TedTest

From the Ted Talk by Menno Schilthuizen: The evolution of animal genitalia

Unscramble the Blue Letters

The evolutionary tango of animal genitalia. Can you guses what you're looking at? If you answered "duck vgaina," you'd be right. Although the bird's outward acnepraape may not strike you as especially odd, it uses this strange, intricate, cork-screw shaped contraption to rrudpeoce. We see saillrmiy unbelievable genitalia in insects, mammals, reptiles, fish, spiders, and even snails. Apparently, no oargns evolve faster and into more viblarae shapes than those involved in procreation. Superficially, it makes ssnee because eliutoovn works via rodpciueortn. When an animal leaves more osfpfnirg, its genes will spread. And since geiiatlna are an animal's tools for reproduction, any iemvnepmrot 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 pneis 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 chikecn flea, for example, looks nothing like a pitpete, 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 amianl 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 rciveee 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 unuusal sareedne, they'll allow the male to father their offspring. This way, the genes of the most musical penises spread, leading to riapd evolution of insects' phalluses. Similarly, some btelees 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 siaoestnn 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 aenpialpg they were. Males using their penises for cutshirop and females cllninotrog their own sperm management are two resonas 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 sveerd 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, feleams have evolved their own cuenturermsoaes. In some bed bug scepeis, the females have evolved an entirely new set of genitalia on their right hand fkanls where the melas usually precie 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 cioeld penis into her, and she dpevprsiaos, 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 tngao of sex that has been going on for millions of yares 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 ______," you'd be right. Although the bird's outward __________ may not strike you as especially odd, it uses this strange, intricate, cork-screw shaped contraption to _________. We see _________ unbelievable genitalia in insects, mammals, reptiles, fish, spiders, and even snails. Apparently, no ______ evolve faster and into more ________ shapes than those involved in procreation. Superficially, it makes _____ because _________ works via ____________. When an animal leaves more _________, its genes will spread. And since _________ are an animal's tools for reproduction, any ___________ 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 _____ 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 _______ flea, for example, looks nothing like a _______, 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 ______ 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 _______ 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 _______ ________, they'll allow the male to father their offspring. This way, the genes of the most musical penises spread, leading to _____ evolution of insects' phalluses. Similarly, some _______ 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 _________ 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 _________ they were. Males using their penises for _________ and females ___________ their own sperm management are two _______ 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 ______ 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, _______ have evolved their own _______________. In some bed bug _______, the females have evolved an entirely new set of genitalia on their right hand ______ where the _____ usually ______ 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 ______ penis into her, and she ___________, 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 _____ of sex that has been going on for millions of _____ and will continue for millions of years to come.

Solution

variable
pipette
improvement
vagina
coiled
appealing
served
rapid
chicken
males
disapproves
organs
females
pierce
evolution
tango
penis
animal
years
sense
offspring
flanks
species
reproduce
courtship
receive
guess
reasons
serenade
countermeasures
appearance
sensation
genitalia
reproduction
beetles
controlling
unusual
similarly

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
animal
animals
answered
apparently
appealing
appearance
arms
assess
attempts
bad
bed
beetle
beetles
belly
bit
black
blocking
body
book
breaks
bug
bulls
bypass
cells
chicken
choose
clock
clockwise
coiled
complex
complicated
conception
conflict
continue
contraption
control
controlling
counterclockwise
countermeasures
courtship
crane
create
creates
cycles
decorative
delivers
depending
deposit
deposits
device
differs
disapproves
disposable
distinction
dr
drumsticks
duck
dung
effect
egg
eggs
enjoy
evolution
evolutionary
evolve
evolved
exploded
exploit
extension
fact
fascinate
faster
father
fathers
featherwing
female
females
fertilize
fertilizes
filter
find
fine
fish
flanks
flea
flex
flies
flubs
function
furious
genes
genetic
genitalia
gizmo
grandfather
guess
hand
hoofed
improvement
inflates
inject
insects
insemination
instance
interests
intricate
involved
kingdom
leading
leaves
left
long
maintain
male
males
mammals
management
mate
mating
meant
millions
muscles
musical
nether
news
odd
offspring
organs
outdone
outward
penis
penises
phalluses
pierce
pipette
play
played
pockets
point
power
procreation
produces
race
rams
rapid
reasons
receive
receives
regions
reproduce
reproduction
reptiles
resembles
result
retain
reverberates
rivals
rub
scraper
sensation
sense
separating
serenade
served
set
seuss
sex
sexual
shaped
shapes
side
similarly
simple
slap
snails
song
south
species
sperm
spiders
spiral
spread
strange
strike
superficially
tango
tap
thingy
thought
tiny
tip
tools
unbelievable
unusual
unwanted
vagina
vaginal
vaginas
variability
variable
washboard
widow
works
years