Scientific American The Amateur Biologist , livre ebook

THE AMATEUR BIOLOGIST
S CIENTIFIC A MERICAN
THE AMATEUR BIOLOGIST
Edited by Shawn Carlson
This book is printed on acid-free paper.
Copyright 2002 by Scientific American, Inc. All rights reserved
Published by John Wiley Sons, Inc., New York
Published simultaneously in Canada
Figures 1.1, 4.1, 4.2 copyright 1998 by Ian Worpole
Figures 10.4 copyright 1996 and 19.1 and 19.2 copyright 1995 by Michael Goodman
Illustrations on page 150 copyright 1997 and Figure 21.1 copyright 1996 by Bryan Christie
No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4744. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley Sons, Inc., 605 Third Avenue, New York, NY 10158-0012, (212) 850-6011, fax (212) 850-6008, e-mail: PERMREQ@WILEY.COM.
The publisher and the author have made every reasonable effort to ensure that the experiments and activities in the book are safe when conducted as instructed but assume no responsibility for any damage caused or sustained while performing the experiments or activities in this book. Parents, guardians, and/or teachers should supervise young readers who undertake the experiments and activities in this book.
Library of Congress Cataloging-in-Publication Data is available from the publisher.
ISBN 0-471-38281-7 (paper)
Printed in the United States of America
10 9 8 7 6 5 4 3 2 1
CONTENTS
Foreword
Introduction
Part 1 Miscellaneous Techniques
1. Video Microscope
2. Electrophoresis
3. Measuring Metabolism of Small Animals
4. High Altitude Chamber
5. Tin-Can Kymograph
6. Microscopy: Subtle Secrets and Advanced Techniques
Part 2 Botany
7. Museum Secrets for Preserving Plants
8. Growing Plants in a Controlled Environment
9. The Essence of Hydroponics
10. Geotropism: The Effects of Gravity on Plant Growth
11. Exploring Growth Inhibitors
12. Experiments with Substances That Stimulate Plant Growth
13. The Effects of Ultrasonics on Plant Development
Part 3 Cellular Biology
14. The Pleasures of Pond Scum
15. Experiments with Animal Cells
16. Exploring Slime Molds
17. Fabulous Phototaxis
Part 4 Entomology
18. Lovely Lepidoptera
19. Measuring Insect Metabolism
20. Getting Inside an Ant s Head
21. Detecting Insect Heartbeats
22. Learning in Sow Bugs
Part 5 Microbiology
23. Mouse Genetics
24. Fruit Fly Genetics
25. Spooling the Stuff of Life
Glossary
Further Reading
Supplier List
Organizations
Index
FOREWORD
The Amateur Scientist
The book in hand, titled The Amateur Biologist , is the second of a series of books that derive from the longest running column in Scientific American , for the past 50 or so years known as The Amateur Scientist. The origin of The Amateur Scientist goes back to a column first published in May 1928 and written by Albert G. Ingalls. It was called then The Back Yard Astronomer. Ingalls first sentence in that new column declared: Here we amateur telescope makers are, more than 3000 of us, gathered together in our own back yard at last. At the top of the page is an illustration of the Back Yard, with an amateur astronomer at work, apparently drawn by one Russell W. Porter, then considered a mentor of telescope makers throughout the land. Porter declared that the name of the new column, contracted to Backyard Astronomer, conferred an honorary B.A. degree on all its readers.
It is fitting that this book series launched in early 2001, because the column in Scientific American has in this same year recently been discontinued to make room for a plethora of new features in the magazine. These volumes will enable the reader to continue to access many of the gems published in the column over the 70 years of its overall existence. The first volume in the present series was titled The Amateur Astronomer and was edited by Shawn Carlson, who also edited The Amateur Scientist column from 1995 to early 2001. Those of us at Scientific American are enormously grateful for Dr. Carlson s devotion to the column in its final period and his willingness to edit this present series, which we hope will preserve for the future many of the highlights of The Amateur Scientist.
Long-time readers of Scientific American invariably recall favorite columns from The Amateur Scientist. For example, as a former naval aviator one of my favorite pieces is from the April 1998 issue, on a home-built high-altitude vacuum chamber, to which I have referred a number of retired navy friends. As I recall the expensive equipment in U.S. Navy training centers, it seems to me amazing that a similar set-up can be replicated in one s garage. This particular column, originally titled Making Experiments Out of Thin Air, seems to me an extremely informative piece, as are so many others that show up in this book and its series. (The column appears here as Chapter 4 , High Altitude Chamber, beginning on page 26.)
I am often asked about the readership of Scientific American -who these readers are and where their interests lie. My strong suspicion is that most of these inquiries come from potential readers who for one reason or another have not yet made the leap. Summarizing our readership in a brief reply is very difficult, because the population is very large and very diverse and includes isolated clusters of people who would not normally be identified as amateur scientists. If pressed for a brief reply, however, I often mention that my image of a reader of Scientific American is someone whose favorite fantasy on a rainy Saturday afternoon is to read The Amateur Scientist and to plan a future scientific experiment based on the information in the column. My sincere hope is that this series of books serves to fill the same precious moments.
John J. Hanley Chairman Emeritus Scientific American, Inc.
INTRODUCTION
I do love physics, but I wasn t a particularly good graduate student. In fact, I failed my first written qualifying exam badly. A second failure would have meant automatic expulsion from the University of California at Los Angeles and the end of my lifelong dream of becoming a physicist. So I spent the entire spring and summer of 1983 pounding the books fourteen hours a day. I worked every problem I could find, struggling to get extremely good at something physicists never actually do: solve problems without access to texts, under extreme emotional duress and in a limited time. I hated every minute of it.
Worse, each glance out my window made my torment more difficult to bear. For out there beckoned the whole natural world. Butterflies taunted me, dancing about the lilacs below my window as though they knew I was too busy to net and admire them. Neighborhood birds woke me up at daybreak with their impromptu symphonies, just as they always had. Earlier, I would often follow them into the fields and marvel at their territorial displays. But the chains to my books made these outings impossible and so this sweet music jolted me awake each day on a crashing wave of despair. And so it was for the blooming flowers that called out to be pressed and cataloged, and for the neighborhood pond Paramecium ripe for a quick dance under my microscope, and for the fossils, unearthed by gentle summer rains, that were out there waiting to be found. The professional within me knew I was doing the right thing, but my inner amateur howled. I was miserable.
Then just five days before the test, a dear friend gave me something that he hoped would improve my mood; a wonderful book called The Amateur Naturalist by Gerald and Lee Durrell. It did improve my mood, and it almost ended (or perhaps it saved) my physics careen. It was a big and beautiful book, full of lavish photos and meticulous drawings and overbrimming with how-to secrets. Every page made the pleasures of homebrew biology seem so appealing. I couldn t take it any longer. I decided to abandon physics on the spot and become a naturalist. I rushed back into the field and spent three glorious days in the national forests bordering Los Angeles, pecking about with my binoculars, my field notebook, a portable microscope, and, of course, the Durrells wonderful book. I was absolutely thrilled with my new choice of vocation.
All this took the pressure off me. What a relief! I didn t think about the test again until the evening before it was scheduled to start. In fact, I only took the exam out of curiosity (or so I told myself at the time) just to see how I d do. When I learned that I had passed, and my position at the university was secure, my sudden career move did seem a tad impulsive. Eventually I completed my doctorate and became a professional physicist. But my heart still sings whenever I indulge my amateur s passion for biology (and now it sings quite often).
So this volume, the second in a series of compendiums from the pages of Scientific American s The Amateur Scientist column, has been a special pleasure for me to compile and edit. In fact, in the five-and-a-half years that I was privileged to write the column, I contributed many more projects from biology than physics. ( Scientific American ended the feature s 73-year run in April 2001, when new management shifted the editorial focus of the magazine and suspended all of its long-running columns, including The Amateur Scientist. ) However, I ve only included a few of my columns here so as to make room for a smattering of the many wonderful biology projects described by my predecessors at The Amateur Scientist s helm: Albert Ingalls, Jearl Walker, and most espe