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颠覆认知:着凉到底会不会导致感冒? | 商周专栏
从1914年德国 Kruse 教授首次发现感冒能传染到现在,一百多年的时间过去了。在过去的一个世纪里,科学界对着凉与感冒的关系已经基本清楚:普通感冒是由感冒病毒导致的急性上呼吸道感染,冷的环境能促进感冒的发生(通过增强病毒在体外的生存时长、增加病毒感染的机会、降低呼吸道细胞对病毒的免疫力等),但着凉和普通感冒无关。
explained  research  medical  body  biology  daily  maladie 
4 weeks ago by aries1988
为什么人的酒量有大有小?
有的人喝一点点酒就脸红,有的人干了一杯酒还若无其事。为什么人的酒量差别这么大?是练出来的吗?一个酒量小的人能不能通过天天喝酒来提高酒量呢?…
explained  alcohol  body  biology  drinking 
february 2019 by aries1988
Jared Diamond: ‘Humans, 150,000 years ago, wouldn’t figure on a list of the five most interesting species on Earth’

It was a painful thought for someone who recalled being told, by an admiring teacher at his Massachusetts school, that one day he would “unify the sciences and humanities”. Clearly, he needed a larger canvas. Even so, few could have predicted how large a canvas he would choose.

1997’s Guns, Germs and Steel – which ask the most sweeping questions it is possible to ask about human history.

Diamond, who describes himself as a biogeographer, answers them in translucent prose that has the effect of making the world seem to click into place, each fact assuming its place in an elegant arc of pan-historical reasoning.

Why? Because 8,000 years ago – to borrow from Guns, Germs and Steel – the geography of Europe and the Middle East made it easier to farm crops and animals there than elsewhere.

vicious jousting between Diamond and many anthropologists. They condemn him as a cultural imperialist, intent on excusing the horrors of colonialism while asserting the moral superiority of the west.

In person, Diamond is a fastidiously courteous 77-year-old with a Quaker-style beard sans moustache, and archaic New England vowels: “often” becomes “orphan”, “area” becomes “eerier”. There’s no computer: despite his children’s best efforts, he admits he’s never learned to use one.

What changed, Diamond argues, was a seemingly minor set of mutations in our larynxes, permitting control over spoken sounds, and thus spoken language; spoken language permitted much of the rest.

It won a Pulitzer prize and has sold more than 1.5m copies in 36 languages. Mitt Romney quoted it admiringly in his 2012 presidential campaign, garbling its message entirely.

he found himself accused of “geographic determinism”: in his critics’ opinion, his arguments squeeze out any role for human agency and decision-making, thereby sparing history’s colonisers – and today’s elites – any responsibility for having created our grotesquely unjust world.

Each of the two books has the unusual distinction of having another book dedicated largely to demolishing it: Yali’s Question, which offers a different answer from Diamond’s New Guinean acquaintance, and Questioning Collapse, which calls the Easter Island “ecocide” a myth.

Whenever I hear the phrase ‘geographic determinism’,” he says, “I know I’m about to waste time discussing with someone who has no right to be discussing [how human societies developed]. Because the fact is that geography has a strong influence on humans. It doesn’t determine everything, but it has a strong influence
bio  book  leader  human  development  inequality  world  history  biology  environment  debate  theory  geography  opinion 
october 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
The evidence is in: there is no language instinct – Vyvyan Evans | Aeon Essays
Our brains really are ‘language-ready’ in the following limited sense: they have the right sort of working memory to process sentence-level syntax, and an unusually large prefrontal cortex that gives us the associative learning capacity to use symbols in the first place. Then again, our bodies are language-ready too: our larynx is set low relative to that of other hominid species, letting us expel and control the passage of air. And the position of the tiny hyoid bone in our jaws gives us fine muscular control over our mouths and tongues, enabling us to make as many as the 144 distinct speech sounds heard in some languages.
brain  language  baby  biology  research  linguist  debate  theory  gene 
september 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
All by Itself, the Humble Sweet Potato Colonized the World
Many botanists argued that humans must have carried the valuable staple to the Pacific from South America. Not so, according to a new study.
agriculture  story  biology  americas  pacific  ocean 
april 2018 by aries1988
How the Fencing Reflex Connects Life and Death - Issue 59: Connections - Nautilus
Doctors talk of patients who, under heavy sedation, grasp someone’s finger, root for a breast to suckle, or twist into the archer’s pose.
biology  human  body  baby  neurology 
april 2018 by aries1988
When Twenty-Six Thousand Stinkbugs Invade Your Home
The brown marmorated stinkbug often congregates indoors in exorbitant numbers. Illustration by David Plunkert Audio: Listen to this story. To hear more feature…
insect  nightmare  chinese  home  biology 
march 2018 by aries1988
‘Daisy-chain’ gene drive vanishes after only a few generations | New Scientist
Each element contains one or more genes that contribute towards the whole gene drive. In Esvelt’s design, element A can only copy and paste itself if element B is present. Element B can only copy and paste itself if element C is present. And element C, crucially, cannot copy and paste itself at all – it can only spread by normal breeding, to half of offspring.

The idea is to release thousands of mosquitoes, say, carrying all three elements. When they mate with wild mosquitoes, all the offspring will inherit element A and B, but only half will inherit element C. In the following generations, element B will spread rapidly and A will spread even more rapidly, but C will gradually die out. Once it does, B will start to disappear, and finally A will too.
biology  engineering  explained  dna 
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
BBC - Future - How flying seriously messes with your mind
There are some studies, however, that show even relatively mild levels of hypoxia (deficiency in oxygen) can alter our ability to think clearly.

Human night vision can deteriorate by 5-10% at altitudes of just 5,000ft (1.5km). This is because the photoreceptor cells in the retina needed to see in the dark are extremely oxygen-hungry and can struggle to get all they need at a high altitude, causing them to work less effectively.

as the change in air pressure can also lead to passengers breaking wind more often.
biology  travel  health  psychology  brain  plane  research  fun  body 
october 2017 by aries1988
The Sucker, the Sucker!
Other Minds: The Octopus and the Evolution of Intelligent Life by Peter Godfrey-Smith Collins

octopuses – and to some extent their cephalopod cousins, cuttlefish and squid – frustrate the neat evolutionary division between clever vertebrates and simple-minded invertebrates. They are sophisticated problem solvers; they learn, and can use tools; and they show a capacity for mimicry, deception and, some think, humour.

Consciousness – the possession of an ‘inner’ model of the ‘outer’ world, or the sense of having an integrated, subjective perspective on the world – is, on his view, just a highly evolved form of what he calls ‘subjective experience’.

the Medawar effect: natural selection tends to weed out mutations whose harmful effects appear early in an animal’s life, but it is less likely to weed out mutations whose harmful effects manifest later on.
instapaper_favs  animal  ocean  intelligence  human  sea  biology  nature  book 
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
To find aliens, we must think of life as we don’t know it | Aeon Ideas

To open our minds, we need to go back to basics and consider the fundamental conditions that are necessary for life. First, it needs some form of energy, such as from volcanic hot springs or hydrothermal vents. That would seem to rule out any planets or moons lacking a strong source of internal heat. Life also needs protection from space radiation, such as an atmospheric ozone layer.

Finally, everything we know about life indicates that it requires some kind of liquid solvent in which chemical interactions can lead to self-replicating molecules. Water is exceptionally effective in that regard. It facilitates making and breaking chemical bonds, assembling proteins or other structural molecules, and – for an actual organism – feeding and getting rid of waste.

Meanwhile, another Saturn moon, Titan, could tell us whether life can arise without liquid water. Titan is dotted with lakes of methane and ethane, filled by a seasonal hydrocarbon rain.

If you think of the spectrum like a set of venetian blinds, there are only a few slats removed.
life  planet  research  astronomy  biology 
september 2017 by aries1988
The Natural History Museum’s new hall of wonders
Although gigantism on land reached a peak with dinosaurs, today’s blue whales are the biggest animals that have ever lived on land or sea. Evolutionary studies suggest that baleen whales, and the blue whale in particular, have grown to this scale within the past three million years in response to the availability of huge concentrations of krill, which they can catch and eat through their specialised filter-feeding mechanism.
london  museum  moi  biology  animal  dinosaur  history  2017 
july 2017 by aries1988
Comment le Sahara nourrit la Méditerranée
« A chaque arrêt, l’eau sera récupérée et mise dans des mésocosmes [réservoirs recréant les conditions d’un milieu naturel]. On augmentera la température de 2 degrés ainsi que la teneur en CO2 pour voir comment le phytoplancton réagit. De cette manière, nous recréons les conditions que nous aurons en 2100 », résume Karine ­Desboeufs. Malgré un appui ­météo au sol, le Pourquoi-Pas ? n’a aucune garantie de croiser la route d’une pluie de poussières sahariennes. En cas de malchance, la campagne ne sera pas vaine pour autant. Des appareils de ­mesure enregistreront simultanément les paramètres chimiques, physiques et biologiques de l’air et des eaux de surface. La comparaison des données permettra de ­rechercher les interactions.
mediterranean  europe  research  science  atmosphere  sea  biology 
may 2017 by aries1988
Shaking Up the Dinosaur Family Tree

After analyzing 32 billion trees, the computer spat out the best possible arrangement of Mr. Baron’s three years’ worth of data collection. The run took just five minutes.
taxonomy  dinosaur  data  theory  discovery  biology 
march 2017 by aries1988
Return of the White Death: the threat of new strains of TB | Aeon Ideas
TB deaths fell dramatically during this time, as did all other infectious diseases. From 1860 to 1950, deaths from infectious diseases fell by nearly 90 per cent in England and Wales, and by similar amounts in other industrialised countries. This decline occurred prior to the general availability of antibiotics. It can confidently be attributed to the implementation of public-health measures, principally the provision of clean water and food, and the development of vaccines. We know how to prevent the spread of infectious disease, a comforting thought in a world in which antibiotics are beginning to lose their invincibility.
epidemic  history  biology  medicine 
december 2016 by aries1988
What the death of an oak tree can teach us about mortality | Aeon Ideas
For humans, ageing invariably leads to loss of function and eventual death. When we lose a limb, it’s a major loss. In the terrible event that we lose a head, it’s game over. For trees, it is almost the opposite: the older they get, the better they get at being trees. The rate at which they sequester carbon increases each year, and the amount of life they can sustain increases proportionally. Scientists know of no fundamental reason why trees must inevitably die, and many times one or more genetically identical ‘scions’ grow where a mature tree once stood. There is no equivalent reincarnation in the human world.
tree  biology  human  comparison  life 
december 2016 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
Man v rat: could the long war soon be over? | Jordan Kisner | Science | The Guardian
Why? How is it that we can send robots to Mars, build the internet, keep alive infants born so early that their skin isn’t even fully made – and yet remain unable to keep rats from threatening our food supplies, biting our babies, and appearing in our toilet bowls?

Rats have the same taste preferences as humans – they love fat and sugar – though Dyer’s experiments with various flavour profiles indicated that their appetite for both exceeds ours.
biology  animal  ecosystem  city  human  trash  food  scientist 
september 2016 by aries1988
Planet of the apps — have we paved the way for our own extinction? — FT.com
Harari’s skill lies in the way he tilts the prism in all these fields and looks at the world in different ways, providing fresh angles on what we thought we knew. No matter how scary and incomplete, the result is scintillating.

He points to the success of the Montreal Protocol of 1987 as a great model of international co-operation and solidarity. This treaty, ratified by 197 countries, played a vital role in reducing the release of harmful ozone-depleting chlorofluorocarbons from aerosols and refrigeration systems.

For the moment, the rise of populism, the rickety architecture of the European Union, the turmoil in the Middle East and the competing claims on the South China Sea will consume most politicians’ attention.
human  future  biology  technology  challenge  environment  book  ai  debate  crisis 
september 2016 by aries1988
BBC - Earth - Organisms might be quantum machines
This is the same kind of resonance you might experience when you sing in the shower – certain notes sound a lot louder and fuller than others. Hitting the right radio wave frequency will make the electron vibrate more vigorously in the same way.

Vanillin smells of vanilla, but eugenol, which is very similar in shape, smells of cloves. Some molecules that are a mirror image of each other – just like your right and left hand – also have different smells. But equally, some very differently shaped molecules can smell almost exactly the same.“

Olfaction requires a mechanism that somehow involves the actual chemical composition of the molecule,” he says. “It was that factor that found a very natural explanation in quantum tunnelling.”

Making use of quantum effects in biologically inspired photovoltaic cells, for instance, could give solar panels a huge boost in efficiency. “At this very moment there is quite a lot of activity in organic photovoltaics, to see whether with natural or artificial structures one can have an enhanced efficiency that exploit quantum effects.”
photosynthesis  photovoltaic  energy  biology  machine  quantum  physics  nature  future 
august 2016 by aries1988
Do animals fight wars and if so what was the largest war?

In New Orleans, something changed. L. humile, invading the United States, spread like wildfire. Instead of forming discrete, competing colonies, they behaved as a united army. They would brutally attack ants of other species, but welcome every L. humile as a long-lost sister in arms.
story  animal  world  war  biology  insect 
august 2016 by aries1988
江湖传说!谁是最大的淡水鱼? | 科学人 | 果壳网 科技有意思
从生态意义上,体型巨大的鱼类并不见得就比其他鱼类来得重要。巨大的体型决定了它们的数量必定稀少,即使灭绝,对河流生态系统的影响也不是致命的。但就如同华南虎、白暨豚一样,它们更多的是作为“旗舰物种”,代表着一个地区生态系统能够达到的进化水平,大鱼们的存在,也意味着这些大河、大湖的健康。

对于我们来说,水中的大鱼并不像陆地上的巨兽那样引人注意,但一旦见到,也足够震撼。白鲟这样的大型淡水鱼可能已经无法再见到,但愿其他大鱼,还有那些还未被人类发现的大鱼们,能在地球上有属于自己的一片水域。
fish  biology 
august 2016 by aries1988
What's behind Japan's moss obsession?
Japanese culture also values age and history. Because moss doesn’t grow dramatically overnight – and instead takes years and years to cover the surface of a stone – the Japanese see something inherently virtuous about the plant. Of course, there’s also the beauty of moss: vibrant colors that vary from bright green to brown, which richly complement the steely grays of stones, the red leaves of autumn and the soft pink of cherry blossoms. Many fans love to touch the plant’s sensual, soft surface.
young  amateur  home  biology  zen  hobby  beauty  aesthetics  japanese 
january 2016 by aries1988
Man of the world
Why a Prussian scientific visionary should be studied afresh
nature  scientist  deutsch  biology  idea  earth 
november 2015 by aries1988
人工智能:何时是“他们”,何时是“我们”? | 科学人 | 果壳网 科技有意思
这种种现象,背后的逻辑往往是8个字:非我族类,其心必异;因此,对于这些异类,就完全不必也不该采取和同类相同的道德标准,怎么狠就怎么来吧。

从以居住地为依据的诸侯国,扩展到以身份认同为主的民族国家(比如“炎黄子孙”就曾被用作与“夷狄”区分开来),人类对于“我的同类”的认定范围,不断的扩大开来,善待自己的同类,甚至可以为了保护自己的同类而作出自我牺牲,而这显然是不利于自己的基因延续的。

无论是出于何种原因,借用道金斯在《自私的基因》一书中的话来说就是: “只有人类,才能够反抗基因的暴政”。
ai  human  biology  mind  enemy  distinction 
june 2015 by aries1988
Flight Paths
Projects like this give us imaginative access to the lives of wild creatures, but they cannot capture the real animals’ complex paths. Instead we watch virtual animals moving across a world of eternal daylight built from a patchwork of layered satellite and aerial imagery, a flattened, static landscape free of happenstance: There are no icy winds over high mountain passes, heavy rains, soaring hawks, ripening crops or recent droughts. Despite these simplifications, following a tagged animal on a map is an addictive pursuit. It’s hard not to become invested in its fate. The bird might die, the tag might fail. You do not know where it will travel next. The bird is unaware of the eyes that watch its progress, and you veer from a sense of power at your ability to surveil at a distance to the knowledge that you are powerless to influence what happens next.
engineering  biology  tracker  story  animal  continent 
may 2015 by aries1988
This is what happens after you die
© Lightning + Kinglyface and Jess Bonham “It might take a little bit of force to break this up,” says mortician Holly Williams, lifting John’s arm and gently…
biology  explained  body  death 
may 2015 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
Meet the Comical Opah, the Only Truly Warm-Blooded Fish
There’s nothing about the opah that says “fast-moving predator”. Tuna, sharks, and swordfish are fast-moving predators and accordingly, their bodies look like streamlined torpedoes. By contrast, th...
biology  fish  discovery  ocean 
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
Slime Mold Grows Network Just Like Tokyo Rail System | WIRED
The researchers then borrowed simple properties from the slime mold’s behavior to create a biology-inspired mathematical description of the network formation. Like the slime mold, the model first creates a fine mesh network that goes everywhere, and then continuously refines the network so that the tubes carrying the most cargo grow more robust and redundant tubes are pruned.

Fricker points out that such a malleable system may be useful for creating networks that need to change over time, such as short-range wireless systems of sensors that would provide early warnings of fire or flood. Because these sensors are destroyed when disaster strikes, the network needs to efficiently re-route information quickly. Decentralized, adaptable networks would also be important for soldiers in battlefields or swarms of robots exploring hazardous environments, Fricker says.
maths  transport  metro  tokyo  biology 
february 2015 by aries1988
Prehistory’s Brilliant Future
Spectacular dinosaur finds represent just a fraction of what the fossil record has to tell us.

New findings accumulate like Olympic records. Here we are, in the age of the microchip and the Mars explorer, and yet some of our most exciting and extraordinary scientific discoveries are extinct species in Earth’s fossil record.

The 1.8 million species of living organisms so far identified and named are but a fraction of the totality of life on Earth. Thanks to the fossil record, incomplete though it is, we can estimate that more than 99 percent of all species that ever lived are extinct. In a deep sense, our understanding of the future of evolution is rooted in the past.

Just 50,000 years ago — a blink of an eye in the deep time of paleontology — there were at least three, and maybe four, species of the human lineages cohabiting on this planet. Yet within that span of time, only our own species made it through the evolutionary sieve.
scientist  dinosaur  story  biology 
november 2014 by aries1988
五瓣花、梅与中国人_刘夙_新浪博客
然而,除了在花的形态上有比较大的共性之外,蔷薇科植物在习性和果实形态上却有很大的差别。有的是高数十米的参天大树,有的却是一年生的矮小草本;有的稍微遇一点霜冻就不能生存,有的却可以在极地和高山的冰天雪地中挺立。有的果实在成熟后会开裂散出种子;有的果实又小又硬,带有一根长长的“羽毛”等待好风送上天;有的果实肉质多汁,吸引动物摄食,却把种子埋藏在坚硬的果核里憧憬着来年的阳光雨露……然而,正是靠着花形的一致,几百年前的植物学家就把所有这些植物都归拢成同一个蔷薇家族。这就好比是天南地北的中国人,言语不同,风俗各异,却总都有些文化核心是相同的,靠着这些文化核心撑起了“中国人”这个共称。

事实上,蔷薇科正好又是中国人最熟悉的科之一。这有两方面原因。第一,虽然蔷薇科总共只有2800多个种,在全世界的被子植物科中只排到第20名,但它在中国却有950种之多,在菊科、兰科、豆科和禾本科之后排到了第5名。在全国任何一个省区都可以见到蔷薇家族的身影。第二,蔷薇科是个“花果之家”,很多种的果实可以食用,而且十分美味,还有很多种的花朵艳丽,赏心悦目。因为这些原因,自古以来,汉语中不仅有很多指称蔷薇科植物的名称,而且有很多指称蔷薇科植物的汉字——从“草”的有蔷、䕷、莓、藨,从“木”的有梅、桃、李、杏、樱、梨、棠、棣、楂、楸、枇杷、榅桲……

尽管梅树并不真的耐寒,但是江南的冬天湿冷难熬,万木萧飒之中怒放的梅花不免给人凌寒独立的感觉;如果梅开之时碰上下雪,更是会形成红梅傲雪的景象。这样一来,梅花渐渐就和坚韧、品洁的高格联系在一起,到宋代便成了它最主要的人格象征。无论是北宋处士林逋“梅妻鹤子”的孤介形象,还是南宋诗人林景熙在亡国之际把梅、松、竹合称“岁寒三友”的精神寄托,都让梅花最终具备了今日我们熟悉的文化意象(更不用说著名的“花中四君子”梅、兰、竹、菊了)。民国政府曾经选梅花为国花;而20世纪80年代以来在评选中华人民共和国国花时,梅花又与牡丹势均力敌,结果国花至今难产。关于这桩公案,后面在讲芍药科的时候还要详细提及。

回顾中国历史,我们不难在族群的关系史中找到类似的场景。根据体质人类学研究,秦汉及以前中原华夏民族的体质与今天岭南地区的居民非常相似。但是,后来随着气候变迁,一波波的草原民族先后南下,逼迫原住民南迁,中原地区居民的体质便逐渐带上了今天华北地区居民的特点,即使是岭南地区的居民也多少受到了影响。但是,这些身上流淌了许多草原民族血液的后人仍然相信自己是华夏民族,事实上,华夏文化正是在他们手中得以继续兴盛发达。换句话说,他们本来是“某”,但他们却让“梅”更加成其为“梅”。这样看来,梅更是不折不扣的中华文化象征了。
explained  biology  flower  china 
october 2014 by aries1988
How human noise affects the ocean – Peter Brannen – Aeon
At 5:30am I awoke to the sound of the diesel chug-chugging of a lone lobster boat carving into the glassy Atlantic. An audience of shrieking gulls hushed in the…aUnder the right conditions, fin- and blue‑whale song can carry thousands of miles, as Clark realised while listening in on the oceans using the US Navy’s global submarine detection network. He was stunned to hear a blue whale singer on the Grand Banks of Canada all the way from Puerto Rico, 1,600 miles away. However, it’s an open question whether these performers are actually trying to be heard by their audiences across the ocean.
ocean  animal  whales  biology 
october 2014 by aries1988
‘Animated Life: Seeing the Invisible’
This animated documentary celebrates the 17th-century citizen scientist Antonie van Leeuwenhoek, whose discovery of microbes would change our view of the…
animal  biology  discovery  netherlands  scientist  moment  history 
october 2014 by aries1988
Our Understanding of Giraffes Does Not Measure Up

Or maybe the giraffes are worried about tripping over their own feet. Heather More and Shawn O’Connor of Simon Fraser University in British Columbia and their colleagues measured so-called sensorimotor responsiveness in the giraffe: how long it takes a nerve signal to travel from a muscle in the ankle up to the brain and back again. Reporting in The Journal of Experimental Biology, the researchers found that the nerve conduction rate in the giraffe is pretty much the same as it is in a shrew, rat or any other mammal.

Given the comparatively greater distance a nerve signal has to travel in the giraffe, Dr. More said, it’s possible the giraffe faces real challenges in reacting quickly to events down under — a rock beneath its hoof, or a bite to its ankle.
animal  discovery  biology 
october 2014 by aries1988
Le Nobel de chimie récompense l’invention de « nanoscopes »
Alors qu'un microscope classique voit des cellules ou des bactéries, les nouvelles techniques développées par les lauréats depuis le milieu des années 1990 permettent de voir des virus, des protéines, les pelotes d'ADN, la dynamique de la machinerie moléculaire au cœur des cellules… Pour marquer la transition, certains parlent désormais de " nanoscopie ". D'autres techniques avaient précédemment atteint de telles précisions mais seulement sur des surfaces et non dans des environnements biologiques.
science  future  invention  today  biology 
october 2014 by aries1988
达尔文和爱因斯坦开启的科学告别哲学之旅

牛顿力学诞生后,开始逐一横扫地球上的怪力乱神。至19世纪末,以牛顿力学为代表,电磁学、光学、声学、热学都获得了重大突破,以至于有人预言,物理学已近完美,不会再有大的发展了。但是随着研究的深入,发现了越来越多牛顿力学难以解释的新现象,令很多科学家又感到了物理学存在的新危机。解决这些危机的一个最重要人物就是爱因斯坦,他当时还不算是科学家,正式身份是一名公务员。

常说的三观之中,人生观和世界观由于科学的发展,进行了重塑,进而也影响到价值观,颠覆了以往众多的陈旧观念。

回想古希腊时期,逻辑论证的出现,令科学告别了巫学,文艺复兴时期,实验验证的出现,令科学告别了神学。科学一路走来,在弱小的时代,曾经隐身于神学,委身于哲学。但是以现代生物学和物理学为标志,科学取得新成就后,已经不再是那个懵懂的少年,在风风雨雨中,构建出庞大、强悍、坚实、独立的知识体系。就像告别巫学和神学的过程一样,科学在20世纪开始了告别哲学之旅。这注定是最后的告别。
science  story  biology  philosophy 
september 2014 by aries1988
Volcanoes? Meteors? No, the worst mass extinction in history could have been caused by microbes having sex - The Times of India
They believe that the sudden acquisition of a new set of genes enabled methane-producing microbes to feed off the abundant deposits of organic carbon that had built up in the oceans at that time. This led to an explosive growth in these Methanosarcina microbes and an equally explosive release of their waste gases, which suffocated almost all other life-forms on land and in sea.

* Ordovician-Silurian (443m years ago): most of life lived in the seas. About 85 per cent of marine species were killed, mostly at two peak dying times separated by hundreds of thousands of years.

* Late Devonian (359m years ago): about three quarters of species went extinct over a period of several million years. Much of the sea became starved of oxygen, possibly due to asteroid impacts.

* Permian (252 million years ago): nicknamed the Great Dying because it was the biggest mass extinction in history, killing off about 96 per cent of marine species. Volcanoes were thought to be involved.

* Triassic-Jurassic (200m years ago): occurred over several million years at the end of the Triassic. About half of all species at the time disappeared, but strangely plants were not badly affected.

* Cretaceous-Tertiary (65m years ago): famous for being the death knell of the dinosaurs. A giant asteroid impact was almost certainly involved, possibly preceded by a long period of volcanic eruptions.
science  biology  life  explained 
april 2014 by aries1988
The Red Queen was right: Life must continually evolve to avoid extinction
“Each group has either lost, or is losing, to an increasingly difficult environment,” Marshall said. “These groups’ demise was at least in part due to loss to the Red Queen – that is, a failure to keep pace with a deteriorating environment.”
biology  hypothesis 
june 2013 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
Explore – When a human being runs
When a human being runs, we have a tiny, little neck that emerges from the center of the base of our skull, and it’s very short in the middle. We’re basically like pogo sticks. We’ve lost, by becoming bipeds, all those mechanisms available to quadrupeds to keep their heads still. It turns out that we’ve evolved other special mechanisms to keep our heads still. One of them, the semicircular canals (the vestibular system in our heads) are especially enlarged, and give us enormous sensitivity to pitching forces, to pitching motions. The semicircular canals, the vestibular system are organs of balance that essentially function as an accelerometer. As your head pitches forward, as it does every time you hit the ground when you run, your head wants to pitch forward. As it pitches forward, the enlarged semicircular canals - these are the anterior and posterior ones, for anybody who actually cares - are especially large. That gives them greater gain in their sensitivity to angular accelerations. Which then, through a three-neuron circuit to our brain activates, without any conscious effort, the eye muscles that actually then stabilize the gaze. So even when your eyes are closed and you move your head, your eyes, the semicircular canals, through that three-neuron system operates those muscles, keeping your gaze stabilized. It’s that fundamental a system.
Daniel Lieberman, author of the fascinating The Evolution of the Human Head, discusses the role of brains and brawn in our species’ evolution.
biology  run 
november 2012 by aries1988
传统中式酱料,今天你吃了吗?
http://www.instapaper.com/read/271692536
面酱在古代叫做麦酱,后来又称甜酱或面酱,现在多叫甜面酱。这类酱是以小麦或面粉,或某些淀粉含量高的豆类为原料制成的酱。甜面酱所用原料主要是淀粉,而蛋白质较少,因此做出的酱通常味道较甜,别具一格,色泽也相比豆酱浅些。在酱类的生产中,虽不及豆酱产量大,但有增加趋势,成为仅次于豆酱的一大类。当前甜面酱主要盛行于华北地区,是北京烤鸭的重要佐料,并借此远渡重洋,走遍世界,也是腌酱菜加工的主要酱类之一,形成酱菜的独特风味。

豆酱发酵常用的霉菌有米曲霉、黑曲霉、酱油曲霉、高大毛霉等,它们对我们身体无害,而且还能分泌各种酶类,包括蛋白酶、肽酶、谷氨酰胺酶、淀粉酶系、植物组织分解酶等,其中蛋白酶和肽酶能将原料中的蛋白质分解成多肽及多种氨基酸,淀粉酶系把淀粉转化成葡萄糖、双糖、三糖及糊精等。霉菌的作用是增加豆酱的风味,且将豆酱的营养物质适当分解,易于人体吸收。因此,只要在制作豆酱过程中,没有污染黄曲霉菌或其他致病霉菌的话,豆酱是无害的
chinese  cuisine  fermentation  speciality  biology  explained 
august 2012 by aries1988
春天的北京,何以满城尽带白毛絮?
春天到,飞絮飘,这是一道美丽的风景,更是一场属于杨柳们的交媾盛会。春天的北京,何以年年都要上演“满城尽带白毛絮”?飞絮给人制造麻烦的背后,又藏着一场怎样的人树交锋?
http://www.instapaper.com/read/275025165
biology  life  beijing  tree 
august 2012 by aries1988
A Brief History of the Brain
New Scientist tracks the evolution of our brain from its origin in ancient seas to its dramatic expansion in one ape – and asks why it is now shrinking
http://www.instapaper.com/read/210859962
discovery  brain  biology  future 
august 2012 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
Wilson, Edward Osborne - Anthill.zip_免费高速下载_新浪爱问共享资料
The two-time Pulitzer Prize–winning biologist delivers “an astonishing literary achievement” (Anthony Gottlieb, The Economist).

Winner of the 2010 Heartland Prize, Anthill follows the thrilling adventures of a modern-day Huck Finn, enthralled with the “strange, beautiful, and elegant” world of his native Nokobee County. But as developers begin to threaten the endangered marshlands around which he lives, the book’s hero decides to take decisive action. Edward O. Wilson—the world’s greatest living biologist—elegantly balances glimpses of science with the gripping saga of a boy determined to save the world from its most savage ecological predator: man himself.
biology  novel  reading 
june 2012 by aries1988
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