(Roughly) Daily

Posts Tagged ‘homo-sapiens

“In a series of forms graduating insensibly from some apelike creature to man as he now exists, it would be impossible to fix on any definite point where the term ‘man’ ought to be used”*…

 

fingerbone

Homo sapiens finger bone, dating back some 86,000 years, found at a site called Al Wusta in Saudi Arabia

 

Darwin turns out to right about the difficulty of dating the emergence of man, not only for the reason he intended (that our emergence from prior species was so gradual as to be indetectable as an “event”) but also because it’s turning out to be difficult to date the earliest examples we can agree are “man” and to figure out when they reached the places they settled…

The Nefud Desert is a desolate area of orange and yellow sand dunes. It covers approximately 25,000 square miles of the Arabian Peninsula. But tens of thousands of years ago, this area was a lush land of lakes, with a climate that may have been kinder to human life.

On a January afternoon in 2016, an international team of archaeologists and paleontologists was studying the surface of one ancient lake bed at a site called Al Wusta in the Nefud’s landscape of sand and gravel. Their eyes were peeled for fossils, bits of stone tools, and any other signs that might remain from the region’s once-verdant past.

Suddenly, Iyad Zalmout, a paleontologist working for the Saudi Geological Survey, spotted what looked like a bone. With small picks and brushes, he and his colleagues removed the find from the ground.

We knew it [was] important,” Zalmout recalled in an email. It was the first direct evidence of any large primate or hominid life in the area. In 2018, lab tests revealed that this specimen was a finger bone from an anatomically modern human who would have lived at least 86,000 years ago.

Prior to this Al Wusta discovery, evidence in the form of stone tools had suggested some human presence in the Nefud between 55,000 and 125,000 years ago. To anthropologists, “human” and “hominin” can mean any of a number of species closely related to our own. The finger bone was the oldest Homo sapiens find in the region.

The bone’s dating contradicts a well-established narrative in the scientific community. Findings, particularly from the area of modern-day Israel, Jordan, and Lebanon, known as the Levant region, have led to the understanding that H. sapiens first made their way out of Africa no earlier than 120,000 years ago, likely migrating north along the Mediterranean coast. These people settled in the Levant and their descendants—or those from a subsequent early human migration out of Africa—traveled into Europe tens of thousands of years later.

Only later, that story goes, did they journey into parts of Asia, such as Saudi Arabia. By some estimates, then, anatomically modern humans would not have been in what is now Al Wusta until about 50,000 years ago.

The fingerbone, then, adds a twist to the tale of how and when our species left the African continent and, with many starts and stops, populated much of the rest of the earth. A new crop of discoveries, particularly from Asia, suggest that modern humans first left Africa some 200,000 years ago, taking multiple different routes…

Politics, geography, and tradition have long focused archaeological attention on the evolution of Homo sapiens in Europe and Africa. Now, new research is challenging old ideas by showing that early human migrations unfolded across Asia far earlier than previously known: “Will Asia Rewrite Human History?

* Charles Darwin, The Descent of Man

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As we return to roots, we might spare a thought for Jean-Léon-François Tricart; he died on this date in 2003.  A physical geographer and climatic geomorphologist known for his extensive regional studies in numerous countries of Africa.

Tricart was a pioneer in many fields of physical geography including the study of a phenomenon central to the migration of early Homo Sapiens, the major dynamic role of climate in landscape evolution.

Screen Shot 2020-05-04 at 4.41.59 PM source

 

Written by (Roughly) Daily

May 6, 2020 at 1:01 am

“So profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being”*…

 

Human skull

A Neanderthal skull shows head trauma, evidence of ancient violence

 

Nine human species walked the Earth 300,000 years ago. Now there is just one. The Neanderthals, Homo neanderthalensis, were stocky hunters adapted to Europe’s cold steppes. The related Denisovans inhabited Asia, while the more primitive Homo erectus lived in Indonesia, and Homo rhodesiensis in central Africa.

Several short, small-brained species survived alongside them: Homo naledi in South Africa, Homo luzonensis in the Philippines, Homo floresiensis (“hobbits”) in Indonesia, and the mysterious Red Deer Cave People in China. Given how quickly we’re discovering new species, more are likely waiting to be found.

By 10,000 years ago, they were all gone. The disappearance of these other species resembles a mass extinction. But there’s no obvious environmental catastrophe – volcanic eruptions, climate change, asteroid impact – driving it. Instead, the extinctions’ timing suggests they were caused by the spread of a new species, evolving 260,000-350,000 years ago in Southern Africa: Homo sapiens.

The spread of modern humans out of Africa has caused a sixth mass extinction, a greater than 40,000-year event extending from the disappearance of Ice Age mammals to the destruction of rainforests by civilisation today. But were other humans the first casualties?…

More at “Were other humans the first victims of the sixth mass extinction?

* “… so profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being; and as we do not see the cause, we invoke cataclysms to desolate the world, or invent laws on the duration of the forms of life!”
Charles Darwin, The Origin of Species

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As we wonder about our lost siblings, we might spare a thought for Marie Jean Pierre Flourens; he died on this date in 1867.  A physiologist, he was the founder of experimental brain science and a pioneer in anesthesia.  He was the first to demonstrate the general functions of the major portions of the vertebrate brain; more generally, through the study of ablations on vertebrate animals, he was the first to prove that the mind was located in the brain, not the heart (as was then believed).

Ironically, he was a Creationist– an opponent of Darwin and the theory of natural selection.

220px-Pierre_flourens source

 

Written by (Roughly) Daily

December 6, 2019 at 1:01 am

Scoping scale…

On AndaBien, web designer Steve Rose pursues his extra-vocational enthusiasms… among them, evolution.

His Evolution Timeline is a marvelous evocation of the sheer temporal scale of our antecedents.

— From first life-forms to homo sapiens

* The background indicates inches and feet.
* 1/20th in. = roughly 100 thousand years. (108,000)
* 1 inch = about 2 million years. (2,160,000)
* 1 foot = about 26 million years. (25,920,000)
* The whole page is about 135 feet wide, almost half a football field, representing 3.5 billion years. (3,500,000,000)

The very beginning of the timeline (and of life on Earth)

So, be prepared to scroll…  and scroll and scroll and scroll…  And to learn.  (By way of reinforcing one’s sense the extraordinary sweep of it all, readers might also appreciate Rose’s “Evolution, The Movie.”)

As we struggle with the recent revisions to the tree of life and the suggestion that humans are more closely related to fungus than to plants, we might recall that it was on this date in 1886 that Coca-Cola was first sold to the public at the soda fountain in Jacob’s Pharmacy in Atlanta, Georgia.  It was formulated by pharmacist John Stith Pemberton, who mixed it in a 30-gallon brass kettle hung over a backyard fire.  Pemberton’s recipe, which survived in use until 1905, was marketed as a “brain and nerve tonic,” and contained extracts of cocaine and (caffeine-rich) kola nut. The name, using two C’s from its ingredients, was suggested by his bookkeeper Frank Robinson, whose excellent penmanship provided the famous scripted  “Coca-Cola” logo.

Pemberton’s Palace

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