovered that there are over 5,000 different slang terms and euphemisms for the word period.

Whether you’re being visited by Aunt Flo, riding the crimson wave, or in that time of the month, their research revealed that nearly three quarters of British women said they have encountered slang terms for their period.

  • UK: ‘Aunt Flo,’ ‘the painters are in,’ ‘Bloody Mary.’
  • USA: ‘Uncle Tom,’ ‘Japan is attacking, ‘on the rag.’
  • France: ‘The English are coming.’
  • Canada: ‘Napoleonic war.’
  • Japan: ‘The red panda.’
  • Australia: ‘Shark week.’
  • Portugal: ‘My ketchup.’
  • Sweden: ‘Lingonberry week.’
  • Germany: ‘Strawberry week.’
  • Norway: ‘How’s the volcano?’

While having these pet names is all well and good, this global attitude to women’s monthly bleeds shows that on the whole, we’re all unusually embarrassed about our periods.

But is that surprising? Growing up, I seldom recollect being educated on periods, and on the rare occasion they were discussed, boys would be swiftly removed from the classroom. Because yuck, who wants to subject them to the realities of having a uterus?

We were bought up to believe periods were meant to be discreet and invisible; I remember having to beg my mum to write a note to my teacher so that I wouldn’t have to explain my frequent trips to the bathroom in class.

And despite being an adult now, I still see female co-workers scuttling past with a tampon up their sleeve, or meeting in the hallway swapping their stashes of sanitary pads.

Don’t get me wrong; I know euphemisms for periods are the least of our worries, but it’s this culture of encouraging women and girls to keep their periods a shameful secret that is the most damaging.

Because while in the UK we can jest about ‘being on the blob,’ and be rightly frustrated at the Tampon Tax, there are still 1.25 billion women around the world who have no access to a toilet during their periods, with many cultures still seeing them as dirty, or sinful.

So whether periods are referred to as ‘the blob,’ vaginas are called your ‘down below’ or the menopause is known as ‘the change,’ let’s try to ensure our chosen pet names aren’t making these subjects taboo. Because we’re running the risk of creating a culture where far too many women suffer in silence.

15 words we use for periods that are funny any time of the month

The Red Badge of Courage. You earned it.

By ANDREA ROMANO, ALISA STERN AND VICKY LETA  on August 21, 2018 – mashable.com

Shark Week. Aunt Flo. Period.

All of these words are euphemisms for one thing: menstruation. So why can’t we just use the word menstruation instead of all of this period slang? Well, there’s probably a lot of reasons we’re always looking for other words for period, ranging from everything from social pressures to the idea that the word menstruation is just a little bit hard to say.

An international survey conducted by the health app Clue found that there are more than “5,000 different slang/euphemistic expressions and phrases for periods: from the gentle English ‘Aunt Flo,’ to the dramatic French ‘Les Anglais ont debarqué’ – ‘the English have landed.'”

In addition, the survey concluded, “French and English were the two most creative languages, and France and China were the two countries in which most people had heard euphemisms being used (91%). By contrast, only half of Costa Ricans had heard any euphemisms.”

Even though there’s no reason to be afraid of the word “period” or “menstruation,” we still like to get a little creative — and it’s almost a language on its own.

It actually makes “that time of the month” almost bearable. Almost.

So here they are, 15 other words for period:

1. Visit from Aunt Flo

2. On the Rag

3. Lady Business

Mashable Image

Period slang: Lady business Credit: VICKY LETA, ALISA STERN, MASHABLE

4. That Time of the Month

5. The Red Badge of Courage

6. Moon Time

Mashable Image

Period slang: Moon Time Credit: VICKY LETA, ALISA STERN, MASHABLE

7. Crimson Tide

8. Checking Into the Red Roof Inn

9. Red Wedding

Mashable Image

Period slang: Red Wedding Credit: Vicky Leta, Alisa Stern, Mashable

10. Girl Flu 

11. Carrie

12. Mother Nature’s Gift

Mashable Image

Period slang: Mother Nature’s Gift Credit: Vicky Leta, Alisa Stern, Mashable

13. The Red Baron

14. Riding the Cotton Pony

15. Shark Week

9 Funny Nicknames To Refer To Your Period


LAST UPDATED JUNE 08 2018, 05:45 PM

Periods go by many nicknames but hardly ever by the term periods itself. From chum to shark week, take your pick for the next time you’re visited by Aunt Flo

The next time you’ve got your period, try out some of these nicknames

Ahh, the one week of cramps, mood swings and rushing hastily to the bathroom. Most of the female population grow used to this monthly routine from the time they turn teenagers and yet, no one refers to it as such. No one actually goes around outrightly calling it ‘menses’ or ‘menstruation’, unless they work in medicine. Today, period names are clever, subtle and funnier than ever. The next time you’ve got your period, try out some of these nine nicknames instead.

1. Chum

The Indian favourite which everyone’s aunties and grandmothers use to refer to their periods. In fact, ‘chum’ is so well-known as one’s period (probably even by the males in the family by now) that you might as well realise all subtlety is lost.

2. Aunt Flo

The tight-lipped English favourite that pretends your much-loved aunt is coming to visit when it’s actually just your usual monthly flow. Used best when playing hookey.

3. Red Wedding

Game of Thrones fans, you get it. No wedding of any kind going on here but damn, it is red and how.

4. Shark Week

Because the blood and gore of being devoured by a shark can compare to having your period for a whole week, especially on those heavy flow days.

5. Time Of The Month

The most subtle nickname of them all. Most girls get it easily and it’s a safe word that you can mutter in office, without gruesome visuals coming to mind.

6. Carrie

Remember the prom scene in Carrie where her school mates play a prank on her and her white dress is covered in pig’s blood so she’s standing in front of the school angry, wet and humiliated? That.

7. Code Red

This right here captures the urgency during your period. You know, the feeling when you know it has arrived and you check your handbag to realise you haven’t carried an extra pad so you make a beeline to the bathroom.

8. Girl Flu

If you think about it hard enough, period week really is like falling ill. The nauseous feelings and strange cravings are all there, excerpt that’s a phenomenon reserved strictly for females.

9. Leak Week

Summing it up perfectly, leak week says what needs to be said. I’m a leaky mess for the next seven days but you can always visit next week.

100 Adorable Nicknames For Menstruation

By Jim Goad, July 9th 2015

Shutterstock / Photographee.eu
Shutterstock / Photographee.eu

1. Arts And Crafts Week At Panty Camp
2. At War
3. Aunt Flo
4. Back In The Saddle Again
5. Beelzebub’s Tea Party
6. Big Red
7. Bitch Is Back
8. Bleeding Dead Babies
9. Blood And Eggs
10. Bloody Mary
11. Blowjob Week
12. The Check Engine Light Is On
13. Checking Into The Red Roof Inn
14. Cherry-Filled Donut
15. Cleanup In Aisle One
16. Closed For Maintenance
17. Code Red
18. The Communists Are In The Funhouse
19. Court Of The Crimson King
20. Crime Scene In My Panties
21. Crying The Bloody Tears Of Unrequited Love
22. The Deathly Hallows
23. Devil’s Juice
24. Diaper Week
25. Dracula’s Teabag
26. The English Have Arrived
27. Eve’s Curse
28. Falling Off The Roof
29. Female Trouble
30. Fighting The Scarlet Crusade
31. Flying The Japanese Flag
32. Gettysburg
33. Girl Flu
34. Hide The Knives Week
35. High Tide
36. The Hunt For Red October
37. Icing On The Cake
38. Jam Sandwich
39. Ketchup On The Steak
40. Lady Business
41. Lady In Red
42. Leak Week
43. Lingonberry Week
44. Lining The Drawers
45. Little Miss Strawberry
46. Making A Glass Of V8
47. Making Marmalade
48. Making Vampire Soup
49. Massacre At The Y
50. MenstroMonster
51. Miss Scarlett Has Returned To Tara
52. The Monkey Has A Nosebleed
53. Monthly Subscription
54. The Monthly Volcano of Doom
55. Moon’s Blood
56. Mother Nature’s Monthly Gift
57. My Cup Runneth Over
58. My Friend TOM (Time Of Month)
59. My Quarterly Dividends
60. Old Faithful
61. On Auto-Drip
62. On The Blob
63. On the Rag
64. Opening The Floodgates
65. Ovum Independence Day
66. The Painters Are In
67. Painting The Town Red
68. Paper Cut
69. Passing A Liver
70. Plumbing Problems
71. Punched With The Red Fist
72. Raggedy Anne
73. Ragnarok
74. Rebooting The Ovarian Operating System
75. Red Badge Of Courage
76. Red Dot Special
77. Red River
78. Redrum
79. Riding the Cotton Pony
80. Riding the Crimson Tide
81. Rusty Beaver Season
82. The Sacred Dance of the Uterus
83. The Sacrificial Goats Have Arrived
84. Santa’s Bringing The Presents
85. Saving Ryan’s Privates
86. Season Of The Werewolf
87. Serving Box Wine
88. Shark Week
89. The Shining
90. Sitting On A Bottle Of Merlot
91. St. Valentine’s Day Massacre
92. Strawberry Salad
93. Taking Carrie To The Prom
94. Technical Difficulties
95. That Time Of The Month
96. Time For Chocolate
97. Transmission Tune-Up
98. Trolling For Vampires
99. Up On Blocks

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