Name: When males are not needed - 6 Minute English
Uploaded: 2021-06-03T21:01:30.000Z
Duration: 6 min 16 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Hello. This is 6 Minute English from BBC Learning English.

Do you think there are big differences between men and women, Neil?

Apart from the old stereotypes we sometimes hear

I mean, men and women's bodies are different.

Right, and it takes both a man and a woman to make a baby.

we'll be hearing about creatures in the wild,

where the classic 'boy meets girl' love story doesn't apply.

Yes, we'll be meeting some female animals who don't need a male to make babies.

These creatures reproduce by parthenogenesis,

This is the process where the female can reproduce without a mate,

a term used for an animal's sexual partner.

All animal species survive by making babies,

reproducing to make copies of themselves.

the female of some species can do it all by herself!

But before that, it's time for my quiz question.

Flora laid eleven eggs that developed into healthy babies.

because Flora had only been kept with other females and had never been near a male.

OK, Rob, we'll find out later if you're right.

Actually, it's not only reptiles who behave this way.

The females of many animal species are able to reproduce without sex.

By doing this they gain several advantages:

they can rapidly spread, colonize and control large areas,

and they don't waste time and energy looking for a mate.

But if a world without sex is so much better,

and one which BBC World Service programme, Discovery, asked evolutionary biologist, Chris Wilson.

I mean, if you're an all-female population,

you don't have to waste time searching and competing for mates,

there are no more sexually-transmitted diseases

and so it seems like the easiest decision

less than one percent of all animal species are completely celibate,

and that's a huge fundamental puzzle in evolutionary biology

that we're still not entirely sure we understand

it's called sometimes the paradox of sex.

Despite the advantages of going without sex,

in reality fewer than one percent of all animals are celibate - live without having sex.

why is sex so common when it seems so inefficient?

A paradox is a situation which seems contradictory because it contains two opposite facts.

For example, the existence of males if we can reproduce without them.

I have to say I'm feeling a little underappreciated right now, Rob!

because it turns out there might be a use for males after all!

It seems the sex paradox has been solved by one of nature's most ingenious insects - aphids.

explaining how to the BBC World Service's Discovery programme.

See if you can hear the strategy American aphids use to reproduce.

the eggs hatch and they'll be all female for several generations,

they will hatch out males and females and mate,

and then create eggs that wait for next year,

In the spring, female aphids lay eggs which hatch,

break open, allowing the young to come out.

The young aphids that hatch are all female.

So, the aphids have the best of both worlds,

they enjoy the advantages of very different things at the same time.

By cloning themselves with 'virgin births' and reproducing sexually,

aphids maximize their chances of survival.

Gardeners around the world will be upset to hear that

those young aphids just love eating tomato plants!

it seems being male can be useful after all.

the female you asked about in your quiz question.

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When males are not needed - 6 Minute English

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