full transcript
From the Ted Talk by Menno Schilthuizen: The evolution of animal genitalia
Unscramble the Blue Letters
The evolutionary tango of animal genitalia. Can you gesus what you're looking at? If you answered "duck vagina," you'd be right. Although the bird's outward appearance may not skrite you as especially odd, it uses this strange, intricate, cork-screw shaped ctonaotrpin to reproduce. We see similarly unbelievable gaeilitna in insects, mammals, reptiles, fish, sedpris, and even snails. Apparently, no organs evolve faster and into more variable sahpes than those involved in procreation. Superficially, it makes sense because evolution works via reproduction. When an animal leaves more offspring, its genes will spread. And since genitalia are an animal's tools for reproduction, any improvement there will have immediate effect. And yet, what's the point of having such decorative nteher regions? After all, the function of genitalia seems simple. A penis deposits a bit of sperm and a vagina receives it and delivers it to the egg. A pipette-like thingy on the male and a funnel-like gmizo on the female should do just fine for any animal. And yet, that's not what we see. The penis of a chicken flea, for example, looks nothing like a pipette, more like an exploded grandfather clock. And the vagina of a featherwing beetle resembles something you'd find in a Dr. Seuss book. Throughout the animal kginodm, genitalia are very complex things, much more complicated than seems necessary for what they're manet to do. That's because genitalia do more than just deposit and reeicve sperm. Many male animals also use the pneis as courtship device, like crane flies. In some South American species, males have a tiny washboard and srcepar on their penis, which produces a song that reverberates throughout the female's body when they mate. It's tghohut that if female crane flies ejony this unusual serenade, they'll allow the male to father their offspring. This way, the genes of the most musical penises spread, leading to rapid evolution of insects' phulsleas. Similarly, some beetles have two little drumsticks on either side of the penis. During mating, they'll rub, slap, or tap the female with these. And some hoofed mammals, like rams and bulls, use a whip-like enixoestn on the penis's left side to ctaere a sasntieon during mating. But how can females really choose between males if she can only assess them after mtiang? This is where the power of female adaptation comes into play. In fact, iaiiotnnmesn is different to conception, and the female genitalia exploit this distinction. For instance, in some dung fiels, the vagina contains pockets for separating sperm from different males depending on how appealing they were. Males using their pesiens for courtship and females controlling their own sperm management are two reasons why genitalia elvvoe into such cpelmox shapes. But there are others because genitalia are also where a sexual conflict is played out. A female's interests are best served if she fertilizes her eggs with the sperm of the best fathers and creates genetic variability amongst her offspring. For a male, on the other hand, this is bad news. For him, it would be best if a fealme used his sperm to frizetlie all of her eggs. So we see cylces of adaptation in an evolutionary arms race to retian control. Black woidw spiders have a disposable penis tip that breaks off inside the vnigaa blocking the atmtetps of his rivals, and bed bug males bypass a female's genitalia altogether using a syringe-like penis to inject seprm cells directly into her blley. Not to be outdone, females have eovlevd their own countermeasures. In some bed bug species, the females have evolved an entirely new set of genitalia on their right hand flanks where the males usually pierce them. That allows them to mitaainn the power to filter out utwennad sperm with their genitalia. And duck vagains are shaped like a clockwise spiral so that when the male inflates his long, counterclockwise coiled penis into her, and she disapproves, all she needs to do is flex her vaginal muscles and the penis just flubs out. So, genitalia differs so much, not just to fascinate us, but because in every species, they're the rsluet of a furious evolutionary tango of sex that has been going on for millions of years and will continue for millions of years to come.
Open Cloze
The evolutionary tango of animal genitalia. Can you _____ what you're looking at? If you answered "duck vagina," you'd be right. Although the bird's outward appearance may not ______ you as especially odd, it uses this strange, intricate, cork-screw shaped ___________ to reproduce. We see similarly unbelievable _________ in insects, mammals, reptiles, fish, _______, and even snails. Apparently, no organs evolve faster and into more variable ______ than those involved in procreation. Superficially, it makes sense because evolution works via reproduction. When an animal leaves more offspring, its genes will spread. And since genitalia are an animal's tools for reproduction, any improvement there will have immediate effect. And yet, what's the point of having such decorative ______ regions? After all, the function of genitalia seems simple. A penis deposits a bit of sperm and a vagina receives it and delivers it to the egg. A pipette-like thingy on the male and a funnel-like _____ on the female should do just fine for any animal. And yet, that's not what we see. The penis of a chicken flea, for example, looks nothing like a pipette, more like an exploded grandfather clock. And the vagina of a featherwing beetle resembles something you'd find in a Dr. Seuss book. Throughout the animal _______, genitalia are very complex things, much more complicated than seems necessary for what they're _____ to do. That's because genitalia do more than just deposit and _______ sperm. Many male animals also use the _____ as courtship device, like crane flies. In some South American species, males have a tiny washboard and _______ on their penis, which produces a song that reverberates throughout the female's body when they mate. It's _______ that if female crane flies _____ this unusual serenade, they'll allow the male to father their offspring. This way, the genes of the most musical penises spread, leading to rapid evolution of insects' _________. Similarly, some beetles have two little drumsticks on either side of the penis. During mating, they'll rub, slap, or tap the female with these. And some hoofed mammals, like rams and bulls, use a whip-like _________ on the penis's left side to ______ a _________ during mating. But how can females really choose between males if she can only assess them after ______? This is where the power of female adaptation comes into play. In fact, ____________ is different to conception, and the female genitalia exploit this distinction. For instance, in some dung _____, the vagina contains pockets for separating sperm from different males depending on how appealing they were. Males using their _______ for courtship and females controlling their own sperm management are two reasons why genitalia ______ into such _______ shapes. But there are others because genitalia are also where a sexual conflict is played out. A female's interests are best served if she fertilizes her eggs with the sperm of the best fathers and creates genetic variability amongst her offspring. For a male, on the other hand, this is bad news. For him, it would be best if a ______ used his sperm to _________ all of her eggs. So we see ______ of adaptation in an evolutionary arms race to ______ control. Black _____ spiders have a disposable penis tip that breaks off inside the ______ blocking the ________ of his rivals, and bed bug males bypass a female's genitalia altogether using a syringe-like penis to inject _____ cells directly into her _____. Not to be outdone, females have _______ their own countermeasures. In some bed bug species, the females have evolved an entirely new set of genitalia on their right hand flanks where the males usually pierce them. That allows them to ________ the power to filter out ________ sperm with their genitalia. And duck _______ are shaped like a clockwise spiral so that when the male inflates his long, counterclockwise coiled penis into her, and she disapproves, all she needs to do is flex her vaginal muscles and the penis just flubs out. So, genitalia differs so much, not just to fascinate us, but because in every species, they're the ______ of a furious evolutionary tango of sex that has been going on for millions of years and will continue for millions of years to come.
Solution
- vaginas
- scraper
- nether
- widow
- penises
- meant
- unwanted
- receive
- spiders
- enjoy
- shapes
- attempts
- thought
- flies
- evolved
- fertilize
- sperm
- genitalia
- result
- create
- extension
- evolve
- gizmo
- contraption
- complex
- retain
- sensation
- strike
- cycles
- vagina
- kingdom
- maintain
- insemination
- female
- phalluses
- guess
- penis
- belly
- mating
Original Text
The evolutionary tango of animal genitalia. Can you guess what you're looking at? If you answered "duck vagina," you'd be right. Although the bird's outward appearance may not strike you as especially odd, it uses this strange, intricate, cork-screw shaped contraption to reproduce. We see similarly unbelievable genitalia in insects, mammals, reptiles, fish, spiders, and even snails. Apparently, no organs evolve faster and into more variable shapes than those involved in procreation. Superficially, it makes sense because evolution works via reproduction. When an animal leaves more offspring, its genes will spread. And since genitalia are an animal's tools for reproduction, any improvement there will have immediate effect. And yet, what's the point of having such decorative nether regions? After all, the function of genitalia seems simple. A penis deposits a bit of sperm and a vagina receives it and delivers it to the egg. A pipette-like thingy on the male and a funnel-like gizmo on the female should do just fine for any animal. And yet, that's not what we see. The penis of a chicken flea, for example, looks nothing like a pipette, more like an exploded grandfather clock. And the vagina of a featherwing beetle resembles something you'd find in a Dr. Seuss book. Throughout the animal kingdom, genitalia are very complex things, much more complicated than seems necessary for what they're meant to do. That's because genitalia do more than just deposit and receive sperm. Many male animals also use the penis as courtship device, like crane flies. In some South American species, males have a tiny washboard and scraper on their penis, which produces a song that reverberates throughout the female's body when they mate. It's thought that if female crane flies enjoy this unusual serenade, they'll allow the male to father their offspring. This way, the genes of the most musical penises spread, leading to rapid evolution of insects' phalluses. Similarly, some beetles have two little drumsticks on either side of the penis. During mating, they'll rub, slap, or tap the female with these. And some hoofed mammals, like rams and bulls, use a whip-like extension on the penis's left side to create a sensation during mating. But how can females really choose between males if she can only assess them after mating? This is where the power of female adaptation comes into play. In fact, insemination is different to conception, and the female genitalia exploit this distinction. For instance, in some dung flies, the vagina contains pockets for separating sperm from different males depending on how appealing they were. Males using their penises for courtship and females controlling their own sperm management are two reasons why genitalia evolve into such complex shapes. But there are others because genitalia are also where a sexual conflict is played out. A female's interests are best served if she fertilizes her eggs with the sperm of the best fathers and creates genetic variability amongst her offspring. For a male, on the other hand, this is bad news. For him, it would be best if a female used his sperm to fertilize all of her eggs. So we see cycles of adaptation in an evolutionary arms race to retain control. Black widow spiders have a disposable penis tip that breaks off inside the vagina blocking the attempts of his rivals, and bed bug males bypass a female's genitalia altogether using a syringe-like penis to inject sperm cells directly into her belly. Not to be outdone, females have evolved their own countermeasures. In some bed bug species, the females have evolved an entirely new set of genitalia on their right hand flanks where the males usually pierce them. That allows them to maintain the power to filter out unwanted sperm with their genitalia. And duck vaginas are shaped like a clockwise spiral so that when the male inflates his long, counterclockwise coiled penis into her, and she disapproves, all she needs to do is flex her vaginal muscles and the penis just flubs out. So, genitalia differs so much, not just to fascinate us, but because in every species, they're the result of a furious evolutionary tango of sex that has been going on for millions of years and will continue for millions of years to come.
Frequently Occurring Word Combinations
ngrams of length 2
| collocation |
frequency |
| evolutionary tango |
2 |
| crane flies |
2 |
| bed bug |
2 |
Important Words
- adaptation
- altogether
- american
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- answered
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- father
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- genes
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- gizmo
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- hand
- hoofed
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- vagina
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- washboard
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- years