Letters to a young scientist
copyright © 2013
also by edward o. wilson:
on human nature (1978), Pulizer prize, general nonfiction, 1979
sociobiology (1975): the new synthesis
(Letters to a young scientist, by edward o. wilson, copyright © 2013)
edward o. wilson, Letters to a young scientist, 2013 [ ]
p.22
Then I had an inspiration: snakes. Most people are simultaneously frightened, riveted, and instinctively interested in snakes. It's in the genes.
p.24
Through high school I paid very little attention to my classes. Thanks to the relatively relaxed school system of south Alabama in wartime, with overworked and distracted teachers, I got away with it. One memorable day at Mobile's Murphy High School, I captured with a sweep of my hand and killed 20 houseflies, then lined them up on my desk for the next hour's class to find. The following day the teacher, a young lady with considerable aplomb, congratulated me but kept a closer eye on me thereafter. That is all I remember, I am embarrassed to say, about my first year in high school.
p.25
... I disavow my casual approach to early formal education. I grew up in a different age. You, in contrast, are well into a different era, where opportunity is broader but more demanding.
My confessional instead is intended to illustrated an important principle I've seen unfold in the careers of many successful scientists. It is quite simple: put passion ahead of training. Feel out in any way you can what you most want to do in science, or technology, or some other science-related profession. Obey that passion as long as it lasts. Feed it with the knowledge the mind needs to grow. Sample other subjects, acquire a general education in science, and be smart enough to switch to a greater love if one appears. But don't just drift through courses in science hoping that love will come to you. Maybe it will, but don't take the chance. As in other big choices in your life, there is too much at stake. Decision and hard work based on enduring passion will never fail you.
p.39
As a researcher who has coauthored many papers with mathematicians and statisticians, I offer the following principle with confidence. Let's call it Principle Number One:
It is far easier to scientists to acquire needed
collaboration from mathematicians and
statistician than it is for mathematicians and
statisticaians to find scientists able to make use of
their equations.
pp.39-40
This imbalance in the role of observation and mathematics is especially the case of biology, where factors in a real-life phenomenon are often either misunderstood or never noticed in the first place. The annals of theoretical biology are clogged with mathematical models that either can be safely ignored or, that when tested, fail. Possibly no more than 10 percent have any lasting value. Only those linked solidly to knowledge of real living systems have much chance of being used.
pp.40-41
Newton, for example, invented calculus* in order to give substance to his imagination. Darwin by his own admission had little or no mathematical ability, but was able with masses of information he had accumulated to conceive a process to which mathematics was later applied. An important step for you to take is to find a subject congenial to your level of mathematical competence that also interests you deeply, and focus on it. In so doing, keep in mind Principle Number Two:
For every scientist, whether researcher,
technologist, or teacher, of whatever competence
in mathematics, there exists a discipline in science
for which that level of mathematical competence
is enough to achieve excellence.
[ calculus* : the calculus notation that we studied in school is not same calculus notation that Newton invented. The particular calculus notation that is in most textbook is invented by a guy (he got the credit), and I don't recall his name or any calculus for that matter. ]
p.44
Of equal importance for science, ants, along with termites and honeybees, have the most advanced social systems of all animals.
pp.45-46
“”
If a subject is already receiving a great deal of attention, if it has a glamorous aura, if its practitioners are prize winners who receive large grants, stay away from that subject. Listen to the news coming from the current hubbub, learn how and why the subject became prominent, but in making your own long-term plans be aware it is already crowded with talented people. You would be a newcomer, a private amid bemedaled first sergeants and generals. Take a subject instead that interests you and looks promising, and where established experts are not yet conspicuously competing with one another, where few if any prizes and academy memberships have been given, and where the annals of research are not yet layered with superfluous data and mathematical models. You may feel lonely and insecure in your first endeavors, but, all other things being equal, your best chance to make your mark and to experience the thrill of discovery will be there.
You may have heard the military rule for the summoning of troops to a battlefield: “March to the sound of the guns.” In science the opposite is the one for you, as expressed in Principle Number Three:
March away from the sound of the guns. Observe
the fray from a distance, and while you are at it,
consider making your own fray.
Once you have settled upon a subject you can love, your potential to succeed will be greatly enhanced if you study it enough to become a world-class expert.
pp.46-47
If the subject is still thinly populated, you can with diligence and hard work even become the world authority at a young age. Society needs this level of expertise, and it rewards the kind of people willing to acquire it.
The already existing information, and what you yourself will discover, may at first be skimmy and difficult to connect to other bodies of knowledge. If this proves to be the case, that's very good. Why should the path to a scientific frontier be hard rather than easy? The answer is stated as Principle Number Four:
In the search for scientific discoveries, every
problem is an opportunity. The more difficult the
problem, the greater the likely important of its
solution.
The truth of this guidebook dictum can be most clearly seen in extreme cases.
p.48
The second strategy is to study a subject broadly, while searching for any previously unknown or even unimagined phenomena. The two strategies of original scientific research are stated as Principle Number Five:
For every problem in a given discipline of
science, there exists a species or other entity or
phenomenon ideal for its solution. (Example: a
kind of mollusk, the sea hare Aplysia, proved ideal
for exploring the cellular base of memory.)
Conversely, for every species or other entity
or phenomenon, there exist important problems
for the solution of which it is ideally suited.
(Example: bats were logical for the discovery of
sonar.)
Obviously, both strategies can be followed, together or in sequence, but by and large scientists who use the first strategy are instinctive problem solvers. They are prone to taste and talent to select a particular kind of organism, or chemical compound, or elementary particle, or physical process, to answer questions about its properties and roles in nature. Such is the predominant research activity in the physical sciences and molecular biology.
p.56
How does an ant know when another ant is dead? It was obvious to me that the recognition was not by sight. Ants recognize a corpse even in the complete darkness of the underground nest chambers. Furthermore, when the body is fresh and in a lighted area, and even when it is lying on its back with its legs in the air, others ignore it. Only after a day or two of decomposition does a body become a corpse to another ant.
p.56
animals with small brains, which are the vast majority of animals on Earth, tend to use the simplest set of available cues to guide them through life. A dead body offers dozens or hundreds of chemical cues from which to choose.
p.57
After a lot of smelly trial and error I found that oleic acid and one of its oleates trigger the response. The other substances were either ignored or caused alarm.
p.57
To repeat the experiment another way (and admittedly for my and others' amusement), I dabbed tiny amounts of oleic acid on the bodies of living worker ants. Would they become the living dead? Sure enough, they did become zombies, at least broadly defined. They were picked up by nestmates, their legs kicking, carried to the cemetery, and dumped. After they had cleaned themselves awhile, they were permitted to rejoin the colony.
p.60
Archimedes is said to have then left the bath, running through the streets, hopefully in his robe, while shouting, Heurika!
p.61
Today the evidence for evolution has been so convincingly documented in so many kinds of plants, fungi, animals, and microorganisms, and in such a great array of their hereditary traits, coming from every discipline of biology, all interlocking in their explainations and with no exception yet discovered, that evolution can be called confidently a fact.
p.61
What remains a theory still is that evolution occurs universally by natural selection, the differential survival and successful reproduction of some combination of hereditary traits over others in breeding populations.
([
Smith, Cameron McPherson, 1967-
The top ten myths about evolution / by Cameron McPherson Smith and Charles Sullivan
1. Evolution (biology)
p.30
“”
WHAT EVOLUTION IS
Darwin described evolution as “descent with modification.” This simply means changes in the properties of organisms over generations. These changes are explained by at least three independent processes that when taken together form what we mean by evolution.15 These are replication, variation, and selection, and they are all observable facts. Replication is simply reproduction. Variation is genetic differences between parents and their offspring. And selection refers to natural selection, the process whereby those best adapted to their environment tend to survive and pass on their genes to the next generation.
REPLICATION
VARIATION
SELECTION
pp.30-31
REPLICATION
Replication, or reproduction, can be either asexual or sexual. Asexual reproduction happens when offspring are created from a single parent without mixing in the genes from a second parent. These offspring are usually identical to that one parent, kind of like Xerox copies. They're natural clones. This form of reproduction is more common in plants than in animals, and it's also how bacteria reproduce. In contrast, sexual reproduction involves combining genes from two parents (male and female) to produce offspring. This is how most animals reproduce, as do many plants--through pollination.
p.32
SELECTION
Natural selection is the great testing ground of variation. It's the mechanism that chooses which individuals will survive long enough to reproduce and transmit their genes to the next generation. Of course, natural selection doesn't choose intentionally. If a certain variation provides an advantage, then the individual with that variation stands a better chance of surviving. If it survives long enough to reproduce, it will transmit that beneficial variation to its offspring.
p.34
But sexual selection can also have its drawbacks since it still must pass the test of natural selection. Large and colorful tail feathers are great for attracting peahens, but they're also great for attracting predators since they're so visible from far away. Also, the tail feathers may require too much energy to fly with or to drag around, even when folded up. If a characteristic, such as large tail feathers, puts peacocks at great risk, then they might not live long enough to mate. In that case the peahens will have to settle for peacocks with smaller displays, which will then pass on their genes for smaller tail feathers.
pp.48-49
COMPLEXITY
Just as the words higher and lower can be misleading, so can the notion of complexity. Living things today are, on average, more complex than their ancestors of billions of years past. Some of the earliest lifeforms were simple bacteria, and if they were to undergo any changes or adaptations, there'd be no place to go but in the direction of complexity, since you can't get much simpler than bacteria.8 It's obvious that natural selection has helped shape the complex evolutionary changes through the generations, from single-celled organism to simple plants and animals, leading to fish, reptiles, amphibians, birds, and eventually mammals. So doesn't this show that progressive complexity is a necessary part of the evolutionary process for all living things? The answer is no.
Bacteria are simple organisms, and many have not changed much for billions of years. Indeed, they may be the most successful group of organisms on the planet, having an estimated total biomass (weight) greater than all other living things combined.9 Crocodiles haven't changed much either from their days living among the dinosaurs over 200 million [200,000,000] years ago. The rather prehistoric looking Coelacanth fish, which first appeared around three hundred and 50 million years ago, was thought to have gone extinct 65 million years ago. But one was caught alive in 1938 off the south east of Africa, and since then over 200 have been discovered. These “living fossils” don't appear to have changed much when compared with the fossilized remains of their ancient ancestors.
It would be a mistake, then, to assume as a general rule that complexity is a universal trend in evolution, or that it always confers an advantage for survival. What matters is how well organisms are adapted to their environment, and how well they can adapt to frequent changes in that environment. If evolutionary changes toward complexity provide an advantage for those who acquire them, then those changes will be selected for. If not, they won't. Interestingly, some species lines have become less complex over time, such as cave dwelling fish that no longer have functioning eyes, and some internal parasites that have lost all means of self-locomotion.10 Moreover, the skulls of birds and mammals have become simpler than those of their early fish ancestors.11
p.56
9. E. Mayr, What Evolution Is (New York: Basic Books, 2001), p.278. See also Gould, Full House, p. 194.
11. Mayr, What Evolution Is, p. 214.
(Smith, Cameron McPherson, 1967-, The top ten myths about evolution / by Cameron McPherson Smith and Charles Sullivan, 1. Evolution (biology), published 2007, )
])
p.62
The second law of biology, more tentative than the first, is that all evolution, beyond minor random perturbations due to high mutation rates and random fluctuations in the number of competing genes, is due to natural selection.
p.63
“”
Because science is the wellspring of modern civilization. It is not just “another way of knowing,” to be equated with religion or transcendental meditation. It takes nothing away from the genius of the humanities, including the creative arts. Instead it offers ways to add to their content.
p.65
Now we understand, in sharp contrast, that our species descended over six million [6,000,000] years from African apes that were also the ancestors of modern chimpanzees.
p.67
As a scientist, keep your mind open to any possible phenomenon remaining in the great unknown. But never forget that your profession is exploration of the real world, with no preconceptions or idols of the mind accepted, and testable truth the only coin of the realm.
p.71
1975 book Sociobiology: The New Synthesis
p.73
A living species Azteca muelleri, which appears to be a direct evolutionary descendant or otherwise close relative of Azteca alpha, still lives in Central America. These ants use large quantities of pheromones, acrid-smelling terpenoids, which they release into the air to alarm nestmates whenever the colony is threatened by invaders.
I told Crichton that I might be able to extract remnants of the pheromone from the Azteca alpha remains, inject them into an Azteca muelleri nest, and get the alarm response. In other words, I could deliver a message from one ant colony to another across a span of 25 million years. This had Crichton's attention. He asked if I planned to do it. In this particular dream there is too much of the circus trick and too little of real science--too little chance, that is, to discover something really new.
p.74
The ideal scientist thinks like a poet and only later works like a bookkeeper. Keep in mind that innovators in both literature and science are basically dreamers and storytellers. In the early stages of the creation of both literature and science, everything in the mind is a story. There is an imagined ending, and usually an imagined beginning, and a selection of bits and pieces that might fit in between. In works of literature and science alike, any part can be changed, causing a ripple among the other parts, some of which are discarded and new ones added. The surviving fragments are variously joined and separated, and moved about as the story forms. One scenario emerges, then another. The scenarios, whether literary or scientific in nature, compete with one another. Some overlap. Words and sentences (or equations or experiments) are tried to make sense of the whole thing. Early on, an end to all the imagining is conceived. It arrives at a wonderous denouement (or scientific breakthrough). But is it the best, is it true? To bring the end safely home is the goal of the creative mind.
pp.78-79
This is so much the case that in most fields most of the time, extreme brightness may be a detriment. It has occurred to me, after meeting so many successful researchers in so many disciplines, that the ideal scientist is smart only to an intermediate degree: bright enough to see what can be done, but not so bright as to become bored doing it.
p.80
There must be an ability to pass long hours in study and research with pleasure even though some of the effort will inevitably lead to dead ends.
p.81
Avoid department-level administration beyond thesis committee chairmanships if at all fair and possible. Make excuses, dodge, plead, trade. Spend extra time with students who show talent and interest in your field of research, then employ them as assistants for your benefit and theirs. Take weekends off for rest and diversion, but no vacations. Real scientists do not take vacations. They take field trips or temporary research fellowships in other institutions. Consider carefully job offers from other universities or research institutions that include more research time and fewer teaching and administrative responsibilities.
Don't feel guilty about following this advice.
p.82
Once deeply engaged, a steady stream of small discoveries is guaranteed. But stay alert for the main chance that lies to the side. There will always be the possibility of a major strike, some wholly unexpected find, some little detail that catches your peripheral attention that might very well, if followed, enlarge or even transform the subject you have chose. If you sense such a possibility, seize it. In science, gold fever is a good thing.
p.83
...should at least try to cultivate. It is entrepreneurship, the willingness to try something daunting you've imagined doing and no one else has thought or dared. It could be, for example, starting a project in a part of the world neither you nor your colleagues have yet visited; or finding a way to try an already available instrument or technique not yet used in your field; or, even more bravely, applying your knowledge to another discipline not yet exposed to it.
p.83
But otherwise it is certainly all right and potentially very productive just to mess around. Quick uncontrolled experiments are very productive. They are performed just to see if you can make something interesting happen. Disturb Nature and see if she reveals a secret.
pp.84-85
p.85
Other scientists and I went on during the following years to work out the dozens or so pheromone signals that compose most of the ant vocabulary.
p.86
If the efforts fails, entrepreneurship requires the character and the means to start over--just as it does in business and other careers outside of science.
p.87
The same progression, from technology worthy of a discipline of its own to a routine part of every well-equipped laboratory, also occurred in the evolution of scanning electron microscopy, electrophoresis, computers, DNA sequencing, and inferential statistics software.
The principle I have drawn from this history is the following: use but don't love technology. If you need it but find it at all forbiddingly difficult, recruit a better-prepared collaborator. Put the project first and, by any available and honorable means, complete and publish the results.
p.91
“”
I've visited the Santa Fe Institute in New Mexico, as well as the development divisions of Apple and Google, two of America's corporate giants, and I admit I was very impressed with their futuristic ambience. At Google I even commented, “This is the university of the future.”
p.92
But is groupthink the best way to create really new science? Risking heresy, I hereby dissent. I believe the creative process usually unfolds in a very different way. It arises and for a while germinates in a solitary brain. It commences as an idea and, equally important, the ambition of a single person who is prepared and strongly motivated to make discoveries in one domain of science or another. The successful innovator is favored by a fortunate combination of talent and circumstance, and is socially conditioned by family, friends, teachers, and mentors, and by stories of great scientists and their discoveries. He (or she) is sometimes driven, I will dare to suggest, by a passive-aggressive nature, and sometimes an anger against some part of society or problem in the world.
p.93
When prepared by education to conduct research, the most innovative scientists of my experience do so eagerly and with no prompting. They prefer to take first steps alone. They seek a problem to be solved, an important phenomenon previously overlooked, a cause-and-effect connection never imagined. An opportunity to be the first is their smell of blood.
On the frontier of modern science, however, multiple skills are almost always needed to bring any new idea to fruition. An innovator may add a mathematician or statistician, a computer expert, a natural-products chemist, one or several laboratory or field assistants, a colleague or two in the same specialty--whoever it takes for the project to succeed becomes a collaborator. The collaborator is often another innovator who has been toying with the same idea, and is prone to modify or add to it. A critical mass is achieved and discussion intensifies, perhaps among scientists in the same place, perhaps scattered around the world. The project moves forward until an original result is achieved. Group thought has brought it to fruition.
Innovator, creative collaborator, or facilitator: in the course of your successful career, you may well fill each of these roles at one time or another.
p.101
THE BETTER EMOTIONS of our nature are felt and examined and understood more deeply during maturity, but they are born and rage in full intensity during childhood and adolescence. Thereafter they endure through the rest of life, serving as the wellsprings of creative work.
I told you earlier that during the earliest steps to discovery the ideal scientist thinks like a poet. Only later does he work at the bookkeeping expected of his profession. I spoke of passion and decent ambition as forces that drive us to creative work. The love of a subject, and I say it again for emphasis, is meritorious in itself. By pleasure drawn from discovery of new truths, the scientist is part poet, and by pleasure drawn from new ways of express old truths, the poet is part scientist. In this sense science and the creative arts are foundationally the same.
p.116
Karl von Frisch, the great German entomologist who made many discoveries concerning the honeybee, including their symbolic waggle-dance communication and their remarkable memory of place, knew that he had only begun to explore the biology of this single insect species.
p.155
“”
I was following the second of two strategies I gave you in an earlier letter: for each kind of organism there exists a problem for the solution of which the organism is ideally suited. One success in this correlative effort was the discovery of the “enemy specification” phenomenon.
p.156
The principle behind its concept is simple. Every species of plant and animal is surrounded in its natural habitat by other species of plants and animals. Most are neutral in their effect upon it. A few are friendly, and at the extreme, there is the symbiotic level. In the latter case, two or more are dependent upon one another for their very survival or at least reproduction--for example, pollinator animals and plants they pollinate. A few other plant and animal species are, on the other hand, inimical to a particular species, so much so in a few cases as to be dangerous to their survival. It is to the great advantage of individuals of that species to recognize dangerous enemies instinctively and to avoid or destroy them if possible.
The principle sounds like common sense. But do species really evolve such an enemy specification response? I had never thought of it much one way or the other. Instead, I discovered it by accident.
pp.157-158
Yet in some natural habitat, colonies of both species are abundant. It became apparent that Pheidole (Pheidole dentata - ant) survive by building their nests a safe distance from the fire ant colonies and killing off fire ant scouts before they can report home.
p.163
Another ant, accidentally introduced to New Caledonia in cargo in recent years, has reached the small offshore island of Isle of Pines and is taking over the forests there, destroying, as it spreads, the native ants, other insects, and in fact almost all of the ground-dwelling invertebrates.
The alien enemy is the “little fire ant” (technical name: Wasmannia auropunctata), which originated in the forests of South America. With humanity's unintended help, the species is spreading throughout tropical regions of the world.
p.165
Invasive species are the second more important cause of extinctions of native species, exceeded only by the destruction of habitats through human activity.
(Letters to a young scientist, by edward o. wilson, copyright © 2013, p.165)
pp.171-172
How can an insect process so much information with a brain not much larger than the period below the question mark at the end of this sentence? The principal reason is the way the insect brain--much more efficient by unit volume--is constructed. Glial cells, which support and protect the brain cells of larger animals, including us, are omitted in the insects, allowing more brain cells to be packed into the same space. Also, each insect brain cell has many more connections on average to other cells than do those of vertebrates, allowing added communication by means of fewer information distribution centers.
pp.177-178
TO MAKE IMPORTANT DISCOVERIES anywhere in science, it is necessary not only to acquire a broad knowledge of the subject that interests you, but also the ability to spot blank spaces in that knowledge. Deep ignorance, when properly handled, is also superb opportunity. The right question is intellectually superior to finding the right answer. When conducting research, it is not uncommon to stumble upon an unexpected phenomenon, which then becomes the answer to a previously unasked question. To search for unasked questions, plus questions to put to already acquired but unsought answers, it is vital to give full play to the imagination. That is the way to create truly original science. Therefore, look especially for oddities, small deviations, and phenomena that seem trivial at first but on closer examination might prove important. Build scenarios in your head when scanning information available to you. Make use of puzzlement.
While I've spent a lot of time thus far on biology, obviously because I am a biologist, I am happy to emphasize that other fields of science yield comparable treasures of discovery. I've worked enough with mathematicians and chemists in particular to know that their heuristics--their process of making discoveries--is closely similar.
(Letters to a young scientist, by edward o. wilson, copyright © 2013, p.177-178)
p.179
organic chemistry, biochemistry
Most of organic chemistry, and within it natural-products chemistry, consists of the study of the synthesis and characteristics of the molecules. Special attention is paid to those occurring in living organisms, where organic chemistry turns into biochemistry. Virtually all of life's processes and all of living structures are but the interplay of organic molecules. A cell is like a miniature rain forest, into which biochemists and molecular biologists conduct expeditions to find and describe organic structure, variety, and function.
pp.189-193
pp.191-193
Here, then, in a nutshell, is the theory. <italic text being> Each kind of pheromone message has been engineered by natural selection--that is, trial and error of mutations that occur over many generations resulting in the predominance of the best molecules, with the most efficient form of transmission allowed by environment. </italic text end>
pp.192-193
“”
Bossert and I agreed: “Let's think about ants and other organisms using pheromones as engineers.” This thought took us quickly to ants recruiting other ants by laying a trail for them to follow. So, at the next picnic (or on your kitchen floor if the house is infested) drop a crumb of cake. It is logical to suppose that the ant scout that finds it needs to dribble out the trail pheromone at a slow rate in order to make the store of the substance she carries in her body last a long time. The piece of cake may be several ant-mile equivalents away. In this function, the ant is like an automobile engine designed for high mileage. In order to achieve such efficiency, the pheromone needs (in theory) to be a powerful odor for the ants following the trail. Only a few molecules should suffice. Also, the pheromone must be specific to the species using it, in order to provide privacy. It is bad for the colony if other ants from other species can pirate the trail, and even dangerous for the colony if a lizard or some other predator can follow the trail back to the nest. Finally, the trail substance should evaporate slowly. If needs to persist long enough for other members of the colony to track it to the end, and start laying trails of their own.
Then there are the alarm substances. When a worker ant or other social insect is attacked by an enemy, whether inside or outside the nest, it needs to be able to “shout” loud and clear, in order to get a fast response. The pheromone must therefore spread rapidly and continuously over a long distance. But it should also fade out quickly. Otherwise even small disturbances, if frequent, would result in constant pandemonium--like a fire alarm that cannot be turned off. At the same time, unlike the case for trail substances, there is no need for privacy. An enemy can gain little by approaching a location teeming with alert and aggressive worker ants.
p.197
The qualities of the active space depend on five variables that can be measured: the diffusion rate of the substance, the surrounding air temperature, the velocity of the air current, the rate at which the pheromone is released, and the degree of sensitivity of the organism receiving it. With these measureable quantities in place, the theory began to take shape in a form that could be taken into the field and laboratory, and used to study animals as they communicated.
p.198
By the late 1950s, the new technique of gas chromatography coupled with mass spectrometry made it possible to identify substances in quantities as little as a millionth of a gram, or less. Where previously chemists needed thousandths of a gram of pure substance to get the job done, now they needed only thousandths of a thousandth [1000 x 1000 = 1,000,0000th]. The technique has allowed the detection of trace substances, including toxic pollutants, in the environment. Along with DNA sequencing (also requiring only a droplet of blood or the wipe of a wineglass), it also soon transformed forensic medicine.
p.199
pp.200-201
Years later, Robert K. Vander Meer, a natural product chemist working on fire ant pheromones in Florida, discovered the reason for our failure. The trail substance, it turned out, is not a single pheromone, but a medley of pheromones, all released from the sting onto the ground. One attracts nestmates of the trail layer, another excites them into activity, and still another guides them through the active space created by the evaporating chemical streaks. All of the components need to be present to evoke the full response in a fire ant worker seen in the field and laboratory. By not realizing this complexity, and thereby taking aim only at one of the components, we had failed to identify any of them.
pp.201-202
There was a different sensory world to be understood, one wholly invisible to human sight and hearing. The signals are in the air, spread over the ground, and beneath in the soil, and in pools of water. They form a crisscrossing of odors and scents, a riot of voices unheard by us that variously broadcast, threaten, or summon: Check me as I approach you, I am a member of your colony. I have discovered an enemy scout, now hurry, follow me. I am a plant whose flowers have opened up this night and I wait here for you, come to me for a meal of pollen and nectar. I am a female cecropia moth calling, so if you are a male cecropia moth, follow my scent upwind, come to me. I am a male jaguar, alone on my territory, if you have detected this scent, you are trespassing, so get out, get out now.
pp.202-203
Now I hope you see how theories are made, and how they work. The process can be messy, but the product can be true and beautiful. As factual information grows about any subject--in this case chemical communication--we dream about what it all means. We make propositions about how the phenomena we discovered work and how they came into existence. We find a way to test these various hypotheses. We look for pattern that emerges when we put the parts together, like a jigsaw puzzle. If we find such a pattern, it becomes the working theory--we use it to think up new kinds of investigation, in order to move the whole subject forward. If this extension doesn't work very well and now facts appear that contradict the theory, we adjust it. When things get bad enough, we junk the theory and create a new one. With each such step, science moves closer to the truth--sometimes rapidly, sometimes slowly. But always closer.
p.207
The dominant groups of the North, Matthew [William Diller Matthew's] went on, are superior because they evolved in rugged, severely seasonal climates, which required a general toughness and ability to adapt to change.
p.208
These cold-blooded vertebrates, he [Philip J. Darlingtom] said, arose not in the north temperate zone as supposed by Matthew for the warm-blooded mammals, but in the vast tropical forests and grasslands that once covered most of Europe, northern Africa, and Asia. They then spread south into the peripheral continents, much reduced in diversity of species, and northward into the north temperate zone. It also turned out from the new wave of fossil research that humanity originated not in Eurasia but in the tropical savannas of Africa.
pp.211-212
Two and a half million [2,500,000] years ago the Isthmus of Panama rose above the sea, bridging the ancient Pacific-to-Caribbean seaway and allowing the mammals of South America to mingle with the mammals of North and Central America. Species from each continent spread into the other.
pp.215-216
Because dominant groups
Because dominant groups spread farther across the land and sea, their population tend to divide into multiple species that adopt different ways of life dominant groups are prone to experience adaptive radiations. Conversely, dominant groups that have diversified to this degree, such as the Hawaiian honeycreepers and placental mammals, are on average better off than those composed of only a single species: as a purely incidental effect, highly diversified groups have better balanced investments and will probably persist longer into the future. If one species comes to an end, another occupying a different niche is likely to carry on.
pp.226-227
“”
When I talked about equilibrium I spoke of the islands near and far as being “saturated.” MacArthur said, “Let me think about this for a while.” I trusted him to come up with something. I'd already seen evidence of MacArthur's ingenuity in breaking down complex systems into simpler ones.
MacArthur soon wrote a letter to me in which he postulated the following:
Start with an empty island. As it fills up with species
there are fewer species available from other islands to
arrive as immigrants, and so the rate of immigration
falls. Also, as the islands fills up with species, it becomes
more crowded and the average population size of each
species decreases. As a result the rate of species extinction
rises. Therefore, as the island fills up, the immigration
rate falls, and the extinction of the species already
present rises. Where the two curves cross, the extinction
rate equals the immigration rate, and the number of
species is at equilibrium.
To continue, on small islands the crowding of the species is more severe, and the extinction rate curve is steeper. On distant islands, immigration is less, and the immigration curve less steep. In both cases the result is a smaller number of species at equilibrium.
p.231
Before telling you how the goal was accomplished, I will pause to reinforce a point I made earlier: that successful research doesn't depend on mathematical skill, or even the deep understanding of theory. It depends to a large degree on choosing an important problem and finding a way to solve it, even if imperfectly at first. Very often ambition and entrepreneurial drive, in combination, beat brilliance.
p.238
“”
Original discoveries, to remind you, are what count the most. Let me put that more strongly: they are all that counts. They are the silver and gold of science. Proper credit for them is therefore not only a moral imperative, but vital for the free exchange of information and amity within the scientific community as a whole. Researchers rightly demand recognition for all their original work, if not from the general public then from colleagues in their chosen field. I have never met another scientist who was not pleased--deeply pleased--by a promotion or award bestowed for original research. As the actor, Jimmy Cagney said of his career in motion pictures, “You're only as good as people say you are.”
The great scientist who works for himself in a hidden laboratory does not exist.
pp.239-240
“”
If you're not sure of a result, repeat the work. If you don't have the time or resources to do so, drop the whole thing or pass it on to someone else. If your facts are solid, but you're not sure of the conclusion, just say as much. If you do not have the opportunity of resources to repeat and confirm your work, don't be afraid to use the words denoting timid uncertainty: “apparently”, “seemingly”, “suggests”, “could possibly be”, “raises possibility of”, “may well be.” If the result is worthwhile, others will either confirm or disprove what you think you found, and all will share credit. That's not sloppiness. It's just good professional conduct, true to the core of the scientific method.
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