Posts Tagged ‘evolution’
“Homo sapiens, the only creature endowed with reason, is also the only creature to pin its existence on things unreasonable”*…
How, Sarah Constantin asks, did we humans get so smart?
If you zoom way out and look at the history of life on Earth, humans evolved incredibly recently. The Hominidae — the family that includes orangutans, chimpanzees, bonobos, gorillas, and humans — only arose 20 million years ago, in the most recent 0.5% of evolutionary history.
Within the Hominidae, in turn, Homo sapiens is a very recent development [see image at top]. We appeared 800,000-300,000 years ago, or in the last 1.5%-5.3% of hominid history.
If you look at early hominid “technological” milestones like tool use or cooking, though, they’re a lot more spread out over time. That’s interesting.
There’s nothing to suggest that a single physical change in brains should have given us both tool use and fire, for instance; if that were the case, you’d expect to see them show up at the same time.
Purposeful problem-solving behaviors like tool use and cooking are not unique to hominids; some other mammals and birds use tools, and lots of vertebrates (including birds and fish) can learn to solve puzzles to get a food reward. The general class of “problem-solving behavior” that we see, to one degree or another, in many vertebrates, doesn’t seem to have arisen surprisingly fast compared to the existence of animals in general.
However, to the extent that Homo sapiens has unique cognitive abilities, those did show up surprisingly recently, and it makes sense to privilege the hypothesis that they have a common physical cause.
So what are these special human-unique cognitive abilities?…
“Is Human Intelligence Simple? Part 1: Evolution and Archaeology,” from @s_r_constantin. Part 2 is here.
* Henri Bergson
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As we study our species, we might send self-examining birthday greetings to Giambattista Vico; he was born on this date in 1668. A political philosopher, rhetorician, historian, and jurist, Vico was one of the greatest Enlightenment thinkers. Best known for the Scienza Nuova (1725, often published in English as New Science), he famously criticized the expansion and development of modern rationalism and was an apologist for classical antiquity.
He was an important precursor of systemic and complexity thinking (as opposed to Cartesian analysis and other kinds of reductionism); and he can be credited with the first exposition of the fundamental aspects of social science (and so, is considered by many to be the first forerunner of cultural anthropology and ethnography), though his views did not necessarily influence the first social scientists. Vico is often claimed to have fathered modern philosophy of history (although the term is not found in his text; Vico speaks of a “history of philosophy narrated philosophically’). While he was not strictly speaking a historicist, interest in him has been driven by historicists (like Isaiah Berlin).
“Two obsessions are the hallmarks of Nature’s artistic style: Symmetry- a love of harmony, balance, and proportion [and] Economy- satisfaction in producing an abundance of effects from very limited means”*…
Life is built of symmetrical structures. But why? Sachin Rawat explores…
Life comes in a variety of shapes and sizes, but all organisms generally have at least one feature in common: symmetry.
Notice how your left half mirrors the right or the radial arrangement of the petals of a flower or a starfish’s arms. Such symmetry persists even at the microscopic level, too, in the near-spherical shape of many microbes or in the identical sub-units of different proteins.
The abundance of symmetry in biological forms begs the question of whether symmetric designs provide an advantage. Any engineer would tell you that they do. Symmetry is crucial to designing modular, robust parts that can be combined together to create more complex structures. Think of Lego blocks and how they can be assembled easily to create just about anything.
However, unlike an engineer, evolution doesn’t have the gift of foresight. Some biologists suggest that symmetry must provide an immediate selective advantage. But any adaptive advantage that symmetry may provide isn’t by itself sufficient to explain its pervasiveness in biology across scales both great and small.
Now, based on insights from algorithmic information theory, a study published in Proceedings of the Natural Academy of Sciences suggests that there could be a non-adaptive explanation…
Symmetrical objects are less complex than non-symmetrical ones. Perhaps evolution acts as an algorithm with a bias toward simplicity: “Simple is beautiful: Why evolution repeatedly selects symmetrical structures,” from @sachinxr in @bigthink.
* Frank Wilczek (@FrankWilczek)
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As we celebrate symmetry, we might recall (speaking of symmetry) that it was on this date in 1963 that the Equal Pay Act of 1963 was signed into law by president John F. Kennedy. Aimed at abolishing wage disparity based on sex, it provided that “[n]o employer having employees subject to any provisions of this section [section 206 of title 29 of the United States Code] shall discriminate, within any establishment in which such employees are employed, between employees on the basis of sex by paying wages to employees in such establishment at a rate less than the rate at which he pays wages to employees of the opposite sex in such establishment for equal work on jobs[,] the performance of which requires equal skill, effort, and responsibility, and which are performed under similar working conditions, except where such payment is made pursuant to (i) a seniority system; (ii) a merit system; (iii) a system which measures earnings by quantity or quality of production; or (iv) a differential based on any other factor other than sex […].
Those exceptions (and lax enforcement) have meant that, 60 years later, women in the U.S. are still paid less than men in comparable positions in nearly all occupations, earning on average 83 cents for every dollar earned by a man in a similar role.
“Oh how wrong we were to think immortality meant never dying”*…
The John Templeton Foundation has undertaken a undertaken a deep investigation into the biology, philosophy, and theology of immortality research. Lorraine Boissoneault offers the first in a series of reports on their work…
Around 100,000 years ago, humans living in the region that would come to be called “Israel” did something remarkable. When members of the community died, those left behind buried the dead in a cave, placing some of the bodies with great care and arranging them near colorful pigments and shells. Although burial is so common today as to be almost unremarkable, for ancient humans to exhibit such behavior suggested a major development in cultural practices. The Qafzeh Cave is one of the oldest examples that humans understand death differently than many other creatures. We seem to have an innate desire to mark it with ritual.
It is an unavoidable fact of biology that all organisms die, whether by disease, disaster, or simply old age. Yet our species, Homo sapiens, seems to be the only creature blessed—or cursed—with the cognitive ability to understand our mortality. And thanks to our powerful intelligence, we’re also the only beings to imagine and seek out death’s opposite: immortality.
In religious traditions, spiritual afterlives and reincarnation offer continuation of the self beyond death. In myth and legend, sources of everlasting life abound, from the Fountain of Youth to elixirs of life. Some people seek symbolic immortality through procreation. Others aim for contributions to society, whether artistic, academic or scientific. And still others have pushed the bounds of technology in search of dramatic life extension or a digital self.
Where does this impulse come from?…
Find out: “Pre-life, Afterlife, and the Drive for Immortality,” from @boissolm @templeton_fdn.
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As we internalize eternity, we might recall that it was on this date in 1826 that the HMS Beagle set sail from Plymouth on its first voyage, an expedition to conduct a hydrographic survey of Patagonia and Tierra del Fuego in support of the larger ship HMS Adventure.
The Beagle‘s second voyage (1831-1836) is rather better remembered, as it was on that expedition that the ship’s naturalist, a young Charles Darwin (whose published journal of the journey, quoted above, earned him early fame as a writer) made the observations that led him to even greater fame for his theory of evolution.
“Relationships have two key components: ‘being close’ and ‘feeling close’.”*…
The marvelous Matt Webb muses on Dunbar’s Number…
150, Dunbar’s number, is the natural size of human social groups. Robin Dunbar’s 1993 paper, where he put forward this hypothesis, is a great read – it’s got twists and turns, so much more in it than just the 150 number…
“Dunbar’s number and how speaking is 2.8x better than picking fleas,” from @genmon.
Dunbar’s original paper is here.
* Robin Dunbar
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As we ruminate on relationships, we might recall that this date in 1954 was, according to the True Knowledge Answer Engine, the most boring day since 1900. The site analyzed more than 300 million historical facts and discovered that April 11, 1954 was the most uneventful news day of the 20th century. No typically newsworthy events occurred at all… though of course now the day has become a bit more newsworthy because it has the distinction of being so completely uneventful.
“We are a species which is naturally moved by curiosity, the only one left of a group of species (the genus Homo) made up of a dozen equally curious species”*…
… and one thing that curiosity might lead us to wonder is where evolution might take humanity from here. As Nick Longrich points out…
Discussions of human evolution are usually backward looking, as if the greatest triumphs and challenges were in the distant past. But as technology and culture enter a period of accelerating change, our genes will too. Arguably, the most interesting parts of evolution aren’t life’s origins, dinosaurs, or Neanderthals, but what’s happening right now, our present – and our future.
He reasons to some fascinating possibilities…
Humanity is the unlikely result of 4 billion years of evolution.
From self-replicating molecules in Archean seas, to eyeless fish in the Cambrian deep, to mammals scurrying from dinosaurs in the dark, and then, finally, improbably, ourselves – evolution shaped us.
Organisms reproduced imperfectly. Mistakes made when copying genes sometimes made them better fit to their environments, so those genes tended to get passed on. More reproduction followed, and more mistakes, the process repeating over billions of generations. Finally, Homo sapiens appeared. But we aren’t the end of that story. Evolution won’t stop with us, and we might even be evolving faster than ever.
It’s hard to predict the future. The world will probably change in ways we can’t imagine. But we can make educated guesses. Paradoxically, the best way to predict the future is probably looking back at the past, and assuming past trends will continue going forward. This suggests some surprising things about our future…
Meet our future selves: “Future evolution: from looks to brains and personality, how will humans change in the next 10,000 years?“– @NickLongrich in @ConversationUS.
* Carlo Rovelli, Seven Brief Lessons on Physics
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As we ponder the possible, we might send insightful birthday greetings to Richard Dawkins; he was born on this date in 1947. An evolutionary biologist, he made a number of important contributions to the public understanding of evolution. In his 1976 book The Selfish Gene, he popularized the gene-centred view of evolution and introduced the term meme. In The Extended Phenotype (1982), he introduced the influential concept that the phenotypic effects of a gene are not necessarily limited to an organism’s body, but can stretch far into the environment. And in The Blind Watchmaker (1986), he argued against the watchmaker analogy, an argument for the existence of a supernatural creator based upon the complexity of living organisms; instead, he described evolutionary processes as analogous to a blind watchmaker, in that reproduction, mutation, and selection are unguided by any designer.
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