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aries1988 : evolution   32

Last hominin standing – charting our rise and the fall of our closest relatives
Through genome sequencing, we now know that chimpanzees are our closest living relatives, sharing nearly 99 per cent of our DNA. But in the roughly 7 million years since our ancestors split from chimps, Homo sapiens has existed alongside a wide variety of closer evolutionary cousins. This video from the American Museum of Natural History tracks scientists’ current best guess at a timeline of hominin species, including when and where they lived, and how extinctions and interbreeding led to Homo sapiens becoming the last hominin on Earth. And yet, due to gaps in the timeline and continued fossil discoveries, it seems we've found only fragments of our evolutionary past, leaving much still to be learned about our family tree.
video  human  origin  evolution 
january 2019 by aries1988
Why language might be the optimal self-regulating system – Lane Greene | Aeon Essays

Now we don’t often need a word for destroying exactly a 10th of something – this is the ‘etymological fallacy’, the idea that a word must mean exactly what its component roots indicate. But it is useful to have a word that means to destroy a sizeable proportion of something. Yet many people have extended the meaning of decimate until now it means something approaching ‘to wipe out utterly’.
language  research  english  pronunciation  evolution 
december 2018 by aries1988
Stretch Genes

the genomes of various human beings fall into several reasonably well-defined clusters when analyzed statistically, and these clusters generally correspond to continent of origin. In this statistical sense, races are real.

To Wade, the implications are big. While behavioral differences among races would surely be subtle, they can, he insists, become amplified at the level of entire societies. Slight differences in behavioral predisposition—to cooperation, aggression, trust, propensity to follow rules, and so on—probably pushed different races in directions that led to different social institutions. Indeed the seeds of difference between the world’s great civilizations were perhaps present from the first settlements.

the evolutionary psychologist Steven Pinker. (Evolutionary psychologists, while acknowledging that human behavior has a partly genetic basis, generally assume that all people share the same predispositions. They then try to explain these human universals.)

This sends Wade into paroxysms of righteous indignation and he declares that whether or not a thesis might be politically incendiary should have no bearing on the estimate of its scientific validity. What Wade doesn’t tell you is that this is what Pinker himself says in his very next sentence: The fact that a hypothesis is politically uncomfortable does not mean that it is false, but it does mean that we should consider the evidence very carefully before concluding that it is true.
book  critic  gene  human  race  biology  political  opinion  debate  society  evolution  racism 
october 2018 by aries1988
专访余英时:中国现代学术“典范”的建立

在《余英时作品系列总序》中,余英时先生自陈:“我的专业是十九世纪以前的中国史,就已发表的专题论述而言,大致上起春秋、战国,下迄清代中期,所涉及的方面也很宽广:包括社会史、文化史、思想史、政治史、中外关系史汉代等。”但诚如其所言,他涉猎广泛的研究也不是无的放矢,“我自早年进入史学领域之后,便有一个构想,即在西方(主要是西欧)文化系统对照之下,怎样去认识中国文化传统的特色。”

微观相当于考证,即对于具体历史事实做最彻底的考察和阐释,但这样的工作往往只见个树木而不见森林。因此在历史研究中,宏观绝不可少。宏观相当于孟子所谓“观其大”,其涵义比宋学所谓“义理”要丰富得多,这是“见森林”的必经之路。但“见森林”又不能不看清楚林中一颗颗的树,否则便不免如傅斯年的名言所说,可能将天际浮云当作森林了。

有关我研究中国史的构想所在,简略概括:在西方现代文化及其发展出来的普世价值挑战之下,我们怎样才能认识中国传统文化的特色?我认为只有抓住了它的特色,我们才能够认识中、西文化的异同,并进一步追问,中国文化中有哪些成分和现代普世价值是互相冲突的?哪些是可以互相呼应的?

我研究中国史特别选择变革时代的独特动态。因为这种独特动态最能显示出精神价值的流变。

已故陈荣捷先生毕生在美国介绍中国哲学和思想。他曾说,如果用一个词字来概括全部中国哲学史的话,那个字便是“人文主义”。这句话在西方已被普遍地接受了。陈先生的人文主义当然是指中国文化对“人”的尊重,尤以儒家为最显著。孔子的“仁”便是“人道”,孟子强调人性善,又特别提醒“人之异于禽兽”,更是把人的尊严提升到最高的地位。所以“天地之性人为贵”成为中国人的共同信仰。稍稍认识西方近代文化史的人都知道,“人文主义”兴起于文艺复兴时期的意大利,当时人文主义者特别倡导人的尊严和人在宇宙中的独特地位。这种人文主义的精神稍后进入西方教育界,塑造了西方现代的独立人格,其影响一直延续到十九世纪。西方自由和民主的成长得力于人文主义教育,无人不知,就不用再说了。

中古时期,由于种种原因,希腊文学传统已在意大利地区消失无踪,既无人讲授,也无人研究。直到十三四世纪以后,意大利人文学者才逐渐从法国图书馆中发现希腊文稿,包括荷马史诗的原稿之类,终于酿成了“文艺复兴”运动。这是文化价值失而复得的一个最伟大的史证。中国经史子集的典籍俱在,何况,当年在传统精神价值中成长起来的先一辈人,早就在有意无意之间把他们的价值意识传到下一代身上。所以“守先待后”决不是一种幻想。

1949年以后的大错误,不在其为“进步史观”,而在其“定于一尊”。

西方的思想界是开放的,种种不同的史观都出现过,其中还有反“进步”的史观大行其道的,如斯宾格勒(Oswald Spengler 1880-1936)的《西方的没落》(The Decline of the West)和汤因比(Arnold J Toynbee 1889-1975)的《历史研究》(A Study of History)

今天很少人还相信有什么普遍规律为各民族或文化所共有;更不相信西方是先走上“现代”阶段,其他各民族落后了一步,但最后也会赶上来。换句话说,现在不存在什么“进步史观”足以构成“挑战”的对象了。
confucianism  chinese  tradition  culture  crisis  evolution  west  book  leader  intelligentsia  taiwan  dissident  instapaper_favs 
october 2018 by aries1988
內亞海洋與帝國秩序(一):豐饒之海 – Zhongjing Liu | 劉仲敬 – Medium
人类的文明,我把它解释成一个规则生成和演化的过程。

真正规则产生的地方,就是我发明了一个名词叫「原始丰饶」来称呼它,很大一部分,甚至大部分,都产生在人类文字和文明以前的时代。为什么会产生在这个时代?照列维·斯特劳斯的解释,恰好就是因为文字和文明的产生,导致了管制系统的加强,因此原先在无文时代,比较自由而多元化的演化,在文明和管制体系产生以后,反而变得缓慢和单一了。

文字产生以后,唯一产生的东西就是官僚制度和国家制度,而发明的速度反而是减慢了。

如果你把世界看成是一种达尔文式的生态演化产物,那你就可以看出,规则在什么情况下能够最大限度的产生和演化。它应该是多元的,应该存在着许多个彼此之间相对孤立的小生态环境,局部规则在这样的小生态环境中间,能够充分的产生,在它产生做大以前,不会受到太多的干涉。它要有一定流动性,但是流动速度是有限的和缓慢的,也就是说,不同的小生态环境,以及各种不同的局部规则,要通过相互渗透接触和碰撞,不断地深化和演进。但是,速度不能快到席卷一切的地步。

这种环境之是不利于规则复杂度的演化的。

文明的核心区,表面上看是最繁荣,光华最盛的地方,恰好是消耗得最厉害的地方。

分为三种在时间上有交错,但是先后顺序还是很明显的类型:高地型,湿地型和草原型。

回顾文明最初产生的状态

一般人理解的文明,就是第二种类型的文明,在湿地建立起来的文明。一般来说这种文明能够供最大量的人口,可能人类的80–90%以上,都是来自于这种湿地的人口,能够建立起大帝国和强大的官僚机构,能够供养大批知识分子,能够建立巨大的神庙和公共建筑物的文明

第三种文明是产生最晚、草原型的文明。

他们不能独立存在,他们的某些至关紧要的物质需要通过交易,从其他周围的文明中取得,而自己没办法产生。所以这种文明一定是次生型的文明。

退到一个更加边远的草原地带以后,更加依赖草原以后,寻求新的技术突破,然后产生新型的文明。

这个文明的重要性在哪呢?它产生了对后来全世界影响很大的突破。它突破了军事技术,通过军事技术产生了军事贵族。而在次生型的大多数文明当中,军事贵族制度是他们宪法制度的核心。

后来产生的文明,特别是雅利安人入侵以后的文明,完全不是这个样子。他们的军事色彩是异常突出的,军事贵族始终在统治权力中间处于核心地位。

极大地加快了传播的速度。加快传播的速度,也就是意味着缩短了孤立系统独立演化规则的时间

武士跟奴隶不一样,商王也用大量的奴隶来殉葬,但是武士恐怕是自愿殉葬的。因为你很难强迫他们殉葬,

为什么这个技术来自中亚?到底还是因为中亚是草原上是竞争最激烈的地方,它是军事演化速度最快的地方。

西亚这个地方,从加息特人(原居于札格罗斯山脉中部。公元前16世纪初占据巴比伦,建立加息特王朝)入侵到雅利安人入侵,基本上几十年就一波

五胡十六国的入侵肯定是扮演了类似的军事革命。而西魏北周,建立隋唐的过程,可以看成是新一波的入侵和革新,残唐五代,一直到辽金元这个系统,又可以看成是一批新的边区武士系统的入侵。每一次都伴随着军事制度的改变和政治制度的相应改变。
china  civ  concep  theory  east-asia  middle-asia  technology  warrior  military  empire  evolution 
september 2018 by aries1988
A Grand New Theory of Life's Evolution on Earth - The Atlantic
Judson divides the history of the life on Earth into five energetic epochs, a novel schema that you will not find in geology or biology textbooks. In order, the energetic epochs are: geochemical energy, sunlight, oxygen, flesh, and fire. Each epoch represents the unlocking of a new source of energy, coinciding with new organisms able to exploit that source and alter their planet. The previous sources of energy stay around, so environments and life on Earth become ever more diverse. Judson calls it a “step-wise construction of a life-planet system.”

Which brings us to the epoch of oxygen. Given an opportunity, oxygen will steal electrons from anything it finds. New oxygen-resistant organisms evolve with enzymes to protect them from oxygen. They have advantages too: Because oxygen is so reactive, it makes the metabolism of these organisms much more efficient. In some conditions, organisms can get 16 times as much energy out of a glucose molecule with the presence of oxygen than without.

“Flesh” is source of concentrated energy, rich in fats and protein and carbon.
evolution  earth  energy  idea  book 
july 2018 by aries1988
The False Allure of Group Selection | Edge.org

I want to point out a potentially important example of group selection that Pinker overlooks: human languages. The function of language is to build communities and groups, as I have argued in many places. If an individual lacks the ability to talk, he or she will still survive. But a group of Homo sapiens that cannot talk will not be competitive with another group that can.

Dawkins, for instance, opines in the opening pages of The Selfish Gene, "We are survival machines—robot vehicles blindly programmed to preserve the selfish molecules known as genes.... a predominant quality to be expected in a successful gene is ruthless selfishness. This gene selfishness will usually give rise to selfishness in individual behavior.... Anything that has evolved by natural selection should be selfish."
gene  debate  evolution  concept  groupe  biology  human  society  to:marginnote 
april 2018 by aries1988
Why did we start farming?
What if the origin of farming wasn’t a moment of liberation but of entrapment? Scott offers an alternative to the conventional narrative that is altogether more fascinating, not least in the way it omits any self-congratulation about human achievement.

The perfectly formed city-state is the ideal, deeply ingrained in the Western psyche, on which our notion of the nation-state is founded, ultimately inspiring Donald Trump’s notion of a ‘city’ wall to keep out the barbarian Mexican horde, and Brexiters’ desire to ‘take back control’ from insurgent European bureaucrats.
CPR 都市帝国 宫崎市定

His account of the deep past doesn’t purport to be definitive, but it is surely more accurate than the one we’re used to, and it implicitly exposes the flaws in contemporary political ideas that ultimately rest on a narrative of human progress and on the ideal of the city/nation-state.

domesticated goats had begun to eat up the local vegetation – the first step to today’s barren landscape.

although farming would have significantly increased mortality rates in both infants and adults, sedentism would have increased fertility. Mobile hunter-gatherers were effectively limited by the demands of travel to having one child every four years. An increase in fertility that just about outpaced the increase in mortality would account for the slow, steady increase in population in the villages.

Collapse could mean nothing more than the abandonment of the centre and the redistribution of the population into independent settlements, to be followed by the next cycle of annexation.

According to Scott, the period of early states was the Golden Age for the barbarians.
book  agriculture  human  debate  evolution  question  civ  idea  invention  destiny  whatif  history  origin  state  read  instapaper_favs 
february 2018 by aries1988
The origin of the thesis; Charles Darwin in his time – TheTLS
Science (which really only means “knowledge”) is a developing conversation and a negotiation with the changing world. What Wilson seems unable to grasp is that science is as much about locating the right question as finding the “right” answer, and it does now seem irrefutable that Darwin’s “tree of life” was the right tree to be barking up.

the fittest of the “survival of the fittest” are not “strong” but rather well adapted to their environment. Wilson’s misapprehension is a serious one because it allows him to elide Darwin’s theory of natural selection with the worst aspects of Social Darwinism and to go dizzily spinning down a track which ends with the Nuremberg Laws, which he says were “all based on bogus Victorian science, much of which had started life in the gentle setting of Darwin’s study at Down House”.
book  review  darwin  nature  biology  evolution 
february 2018 by aries1988
The red and green specialists: why human colour vision is so odd | Aeon Ideas
Most mammals rely on scent rather than sight. Look at a dog’s eyes, for example: they’re usually on the sides of its face, not close together and forward-facing like ours. Having eyes on the side is good for creating a broad field of vision, but b...
comparison  human  eye  color  perception  biology  insect  evolution  research  theory 
february 2018 by aries1988
Wolf Puppies Are Adorable. Then Comes the Call of the Wild.

As close as wolf and dog are — some scientists classify them as the same species — there are differences. Physically, wolves’ jaws are more powerful. They breed only once a year, not twice, as dogs do. And behaviorally, wolf handlers say, their predatory instincts are easily triggered compared to those of dogs. They are more independent and possessive of food or other items. Much research suggests they take more care of their young. And they never get close to that Labrador retriever I-love-all-humans level of friendliness. As much as popular dog trainers and pet food makers promote the inner wolf in our dogs, they are not the same.

Dog puppies will quickly attach to any human within reach. Even street dogs that have had some contact with people at the right time may still be friendly.

Some recent research has suggested that dog friendliness may be the result of something similar to Williams syndrome, a genetic disorder in humans that causes hyper-sociability, among other symptoms. People with the syndrome seem friendly to everyone, without the usual limits.

As I was emphatically told in a training session before going into an enclosure with adult wolves, the one thing you definitely do not do is look them in the eye.

whether a delay in social development in a dog’s early life could explain the difference between wolves and dogs

That’s very important, because both wolves and dogs go through a critical period as puppies when they explore the world and learn who their friends and family are.

With wolves, that time is thought to start at about two weeks, when the wolves are deaf and blind. Scent is everything.

In dogs, it starts at about four weeks, when they can see, smell and hear. Dr. Lord thinks this shift in development, allowing dogs to use all their senses, might be key to their greater ability to connect with human beings.

Perhaps with more senses in action, they are more able to generalize from tolerating individual humans with a specific scent to tolerating humans in general with a scent, sight and sound profile.

When the critical period ends, wolves, and to a lesser extent dogs, experience something like the onset of stranger anxiety in human babies, when people outside of the family suddenly become scary.
quebec  wolf  zoo  dog  biology  gene  animal  evolution  human  comparison  research  scientist  experiment  development  baby 
october 2017 by aries1988
On epigenetics: we need both Darwin’s and Lamarck’s theories | Aeon Essays
One problem with Darwin’s theory is that, while species do evolve more adaptive traits (called phenotypes by biologists), the rate of random DNA sequence mutation turns out to be too slow to explain many of the changes observed.

To quote the prominent evolutionary biologist Jonathan B L Bard, who was paraphrasing T S Eliot: ‘Between the phenotype and genotype falls the shadow.’

In evolution and biomedicine, the rates of phenotypic trait divergence is far more rapid than the rate of genetic variation and mutation – but why?

Waddington recognised the potential impact his discovery could have on the theory of evolution: the single-generation change in the fruit-fly wings were supportive of the original ideas of the heretic Lamarck. It appeared that the environment could directly impact traits.

the vast majority of environmental factors cannot directly alter the molecular sequence of DNA, they do regulate a host of epigenetic mechanisms that regulate how DNA functions – turning the expression of genes up or down, or dictating how proteins, the products of our genes, are expressed in cells.

Today, that is the precise definition of epigenetics: the molecular factors that regulate how DNA functions and what genes are turned on or off, independent of the DNA sequence itself.

epigenetic inheritance does not follow many of the Mendelian rules that apply to classic genetics and the neo-Darwinian theory of evolution. These rules hold that DNA sequences and genes function discretely, like particles; upon reproduction, the ‘particles’ from each parent unite at random with a matching pair from the other parent, leading to a new DNA sequence and new expression of inherited traits.

In conclusion, exposure to the fungicide permanently altered the descendant’s sperm epigenetics; that, in turn, led to inheritance of sexual selection characteristics known to reduce the frequency with which their genes might propagate in the broader population and directly influence evolution on a micro-evolutionary scale.
biology  evolution  theory  epigenetics  science  debate  scientist  history 
september 2017 by aries1988
Interview with Ornithologist Richard Prum: What Duck Sex Reveals about Human Nature - SPIEGEL ONLINE - International

Prum: To understand this, you have to consider the evolutionary mechanisms involved: If the female gets the mate she likes, then her offspring will inherit the green head and the quack-quack-quack, all those displays that she likes so much. And since all other females have coevolved to prefer those same traits, her sons will be very successful and she will have lots of grandchildren from him. But if she's fertilized by force, then some random male will father her kids, which means that her offspring are less likely to inherit the attractive traits that she and other females like. That means fewer grandkids. Therefore, evolution will favor any mutation that allows her to get her own choice -- for example by protecting her vagina against forced sex.

Unlike ducks, 97 percent of birds cannot be forcibly fertilized, because the males don't have a penis. Copulation in most birds is achieved by a cloacal kiss, just an apposition (or touching) of orifices. So, to be fertilized, the female has to actively take up the sperm, which means that she retains full control of her sexual choice. By the way, I think this is the essential reason why birds are so beautiful. Since they have the freedom of choice, females exhibit aesthetic preferences. And, as a result of these preferences, males developed amazingly elaborate ornaments.

SPIEGEL: You are suggesting that women were attracted to small teeth?

Prum: Yeah, and I even think that this is where our smile comes from. It is a sexual symbol advertising one's state of de-weaponization.

SPIEGEL: And females made them give up this bad habit by choosing more good-natured males?

Prum: Yes. Solving the infanticide problem was the biggest hurdle in human evolution. Infanticide is the single largest source of infant mortality in gorillas and chimpanzees. Approximately 30 percent of all infant deaths are the result of infanticide by males. On the other hand, everything that is special about human biology requires greater investment in longer childhoods -- whether it's complex cognition, language, culture or technology. None of that could possibly have evolved if a large portion of babies are being murdered by sexual violence.
bird  sex  human  animal  evolution  interview  opinion  research  duck  penis 
july 2017 by aries1988
Joseph Henrich on cultural evolution, WEIRD societies, and life among two strange tribes

To anthropologist Joseph Henrich, intelligence is overrated. Social learning, and its ability to influence biological evolution over time, is what really sets our species apart.

If we look at the earliest human societies, the first time you see monumental architecture, it’s always religious. It’s always a temple or a tomb. This seems to help consolidate power and expand this fear of reliable social interactions.

If we look at the smallest-scale human societies, hunter-gatherers, they still rely on all kinds of social norms and beliefs to cooperate even when they’re cooperating in relatively small bands.

We learn about ourselves by seeing ourselves projected in other peoples and other cultures and other societies.

HENRICH: In my latest project I’m really looking at the kind of spread of the Western church into Europe and how it transformed the social structure in ways that I think led to individualism, it led to a different kind of cultural psychology that would eventually pave the way for secular institutions and economic growth. The church is the first mover in that account.
thinking  culture  evolution  human 
january 2017 by aries1988
How domestication changes species, including the human | Aeon Essays

The overall picture is that domestication was a gradual affair, full of pitfalls and false starts. It took thousands of years of tinkering before agriculture as we know it came into being, and for much of that time, the border between wild and tame remained fluid. At the outset, this probably didn’t matter much. Early sea-faring pioneers who travelled from the Middle East to Cyprus brought wheat, barley and pigs, according to archaeological investigations of village sites dating back 10,000 years. But they also took with them species that weren’t domesticated, such as fallow deer and foxes. They didn’t distinguish between wild and tame. Instead of transporting just a few valuable species, they took with them a whole ecological niche. As Zeder writes: ‘They simply took with them the world that they knew.’

Brains of domestic pigs are 35 per cent smaller than those of boars, for example, while dogs’ brains are around 30 per cent smaller than those of wolves.

it was probably advantageous for domestic animals to have reduced sensory acuity. In the wild it paid to be skittish, while under human management, those individuals who could handle stress with equanimity did best.

Known as ‘lactase persistence’, a term that refers to the enzyme that breaks down lactose in milk, it’s one of the greatest evolutionary adaptations in any species of the past few thousand years. Tolerance developed in humans at least five times, once in Europe and four times in areas of sub-Saharan Africa.
human  biology  evolution  animal  culture  instapaper_favs 
december 2016 by aries1988
Yuval Harari on big data, Google and the end of free will - FT.com
For thousands of years humans believed that authority came from the gods. Then, during the modern era, humanism gradually shifted authority from deities to people. Jean-Jacques Rousseau summed up this revolution in Emile, his 1762 treatise on education. When looking for the rules of conduct in life, Rousseau found them “in the depths of my heart, traced by nature in characters which nothing can efface. I need only consult myself with regard to what I wish to do; what I feel to be good is good, what I feel to be bad is bad.” Humanist thinkers such as Rousseau convinced us that our own feelings and desires were the ultimate source of meaning, and that our free will was, therefore, the highest authority of all.
human  god  evolution 
august 2016 by aries1988
Music in the age of the algorithm — FT.com
Distinction increasingly resides in the range of our listening, its eclecticism, not a narrow attachment to genre. Yet without a map, some sense of what we like and dislike, how do we make sense of the expanse of music stretching around us?
book  consumer  habit  data  music  online  evolution  spotify 
june 2016 by aries1988
How the New York Times plans to conquer the world
We believe there’s a gap we’re well positioned to fill, said Dunbar-Johnson. The Economist addresses its readers as if they’re aspiring heads of state. The Financial Times and the Wall Street Journal try to address them as if they’re captains of industry. Our readers are people who are deeply curious about the world, not necessarily because they want to run it, but because they want to understand it and make it better.

The bigger question, he said, is what the problem that the Times solves for people is supposed to be, and whether it helps people be part of communities that they want to or need to be part of. Reading the New York Times is part of being a certain kind of person in the US. It is less clear that the Times occupies a similar position with its target audiences around the world.

From the perspective of Latin America, that was much more important, said Polgreen. Similarly, she said, Imagine you’re a reader in France and come to the New York Times homepage. It’s completely dominated by what to a foreign reader feels like really small-bore American politics.
media  journalism  american  world  globalization  competition  evolution  relevancy  business  news 
may 2016 by aries1988
How humans evolved language, and who said what first | New Scientist
What’s more, language is inherently symbolic – sounds stand for words that stand for real objects and actions. But there is scant evidence that Neanderthals had art or other symbolic behaviour – a few pieces of pigment and some disputed etchings. By comparison, the humans who lived alongside them in Western Europe painted beautiful murals, made musical instruments and had a wide variety of tools and weapons.
human  history  evolution  language 
may 2016 by aries1988
The truth about migration: How evolution made us xenophobes | New Scientist
Schaller and Neuberg believe that for both these reasons, human cultures evolved to be wary of close interaction with people who were different from their group.
evolution  immigration  people 
april 2016 by aries1988
Bamboo Mathematicians
In the late 1960s, a species of bamboo called Phyllostachys bambusoides--commonly known as the Chinese Mainland Bamboo or Japanese Timber Bamboo--burst into flower. The species originated in China,...
biology  evolution  model  maths 
may 2015 by aries1988
The Book of Barely Imagined Beings, by Caspar Henderson – review | Science | The Guardian
a gripping story of evolution that leaves us to ponder on the concept of “deep time”, the billions of years that life on Earth has evolved and of which humans are the merest fraction of a part. As Henderson puts it: “Human history with respect to life on Earth is as deep as the displacement of the smallest seabird floating on top of a wave over the deepest part of the ocean.”
book  review  biology  animal  human  evolution 
may 2015 by aries1988
In Bedbugs, Scientists See a Model of Evolution
New research indicates that some bedbugs are well on their way to becoming a new species.
animal  history  evolution 
february 2015 by aries1988
东亚人头发粗胸部小与古代基因变异有关 - 纽约时报中文网 国际纵览
人们有时假设东亚人曾在一个寒冷的环境里进化,因为他们的窄鼻孔可以保存热量、多余的眼皮脂肪可以防止眼部热量流失。但是博德团队估计,相关EDAR基因的变体大概在3.5万年前出现在中国的中部地区,而那时这一地区相对温暖、潮湿。更多的汗腺对当时生活在那里依靠狩猎和采集为生的人是有好处的。

但是,西雅图华盛顿大学(University of Washington)的遗传学家乔舒亚·阿基(Joshua Akey)说,他认为这种基因在东亚的传播更可能是由于性选择。粗毛发和小胸是肉眼可见的性信号,如果男性偏好这种特质,随着携带此特征的女性孕育更多孩子,这种特质就可以迅速变得更普遍。阿基博士说,决定显性特征的基因,如欧洲人中的蓝眼、金发,有着很强的选择信号。与汗腺相比,EDAR基因可见的吸引异性的影响很可能在自然选择上发挥了更大作用。

大概有93%的中国汉族人携带这种变异,大概有70%的日本人和泰国人、60%到90%的美洲印第安人携带这种变异。而美洲印第安人是东亚人的后裔。

每一个种族都有一系列不同的所选区域,这反映了一个事实:人类离开非洲以后散布各地,面临了不同的挑战,因而导致每一个大陆上基因适应环境的情况并不一样。大概其中140个受自然选择影响的位置在欧洲人身上,140个在东亚人身上,132个在非洲人身上,作者们在另外一篇于周四发表在《细胞》杂志上的文章里写道。
biology  human  evolution  asia  sex 
february 2013 by aries1988
The science of righteousness
Evolution helps to explain why parties are so tribal and politics so divisive
http://www.instapaper.com/read/298862018
biology  evolution  darwin  politics 
june 2012 by aries1988

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