Las leyes del Serengeti: Cómo funciona la vida y por qué es importante saberlo

by Sean B. Carroll, Sean B. Carroll

¿Cómo funciona la vida? ¿Cómo logra la naturaleza producir la cantidad adecuada de cebras y leones en la sabana africana, o de peces en el mar? ¿Cómo produce nuestro cuerpo el número adecuado de células para nuestros órganos?

En Las leyes del Serengeti el premiado biólogo Sean B. Carroll cuenta la historia de los pioneros científicos que buscaron la respuesta a estas preguntas tan sencillas como fundamentales, y muestra hasta qué punto sus descubrimientos son importantes para nuestra salud y para la salud del planeta.

Una de las revelaciones más importantes sobre la naturaleza es que todo está regulado: hay leyes que regulan la cantidad de cada molécula de nuestros cuerpos como la cantidad de animales y plantas en la Tierra. Y la revelación más sorprendente acerca de las leyes que regulan la vida a escalas tan distintas es que son muy similares; la vida tiene una lógica común subyacente. Carroll explica cómo nuestro profundo conocimiento de las leyes y la lógica del cuerpo humano ha acelerado la llegada de medicamentos revolucionarios, y plantea la fascinante propuesta de que es hora de aplicar las leyes del Serengeti para sanar a nuestro achacoso planeta.

Genres: Science, Nonfiction, Biology, Nature, Evolution, Ecology, History

399 pages, Kindle Edition

First published February 16, 2016

About the author

Sean B. Carroll (born September 17, 1960) is a professor of molecular biology, genetics, and medical genetics at the University of Wisconsin–Madison. He studies the evolution of cis-regulation in the context of biological development, using Drosophila as a model system. He is a Howard Hughes Medical Institute investigator. Since 2010, he has been vice-president for science education of the Howard Hughes Medical Institute.

Reviews

[David Rubenstein · Rating 5 out of 5]

This marvelous book is about how life regulates itself. The regulation is described on two levels; at the molecular level, and on the ecology level. These regulations, or "rules" are developed through stories, and it is these fascinating stories that bring the narrative of discovery to life. Below I have tried to convey a hint of the many engrossing stories.

Physiologist Walter Cannon was an amazing scientist-soldier. During World War I he volunteered to be a doctor at the front. He saw many injured soldiers die of shock as their blood pressure plummeted. He tried feeding them sodium bicarbonate to reduce the blood's acidity. And the injured soldiers' blood pressure jumped up overnight, avoiding death due to shock! Later he observed many different ways the body maintains a balance through self-regulation.

Then the story-line switches to Charles Elton, the founder of modern ecology. The book describes how he got his education during expeditions to the Arctic. He discovered the population periodicities between various predator-prey pairs.

Then there is the story of the remarkable scientist, Ancel Keys. He earned an undergrad degree in economics, earned a PhD in oceanogray and biology at Scripps Institute, and then earned another PhD in physiology at Cambridge University. Then he joined the Harvard "Fatigue Laboratory" which organized an adventure in the Andes in northern Chile. There, he personally studied survival at 20,000 feet elevation for fifteen days. For six of these days he stayed on a diet of water and condensed food. Later he was called on by the Army to develop a nonperishable, light-weight food ration. He developed the so-called K-ration, which was named after him. After the war he did pioneering research on the relationship between cholesterol in the bloodstream and heart attacks. He collaborated in a large-scale epidemiological study in Europe and the U.S. and discovered a strong correlation between cholesterol and heart attacks.

At this point in the book, Sean Carroll points out that the rules regulating molecular giology are analogous to the rules regulating ecologies. He relates how three scientists came to the realization that populations are not primarily regulated by the weather. Instead, smaller herbivores are not usually food-limited, but are limited by their predators. But it was not easy to prove this hypothesis. Instead of trying to prove it simply through observations, it was necessary to intervene. It is called the "kick it and see" ecology.

In one example of this approach, Robert Paine peeled starfish from rocks and threw them into the sea in some areas, and left them alone in other areas. He carefully calculated the density of 15 species. He noted that acorn barnacles spread out, then were themselves crowded out by goose barnacles and mussels. Four species of algae limpets and chitons disappeared. A small predatory snail increased in number. Overall, the number of species reduced from 15 to eight.

The presence of one predator can control the composition of species in a community through its prey. Its presence affects not only the animals that it eats, but those it doesn't eat, as well. Starfish negatively regulates the population of the competitively dominant species. This flipped traditional thinking upside down.

The most fascinating story is that of the Serengeti nature reserve. In this area of 10,000 square miles, there are 360,000 large animals. The question Carroll raises is why did the number of buffalo increase from 16,000 to 37,000 from 1961 to 1965, and then to 54,000 in 1969? And, why did wildebeest increase from 99,000 to 770,000 from 1958 to 1973? The answer appears to be that East African domesticated cattle were vaccinated in those years against the rinderpest virus. It turned out that domesticated cattle were the reservoir for rinderpest, not the wildlife. The vaccinations had the effect of eliminating the virus from wild animals, too. The virus was a microscopic keystone in the ecology. Its presence negatively regulated the ruminants; its suppression allowed them to surge in number.

There is a remarkable story about how two researchers, Sinclair and Norton-Griffiths, flew a plane from Kenya to Tanzania to photograph wildebeest herds. They landed in Tanzania and were arrested for spying. They were confined under guard, but after three days escaped and dashed for their plane. They finally got home, developed their film, and discovered that the wildebeest population had doubled to 1.4 million!

There were many other effects on the ecology of the Serengeti. The numbers of lions and hyenas increased. This is understandable, as they are predators of the antelope herds. But the number of giraffes also increased! The reason is that there was less grass available, due to the growing herds, which suppressed wild fires, so more young trees could grow. This provided more food for giraffes. The ecology and food chains are quite complex. The shorter grass allowed more species of herbs to grow, thus supporting a more diverse population of butterflies. The grasses evolved compensatory growth response, regenerating above-ground growth. So the grasses provided MORE food when grazed than when they were protected!

Smaller animals tend to die mostly from predation, while large mammals (giraffes, hippos, elephants) are regulated by food supply. The dividing line is around 150 kg. But this is not a hard and fast rule. Deaths by predation occur mostly to resident antelope populations. They are more vulnerable to lions that are confined to a region to raise and protect their own young. As a result, migrating herds are much bigger than resident populations.

Throughout the book, it is emphasized that regulations at the molecular level and at the ecology level are very similar. They are often due to double-negatives, that indirectly increase trophic layers (prey of the prey) two down from the "keystone" predators.

Ecologies are often out of balance, due to human interference. Ecologies are often very complex. The real theme of the book is that we need to learn the "rules of nature", to help protect the world's ecologies. Human interference often goes awry because we do not fully understand the consequences. The entire book is told from a point of view of mysteries and discoveries. There are some very human stories that grabbed my attention. Carroll has written a beautiful book that got me to think how nature works.

[Tucker · Rating 3 out of 5]

In “The Serengeti Rules” Sean Carroll has combined his extensive background in biology with masterful storytelling to present an eminently readable and understandable book about the rules and laws of biology and how they regulate life. A compelling and informative book that is definitely recommended.

Thank you to Princeton University Press and NetGalley for an advance copy of this book.

[Book Shark · Rating 4 out of 5]

The Serengeti Rules: The Quest to Discover How Life Works and Why It Matters by Sean B. Carroll

“The Serengeti Rules” is a very good book that looks back at how the revolution in understanding the rules that regulate our biology unfolded and to look at where it is heading. Professor of molecular biology and genetics and member of the National Academy of Sciences, Sean B. Carroll takes the reader on adventure of amazing people who took on great challenges and accomplished extraordinary things. This captivating 288-page book includes ten chapters broken out into the following three parts: I. Everything is Regulated, II. The Logic of Life, and III. The Serengeti Rules.

Positives:
1. An engaging, well-written book.
2. Interesting topic, how life works at different scales and what we can do with such knowledge. Dr. Carroll is a gifted writer.
3. Good use of photos and charts to complement the excellent narrative.
4. In the introduction Dr. Carroll doesn’t waste time in laying down the expectations of the book. “The most critical thing we have learned about human life at the molecular level is that everything is regulated.”
5. Complex topics written at an accessible level for the masses. “And when cells escape the controls that normally limit their multiplication and number, cancer may form.”
6. A lot of interesting findings throughout the book. “In his own laboratory, Cannon aimed to figure out how emotions affected digestion. He observed that emotional distress also ceased digestion in rabbits, dogs, and guinea pigs, and from the medical literature that also seemed to be true of humans.”
7. At its heart this book is about extraordinary people who through determination overcome amazing challenges to make extraordinary discoveries. “Charles Elton is nowhere near as famous as Darwin or Malthus, but he is known to biologists as the founder of modern ecology, and the central mystery that gripped him was how the numbers of animals are regulated.”
8. Stories of how rules of physiological regulation were discovered. “But it turns out that life—from the molecular scale all the way up to the ecological scale—is usually governed by longer chains of interactions than we first imagine, with more links in between. We need to know about each of those links and the nature of the interactions between them to truly understand, and to intervene in, the rules of regulation on every scale.”
9. A look at the discovery of the link between heart disease and serum cholesterol levels. “Men with levels greater than 260 milligrams of cholesterol per 100 milliliters of blood had five times the heart attack risk of those with levels below 200. The Seven Countries study found the same at the five-year mark. For example, the average cholesterol level of east Finlanders was 270, and they had more than four times as many heart attack deaths as Croatians with cholesterol levels below 200.”
10. Janet Davison Rowley’s impact to cancer research. “Rowley’s discoveries of specific but different chromosomal changes in two different types of leukemia was strong evidence that at least some cancers were caused by specific, perhaps unique, genetic mutations.”
11. Rules of regulation on the larger scale. “The proposal that predators regulate herbivore populations is now widely known as the “HSS hypothesis” or “Green World Hypothesis.””
12. Explains the Serengeti Rules. “Some species exert effects on the stability and diversity of their communities that are disproportionate to their numbers or biomass. The importance of keystone species is the magnitude of their influence, not their rung in the food chain.”
13. A look at the Serengeti. “And indeed, the Serengeti is biologically very special. It is a vast ecosystem of almost 10,000 square miles that is bounded by natural barriers on all sides.”
14. How key creatures have the biggest impacts. “The wildebeests’ many direct and indirect effects on grasses, fire, trees, predators, giraffes, herbs, insects, and other grazers reveal that they are a keystone species in the Serengeti, with disproportionate impacts on the structure and regulation of communities. As Tony Sinclair put it, “Without the wildebeest, there would be no Serengeti.””
15. The story of Lake Erie. “Spurred by the dire condition of Erie and other lakes, the US Congress passed the 1972 Clean Water Act that authorized the Environmental Protection Agency to regulate the discharge of pollutants into waterways and to set the acceptable limits for water quality for humans and aquatic life.”
16. Find out how some species explode in numbers. “Microcystis, planthoppers, baboons, cownose rays. What rule or rules of regulation have been broken that enabled these organisms to explode in numbers?”
17. A look at how the trophic cascades were manipulated to benefit the Wisconsin lakes.
18. A look at the Yellowstone Restoration.
19. The fascinating resurrection of the Gorongosa National Park. “In October 2004, he pledged $500,000 toward the park’s restoration to Mozambique’s Ministry of Tourism. That was to be a small down payment. In November 2005, he agreed to provide $40 million to the park’s restoration over a thirty-year period. But this would not be a matter of merely sending checks from the United States. Carr and his foundation were to co-manage the endeavor on the ground with the Mozambicans.”
20. An excellent section on lessons learned. “Every scientific recommendation requires political action for implementation. Scientists must equip politicians with the information necessary for making good public policy. I would add that another approach to securing the necessary political will is for scientists themselves to pursue public office.”
21. Extensive notes and bibliography.

Negatives:
1. Even at its most accessible, molecular biology is difficult and some readers may feel lost early on in the book but don’t give up as it progresses nicely and is ultimately rewarding.
2. Missed opportunity to add supplementary material such as a table of all the animals currently in the Serengeti and their vitals and/or interesting facts.
3. Not at the same level as his previous books, as an example Endless Forms and The Making of the Fittest are superior books.

In summary, Dr. Carroll succeeds in presenting a compelling case for how life works at its different levels through interesting stories. It’s hard to match his previous works but overall this book is satisfying and makes an interesting link between physiology and ecosystems. Not perfect but if you are a layperson interested in how life works and why it matters this is a recommended book.
Further recommendations: “The Making of the Fittest” and “Endless Forms Most Beautiful” by the same author, “The Extended Phenotype” and “The Greatest Show on Earth” by Richard Dawkins, “The Gene” by Siddhartha Mukherjee, “I Contain Multitudes” by Ed Yong, “Life’s Engines” by Paul G. Falkowski, “A Most Improbable Journey” by Walter Alvarez, and “A New History of Life” by Peter Ward.

[Charlene · Rating 3 out of 5]

I love Sean B. Carroll but this book was just ok for me. I was hoping for something as mind-blowing as Endless Forms Most Beautiful. I read that and have never looked at life the same again. The beginning of the book started out great, so great in fact that I felt like Carroll should be the person to replace Dawkins' old tired rhetoric, which should have been left behind with the 90s, with his own better understanding of life and evolution. However, the following chapters made it clear why Dawkins is still leading the pack while a more relevant, smarter, more current Carroll has a voice that doesn't reach cult following status. Carroll loves his history. I too love the history of science, but history can only be the backdrop when trying to help humans shift paradigms. History cannot take over in such a way that is obfuscates the present advances. I felt as if Carroll led us to water, time and time again, but never let us drink, like he did in Endless Forms. The beginning of the book promised a look at universal rules that would make clear how genetics is only part of the picture when trying to understand life. With such an introduction, I expected more discussion of the universal rules throughout the past and present and how those rules led to the increasing complexity seen throughout evolutionary time. Every time I finished reading about the history, I thought, 'Here it comes. He is going to relate it to our new understanding of networks, complexity, emergence, etc.' But, it always seemed to stop short of that.

If you are interested in a deep history of scientific discovery, than this book will not disappoint. Carroll excels in bringing scientific history to life for his reader.

I will continue to read Carroll books but I hope the next one will be more like Endless Forms and tie together all of the history with the most eye-opening phenomena unfolding around us.

[Joshua Buhs · Rating 2 out of 5]

Sometimes you swing for the fences--and miss.

(Yes, I'm watching baseball as I review this.)

In the acknowledgments section, Carroll says that his editor asked him to write a short, provocative book. This was his attempt.

Well, it was short.

The argument that Carroll wants to make is that the same kinds of rules that organize life on the molecular level also operate on the ecological level. The suggestion he wants to make follows from this--we have learned to intervene in disease processes and re-establishing these rules when they go awry; we will probably continue to do so. And what we need to do now is intervene in ecosystems where these rules have also been altered beyond working, and get them up and running again.

It's not very provocative, is it, except in tangential ways.

After an introductory chapter, Carroll moves through two sections, each of a couple chapters. The first deals with molecular biology, building to the idea that biological processes are often regulated by negative regulation--that is to say, the immediate regulating agent might keep something from happening, unless in the presence of some other condition. He goes through a number of the usual topics. There is Walter Canon and the wisdom of the body; and, importantly, Jacob and Monod.

He adds some more examples, but this is really a Biology 101 lecture.

The second section moves on to organismic and ecological biology, but stays in the Biology 101 mode. We have Charles Elton and food chains, then Robert Paine and trophic cascades--plus, again, some more recent work. Again, Carroll is at pains to point at that negative regulation is important. Urchins destroy kelp. But put otters into the system, and kelp forests flourish again.

I am sure that Carroll would admit that this is very basic biology--it's meant to be popular. But I think the book could have stood *some* complication, on another levels. There are some annoying American habits--treating Africa as largely undifferentiated: a unified place. A blindness to issues of cultural imperialism (white man comes to save African big game.) There's no discussion of economics--and what there is is (subtly) odd, tut-tutting over socialist experiments and praising the philanthropy made possible by capitalism, but not really looking at capitalism as a driving force of ecosystem alteration.

In a popular science book, one could skip that, I guess, but the biology, too, is overly simple. He writes about cholesterol as a cause of heart disease, without taking into account recent contradictory evidence. He writes about tropic cascades as straightforward, easily diagnosed and easily manipulated--as long as there's enough money--without really taking into account stochastic ecological processes. I guess the point was to keep it simple for comparisons sake, but that just really raises other questions.

Ok, both molecular and ecological organizations rely on negative regulation. This hardly makes them the same. Are there other reasons to consider them different? Are molecules the same as organisms? I'm not sure Carroll--or anyone--would agree, but there's where the analogy leaves us. The upshot is this: the comparison is too brief--and not provocative enough. Whether I know that negative regulation is also present in molecular biology or not--this will not change my view on the need to quit fucking up ecosystems. Or even what to do about it. What is the ultimate point here?

For real, I think the point is to make a documentary; the book, it seems, was an afterthought even as it was written. Carroll has done some executive producing, and it is hard (impossible!) not to see the chapters as parts of a larger documentary. The introduction comes not only with visuals, but with its own soundtrack.

Even the name, he admitted, was chosen more for its evocativeness than it epitomizing the argument. "The Serengeti Rules"--the discovery that animal populations are regulated, and how--were worked out, mostly, in places other than the Serengeti--the Great Lakes was home to a lot of it, as was the Pacific Northwest and a number of islands. But these don't sell the same way Serengeti does: they do not connote the primitive splendor that is associated with that mythical place called Africa.

And maybe this would make a better television documentary, though I wouldn't bet the rent on it. The visuals would be better, true enough.

As a book, though, it's a miss.

PS: The book has one of the most annoying citation systems possible; I guess it doesn't matter too much, though, since most of the endnotes are just to specific studies and don't try to place the book in any wider literature. It's Bio 101, after all.

[Rossdavidh · Rating 4 out of 5]

Sean B. Carroll has an analogy to tell you about, and this book is how he is going to do it. Essentially, it is this: life has basic rules for how it keeps a complex system more or less in balance, even when it is perturbed, and they are very similar at the level of a single mammal or an entire ecosystem. We maintain our blood pH, internal temperature, and many other things with a narrow band, so long as we are alive, and in spite of many changes in climate or diet. If any of these depart from that narrow band, for example if our blood pressure is too low or our sodium levels get too high, it can be a very bad sign. Carroll's assertion is that ecosystems do the same thing, and that the systems it uses to do it are very similar. I'm not sure that Carroll would even use the term "analogy" for this, he might say they are fundamentally of the same type.

One of the basic principles that recurs in this book is the idea that nature uses push and pull to control things, like a driver that drives with the gas pedal down, and controls the speed by pushing down more or less on the brake pedal. Thus, our DNA may have a gene for making a particular protein, but normally this is suppressed by another molecule (e.g. one that clamps onto that portion of the DNA and prevents it from serving as the template to make the protein in question). When the cell needs to make that protein, a third molecule disrupts the suppressor, and the protein gets made in abundance. This is, for example, how we can have the same DNA in every cell, but proteins only get made in the cells where they're needed.

This is, needless to say, a bit more complicated to think about than a simple set of on-off switches. It is as if in order to turn on the lights we need to short circuit the light-circuit-breaker. Perhaps for this reason, it took quite a while for biologists to figure out what was going on here. Carroll takes us through the history of it for a few chapters, introducing us to a number of historical figures from all around the world who figured it out. Once it was known, it was possible to start putting it to use in the field of medicine. Many of our modern pharmaceuticals work on the principle that it is not just the gene that makes a protein which can go wrong; it can also be the other gene that is supposed to (but sometimes fails to) suppress the first.

There is also a discussion of a similar phenomena in recent cancer research, where it has been discovered that cancer requires not only a carcinogen, but also the failure of the several genes that normally help to suppress cancer. Once again, the malfunction may not have begun in the obvious place (the carcinogen), but in the failure of the suppressor (in this case, genes for natural cancer-fighting proteins). There are a number of good stories here, of great minds motivated to understand how our bodies work and how to make them right again when they start to fail. In particular, hearing about how even these great minds struggled and stalled for a time on the way to their eventual breakthrough is always more interesting than presenting them as having the right idea from the get-go and just confirming it with an experiment. Real science has a lot of hard work and puzzle-solving involved. It also has to be carried out in between the times when real life intervenes, as when Jacques Monod was working inside France as a member of the French Resistance, using several different names and coordinating sabotage. Carroll is a good storyteller, and he weaves the science and the history together well.

Next, it is on to ecosystems. Here, we discover odd facts like the fact that more wildebeest on the Serengeti can result in more giraffes. Why? Well, if the wildebeest have died off to lower numbers (e.g. by a disease, rinderpest, that was a great problem in the early 20th century), then the grasslands will not be grazed as much, and there will be more tinder in the dry season for fires. These fires can kill off the new trees which grow up to become giraffe food. The links between rinderpest in wildebeest, grassfires, trees, and giraffes has a daisy chain of positive and negative feedback in it, which can resemble our own internal metabolism.

Thus, the normal (and often quite chaotic, in the mathematical sense) variation of a given species population can get moderated, by things such as a reduction in prey leading to a reduction in predator numbers, or a shift by them to an alternate food source. Carroll takes us through a number of examples, some of them closer to home in the fishing lakes of the northern Midwest (where the loss of a link in the food chain can result in algae mats choking a lake). I quite enjoyed this part as well, since it was telling me more about ecology than the standard "oh we have sinned and if we don't repent soon it is DOOM for us all!" that so many with concern for the environment concentrate on (which is both depressing and uninformative, and also by the way not very likely to convert anyone to your cause who wasn't already on board).

The very last part of the book is an attempt to make the case that, just as we were able to solve problems in medicine using our knowledge of how the interrelations of molecular biology worked, we can solve problems with our environment by using what has been learned in recent decades about how ecosystems work. Some of it, like the case study of Gorongosa Park in Mozambique, is quite good. Towards the very end, Carroll gets a bit carried away with an analogy between the effort to eradicate smallpox and the need to restore ecosystems. I'm not sure that this part holds up to close scrutiny, since the competition between manufacturing in different countries to have the lowest cost has a tendency to drive everyone together towards lower environmental standards, and smallpox didn't face a similar pressure on countries to NOT vaccinate their population. But it's a small blemish on an otherwise excellent book, and in any case the story of how smallpox was eradicated is in itself interesting enough.

When the book was finished, I wished there were more of it to read.

[John · Rating 5 out of 5]

Quite Possibly The Most Important, Most Influential Popular Science Book on Biology for Our Time

How do animals (and plants) regulate their numbers? Why does the human body possess a great degree of self-regulation, culminating with healing? Why should biology matter to you and me? Distinguished evolutionary developmental biologist Sean B. Carroll explains how and why the rules regulating ecosystems apply to the human body in his "The Serengeti Rules: The Quest to Discover How Life Works And Why It Matters". One of our foremost communicators of science, Carroll combines his vast scientific knowledge, superb storytelling talent and fine prose in demonstrating that there is indeed a "common underlying logic to life" as expressed by the similar rules regulating vast scales of biological organization, from the organ systems of the human body to immense ecosystems like East Africa's Serengeti. Organized into three sections, Carroll's latest book is a bold, provocative, and compelling exploration of the rules governing life on Earth, conveyed through his vivid, often insightful, accounts of those biologists who discovered them. In "Everything Is Regulated", he introduces to two pioneering figures of early 20th Century biology, Harvard University physiologist Walter Cannon, and Oxford University ecologist Charles Elton, describing how Cannon stumbled upon homeostasis and Elton made sense of the "economy of nature", recognizing the importance of regulating numbers of animals via the existence of food webs. In “The Logic of Life”, Carroll describes the importance of Jacques Monod’s and Francois Jacob’s discovery of enzyme regulation, and how it influenced a later generation of molecular biologists in the United States and Japan in understanding the origin of cancer and in developing suitable drugs for treating it. In “The Serengeti Rules” – the book’s longest section – Carroll describes how marine ecologist Robert T. Paine recognized the existence of keystone predators on top of the food chains of ecosystems, and how this led to the discovery of trophic cascades, in which the presence or absence of keystone predator and prey species have substantial impacts on regulating the structure and population densities of ecosystems. He concludes by showing how the ecological rules of regulating animal numbers – “The Serengeti Rules” - have been applied successfully in bringing back from the verge of extinction, the once lush Gorgongosa of Mozambique and in wiping out forever, the lethal scourge of mankind that was smallpox. In citing these and other examples, Carroll impresses upon us the need to employ “The Serengeti Rules” to preserve forever, Earth’s biodiversity, not merely for our sake, but for the sake of succeeding generations of humans. For these reasons “The Serengeti Rules” may be recognized as one of the most important popular science books published this year, and perhaps, one of the most influential of our time.

[Jonna Higgins-Freese · Rating 2 out of 5]

I was disappointed, I'd expected something much more interesting. But let me save you some time: keystone predators are important to controlling populations, as are food supplies. There are positive and negative feedback loops in nature.

[Jimmy · Rating 5 out of 5]

I love his dedication:

For the animals,
and the people looking out for them.

Let's all try to look out for the animals, including the human ones.

Here are three interesting questions from the Introduction that came about when "a second revolution" in biology occurred:

1. Why is the planet green?

2. Why don't the animals eat all the food?

3. What happens when certain animals are removed from a place?

The first revolution had to do with molecular rules. The second revolution based on those questions above led to "ecological rules that regulate the number and kinds of animals and plants in a given place." The author calls them "the Serengeti Rules."

And he also states "We have done a very poor job in considering and applying these Serengeti Rules in human affairs."

So we apply molecular rules to medicines. About 85% are rejected in testing. But we hunt, fish, farm, burn, forest whatever we please with little or no consideration of what we are doing to other species or their habitats.

Chapter 1 deals with the life and discoveries of Walter B. Cannon who served in WWI. He was disturbed by the number of soldiers who died after they were brought to him for help. He came up with the idea that regulation is the key to maintaining a healthy human body. The job of medicine, therefore, was to find ways to correct abnormal regulation in sick humans.

This becomes a metaphor for the planet as a whole. The earth needs to be regulated as well. For example, there are only so many food and water sources. This fits in well with ideas about over population. There are way too many humans to survive on this planet.

I am reminded of the concept of a keystone species by the question above: What happens when a species is removed from an area? It was the zoologist Robert T. Paine who first wrote about the concept in 1966 and 1969. He probably should have won a Nobel Prize. Now that idea is critical.

Chapter 2 discusses Charles Elton, known to biologists as the founder of modern ecology. He wanted to know how the numbers of animals are regulated. He is not as famous as Darwin or Malthus, but he should certainly be more famous than he currently is.

Elton went to the Arctic to study the food chain. He observed the importance of food, scarce on land but plentiful in the ocean. So it all starts with the oceanic food sources. Creatures eat fish, and land animals eat those creatures, and the droppings promote land growth. Numbers depend on what part of the chain you are on.

Elton came up with phrases like "food chains" and "food-cycles" and "food-webs." He drew a schematic of these chains with Summerhayes in 1923.

Here are some photos:

https://commons.wikimedia.org/wiki/Fi...

And other chains:

https://www.google.com/search?q=elton...

Elton found out that foxes and owls increased when the lemming population was high and vice versa. There were also forces that could make large populations crash. (Humans some day?) His 1926 book Animal Ecology became a classic written in just 85 days while he worked on it at a breakneck pace.

A pyramid is also formed with the dominant predator at the narrow top. Elton was fond of Chinese proverbs like "One hill cannot shelter two tigers." Predators need to stake out their territory. I can't imagine how much territory a snow leopard needs with its scarcity of food in the Himalayas. Must make it so difficult now to save them.

It was commonly believed, even by Mr. Elton, that lemmings engaged in mass suicide when they overpopulated. There is actually no evidence of that, but the belief persists. The 1958 Disney film White Wilderness showed lemmings leaping off a cliff to their demise. The scene was faked: the animals were flung off the cliff by the filmmakers. The movie won an Academy Award.

"Anything that is found to be true of E. coli must also be true of elephants."--Jacques Monod and Francois Jacob.

Chapter 3: Jacques Monod almost died in a shipwreck. Fortunately, he lived to become a co-founder of the new field of molecular biology. He and his collaborators would discover some of the first general rules of the regulation of life at the molecular level, a feat that would earn him a Nobel Prize.

Monod had to deal with WWII for six years. Then, like the others I mentioned, he asked great questions. Like, How did a bacterium, so tiny it was barely visible in a microscope and without any nervous or endocrine system--just a bag of chemicals inside a membrane--"know" to make the right enzyme for whatever sugar was available? It all came down to "regulation." All life is "governed by longer chains of interactions than we first imagine, with more links in between."

What I find fascinating about all this is how it gets back to us and our feelings of free will. We are also "governed by long chains of interactions." Free will is a feeling not based in scientific reality.

Francois Jacob became Monod's partner and helped him to move further in his discoveries. Together they would crack the logic of enzyme regulation. Monod would famously say, "I think I have discovered the second secret of life." DNA was the first secret of life, and "allostery" would be the second. There would be connections to cancer and why it occurs.

Gradually, these discoveries led to the conclusion that what people eat makes them sick. It led to the use of statins for managing cholesterol.

Chapter 5 deals with Janet Davison Rowley, a pioneer in cancer research. She wanted to establish that cancer was a genetic disease. She took the same approach: find how the rules of regulation have been broken. Leukemia is a disease of regulation. The metaphor is used of a stuck accelerator so a car careens out of control.

Rowley herself was diagnosed with ovarian cancer in 2010. Throughout her treatment, she had biopsies and other samples of the tumor to her colleagues. She died on December 17, 2013. She had pre-arranged her own autopsy so researchers could study the progress of her disease.

For the remainder of the book, the author looks at rules that regulate populations: Chapter 6 about pioneering discoveries in various parts of the world, Chapter 7 about how those rules and a few others operate in the Serengeti, Chapter 8 about places where the rules have been broken, and Chapter 9 and 10 about extraordinary efforts to restore entire ecosystems.

"You push an ecosystem too far and suddenly all the rules change."--Robert Paine.

In Chapter 6 we learn about Mr. Robert Paine, an ecologist who deserves much more popular fame. As a young man, he asked questions like "Why is that tree green?" And then when someone answered "Chlorophyll," he responded, "Why isn't all of its greenery eaten?" Once again, it's the great questions that take these scientists to new places.

Paine discovered that the predatory starfish of Washington and New Zealand were "keystones" in the structures of intertidal communities. He coined the term "keystone species." What a great accomplishment.

He began tinkering with nature to make even more remarkable discoveries. He termed a new phrase "trophic cascades." It showed the cascading effect of the decline of a predator like the sea otter in an ecosystem. Many other examples of trophic cascades are given in the chapter.

Paine summed up his knowledge with a quote from George Orwell's 1984: "Some animals are more equal than others."

Serengeti Rule #1: Keystones: Not all species are equal. Some species exert effects on the stability and diversity of their communities that are disproportionate to their numbers or biomass. The importance of keystones species is the magnitude of their influence, not their rung in the food chain.

Serengeti Rule #2: Some species mediate strong indirect effects through trophic cascades. Some members of food webs have disproportionately strong (top-down) effects that ripple through communities and indirectly affect species at lower trophic levels.

Chapter 7 deals with Tony Sinclair and the Serengeti. Rinderpest was a virus that killed many buffalo and wildebeest. As rinderpest was eliminated, more wildebeest meant more predators, less grass, more trees, fewer fires, more giraffes in a trophic cascade. Fascinating.

Serengeti Rule #3: Some species compete for common resources. Species that compete for space, food, or habitat can regulate the abundance of other species.

Serengeti Rule #4: Body size affects the mode of regulation. Animal body size is an important determinant of population regulation in food webs, with smaller animals regulated by predators (top-down regulation) and larger animals by food supply (bottom-up regulation).

Serengeti Rule #5: The regulation of some species depends on their density. Some animal populations are regulated by density-dependent factors that tend to stabilize population size.

Serengeti Rule #6: Migration increases animal numbers. Migration increases animal numbers by increasing access to food (reducing bottom-up regulation) and decreasing susceptibility to predation (reducing top-down regulation).

Tony Sinclair would be given the nickname "Mr. Serengeti."

Chapter 8: "It is failures in regulation of numbers of animals which form by far the biggest part of present-day economic problems in the field."--Charles Elton.

A major American city needs about 80 million gallons of water daily to survive. That's why Lake Erie and other water sources are critical to the survival of life. The spread of algae in such a lake is an ecological cancer.

Another example of Indonesia where tons of pesticide were used to kill brown planthoppers on rice. The predator of the insect was also killed, so there ended up being more planthoppers!

Another example is given of sharks and their critical role in the environment.

Chapter 9: The study of lakes (limnology) began at the University of Wisconsin in Madison in 1875. Lake Mendota would use some Serengeti Rules to cure some of its ills. To stop algae blooms, scientists who were proponents of trophic cascades proposed increasing predator fish. The result was a success story, and the details are fascinating. One key was that local fishermen supported the scientists and government regulators.

Another success story was the reintroduction of grey wolves at Yellowstone. They are many great videos available on Youtube. Preventing elk from browsing, willows and aspen flourished again.

Chapter 10: Focus on Ken Tinsley's efforts to save Gorongosa Park in Mozambique. Then a civil war drove people to poaching. Man, am I ever sick of revolutionaries. In 2002, Greg Carr came and focused on increasing tourism as a way to save the park. He brought in animals to start again. Important point: he helped the people in the surrounding areas. Want to help? Here's a tip: Buy shade-grown coffee from Mozambique like I do. Carr also focused on law enforcement.

In his Afterword, Carroll suggested some optimistic notes from the book House on Fire by Bill Foege:

1. Global efforts are possible.
2. Smallpox eradication did not happen by accident.
3. Coalitions are powerful.
4. Social will is crucial, and must be transformed into political will.
5. Solutions rest on good science, but implementation depends on good management.
6. The objective may be global, but implementation is always local.
7. Be optimistic.
8. The measure of civilization is how people treat one another.

Here is my negative takeaway as I read that list. It is time to fight back hard against "libertarianism." That ideology has caused more problems, at least here in America.

Enjoyed this book immensely.

[Lauren · Rating 4 out of 5]

3.5 - I was surprised that I actually didn’t dislike this book too much haha. I found the parts about ecology to be very interesting. The book did get boring at times, but I still found parts to be interesting and it had some important messages.

[DiscoSpacePanther · Rating 5 out of 5]

This book is a fascinating insight into the scientific rules that govern populations of things in complex systems, from cancerous cells in the body to the number of wildebeest on the savannah.

I found the author’s writing to be clear, clean and concise, with useful examples to illustrate the phenomena he is trying to explain. The origins of the key concepts in ecology are recounted engagingly, and each part of the book flows logically from the preceding one.

None of the ideas is difficult or heavily theoretical on its own, but the author is very good at showing how simple rules can lead to complex or counterintuitive outcomes.

However, the one criticism I would level at the book is the author’s antediluvian adherence to Imperial measures. A serious scientific work loses credibility whenever it refers to something being a ‘quarter-inch-long’. This book was published more than 15 per cent into the 21st century - is it too much to ask for it to use metric, like the rest of the scientific world?

Despite this one niggle, I would strongle recommend this book to anyone wanting a good introduction to ecological thinking. If you liked Dawkins’ The Selfish Gene or Jared Diamond’s Guns, Germs and Steel, you will probably enjoy this, too.

[Thomas Ray · Rating 4 out of 5]

The Serengeti Rules, Sean B. Carroll, 2016, 213 pp. ISBN 9780691167428

Carroll tells us about how researchers find out how living systems (ecologies or individuals) work—usually by noticing the effects of a change. Change can have unlooked-for effects. We need to know the consequences of changes—and mitigate them.

Introduction:

In 1804, world human population reached 1 billion [up from perhaps 5,000–15,000 after the Tova eruption in Indonesia, 72,000 BCE—but Carroll doesn’t mention it]. Now, we’re adding a billion every 12 years. (p. 5) Ecologists estimate that Earth can sustainably regenerate enough plants and animals to support 4 billion humans. That line was crossed in 1980. The 2016 7-billion-human economy is using up Earth’s resources at about seven-fourths of the rate at which Earth can replenish them. (pp. 8–10) [This gives mass extinctions, mass destruction of unique habitats, catastrophic climate change. But Carroll doesn’t hit that note too hard in this book.]

In 1966, world lion population was 450,000. In 2016, it was 30,000: 40% in Tanzania. Zero in 26 African countries of its 1966 range. Ocean shark populations have fallen 90–99% in these 50 years. (p. 8) In 2016, there were 31 black rhinos in the Serengeti: once over 1000 there.

Chapter 1: effect of emotion on digestion.

Chapter 2: food chains.

Chapter 3: induction of enzyme production within cells.

Chapter 4: statins lower cholesterol, reduce arteriosclerosis deaths.

17,500 feet elevation is the world’s highest permanent human population, on Mount Aucanquilcha, Chile. (p. 73)

Men with cholesterol over 260 mg/dl have 5 times the heart attack risk of men with cholesterol below 200 mg/dl. (p. 76)

Chapter 5. genetic causes of cancers.

Chapter 6: keystone species, without which biodiversity plummets.

A predator may be a keystone species: by preventing one prey species from exploding in population, the predator makes room for many other species. Examples:

Starfish in a tide pool keep mussel populations in check; many other species share the pool. Starfishless pools explode with mussels, excluding everything else.

Bass keep minnows in check, letting plants grow.

Sea otters keep anemones in check, letting kelp forest grow, which harbors a profusion of life. Seals and sea lions provide orcas something to eat besides sea otters, letting sea otters survive. Orcas extirpate sea otters where there are no seals, dooming the kelp forest.

Or, grazers can be a keystone: grazers eat the grass, so there’s less fuel in the dry season, so fewer fires, so trees can grow, so more species can exist that use trees. Dry areas of East Africa with too few grazers have many fires, few trees, few giraffes, few tree-using birds and other animals.

Chapter 7: In the Serengeti (among lions and hyenas), herbivores smaller than 300 kilograms usually die from predation; herbivores larger than 300 kilograms rarely die from predation.

[Hey! /We/ are smaller than 300 kg!! We’re gonna need some fire, sharp sticks, projectile weapons—whatever it takes!!!]

Chapter 8: human food requires keystone species too!

Shark overfishing off the Eastern United States allowed cownose ray populations to explode—which then extirpated the scallops that had been a millions-of-pounds-per-year human food source—down to zero.

Insecticide use killed the spiders that kept the insects from eating all the rice—causing Indonesia to become the world’s largest importer of rice. The insects gained immunity to the pesticides, and increased their egg-laying by a factor of 2.5 in the presence of pesticide. All leading to an 800-fold increase in rice-eating-insect density, without the spiders.

Fewer lions in Africa allowed baboons to explode in population, preying on human crops.

Chapter 9: Reintroducing keystone species.

Lake Mendota in Madison WI: without many bass and pike, small fish proliferated, zooplankton plummeted, and algae proliferated. Reintroduction of large fish (with fishing limits!) kept the small fish in check, allowed the zooplankton to increase, which ate the algae and made the water clearer. Just the reintroduction of big fish wouldn’t’ve done so much, but there was a massive dieoff of small cisco fish in a very hot summer. [Lake Mendota had clear water in the early 1960s, before Cherokee Marsh Subdivision was built—but Carroll doesn’t tell us that. He may not know. Carroll first saw Lake Mendota in 1987; he was at the University of Wisconsin–Madison 1987–2018. He’s now at Maryland. http://biology.umd.edu/sean-carroll.html also http://seanbcarroll.com/about/]

Yellowstone wolves were extirpated in 1926. Seventy years later, 95% of the aspen trees were over 75 years old. Without the wolves, elk proliferated, browsing almost all new trees down to the ground. Wolves were reintroduced in 1995. Ten years after releasing 31 wolves, there were 301. Winter elk population dropped from 17,000 to 8,000 by 2004. Trees are coming back. Beaver rebounded from 1 colony to 12 colonies in Lamar valley by 2009. But beaver have not returned to the streams most heavily eroded during the 70 overbrowsed years. Also, coyotes are down, so small pronghorn antelope are up. Ranchers lose 1% of sheep, 0.01% of cattle to wolves yearly. (pp. 179–180. Update: nps.gov/yell/learn/nature/wolves.htm)

Chapter 10: restoring Gorongosa National Park in Mozambique.

Gorgongosa is so lush it can support some 8,000 kg of animals per square kilometer. (p. 200)

A violent faction in Mozambique expelled the Portuguese in 1975, becoming a violent government. Civil war destroyed the park: animals were slaughtered for meat; forests were cut for fuel.

Restoration was a combination of bringing back extirpated species, anti-poaching and anti-lumbering enforcement, and creating value for local people in preserving the park rather than continuing to despoil it. Locals were hired as law-enforcement rangers; shade-grown coffee was introduced, to earn locals more than they could by deforesting to grow maize; tourism was redeveloped, to give locals employment; hospitals and schools were started. Much of this was funded by a U.S. telecom billionaire [as a tax-free way to remake the world in his image, out of the /interest/ on his wealth. Applause for what he accomplished. Thumbs down on monopoly profit and tax-avoidance.]

Afterword

Smallpox was eradicated in 15 years, from 1965—10 million cases, 2 million deaths, in 59 countries containing 1.1 billion people—to 1980—zero cases. [The virus exists now only in biological-weapons labs in the United States and Russia. What could go wrong?] Smallpox was eradicated by an army of dedicated, imaginative health workers who did not know that experts said it was impossible. See the book, House on Fire, by Bill Forge, for the full story of how it was done. Forge lists 18 lessons from the effort, of which a few:

Global efforts are possible.

We don’t have to live in a world of plagues, disastrous governments, conflict, uncontrolled health risks, pollution, mass extinction, erosion, climate catastrophe. By good management and teamwork, we can bring about a better future.

Coalitions are powerful.

The objective may be global; implementation is always local. Local cultures and needs determine which tactics are successful. The global effort will be the sum of countless local initiatives.

Optimism can be a self-fulfilling prophesy. There’s a place for pessimism, but not on the payroll!

The measure of civilization is how people treat one another.

Sean Carroll adds these:

Nothing gets conquered everywhere at once. Progress is important wherever it can be made.

Don’t wait until everyone gets on board. The experts thought smallpox-eradication wasn’t worth trying. Get started.

Individuals’ choices matter.

So—the book was mostly about ecology; some about physiology and medicine. Carroll’s book titles, and chapter titles, give little clue to what it’s about. It ends well, with the positive message, get together, do what you can.

quiz:
https://www.goodreads.com/trivia/work...

permalink:
https://www.worldcat.org/profiles/Tom...

https://www.goodreads.com/review/show...

[Sara · Rating 5 out of 5]

Well, I finished this book in a week, which tells you how much I enjoyed it!

Certainly, this is a different style from previous Sean Carroll books. I had read Endless Forms Most Beautiful, which was enjoyable, but more convoluted and challenging to read. (But it is an important book given that evo devo is an important development in evolutionary sciences and Carroll is a pioneer in this field).

Apparently, it says in the acknowledgments section that Carroll's editor challenged him to write a shorter book. In addition to being shorter, the book is mostly organized by the accomplishments of different scientists. The narratives make the book very entertaining and less dry. It's a bit more simple to understand with the exception of the chapter on allosteric regulation.

The topic of the book is about regulation and homeostasis in both the human body and ecology; the latter is the bigger focus of the book. I thought the book was very good and a quick read. The methods of regulation and the discovery of biological principles were fascinating (I particularly enjoyed Elton's story, the scientist who basically discovered ecology). I might even introduce this to my biology classes as it fits nicely into a lot of Common Core ideas.

Recommended!

[Adam · Rating 4 out of 5]

I was pleasantly surprised at first when this book bait-and-switched me into reading hours of stories about medicine and physiology. It promises a novel and potentially insightful juxtaposition of ideas, and got me to learn interesting things I might not have picked up otherwise. As a pop history of science writer, Carroll is fine--a bit stiff somehow, but more than adequate. There aren't that many good history of ecology books out there, and this is a fine read in that vein that covers stuff I hadn't learned about elsewhere.

What's more interesting to me is the theory. Carroll posits feedback mechanisms--what I guess might be called cybernetics, though he doesn't use that term--as a universal ruleset for life at all scales. That metaphor, analogy, or model links the first half of the book, which focuses on the enzymes that maintain homeostasis within the body, to trophic cascades in ecosystems discussed in the second half. Of course, to me that raises all sorts of other questions--ecosystem-scale evolution and ecological values more than anything. It's very clear that leaving certain bounds of concentration and temperature in a body are "bad" but much less so in shfiting ecological stable states. Carroll elides all of that. Nearly all of his case studies involve the absence of a predator one way or another, and the release of prey that results, but that has no consistent relationship with the "naturalness" of the system. Whether we're talking about a crop we want to protect, an invasive we want to destroy, or an ecosystem we want to restore, it's the rewilding (not a term he uses but it's the same idea) of the relevant predator that will get it done. The logic here is extremely simple--predators reduce the abundance of prey, and increase the abundance of their prey's food. The way he reframes these observations into "rules" as if they a) they have some inherent value directionality to them and b) apply more or less universally is misleading and corny, a bad blend of ecological insight and normative engineering rule-of-thumb that diminishes both. Like, what does it mean to say that "The regulation of some species depends on their density" is a "rule to live by"? The implied universality is annoying because it leaves some of the biggest questions hanging open: when are these rules applicable and when they're not, why not? What happens instead? etc.

All the interesting questions are in the specifics, and most of the case studies are not presented with enough of their complexities intact to really dig into. The best by far, unsurprisingly, is the Serengeti case study, and I actually really wish this section were much longer or that the whole book had been about it. I remember reading about a lot of this stuff when I was in Tanzania, and never quite being able to wrap my head around it. Some of it did click into place a bit better for me here, though some of that might already have evaporated. Planning to read further into the literature again either way. The most interesting insight for me was the idea that we can predict top-down v bottom-up regulation by body size (part of the answer to that universality issue). But it still only whet my appetite for more rigorous and detailed explanations, especially focusing on the edges of the ecosystems Carroll only barely touches (eg that the population of grasshoppers fell after rinderpest was eradicated and wildebeest returned--what were the consequences for the rest of the insect, bird, etc, ecology of all that??). I also note that niche construction never really comes up. Lotka-Volterra stuff and trophic cascades focus tightly on specific coupled populations and relegate everything else to background, but that doesn't mean it doesn't matter. Curious about how that all works.

[Andrea · Rating 4 out of 5]

A thorough look at checks and regulations that rule natural world. So thorough in fact that I caught myself wondering where the author was going with his line of thought on multiple occasions. However, everything makes sense in the end, so appreciate Carroll being able to juggle so many threads of supporting evidence towards a logical conclusion.

That conclusion made me pause and think for a while. In afterword chapter Carroll uses an example of smallpox eradication as supportive argument for the possibility of many nations uniting together to solve a global problem that used to be deemed impossible, ie. reversing our impact on the environment caused by indiscriminate and irresponsible use of resources. That made the gears in my brain turn. Aren't pandemics a direct result of Serengeti Rules, where large density populations competing for limited resources become victim to disease as nature's way to balance out the books? Here in Alberta we are too familiar with the equivalent pandemics among burgeoning population of coyotes that develop mange. Are we fighting nature in our quest to preserve lives or to extend our life expectancy with our engineered drugs and sanitized way of living? That made me speculate further on cause and effect, as well as moral obligations of population control and our future as ever-expanding species in global environment. Perhaps this book puts humans on a special pedestal, like we are somehow above the Serengeti Rules, but I don't think that's the case at all. I think in a way we prevent nature to balance itself by being simply us. Interesting subject and I recommend everyone to familiarize themselves with it.

[lu · Rating 3 out of 5]

There was a lot of stuff about Biology... which I don't like....
But I liked the start of the book and also the ending:)) I also liked the use of anecdotes and referral to different discoveries at different times.

[Toni · Rating 4 out of 5]

Gut

[Sophia D · Rating 3 out of 5]

The feeling when you read a book for class over the course of an entire semester and you forget if you even liked it or not

[Ushan · Rating 1 out of 5]

The human or any other animal body keeps itself regulated. The pH of blood, the blood sugar concentration, the blood pressure etc. has to be kept within certain limits or the organism will die, so there are physiological feedback mechanisms that ensure this. Cells have to reproduce when they have to; if they reproduce when they aren't supposed to, this is called cancer, and there are also mechanisms to prevent this. The first part of the book tells about the physiologists who discovered these mechanisms.

The second part of the book draws an analogy between the organism and the ecosystem, and tells about the ecologists who investigated food chains and keystone predators, and the conservationists who restored damaged ecosystems in African national parks.

The problem with this analogy is that an ecosystem is not an organism. If an organism fails in regulating itself before or in the middle of reproductive age, it will die without reproducing, so organisms that did a better job will take its place. If an ecosystem lacks keystone predators, it is still an ecosystem: the herbivores will not be preyed upon but they may fall victim to pathogens or parasites. There is a famous story about reindeer being introduced to a small island in the Bering Sea as a food reserve for a Coast Guard station. Lacking natural predators, the deer bred until they ate all the vegetation on the island and starved to death. Yet even without reindeer the island remains an ecosystem with grass, lichens, voles, foxes, seabirds and so on. There is no "every Part was full of Vice, Yet the whole Mass a Paradise" mechanism to keep an ecosystem rich and diverse; there is just the self-interest of each organism, including pathogens and parasites.

[Andrea Norton]

I received a copy of The Serengeti Rules from NetGalley in exchange for an honest review.

When I started reading this one, I did what I usually do: took notes in Word since I don't have a hardcopy to highlight and write in; updated my status on Goodreads; and discussed it with my husband as I went.

Then something happened. I stopped doing all of those things, because I became so engrossed in this book that I forgot to take notes and update my status as I went.

That's how good this is. I admit, I'm what they call a science geek. I have always had a deep interest in ecosystems and why certain things happen to animal communities on our planet. This book answers those questions from a different perspective: humans aren't to blame for every little thing. There is a reason why this species thrives while that one takes a hit in communities, and this book shows why with the evidence to back it up.

I absolutely love the stories included. The backstory to how we got to today in science is another thing that has always interested me, and this book didn't disappoint. There are diagrams and photographs throughout the book. The way it's written by Mr. Carroll made me feel like I was sitting in front of him talking to him, not just reading his words. He talks to the reader as if we're all equal, not like he's better than us because he's spent years doing this study. There were parts that made me cry, laugh and stare in shock.

I recommend this to anyone who likes science in general, but especially those interested in natural science, extinction, ecosystems and animal behavior. I don't think you'll be disappointed in this one!

[Illiterate · Rating 2 out of 5]

I’d suggest the different mechanisms of regulation in ecology and molecular biology mean the relevant theories are analogous rather than continuous.

[Abu Hayat Khan · Rating 5 out of 5]

this book was in a list published last year by physicist Sean M Carroll. interestingly Sean B Carroll is a biologist, I’m not sure if both of them have any family ties or not.

you may have stumbled upon a popular sci-fi doomsday scenario on alien nanobots. it goes like this: an advanced alien civilization can create artificially intelligent nanobots with few simple logic: find any interesting material (hydrocarbon or metals or anything), dismantle the material into its basic constituents, use these constituents to replicate yourself. if such nanobots ever reach our planet, they will devour everything on its path and that would be the demise of human civilization. (for more such scenarios, please see "Life 3.0: Being Human in the Age of Artificial Intelligence" by Max Tegmark)

but if you think for a while, you would realize that bacterias are the ultimate nanobot of nature, but they never do this to human or planet earth.

E Coli bacteria double itself within twenty minutes, with this speed, a single E Coli can bring about a population that weighs as much as the planet earth in just two days. but we never see that happens, not only for E Coli but also for other millions of species of microbial flora.

it was quoted that: anything that is found to be true of E. coli must also be true of Elephants. one may argue that elephants have longer gestation period and they bear few offspring in a lifetime. but, Charles Darwin himself calculated that despite its slow breeding capacity elephant within fifty generation or only within 2500 years would exceed the volume of the earth. so why doesn’t it happens for the elephant either?

Serengeti national park is a UN world heritage lies mostly in Tanzania and least in Kenya. it harbors earth's biggest and the last megafauna in a vast natural grassland (or meadow or Savannah or steppe or tundra whichever name you prefer). this book describes the rules those govern how such a vast ecology regulates itself by the mean of predator and prey, a delicate trophic balance.

US scientist Walter Cannon first coined the term "homeostasis" to describe how various physiological process within human body regulates themselves to maintain an optimal operating condition. later this idea was further extended into molecular biology. Mr. Carroll citing the example of how E Coli switch between glucose to lactose metabolism, how human body regular blood (LDL) cholesterol etc. these all breakdown into something called negative feedback control. apparently, as an organism from E Coli to an elephant, in all biological system homeostasis is maintained through negative logic, there is virtually no positive regulation. he also explained what happens when such negative feedback is broken, the condition is called cancer.

this book is about ecology and its regulation rules: the Serengeti rules. Mr. Carroll tried to demonstrate that the idea of Cannon’s homeostasis is also applicable to Serengeti ecology and to any ecosystem in general. homeostasis of an ecosystem depends on the predators. predator play the role of negative logic in a trophic hierarchy, some apex predators are thus dubbed as the keystone species.

what happens when a negative feedback is removed from an ecological equation? well, it creates ecological cancer. deoxygenation of a lake due to green-blue algae bloom or crop devastation due to pest infestation are the sign of such missing negative logic.

how is the topmost predator population controlled (like the elephants)? this final piece is controlled by economics, formally known as the food chain, it is a bottom-up positive logic. if there is no food, the apex predator population will simply collapse.

what I understand, human as an apex predator can be regulated in two ways. the unfortunate path would be through the economics of ecosystem via the collapse of the food chain, that’s what going to happen with anthropogenic climate change. or through humans good conscious to heed the Serengeti rules.

it is not a good idea for the human to become ecological cancer.

back to alien nanobot, is it possible to build nanobot that overrides Serengeti rules? I don’t think so.

anyway, after listening to this book I want to visit Serengeti (such a cool name).

[Sarah Clement · Rating 4 out of 5]

I was very excited by this book because it brought two key fields together, which I care about a lot. I also like the narrative tool of talking about scientific discoveries through the lens of individual human tales. I enjoyed every chapter, even the ecological ones whose theories and concepts were already so familiar, as I learned more about the people behind the discoveries. The main reason I give this book 4 stars instead of 5 is that it doesn’t bring together the two strands, which is the main thing I thought it would do. In reading the synopsis and the first few chapters, I thought the author would be just the sort of person to bring us big revelations, thinking laterally and having big ideas. I thought he might offer, in this book, some semblance of order in messy environmental science. But I didn’t get that. The last chapter and the afterward did not; as I had hoped, bring the rules together to explain the world we’ve created or even the world we have destroyed. I am not quite sure what it did in the end. I enjoyed it all. I read every word and thought it was all beautifully told, but sadly it didn’t quite live up to its promise. I recommend it, for sure, but be aware that if viewed through one half or the other, it won’t necessarily provide that lateral thinking and subsequent insight you crave. It’s good. It’s insightful. It’s well written. But it doesn’t really provide the ultimate insights into nature or life, as is claimed. Well worth a read nonetheless.

[R Nair · Rating 4 out of 5]

Complex biological systems whether they be regulating the cellular workings of the body or regulating the massive ecosystems of co-dependant species across the planet are actually kept in balance using some simple inherent laws of nature. This book is an excellent introduction to such regulatory laws involving keystone species which shows how important it is to understand ecology on a fundamental level even if you have never been exposed to it before. The book drives in the realization that humans have been wreaking havoc in the natural world because of an unfortunate lack of understanding among folk of how ecological rules regulate the number and kinds of animals and plants in a given place and why these rules are so important.

[Miguel · Rating 4 out of 5]

An overview of how ecological systems work, the Serengeti Rules discusses a range of topics including keystone species, species diversity and the food chain. I would be wholly out of my depth to comment as to whether the ideas put forward here are in the mainstream of this field, but as they’re introduced they seem reasonable. I had read about the Mukkaw Bay experiment (and hope to read more about it in the future) and this book ties that in with its descriptions about how similar trends are seen in differing ecosystems such as Yellowstone to the Serengeti.

[giselle · Rating 4 out of 5]

this was a very good book but sometimes reading it felt more like a textbook than a novel LMFAO but i'd still recommend !! i think it helped me conceptualize macro-level concepts like evolution on a smaller scale, and it had a very cohesive theme while still applying it to so many different scientific discoveries! :)))

[Brady Nitschmann · Rating 5 out of 5]

This book was really unique. I really enjoyed it. People who like ecology and biochemistry will enjoy this book.

[Linda · Rating 3 out of 5]

Hmmm.
So let's see. I liked reading about the Serengeti, not the least of which reasons is because I just two months ago visited the Serengeti and it was as fulfilling and wondrous as you might think. On the other hand, I did NOT like reading the molecular biology chapters because he's matter of fact, supportive, and even enthusiastic about the experiments on animals that discovered these "rules." And I mean EXPERIMENTS... toxicity, induced diseases, wicked shit.
So apart from these extreme personal biases, is it a good book?
Well, now we get to the rules part...the rules are things like "predators determine ecosystem balance as much as food sources" and "there's a connection between your pesticide spraying and more pests."

Because NO FUCKING SHIT, HUMANS!!
I hate us so much.

But yes, you'll learn some things that are valuable.
So, you know, read it. And weep.

[Jade Fanning · Rating 4 out of 5]

honestly for a book that i had to read for class this book wasn’t bad. it gave some really cool examples and case studies of things i’ve learned in biology. and i thought it made some points ive never thought about. pretty good

[Pedro · Rating 4 out of 5]

Amazing book, the last chapters where the author goes deep into ecological rules and systems are incredible. The writting is light and accessible. The only drawback is the middle chapters that were a bit tiring, although they were good.