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Posts Tagged ‘human beings

[LINK] “Humans have more primitive hands than chimpanzees”

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Science does its readers a service in reporting new findings suggesting that chimpanzees cannot be taken to represent the original state of proto-humans, that this species also evolved over time. Michael Balter writes.

Humans and chimps diverged from a common ancestor perhaps about 7 million years ago, and their hands now look very different. We have a relatively long thumb and shorter fingers, which allows us to touch our thumbs to any point along our fingers and thus easily grasp objects. Chimps, on the other hand, have much longer fingers and shorter thumbs, perfect for swinging in trees but much less handy for precision grasping. For decades the dominant view among researchers was that the common ancestor of chimps and humans had chimplike hands, and that the human hand changed in response to the pressures of natural selection to make us better toolmakers.

But recently some researchers have begun to challenge the idea that the human hand fundamentally changed its proportions after the evolutionary split with chimps. The earliest humanmade stone tools are thought to date back 3.3 million years, but new evidence has emerged that some of the earliest members of the human line—such as the 4.4-million-year-old Ardipithecus ramidus (“Ardi”)—had hands that resembled those of modern humans rather than chimps, even though it did not make tools. And back in 2010, a team led by paleoanthropologist Sergio Almécija, now at George Washington University in Washington, D.C., began arguing that even earlier human relatives, dating to 6 million years ago—very soon after the human-chimp evolutionary split—already had humanlike hands as well. This even included the ability to press the thumb against the fingers with considerable force, a key aspect of precision gripping.

To get a grasp on what early hands really looked like, Almécija and his colleagues analyzed the thumb and finger proportions of a large number of living apes and monkeys, including modern humans. They then compared these to the hands of several extinct species of apes and early humans, including Ardi, the Neandertals, and the 2-million-year-old Australopithecus sediba from South Africa, which its discoverers controversially think might be a direct ancestor of humans. The sample also included the 25-million-year-old fossil ape known as Proconsul.

The team crunched the measurements from all these samples using sophisticated statistical methods designed to determine the course of hand evolution over time. The researchers found that the hand of the common ancestor of chimps and humans, and perhaps also earlier ape ancestors, had a relatively long thumb and shorter fingers, similar to that of humans today. (Gorillas, which spend most of their time on the ground and not in trees, have similarly shaped hands.) Thus, the human hand retains these more “primitive” proportions, whereas the elongated fingers and shorter thumbs of chimps, as well as orangutans, represent a more specialized and “derived” form ideal for life in the trees, the team reports today in Nature Communications.

Written by Randy McDonald

October 3, 2015 at 3:57 am

Posted in Science

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[BLOG] Some Wednesday links

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  • At Antipope, Charlie Stross starts a discussion about the consequences of satellites getting knocked down. How would a newly satellite-less world cope?
  • Centauri Dreams looks at red dwarfs and the challenges of their potentially habitable exoplanets.
  • The Dragon’s Gaze considers ways to detect the spectral signatures of rocky impacts on young stars.
  • The Dragon’s Tales considers why nuking Mars in the aim of terraforming will not work.
  • Language Hat considers languages with royal and commoner registers.
  • Languages of the World starts a consideration of the links between genes and history and language.
  • Lawyers, Guns and Money notes the popularity of Planned Parenthood.
  • Marginal Revolution thinks the added pollution from the Volkswagen fraud had a trivial negative effect.
  • pollotenchegg maps Russian language use in 1926 Ukraine.

[BLOG] Some Friday links

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  • blogTO notes a proposal to make the Gardiner Expressway an equivalent of New York City’s High Line park and observes the dropping of charges against Toronto rooftopping photographers.
  • Crooked Timber notes that Trump is a consummate populist.
  • The Dragon’s Gaze maps the WASP-33 system and suggests Uranus was formed by a planetary collision.
  • The Dragon’s Tales notes progress has been made on synthetic telepathy.
  • Lawyers, Guns and Money examines the myth of the failure of public housing in the United States and notes the perverted minds of anti-sex conservatives.
  • The Russian Demographics Blog links to scenarios for Jewish population growth.
  • Window on Eurasia looks at the vulnerability of Belarus and notes anti-German sentiment in Kaliningrad.

[FORUM] How will we see the present in the longue durée?

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At the beginning of the month, rather acute science fiction writer Charlie Stross started a 1308-post discussion thread at his blog asking a question: How will the future see our present day? What will be the profound trends of note in the 1700-2300 period?

Please note that this is a 600 year span—around the duration of the entire mediaeval period. Events a mere 20 years apart, such as the first and second world wars, merge together when viewed through the wrong end of a temporal telescope, just like the 30 years’ war or the Wars of the Roses. Individual people, even hugely influential thinkers and rulers and tyrants, are a jumbled mass of names with dates attached. This is a question about the big issues—the ones big enough to remember half a millennium hence, like the Black Death, the Crusades, or the conquest of the Americas.

I’m not asking for specific historical events but for major trends. Anthropogenic climate change is obviously one of the big ones, and I have a number of others in mind; I want to see if I’ve missed anything obvious.

I’m inclined to think that the abandonment of traditional high-mortality/high-fertility demographic patterns is going to be one, along with the creation of a unified global society.

And you?

Written by Randy McDonald

September 19, 2015 at 10:19 pm

[LINK] On newly-discovered hominin species Homo naledi

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Homo naledi has just been discovered in South Africa, and as IFL Science notes this is hugely important.

textbook-worthy accident, H. naledi was first stumbled upon two years ago by amateur cavers during an exploration of a cave system known as Rising Star, located within South Africa’s famous Cradle of Humankind World Heritage Site. From this, the Rising Star Expedition was born, starting in November 2013 with a 21 day exploration involving a team of 60 scientists and volunteer cavers. Expecting to recover a single skeleton, just three days in they realized they had much more than that, “something different and extraordinary,” research leader Lee Berger said at a press event IFLScience attended.

That something different turned out to be not several, but 15 individuals from a single hominin species, represented by more than 1,500 fossil elements found within a single chamber in total darkness some 90 meters (295 feet) from the entrance. Named in tribute to the chamber, naledi means “star” in the South African language Sesotho. And sure, 1,500 sounds like a lot, is a lot, but the team believes that there are thousands and thousands of remains still untouched. “The floor is practically made of bones of these individuals,” Berger added.

Homo naledi. cc John Hawks_Wits University

In fact, so many have been recovered that almost every skeletal element of the body is represented multiple times throughout different age groups, from infants to teens, to young adults and the elderly. And the species seems to be a wonderful pick and mix of both primitive and human-like features. An exceptionally tall hominid, the bipedal H. naledi stood at around 150 centimeters (5 feet) and was distinctively slender, with powerful, well-muscled joints. Its skinny human proportions and long legs likely relate to the fact that it didn’t have to support much bodyweight, weighing in at around 45 kilograms (100 pounds).

Tall this species may have been, but members had an astonishingly tiny head. So tiny that their brains were as small as that of the smallest australopith – a group of extinct early hominins – with the females’ brains only being slightly larger than a chimpanzee’s at around 450-550 cubic centimeters (27-34 cubic inches). There was only a very small discrepancy between males and females, not just in terms of brain size but throughout the entire body. In fact, all of the individuals were remarkably similar, more so than if you were looking at sets of identical human twins, Berger said. Consequently, it is believed the individuals were likely closely related, perhaps a multi-generational family.

Written by Randy McDonald

September 10, 2015 at 9:10 pm

[BLOG] Some Wednesday links

  • blogTO notes that John Tory wants private industry to fund a Toronto bid for the Olympics.
  • Centauri Dreams notes a paper suggesting that the effects of panspermia might be detectable, via the worlds seeded with life.
  • The Dragon’s Gaze links to a paper suggesting that the Earth’s geological composition is likely to be unique.
  • The Dragon’s Tales notes the technological advancement of Neanderthals in Spain.
  • Far Outliers notes the extent to which some opposition to the Anglo-American invasion of Europe in the Second World War was motivated by pan-European sentiment.
  • Geocurrents dislikes very bad maps of human development in Argentina.
  • Language Hat notes that Jabotinsky wanted Hebrew to be written in Latin script.
  • Lawyers, Guns and Money reports on the Sad Puppies.
  • The Russian Demographics Blog notes a book talking about a specifically Orthodox Christian take on demography.
  • Spacing Toronto looks at the first ride at the CNE.
  • Torontoist notes a Toronto libraries “passport”.
  • Understanding Society notes M.I. Finley’s excellent book on the dynamics of the Roman Empire.
  • The Volokh Conspiracy notes a bizarre article published in a journal arguing that professors are equivalents to terrorists.
  • Why I Love Toronto recommends Dream in High Park.

[LINK] “FYI: Giving Birth in the Ocean with Wild Dolphins is *Still* a Fantastically Awful Idea”

Science Sushi’s Christie Wilcox reposted a 2013 article on the continuing popularity of the idea of giving birth admist dolphins. This might be a good idea if the dolphins were actively consenting to this activity. One wonders what the hell they think is going on.

Let’s talk about dolphins for a moment. I get it — they’re stunning creatures. These sleek, smart, playful animals are almost universally loved by people. Dolphin interactive experiences are hot sellers at tourist locations worldwide, and we naturally want to trust their cheeky, smiling faces. So many people I know got into marine science because of their affinity for dolphins and other marine mammals. I understand why a to-be mother might want to calm her nerves by having a dolphin in the tub during an underwater birth. I can even stretch my imagination and see why a woman would enjoy swimming with a pod of dolphins and giving birth while watching the beautiful displays of these majestic animals.


Because of their friendly disposition and common occurance in aquariums, we tend to think of dolphins as trustworthy, loving creatures. But let’s get real for a minute here. Dolphins don’t eat sunshine and fart roses. They’re wild animals, and they are known to do some pretty terrible things.

Et cetera.

Written by Randy McDonald

September 2, 2015 at 7:37 pm


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