The Rise and Fall of the Third Chimpanzee: How Our Animal Heritage Affects the Way We Live

I first became aware of Jared Diamond while having lunch in Tampere in the summer of 2001. I was there in Finland for a conference, and one of my lunch companions was raving about Guns, Germs, and Steel. A quick glance at other reviews indicates that's his most revered book; it seems to be an expansion of a single chapter in The Third Chimpanzee. Indeed many if not all of his subsequent books seem to expand on themes he first addressed here. That says a lot about the scope and ambition of Third Chimpanzee.

I was drawn to this book because of its focus on human origins. This is a subject about which I knew little, and I learned plenty here, which was gratifying. But I was surprised by how much more I found here, everything from ruminations on extraterrestrial life to an examination of genocide.

Diamond takes aim at the biggest questions of human existence, and attempts to explicate them with passion and honesty. Occasionally his reach exceeds his grasp, occasionally he doesn't seem to deliver the goods he promises — but only very occasionally. And honestly, if he's half-right about half the issues he takes on, it's still an impressive effort. I found his outlining of the questions at least as valuable as the answers he provides.

Utterly fascinating.

Cuốn sách được xuất bản đã khá lâu (1991) nên nhiều thông tin không còn hữu ích lắm. Ngoài ra, tác giả nhồi nhét rất nhiều kiến thức vụn vặt, với cách viết khá lan man khiến người đọc cảm thấy như không có hồi kết. Những điều này làm cho độ dày của cuốn sách tăng lên đáng kể so với tính thiết thực của nó.

Ví dụ về chương 7 mà mình khá quan tâm là "Tại sao chúng ta lại già và chết đi", với chỉ một nội dung đơn giản là con người (và tất cả sinh vật) đều được tiến hóa để tối ưu cho mục đích sinh sản, tác giả đi lòng vòng hết chuyện xe hãng này sang xe hãng nọ một cách thừa thãi. Sẽ hữu ích hơn nếu tác giả có thể phân tích sâu hơn về mặt tế bào, cơ chế sinh học, gen hay các hóa chất ảnh hưởng điều đó. Vấn đề này cho tới ngày nay vẫn là một điều lý thú đối với các nhà khoa học.

Rồi đến chương 11 bàn về việc con người hút thuốc, uống rượu. Tác giả đưa ra một suy đoán và so sánh việc này tương tự như việc những con chim có bộ lông sặc sỡ như một cách thể hiện khả năng sinh tồn để thu hút con cái (mặc dù với con người thì nó chả có tác dụng như vậy). Cách so sánh này có vẻ khá khập khiễng và không thuyết phục. Con người tiêu thụ những thứ đó phần lớn là do tò mò và sau đó nghiện.

Nhìn chung thì tác giả đã cố đi quá rộng so với kiến thức của ông, khiến những luận điểm có những lỗ hổng và thiếu tính thuyết phục. Sẽ tốt hơn nếu ông chỉ cô đọng và tập trung vào một số vấn đề liên quan đến sự "tiến hóa của con người" (như tiêu đề của cuốn sách), điều mà tác giả chưa khiến người đọc thỏa mãn với những gì ông đem lại trong cuốn sách.

Cuốn sách này cũng tương tự như "Sapiens: Lược sử loài người", với mình thì cuốn sách của tác giả Yuval Noah Harari hữu ích và hấp dẫn hơn. Hi vọng những cuốn sách sau này của tác Jared Diamond sẽ có nhiều thú vị.

I was unimpressed as I had read so many other books on the same, or on similar topics, nevertheless, this book can serve well as good framing for those interested in anthropology in its lens of human evolution.

The one idea I saw discussed here which is often neglected is the idea of human cultural elements existing within animals. That is really freaking cool and I would love to see a book handle that topic in more depth. If you have any recommendations lemme know.

I recommend this for those who liked books like sapians, the selfish gene, the moral animal and books of the kind, this will help you gain some more depth in your understanding of humanity.

Having been on a evolutionary biology and history trip of late, I couldn't resist revisiting this 1991 classic by Jared Diamond. It is a good introduction to his favorite subjects that get fuller treatment in Guns, Germs & Steel and Collapse.

Part One (Just Another Species of Big Mammal) focuses on the evolutions of primates and the split between apes and monkeys and the further splits down the line between gorillas, chimpanzees, and finally homo habilus, homo erectus, and homo sapiens. This is the strongest part of the book, discussing the incredibly similar genome between chimpanzees and humans, which share 98% of their DNA. It posits that the development of language triggered the Great Leap Forward that gave homo sapiens the edge against the larger, stronger Neanderthals in the struggle for survival, especially in their ability to collaborate in hunting and communicate complex plans and concepts.

Part Two (An Animal With a Strange Life Cycle) discusses the sexual behavior of humans from an evolutionary perspective. It dives into the previously taboo subject of the potential evolutionary rationale for adultery, as a means for males to spread their genes as far as possibly, while on the flip side women (mothers) seek a stable mate to provide sustenance for themselves and their children in a monogamous relationship, and the inevitable friction this causes in modern couples. It also discusses the seeming evolutionary disadvantages of humans vs other animals: female menopause, having only 1-2 babies at a time and only after reaching the teenage years, and living beyond a reproductive age. The answers are thought-provoking and well extrapolated.

Part Three (Uniquely Human) discusses the development of human language; the animal origins of art and its function in modern humans; the mixed blessings of adopting a sedentary, agrarian lifestyle rather than being roving hunter-gatherers; why human beings exhibit the seemingly self-destructive behavior of smoking, drinking alcohol, and taking drugs; and how likely we are to be alone in the universe. The section on the agriculture vs hunter-gathering is fascinating and gets much more detailed treatment in Guns, Germs & Steel.

Part Four (World Conquerors) is one of the most interesting sections, detailing the influence of environmental factors in the different rates of technological development among different cultures on different continents, which was the centerpiece of Guns, Germs & Steel. Here he discusses how the domestication of native edible grains and animals such as horses, pigs, cows, and sheep provided the nutrition and energy for Eurasian peoples to conquer and dominate other societies that lacked advanced weapons like guns and cannons, lacked horses to form cavalry, which afforded a massive advantage in warfare, and also the proximity to domesticated animals also exposed Eurasians to myriad animal diseases that then allowed them to develop immunities that New World people lacked, leading to disastrous epidemics after contact. This section also details the spread and dominance of Indo-European languages over other languages, which reflected the population movements over the past few millennia.

It also contains one of the most disturbing chapters in modern human history, the systematic extermination of the aboriginal blacks of Tasmania by Australian white settlers, and the various religious and cultural superiority beliefs that allowed them to justify genocide. The actual excuses provided for hunting down and killing natives that were viewed as barely human is pretty stomach-turning from a modern perspective, but is detailed without holding back. He then expands on the long and repeated ethnic genocides in human history during the 1492-1900 and 1900-1950 periods. I think this should be required study for high school or university students to remind us all the atrocities humans are capable of, and why we need to curb our worst instincts to demonize and dehumanize “others”.

Part Five (Reversing Our Progress Overnight) is another sobering chapter that is a precursor to his book Collapse. Diamond details in lucid and unblinking details the numerous waves of extinctions that have happened on the Earth over many eras including the dinosaurs, and then the waves of extinctions directly caused by the explosion in global human population and our destruction of animal habitats and spread across the planet. It also talks about our ability to destroy ourselves overnight via nuclear holocaust, and how on our present path we are likely to exhaust our resources and multiply till the point of ecological collapse. It’s pretty disturbing reading, but very convincing as well. Again, if all students could read this book, they would have a greater sense of urgency that we need to change the path of human civilization if we want to avoid disaster and collapse.


Recommended reading for evolutionary biology and historical anthropology:
1. The Selfish Gene, The Blind Watchmaker, The Ancestor's Tale, The Greatest Show on Earth - Richard Dawkins
2. The Third Chimpanzee, Guns, Germs, and Steel - Jared Diamond
3. Sapiens: A Brief History of Mankind - Yuval Noah Harari
4. Before the Dawn: Recovering the Lost History of Our Ancestors - Nicholas Wade
5. The Human Instinct - Kenneth R. Miller

Excellent. I'm giving it four stars instead of five only because from the vantage of 2014 its age shows, mainly in the absence of some information learned since it was written about the Neanderthals and the similar but then-unknown Denisovan people - specifically, the presence of small amounts of Neanderthal and Denisovan DNA in the modern human gene pool - and in the absence of that knowledge, the author makes some assumptions about our history with those other peoples that are incomplete at best; but the book is impressive in its accurate anticipation of the situations of the present and probable future.

The title is based on our very close genetic links with the two species normally called chimpanzees, i.e. the 'common' chimp and what Diamond calls the pigmy chimp, normally referred to now as the bonobo. Any other species as closely related to those two as we are would be recognized as simply a third type of chimpanzee by naturalists, hence the title.

But this book is not only about our species, but about the environments that have shaped us and how we in turn began shaping the rest of the natural world, usually unintentionally but no less powerfully, once our numbers and technology made that possible, starting with humankind's probable role in the mass extinctions of large animals wherever we showed up and continuing through today's problems of climate change, overfishing and -hunting, introduction of invasive species, and habitat encroachment. The threat of nuclear war is in there, but Diamond accurately predicted that it would become less likely as the catastrophic consequences of environmental devastation grew more visible and irreversible.

Informative, thought-provoking, often funny - I recommend this strongly to anyone interested in human history and prehistory and our relationships with the places and the other life forms on our planet.

As I began reading The Third Chimpanzee, a little voice in my head told me that I should stop reading books by Jared Diamond. His subsequent three popular science books all have their origins in this one; I began with n  Guns, Germs, and Steeln and then read Collapse. So reading The Third Chimpanzee was sort of like getting a summary of those two books, plus the one I haven't read yet. Thus, I sought out to determine if the latter books suffered because they were too long an exploration of Diamond's ideas, or if they are superior to his original formulation of arguments concerning those three subjects. The shocking answer will soon be revealed!

Caveat: parts of this book are now dated, as it was written nearly twenty years ago. Hence, while I usually find Harper's "P.S." sections boring, this one was useful because it allowed Diamond to update us on some of the advances in science and historical discoveries since the book was first published.

My reaction to this book is probably the most mixed reaction I've had to any of Diamond's books thus far. As the aforementioned "P.S." author interview says, Diamond's life as a modern scientific polymath stems from a desire not to be confined to "one tiny slice of life's palette." He began as a physiological researcher and has since distinguished himself for writing on subjects like ornithology, anthropology, history, and geography, earning him the title of "biogeographer." I applaud Diamond for his varied interests and ability to apply those interests and synthesize an argument about human development from multiple disciplines. However, it's important that the reader remember that Diamond isn't a geneticist, astronomer, anthropologist, etc. And sometimes, he overreaches himself when attempting to apply his considerable life experience to his arguments. Oh, and he also tries to be witty and . . . well, once and a while it works, but most of the time his attempts at humour fall flat.

In Part One, Diamond begins by examining how we differ from our closest relatives. There's a fancy chart that shows the estimated dates of evolutionary divergence from common ancestors (gibbons and orangutans split off earlier, then gorillas, then chimpanzees and humans finally went their separate ways around 7 million years ago). Still, the human genome and chimp genome are 98 per cent similar, and Diamond argues that this is enough of a similarity that humanity should constitute the "third chimpanzee." He then postulates that the rise of complex spoken language was the cause of the anthropological "Great Leap Forward" that allowed humans to begin developing the behaviour required for societies to arise. This is the "teaser" part of the book, in which Diamond whets our appetite for details he'll later reveal. He also makes a one-off attempt to plead for the cessation of medical experimentation on chimpanzees, implying that because we are—in his view—of the same genus, it's just as bad as experimenting on humans. Regardless of one's views on the subject, Diamond raises an interesting point . . . and then doesn't return to it at any subsequent moment in the book.

Next, Diamond looks at humans' anomalous "life cycle" compared to the rest of the animal kingdom, particularly primates. Humans are the only primates in which the women go through menopause and cease being fertile. Chimpanzee males have larger testicles than human males because chimpanzee males mate so frequently they need the extra sperm, but most couplings last only seconds! I've always been interested in how our different sexual characteristics have helped humanity rise to its present status on the planet, so I loved this part of the book. Furthermore, unlike some later parts, Diamond remains on firm ground when he seeks evolutionary explanations for human sexual behaviour.

That ground becomes progressively shakier in Part Three, perhaps the worst of the five parts to Diamond's book. Here, he examines aspects of human society that are uniquely developed—the two most notable examples are art and drug abuse. Unfortunately, Diamond over-extends his attempts to explain these behaviours purely from an evolutionary perspective. Is this because evolution can't solely explain them? Or is this merely a failure on Diamond's part as thinker? It's a little of both, in my opinion: Diamond is great at synthesizing disparate sources of information to create a compelling thesis; unfortunately, as he does so, he tends to get somewhat reductionist in his perspective. While his argument is not wrong, it is at the very least incomplete, which still makes it flawed.

I was annoyed when, in the chapter on extraterrestrial life, Diamond began to explain why it's not necessarily likely that an advanced species would develop radio:

You might object that I'm being too stringent in looking for early precursors of radios themselves, when I should instead look for just the two qualities necessary to make radios: intelligence and mechanical dexterity. But the situation there is little more encouraging. Based on the very recent evolutionary experience of our own species, we arrogantly assume intelligence and dexterity to be the best way of taking over the world, and to have evolved inevitably.

Now, I actually agree with the latter part of that quotation. The fact that, on Earth, so far humans are the only form of life to have developed what we term "intelligence" indicates it may not be the only path to global domination. After all, prior to their extinction, the dinosaurs ruled the Earth, and they were certainly dumb by our standards. Still, Diamond is short-sighted; he wrongly assumes that intelligence or dexterity are prerequisites to leveraging radio. They're prerequisites in the invention and construction of mechanical radio transmitters and receivers, sure. "Radio" itself is a medium; radio waves constitute part of the electromagnetic spectrum of radiation. Just as many species have independently evolved eyes to see visual light (and some species can see into other spectrums), what's to stop a species on another planet from evolving a radio transceiver organ? Perhaps the absence of any such creature on Earth would make such an evolutionary development unlikely, at least on Earth-like planets. However, not every habitable planet has to be exactly Earth-like. Maybe there exists conditions on another planet where the evolution of biological radio makes sense. This is a totally hypothetical, spontaneous scenario, but I hope it demonstrates my problem with Diamond's reasoning. In an effort to produce the best arguments possible, he often generalizes or focuses too narrowly on subjects beyond his best areas of knowledge.

In Parts Four and Five, Diamond explores the seeds of the ideas that would turn into two of his later books, Guns, Germs, and Steel and Collapse. Since I've already read these books, I have to admit I skimmed a great deal of these sections. The chapter on language was interesting, but I had already learned much the same from the more recent n  Before the Dawnn. If you read a great deal of anthropological non-fiction, you too may find these sections less-than-fascinating. The one exception is Chapter 17, "The Golden Age That Never Was."

Thank you, Mr. Diamond, for that chapter. It irks me to no end when I hear someone talk about the "good ol' days" of human society, some sort of pastoral paradise where everyone was happy and we experienced no strife. The idea that simpler times were better times is a myth, one that Diamond thoroughly discredits in this chapter. He shows us that people, for the most part, have perpetrated the same sort of acts in the past as we see happening now—the difference is one of degree. Modern technology allows us to expand the scale and speed with which we create problems, making us more efficient at marshalling chaos. Unfortunately, Pandora's box has been opened, and there's no going back. Diamond comes to the same conclusion and so focuses on what hope we might have for the future of our spaces, however slim.

As with Collapse, Diamond broadcasts a message of cautious optimism. We may be able to survive, provided we as a society "choose" to begin living in a way that's more sustainable. He's vague on the details, claiming that his book is "an analysis" of our problems rather than a laundry-list of potential solutions. The solutions, he maintains, are already well-known; we just have to choose to implement them. While that sort of rhetoric isn't very appealing to me, I understand Diamond's difficulty in writing prescriptions. Nevertheless, that call for optimism is less effective in such an unhelpful context.

Right from the start of The Third Chimpanzee, Diamond was up front about his mad love for New Guinea and its peoples and his opinion that it's somehow a microcosm for the development of society. Those who have read my review of Guns, Germs, and Steel know how I got tired of hearing that line. Paradoxically, the New Guineans feature more heavily in this book, but I found their inclusion both more tolerable and more interesting. I actually learned things about New Guinea that made me exclaim, "Oh, that's cool!" rather than roll my eyes and snort, "Right, OK Diamond. Whatever you say." My experience with The Third Chimpanzee has therefore provoked the least amount of sarcasm from me regarding Jared Diamond's writing. It is both the best and the worst of his work: where it is flawed, it is more flawed; where it is useful, it is far more useful. If you read one Jared Diamond book, this should be the one.

And there's the rub. It's difficult to write popular science books. There's a fine line between intelligent and esoteric, between academically rigorous and overly-complicated. Diamond has undertaken a challenge, and for that I respect him; at least he isn't writing puff pieces. For the majority of people, The Third Chimpanzee is worthy of dinner table conversation or book group discussion; it's a great starting point in the quest to read anthropological non-fiction. It is not the culmination of that quest, but a stepping stone along the way to more rigorous, more intense non-fiction on this subject. And that's all it can be.

Presently, there are: 1. the pygmy chimpanzees of Zaire; 2. the chimpanzees of the rest of tropical Africa; and 3. us, “humans.” We are the third chimpanzee. We share 98.4% of our genes with the first two kinds of chimpanzees. This is because all these three chimpanzees had evolved, in millions of years, from a common ancestor, most likely a fascinating tree-dwelling creature some of whose many descendants had gone extinct but some left the trees, learned to walk in their two feet. and eventually became us.

I had imagined, while reading this book, if we managed to evolve in the same manner that we are now except the gait and posture so that we’ll be lumbering about like our surviving chimp cousins. Had that been the case, Adidas and Nike would not only have a footwear line, but a handwear line as well, probably glove-like, to protect our hands as they touch the ground or grasp things as we climb or hang about. Fashion would of course be very much different too. No plunging necklines for women as their breasts could easily pop out in a chimp-like locomotion. Architecture would not also be the same. Maybe there’d be no stairs in buildings but trellises and rope which we can us going up and down or sideways.

But these may not have been possible, really. It is said that our ability to walk upright on two feet, which freed our hands to make and use tools, greatly contributed to the enlargement of our brains—spelling the difference now between us and the present chimpanzees.

Nevertheless, we are still animals. This explains practically all our behaviour from the altruistic to the destructve. We cannot escape our true, lowly past.

::انطباع عام::
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رائع بكل معنى الكلمة. لا أستطيع كتابة مراجعة وافية عن هذا العمل الجبار لجاريد دايموند، الذي أتشوف لقراءة كتابه الحائز على البولتيزر: أسلحة، جراثيم، وفولاذ : مصائر المجتمعات البشرية. هذا الرجل موسوعة. وطريقة كتابته تجمع بين المعلومات الغزيرة والأسلوب الفياض بالجمال. ربما يجعلك تعشق المواضيع البيولوجية ويستحث فضولك للبحث أكثر وأكثر في دهاليز هذا العالم خصوصًا عندما تتحد البيولوجيا مع الأنثروبولوجيا.
طبعًا لن أكون قد أفسدت الاستعارة في العنوان على من يريد قراءة الكتاب لو قلت من المقصود بالشمبانزي الثالث! ولكن للمفاجأة، إنها ليست استعارة؛ وربما يكون سقوط هذا الشمبانزي من نذائر تشاؤم صاحب الكتاب أو خوفه لكي نتدارك أنفسنا قبل السقوط الحقيقي.
جدير بالذكر، أشيد بترجمة زياد العامر الرائعة ذات الأسلوب العلمي الرصين، وكذلك للإخراج المتميز من دار التكوين خصوصًا غلاف الكتاب الذي يدل على عبقرية مصممه في استخدام أيقونة صورية فوق حرف الطاء، وخلفية الوجوه السيلوليتية الثلاث التي تمثل الشمبانزي الشائع، والشمبانزي القزم، والشمبانزي الثالث.
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::في سطور::
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1_ الشمبانزي الثالث: تطور الحيوان البشري ومستقبله هو كتاب صدر عام 1991 للمؤلف الأكاديمي والعلمي جاريد دايموند، يعرض فيه المؤلف المفاهيم المتعلقة بالأصول الحيوانية للسلوك البشري. كما يتبع الكتاب سلسلة من المقالات التي نشرها دايموند إذ يفحص الأدلة وتفسيرها في المعالجات السابقة للأنواع ذات الصلة، بما في ذلك الخصائص الثقافية أو السمات التي غالبًا ما تعتبر فريدة من نوعها للبشر. تم إصدار الكتاب في المملكة المتحدة بعنوان بديل: صعود وسقوط الشمبانزي الثالث: كيف يؤثر تراثنا الحيواني على الطريقة التي نعيش بها بينما نشر في الولايات المتحدة تحت عنوان الشمبانزي الثالث: تطور الحيوان البشري ومستقبله. نشر دايموند نسخة معدلة للشباب بعنوان الشمبانزي الثالث للشباب.

2_ يطرح دياموند القضية حول كيفية سيطرة الإنسان العاقل على أقرب أقاربه، مثل الشمبانزي، ولماذا تمكنت مجموعة من البشر (أوراسيا) من السيطرة على مجموعات أخرى (الشعوب الأصلية في الأمريكتين). وفي الإجابة على هذه الأسئلة، يطبق دياموند مجموعة متنوعة من الحجج البيولوجية والأنثروبولوجية لرفض وجهات النظر التقليدية التي تقول إن الشعوب المهيمنة جاءت من سلالة وراثية متفوقة، ويزعم بدلاً من ذلك أن الشعوب التي هيمنت على الآخرين فعلت ذلك بسبب المزايا الأداتية الموجودة في بيئتها المحلية والتي سمحت لها بتطوير أعداد أكبر من السكان، ومناعة أوسع ضد الأمراض، وتقنيات متفوقة للزراعة والحرب.

3_ كما يدرس الكتاب كيف يتم حل عدم التماثل في سلوك التزاوج بين الذكور والإناث من خلال الهياكل الاجتماعية المختلفة عبر الثقافات، وكيف أن الاتصال الأول بين الحضارات غير المتكافئة يؤدي دائمًا تقريبًا إلى الإبادة الجماعية. وينتهي الكتاب بالإشارة إلى أن التقدم التكنولوجي قد يتسبب في تدهور البيئة على نطاق يؤدي بالنوع كله إلى الانقراض.
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::الكتاب::
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1_ الجزء الأول: مجرد نوع كبير من الثدييات
يشير عنوان الكتاب إلى مدى التشابه التصنيفي بين الشمبانزي والبشر، حيث تختلف جيناتهم بنسبة 1.6% فقط، في حين يختلف الشمبانزي والغوريلا بنسبة 2.3%. وبالتالي فإن أقرب أقرباء الشمبانزي ليس القردة الأخرى التي يتم تصنيفها معها، بل البشر. في الواقع، فإن الاختلاف بين الشمبانزي والإنسان أصغر من بعض المسافات داخل النوع: على سبيل المثال، حتى الطيور ذات الصلة الوثيقة مثل طيور الأخيضر ذات العيون الحمراء والبيضاء تختلف بنسبة 2.9%. بناءً على الاختلافات الجينية، يجب التعامل مع البشر كنوع ثالث من الشمبانزي (بعد الشمبانزي الشائع والبونوبو). أو ربما يجب أن يكون الاسم العلمي للشمبانزي هو هومو تروغلودايتس بدلاً من بان تروغلودايتس. يلاحظ دايموند في كتابه أن هذا من شأنه أن يوفر غذاءً للفكر للأشخاص الذين يمرون بهذا الجانب من قضبان القفص بحديقة الحيوان الذي يحمل علامة (هومو).

2_ الجزء الثاني: حيوان ذو دورة حياة غريبة
يتناول هذا الجزء التباين الجنسي بين الثدييات، وخاصة البشر، وآليات الانتقاء الجنسي. ويتناول كيف أن الإناث في مختلف الأنواع أكثر حرصًا على اختيار شريكهن من الذكور (فهن يستثمرن قدرًا أعظم من الطاقة في كل نسل). وهذا يحدد قدرًا كبيرًا من السلوك البشري: كيف نختار شريكاتنا، وكيف ننظم المجتمع وأنظمة رعاية النسل، الأمر الذي يؤدي إلى نشوء هياكل اجتماعية مختلفة في ثقافات مثل بابوا غينيا الجديدة، وكيرالا. ويتناول أيضًا قضايا طول العمر ــ فالجيل السابق يموت لأن ساعته البيولوجية تغلق عملية التمثيل الغذائي والإصلاح من أجل تحويل الاستثمار من الفرد الوالد إلى استثمار النسل.

3_ الجزء الثالث: البشر المتفردون
يمتد هذا الجزء ليشمل تأثيرات الانتقاء الجنسي في اللغة والفن والصيد والزراعة، من خلال فكرة الإشارات الصادقة ـ الإشارات الجنسية التي تكلف أيضًا من يوجهها. ويستند هذا إلى تفسير جاذبية المخدرات وتعاطيها. كما يناقش إمكانية الاتصال بحضارة ذكية خارج كوكب الأرض (ويعتقد دايموند أن هذا من شأنه أن يكون كارثة).

4_ الجزء الرابع: غزاة العالم
إن هذا السؤال يطرح نفسه الآن: لماذا تمكن الأوراسيون من غزو الثقافات الأخرى؟ إن إجابة دياموند هي أن هذا يرجع جزئيًا إلى تخطيط القارة الأوراسية من الشرق إلى الغرب، والذي سمح بتبني حزم ناجحة من الاستئناس الزراعي والحيواني (مزيج من بعض النباتات والحيوانات المستأنسة) في مناطق أبعد شرقًا أو غربًا. ومن ناحية أخرى، كان توسيع حزم الاستئناس على طول المحور الشمالي الجنوبي ــ كما هو في حالة القارتين الأميركية والأفريقية ــ أكثر صعوبة بسبب الاختلالات المناخية الشديدة. كما أن الاتصال الطويل الأمد بالحيوانات المستأنسة في المجتمعات الزراعية يسمح بمقاومة أكبر للأمراض، وهو سبب آخر يجعل الاتصال بين الثقافات المنفصلة جغرافيًا ــ معظمها مجتمعات زراعية مقابل مجتمعات الصيد والجمع ــ يؤدي غالبًا إلى انقراض هذه المجتمعات من خلال العدوى المدمرة. ويتم فحص عملية الاتصال الأول بين الحضارات المختلفة من خلال أوصاف سكان المرتفعات في بابوا غينيا الجديدة، الذين زاروا المنطقة لأول مرة قبل نصف قرن من الزمان. من الناحية التاريخية، يزعم دايموند أن مثل هذه الاتصالات بين السكان المختلفين على نطاق واسع كانت تؤدي في كثير من الأحيان إلى انقراض المجموعات مثل العديد من قبائل الهنود الحمر، والتسمانيين، إلخ. وهناك قائمة طويلة من الإبادات الجماعية في التاريخ. جدير بالذكر أن القضية حول سبب غزو بعض الحضارات لحضارات أخرى هو الموضوع الرئيسي لكتاب اللاحق أسلحة، جراثيم، وفولاذ : مصائر المجتمعات البشرية

5_ الجزء الخامس: النكوص في تطورنا بين عشية وضحاها
وهنا يتلخص الجدل في أن الحضارات تنشغل أحيانًا بمنافسات التفوق الداخلي، فتستنزف البيئة إلى الحد الذي قد لا تتعافى معه أبدًا. ومن الأمثلة على ذلك جزيرة إيستر وأطلال البتراء، وكلاهما نتيجة لإزالة الغابات مما أدى إلى التصحر. جدير بالذكر أن القضية حول سبب انهيار بعض الحضارات وبقاء حضارات أخرى هو الموضوع الرئيسي في كتاب دايموند: الانهيار : كيف تحقق المجتمعات الإخفاق أو النجاح
يتبصّر دايموند مدى قربنا من الكارثة التي قد تنجم عن تدمير بيئتنا العالمية، وكيف قد يكون من الممكن أن نشهد محرقة نووية في المستقبل. ويحذر من أن محرقة بيئية قد بدأت بالفعل، وأن إصلاح الضرر الذي لحق بها أصبح أكثر صعوبة. ورغم أن النهاية قاتمة إلى حد ما، فإن الخاتمة تذكرنا بشكل صارخ بكيفية تدمير حروبنا الداخلية في مجتمعنا العالمي الأوسع للوطن الوحيد الذي نملكه جميعًا.
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