Andrew Parker

Seven deadly colours

If we want to colour an object then we would generally use some sort of pigment. However, in the natural world there are a surprising number of different mechanisms for producing colour. In this book Andrew Parker looks at the variety of ways in which animals can create colours, and their uses for signalling or camouflage. Each chapter deals with a different colour of the spectrum (with ultraviolet replacing indigo), and poses a problem concerning an animal of that colour. Alternative possibilities are discussed, with the accepted solution being given at the end of the chapter. Overall it is a highly informative book, and is likely to have something of interest for all readers, whatever their current knowledge of the subject.

Throughout the book Parker looks at the evolutionary development of animal colours, and addresses Darwin's worry about the evolution of the eye - that it was too perfect. On the contrary, colour can be thought of as a way of fooling the eye.

One criticism I have of the book is that the chapters sometimes seem to lose their way. I realise that this is partly due to their structure, but I think Parker carries it too far. I wouldn't like to lose the descriptions of his field work, but one thing I wouldn't miss would be his hypothetical NanoCam - a camera that can view things at any scale. I think a simple description of what is happening would be better.

Amazon.com info

Hardcover 286 pages
ISBN: 0743259394
Salesrank: 974365
Weight:1.37 lbs

Published: 2005 Simon & Schuster

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Amazon.co.uk info

Hardcover 286 pages
ISBN: 0743259394
Salesrank: 478240
Weight:1.37 lbs

Published: 2005 Free Press

Marketplace:New from £16.99:Used from £25.00

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Synopsis
'To suppose that the eye ...should have formed by natural selection, seems, I freely confess, absurd in the highest degree' -- thus wrote Charles Darwin in ON THE ORIGIN OF SPECIES. The eye's 'perfection', he found, was the one problem he could not resolve with his theory of evolution by natural selection: no intermediate stages between a non-eye and a working eye seemed possible. But was he right? Taking the colours of the spectrum as his keys to the natural world, Andrew Parker shows us that Darwin in fact had no reason to worry, and that Nature's palette is a far more miraculous thing than we had previously imagined. With vivid and fascinating examples of how colour has affected flora and fauna in different environments across the globe, SEVEN DEADLY COLOURS not only shows the endless wonder of the natural world but also extends our understanding of evolution itself.

Synopsis

'To suppose that the eye ...should have formed by natural selection, seems, I freely confess, absurd in the highest degree' -- thus wrote Charles Darwin in ON THE ORIGIN OF SPECIES. The eye's 'perfection', he found, was the one problem he could not resolve with his theory of evolution by natural selection: no intermediate stages between a non-eye and a working eye seemed possible. But was he right? Taking the colours of the spectrum as his keys to the natural world, Andrew Parker shows us that Darwin in fact had no reason to worry, and that Nature's palette is a far more miraculous thing than we had previously imagined. With vivid and fascinating examples of how colour has affected flora and fauna in different environments across the globe, SEVEN DEADLY COLOURS not only shows the endless wonder of the natural world but also extends our understanding of evolution itself.

Light, Eyes, and Evolution *****
Charles Darwin, among the most candid of all scientists, did not pretend all was well when he came across counter-arguments to his ideas. In fact, he deliberately included possible objections to his own proposals; not only did this give him an opportunity to respond to them, he realized that it was fair and objective to attempt to give all sides of ideas he knew were controversial. The eye gave him restless nights. Indeed, he considered it one of the "organs of extreme perfection and complication" and wrote "To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree." Creationists are fond of citing this quote out of context, forgetting that the operative verb is "seems" and that Darwin immediately follows up to show why all is not what it seems. Such an organ could have evolved, especially if one considers the many degrees of complexity in different rudimentary or sophisticated animal eyes. More evidence has been the recent discoveries that rudimentary eyes as well as the sophisticated ones of us mammals or of octopuses have some identical genes, indicating a common foundation. Nonetheless, Darwin considered the eye an organ of perfection; he considered that nothing got past the eye. It is this burden of assumed perfection that Andrew Parker lifts in _Seven Deadly Colours: The Genius of Nature's Palette and How it Eluded Darwin_ (Free Press). Parker shows that eyes certainly lack the sort of perfection that Darwin imagined, that different animal eyes have very different capacities, that there is no perfect eye able to take all visual stimuli in, and that creatures have evolved to take advantage of the imperfections in the eyes of others. Among the surprising facts here is that color is not just pigment, like the paints an artist applies to a canvas. "Behind the scenes of a colour lies a microscopic factory, responsible for the light that leaves an animal's body or an artist's paint." But pigments are only one color factory; there are many others. In fact, in each of the seven chapters of Parker's book (laid out for the seven colors of the rainbow minus indigo but plus ultraviolet), there are other ways of manufacturing colors. In the chapter on violet, for instance, an examination of the iridescent violet colors of wings of the Malayan Eggfly butterfly shows no violet pigment - you could try to grind such wings to make a violet dye, but you would fail. The color from them is "structural" - it comes from astonishingly complicated microscopic structures on the surface of the scales of the butterfly, the layers of which are at a distance from each other which can reflect only the violet colors in phase. Each chapter ends with "A tonic for Darwin", an explanation of how all eyes have imperfections and that there can always be found some pigment, reflection, or blur which an eye cannot see. Darwin assumed simply that color was color and not subject to faulty eyes within an environment. He would have been fascinated by the visual arms races described here as one creature after another balances conspicuousness (for warning or attraction of mates) with camouflage, and predators change their own tactics to take advantage of any alterations. The perfection which Darwin saw in eyes, and which he thought a possible objection to his concept of descent with modification, is illusory; the imperfections, as revealed here in a stimulating and clear book, form more evidence to support his theories.

Light, Eyes, and Evolution *****

Charles Darwin, among the most candid of all scientists, did not pretend all was well when he came across counter-arguments to his ideas. In fact, he deliberately included possible objections to his own proposals; not only did this give him an opportunity to respond to them, he realized that it was fair and objective to attempt to give all sides of ideas he knew were controversial. The eye gave him restless nights. Indeed, he considered it one of the "organs of extreme perfection and complication" and wrote "To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree." Creationists are fond of citing this quote out of context, forgetting that the operative verb is "seems" and that Darwin immediately follows up to show why all is not what it seems. Such an organ could have evolved, especially if one considers the many degrees of complexity in different rudimentary or sophisticated animal eyes. More evidence has been the recent discoveries that rudimentary eyes as well as the sophisticated ones of us mammals or of octopuses have some identical genes, indicating a common foundation.

Nonetheless, Darwin considered the eye an organ of perfection; he considered that nothing got past the eye. It is this burden of assumed perfection that Andrew Parker lifts in _Seven Deadly Colours: The Genius of Nature's Palette and How it Eluded Darwin_ (Free Press). Parker shows that eyes certainly lack the sort of perfection that Darwin imagined, that different animal eyes have very different capacities, that there is no perfect eye able to take all visual stimuli in, and that creatures have evolved to take advantage of the imperfections in the eyes of others. Among the surprising facts here is that color is not just pigment, like the paints an artist applies to a canvas. "Behind the scenes of a colour lies a microscopic factory, responsible for the light that leaves an animal's body or an artist's paint." But pigments are only one color factory; there are many others. In fact, in each of the seven chapters of Parker's book (laid out for the seven colors of the rainbow minus indigo but plus ultraviolet), there are other ways of manufacturing colors. In the chapter on violet, for instance, an examination of the iridescent violet colors of wings of the Malayan Eggfly butterfly shows no violet pigment - you could try to grind such wings to make a violet dye, but you would fail. The color from them is "structural" - it comes from astonishingly complicated microscopic structures on the surface of the scales of the butterfly, the layers of which are at a distance from each other which can reflect only the violet colors in phase.

Each chapter ends with "A tonic for Darwin", an explanation of how all eyes have imperfections and that there can always be found some pigment, reflection, or blur which an eye cannot see. Darwin assumed simply that color was color and not subject to faulty eyes within an environment. He would have been fascinated by the visual arms races described here as one creature after another balances conspicuousness (for warning or attraction of mates) with camouflage, and predators change their own tactics to take advantage of any alterations. The perfection which Darwin saw in eyes, and which he thought a possible objection to his concept of descent with modification, is illusory; the imperfections, as revealed here in a stimulating and clear book, form more evidence to support his theories.

The Magic of Colour *****
Excepting the subtitle - why must so many of today's science writers suggest shortcomings in Darwin's analysis? - this is an excellent depiction of how natural selection has dealt with vision. The second volume of Parker's trilogy on the topic, this one shows how colour perception - or lack of it - has guided the track of natural selection. Vision issues have received little attention from zoologists. As the author demonstrates so well, there are many hidden facets to vision and perception. We tend to think we can see everything, but in fact, our visual acuity has serious limitations. Other creatures, such as bees, see in the ultraviolet range. Many ocean fish have colour limitations due to their habitat, particularly those in deep water. Parker describes how these abilities evolved by using seven - well, eight, actually - commonly detected colours. "The" eye's complexity, which disturbed Darwin, is nearly always limited to the human version. Parker explains how eyes are structured. Certain types have differing colour detection abilities. Within the eye are organelles known as "rods" and "cones". The rods are the light intensity detectors, while the cones are colour selectors. As he explains, light is meaningless until the signals reach the brain where they are decoded. Eye and brain are thus closely linked, the arrangement having evolved with each species over time. Changes in habitat are reflected in changes in visual abilities. Eyes, and which colours they perceive, as Parker indicated in his first volume, are a major indicator of evolution's path. Some colours seem straightforward and unambiguous, like leaves or fruit. Others, however, are generated by pattern or movement. Moth and bird wings have delicate shifts of colour from rest state to flapping, for example. Birds and many insects have evolved superior colour perception as a result. Not all colour is simply variations of reflectivity. Some creatures produce light. Parker's chapter on "Blue" takes us through the realm of "bioluminscence". Sailors tell of sparkling lights in a ship's wake. Fireflies are well known in many places, and the range of tactics in their mating and seeking prey is delightfully described. Some fish, which seem to have special abilities in generating light actually host and manipulate colonies of bacteria in their bodies. The fish control the luminescence with a flap of skin, seemingly providing the fish with "headlights" to illuminate the surroundings. Mimicry is a common means of defense against predators. If an animal blends into its surroundings, it's difficult to see. This ploy is used by many insects, such as the "Stick Insect" or the "Spicky Leaf Insect", to avoid birds. It's also effective to look like a prey species which is toxic to many predators. A fly that looks like a wasp is likely to be left alone. Another trick Parker describes is more subtle. The tree frog is blue and should show up plainly against a green-leafed tree. Instead of mimicry, it adopts a hemispherical shape, resulting in its casting almost no shadow to betray its presence. Parker's collected information on these variations in protection make fascinating reading. It will be even more fascinating when his third volume in this set is released. In the meantime, take up this book to see what evolution has produced. Darwin would be delighted to see what has been learned about that organ he felt carried the greatest challenge to his theory of natural selection. [stephen a. haines - Ottawa, Canada]

The Magic of Colour *****

Excepting the subtitle - why must so many of today's science writers suggest shortcomings in Darwin's analysis? - this is an excellent depiction of how natural selection has dealt with vision. The second volume of Parker's trilogy on the topic, this one shows how colour perception - or lack of it - has guided the track of natural selection. Vision issues have received little attention from zoologists. As the author demonstrates so well, there are many hidden facets to vision and perception. We tend to think we can see everything, but in fact, our visual acuity has serious limitations. Other creatures, such as bees, see in the ultraviolet range. Many ocean fish have colour limitations due to their habitat, particularly those in deep water. Parker describes how these abilities evolved by using seven - well, eight, actually - commonly detected colours.

"The" eye's complexity, which disturbed Darwin, is nearly always limited to the human version. Parker explains how eyes are structured. Certain types have differing colour detection abilities. Within the eye are organelles known as "rods" and "cones". The rods are the light intensity detectors, while the cones are colour selectors. As he explains, light is meaningless until the signals reach the brain where they are decoded. Eye and brain are thus closely linked, the arrangement having evolved with each species over time. Changes in habitat are reflected in changes in visual abilities. Eyes, and which colours they perceive, as Parker indicated in his first volume, are a major indicator of evolution's path. Some colours seem straightforward and unambiguous, like leaves or fruit. Others, however, are generated by pattern or movement. Moth and bird wings have delicate shifts of colour from rest state to flapping, for example. Birds and many insects have evolved superior colour perception as a result.

Not all colour is simply variations of reflectivity. Some creatures produce light. Parker's chapter on "Blue" takes us through the realm of "bioluminscence". Sailors tell of sparkling lights in a ship's wake. Fireflies are well known in many places, and the range of tactics in their mating and seeking prey is delightfully described. Some fish, which seem to have special abilities in generating light actually host and manipulate colonies of bacteria in their bodies. The fish control the luminescence with a flap of skin, seemingly providing the fish with "headlights" to illuminate the surroundings.

Mimicry is a common means of defense against predators. If an animal blends into its surroundings, it's difficult to see. This ploy is used by many insects, such as the "Stick Insect" or the "Spicky Leaf Insect", to avoid birds. It's also effective to look like a prey species which is toxic to many predators. A fly that looks like a wasp is likely to be left alone. Another trick Parker describes is more subtle. The tree frog is blue and should show up plainly against a green-leafed tree. Instead of mimicry, it adopts a hemispherical shape, resulting in its casting almost no shadow to betray its presence. Parker's collected information on these variations in protection make fascinating reading. It will be even more fascinating when his third volume in this set is released. In the meantime, take up this book to see what evolution has produced. Darwin would be delighted to see what has been learned about that organ he felt carried the greatest challenge to his theory of natural selection. [stephen a. haines - Ottawa, Canada]