Stripping Down Science

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Copyright Act 1968
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Stripping Down Science: The Naked Scientist Exposes The Facts

ePub ISBN 9781742741642
Kindle ISBN 9781742741659

A William Heinemann book
Published by Random House Australia Pty Ltd
Level 3, 100 Pacific Highway, North Sydney NSW 2060
www.randomhouse.com.au

First published by William Heinemann in 2010

Copyright © Christopher Smith 2010

The moral right of the author has been asserted.

All rights reserved. No part of this book may be reproduced or transmitted by any person or entity, including internet search engines or retailers, in any form or by any means, electronic or mechanical, including photocopying (except under the statutory exceptions provisions of the Australian Copyright Act 1968), recording, scanning or by any information storage and retrieval system without the prior written permission of Random House Australia.

Addresses for companies within the Random House Group can be found at
www.randomhouse.com.au/offices
.

National Library of Australia
Cataloguing-in-Publication Entry

Smith, Christopher, 1975–.
Stripping down science: the naked scientist exposes the facts.

ISBN 978 1 74166 645 8 (pbk).

Science – Popular works.

Dewey classification: 500

Cover design by Luke Causby/Blue Cork
Internal design by Xou Creative,
www.xou.com.au
Internal illustrations by Shane Nagle,
www.shanenagle.com

To Sarah, Amelia and Tim,
whom I adore.

Cover

Title Page

Copyright

Imprint Page

Dedication

 

Age no impediment to hot sex!

A hard pill to swallow: why vitamins might be the death of you

Clone Alone: why modern technology won't bring back your pet pooch

Boom times are bad for you

Food for thought: diet-sized snacks make you eat more

How the cookie crumbles: you can stay slim by thinking about lunch

There was no greenhouse effect!

Coats of many colours

Deer-dating data reveals ‘survival of the fittest' is a myth

Time to clock off…if you're a reindeer

HIV only fatal for humans?

Less with a bang than a whimper

Nitrous oxide: no laughing matter

No experience necessary, no immunosuppression needed

Drowning in quicksand? It's a myth

Aspirin' chemist

Life, Jim, but not as we know it…

Storing up trouble from radioactive waste

It don't necessarily glow, bro!

Science in the lap of luxury

Women turn on testosterone (in men)

Solar flower power

The darkest surface: not all black and white

Painful genes

Veins contain blue blood…don't they?

Vile-din? Certainly not!

When does a fruit fly not smell like a fruit fly?

Pure as snow? Not so!

How does a heart come by its own arteries?

Is the sea
really
blue?

Bee careful: why bees are nature's risk assessors

Plants don't drink salt water, do they?

Do woodpeckers suffer brain damage?

Cost of keeping me cool? Put it on my bill

Sing a song of distance

Magnetism's invisible, isn't it?

It's not what you say, it's how you say it

Babies learn to talk like mum,
in utero

Blind as a bat? Or should that be rat?

You never make the same mistake twice, do you?

Your thoughts are no longer your own

Brain dead…or maybe not?

Face it! Emotions aren't always easy to read

Pollution superhighway skyward

Will there be an earthquake ‘toad-day'?

Is love really an addiction?

Planets don't alter their orbits, do they?

People don't really walk in circles, do they?

Baby brain drain: does pregnancy kill your IQ?

Forgetful fish, or ‘carp-acious' memory?

Stone the crows! Aesop was right

Don't talk to strangers

Let it go! Fingerprints are not for gripping

Dinosaurs were warm-hearted

Testosterone beefs up money markets?

Sugar and spice and all things nice…and
E. coli

 

Footnotes

Also by the Naked Scientist

Random House

Most people are comfortable with the concept that plants use sweet rewards to attract insects, which fly in for a drink of nectar and pick up pollen in the process. When the same bugs later drop in on other plants of the same species, they shed some of the pollen and fertilise the flowers.

But it's not true that plants aim to be attractive to insects all the time, as scientist Irene Terry from the University of Utah, together with colleagues at the University of Queensland,
¹
discovered when she began to study one member of a family of primitive plants called cycads. Dubbed ‘living fossils' because they have hardly changed since the time of the dinosaurs, cycads resemble palms or ferns, although they are not related to either. In fact, they're members of the conifer and fir family and, consequently, reproduce using a fir-cone-like fruiting body which pops up for a fertile period lasting about four weeks every one-to-four years.

Like humans, these plants come in male and
female varieties, with the male cones producing pollen, which then fertilises the female cones. Previously, scientists thought that the wind carried the pollen between the two, until it was realised that the scales that make up the cones are packed together too tightly for the pollen to enter efficiently. Intrigued by the mystery, the researchers subsequently discovered that a species of insect called a thrip – in this case
Cycadothrips chadwicki
– was responsible. The insects visit the male cones to eat the pollen and then carry some of it to the female cones. But therein lies a problem: how to persuade the insects to abandon their banquet in the male cones and visit the female cones, which are devoid of pollen and therefore food?

It turns out that the cycads resort to the plant equivalent of chemical crowd control to force the insects to pay for their free lunch. Each day, between 11 am and 3 pm, the temperature of the cones, and particularly the male cones, shoots up by over 12 degrees Celsius. The plants achieve this thermal feat by breaking down stockpiled starch, sugars and fats. The resulting temperature boost makes the environment inside the cone uncomfortable for the thrips. It's also accompanied
by a million-fold surge in the production of an odorous chemical called beta-myrcene.

At low levels, thrips find the smell attractive, which helps to lure them into the cone in the first place; but at higher concentrations it smells repugnant and drives them out. Humans also find the stink offensive. ‘It takes your breath away. It's a harsh, overwhelming odour like nothing you ever smelled before,' remarks Irene Terry, presumably while holding her nose.

So, repelled by the smell but still covered in the vestiges of their last pollen meal, the insects abandon their feast and seek refuge in the
surrounding bushes. By mid-afternoon the cones have cooled again and the concentration of beta-myrcene drops, encouraging the thrips to return, pollen still clinging to their bodies. And, since the male and female cones both look and smell alike, the insects flock back to both, carrying pollen into the female cones and fertilising them.

The cycad cycle repeats itself day after day ‘until the males wear out and the females are happily pollinated', says Terry. Not that different from humans then, despite the 300-million-year age gap!

Sexual subversion elsewhere in nature …

It's not just cycads that have mastered the art of olfactory allure. Other species have also evolved to take advantage of insects' insatiable desires for food, including an orchid that makes itself pong like a bee to attract a hungry hornet.

Until recently, no one was sure what pollinated the
Dendrobium sinense
, a pretty
white-and-red flowered orchid that grows on the Chinese island of Hainan. The mystery was solved after Jennifer Brodmann, a scientist at the University of Ulm,
²
mounted a 121-hour vigil to spot potential pollinators. The flowers are actually rewardless, meaning that they don't produce any nectar, but they still received passing interest from 35 insect visitors, 30 of which were a species of hornet that is known to prey on honey bees.

Intriguingly, the arriving hornets didn't just inspect the flower and then buzz off, but pounced aggressively, aiming for the flower's red centre, then abruptly left. A closer look revealed that, in doing so, they were carrying off pollen sacs from the flower and depositing pollen from other members of the same orchid species. But why would they do this when they stood to gain nothing in return?

The answer, it turns out, is a story of sexual subversion never seen before in nature. To get to the bottom of it, the team used solvents to
extract and analyse the odorant chemicals from the flowers. They then presented each of the chemicals they had isolated to the antennae of a hornet which had been wired up to an ‘electro-antennogram'. This meant that when a chemical was present to which the antenna was sensitive, it produced electrical discharges which the team could measure.