Origins of Human Evolution

[hardaker]

Here is a source for a Surfer Joe scenario for human evolution. Seems to be gaining relevancy every day. Neat stuff. It may even pertain to how erectus evolved the smarts to make boats 800ky, maybe even the great journeys taken by 1.7ma to Dmanisi, Indonesia, China. Phys Anths seem to be bothered by it, but what else is new.
http://www.google.com/search?num=50&hl= ... tnG=Search

Chris

[Beagle]

In the search for origins - the use of fire and it's associated technologies are distinctly human. In this scientific article, the evidence presented is the use of fire - in hearths used to harden flint tools.

How many of us know that flint can be hardened with the proper use of fire? Too much, and you damage the flint, and too little, you do nothing. This seems relatively sophisticated. Especially for 790,000 years ago.

http://www.paleoanthro.org/journal/cont ... 070001.pdf

This scholarly paper is best read in full screen, and when you have a few minutes.

[Forum Monk]

Interesting article, Beagle - thanks for posting it. In reading it, I didn't get the impression flint was being intentionally "worked" or tempered in fire although the presence of burnt flint helped to confirm the use of fire.

Brings up an interesting question however: what is the approx. date of the first wide-spread use of flint for tools?

[hardaker]

Thanks Beagle. Downloading it now. Is this about heat-treating of flint? At 790k, it should ruffle some feathers. Looking forward to it. Thanks.

[Beagle]

Hi Chris/FM. The article above is only about the controlled use of fire at around 800kya. It doesn't attempt to prove anything else. My comments about the flint findings were partly to deflect the thought "Why are those dummies trying to cook flint?".

http://donsmaps.com/heatflint.html

In comparing fracture surfaces produced before and after heat-treatment, they find that heat-treated cherts fracture to form much smoother surfaces. In unheat-treated cherts, fracture fronts appear to pass between the quartz microcrystals, breaking the relatively weak bonds holding the crystals together. At the high magnification used in SEM, these surfaces appear topographically rough. In heat-treated cherts, however, the fracture appears to pass through many of the microcrystals, leaving a much smoother fracture surface. The smoother surface reflects light more evenly and produces an increased surface luster or "greasy" texture that is macroscopically visible and has served as an indication of thermal alteration to many investigators

This is a brief review of heat treatment. I do wish the authors of the previous paper had gone that one step further and declared that the heating of those flints were consistent with known thermal techniques. All I can say is it looks like it to me. That would be something at that early date. But that coincides with the date of proposed early seafaring also.
Your thoughts are appreciated.

And while I've got you Chris, I'm confused about the Lupemban technology that Charlie referred me to. I've been looking at it this last weekend and I may pmail you later with questions.
Something does not click.

[hardaker]

Hi. Yeah, I was thrown off because heat-treating trick is to heat it up but not too much and not too close to the fire itself. It is an annealing process, and generally done under a fire in a sand bath and left in place for about a day before digging up the flakes or preforms. But the article is great because it puts fire back a long ways and it is an xlnt way to establish human (intentional) from natural fires.

Looked up Lupemban and it says it is about 40ky. It also has tool types that suggest bipolar flaking was used (adzes, wedges and planes). What did Charlie give you?
Chris

[Beagle]

Looked up Lupemban and it says it is about 40ky. It also has tool types that suggest bipolar flaking was used (adzes, wedges and planes). What did Charlie give you?
Chris

I'll pmail you. Thanks Chris.

[hardaker]

Yeah, thanks. I thought it was older, and more advanced and also a Mid Stone Age assemblage. Will try to look into it further when time permits.

[john]

Just when you thought das klub was safe ......... from Archeological News (yeah, that other button)........

Did seafood encourage 'Out of Africa' trips?

October 17 2007 at 10:28AM
By Richard Ingham

Paris - Archaeologists have uncovered the earliest known remains of human habitation by the coast, a finding that may explain how humans ventured beyond Africa at the start of their planetary odyssey.

Mussel shells, sharpened pieces of red ochre and stone micro-tools found in a sea cave in South Africa suggest that Homo sapiens headed for the beach quite soon after emerging from the savannah, they say.

By stumbling upon the rich harvest of the sea, Man found the means to explore beyond Africa, sustaining himself through maritime edibles by probing along the coast, they suggest.

Until now, the earliest evidence of human settlement by the coast dates from 120 000 years ago - about 80 000 years after the approximate time when, according to fossil evidence, H. sapiens arose in the grasslands of East Africa.

Experts have long suspected that coastal migration must have occurred earlier than this.

The problem, though, has been finding proof to back this belief.

Turn the clock back to an era between 195,000 and 135,000 years ago, and you will find Earth in the grip of an Ice Age.

So much water was locked up in glaciers that the sea level was as much as 125 metres lower than today. When the glaciers eventually retreated, the sea rose once more, swamping coastlines and sweeping away the traces of habitation.

One remarkable location that survived, though, was a cave overlooking the Indian Ocean in coastal cliffs at Pinnacle Point, near South Africa's Mossel Bay.

The cave is so high that, even now, it is 15 metres above the sea. At the time when it was inhabited, it was located within five to 10 kilometres of the coast.

Curtis Marean of Arizona State University led a team that sifted through the cave's walls and floor and found remains of hearths, of some two dozen shellfish, mainly brown mussels, as well as 57 pieces of ochre pigment, some of them brilliant red, and nearly three dozen "bladelets", or tiny tools made of chipped stone.

The find has been dated to around 164 000 years ago, give or take 12 000 years, according to their paper, which appears on Thursday in the British weekly journal Nature.

Marean believes the discovery opens a door to understanding the movements of our early forebears.

During the long glacial period, southern Africa was cooler and drier, and hunter-gatherers probably found it hard to get food from animals, fruits and berries, he says.

Moving to the coast thus opened up a whole new larder of food.

"Shellfish may have been a critical food source to the survival of human populations when they were faced with depressed terrestrial productivity during glacial stages... when much of southern Africa was more arid and populations were isolated and perhaps concentrated on now-submerged coastal platforms," the study says.

Seafood was the biggest shift in the human diet until animal farming began at the end of the last Ice Age, roughly 11 000 years ago, it contends.

Once humans realised the bounty of food that lay within their grasp, they could use it for sustenance as they moved out of Africa, along the coast of the Red Sea and northwards into the Middle East and beyond, as the species embarked on its trek around the world.

Humans expanded into southern Asia along the coast and also island-hopped their way to Australia and New Guinea using coastal food resources.

In a commentary, also published by Nature, anthropologist Sally McBrearty of the University of Connecticut and palaeontologist Chris Stringer of London's Natural History Museum say the pigment is an equally exciting find.

This substance, also called haematite, has some practical use as an adhesive.

However, the brilliant red colours that feature in the find suggest it was also used for decorating the body or objects, given that red has always played a key role in human rite and society.

"It suggests that early humans in Africa inhabited a cognitive world enriched by symbols before 160 000 years ago," the pair say. - Sapa-AFP

Eeeenteresting!

We got hematite (red ochre), we got blades, we got sushi. Also, I believe, though I can't remember where I read this, some very old seashells perforated for a necklace. S. Africa, circa 70,000 BP?

This article has some resonance over in the Neandertal thread, also.

And where you have people using the ocean as a food resource, you're gonna have boats.

I'll make my point once again: we have severely underestimated the intellectual and organizational abilities of early man.

This time its the 164,000 year question.

Gotta love it.


john

Minimalist -

Are you referring to the (news) article quoted above?

Now, if all it's used for is to "prove" the Out of Africa theory, I'll agree with you.

My own take is this: this site provides physical evidence of the occurrence of complex cognitive behavior well before the horizon assigned by Das Klub. There is no mention of human species-specific remains associated with these artifacts; therefore any conclusion about species is, by definition, suspect.

On the other hand of the absurd, the concept that a group of mussels emigrated several kilometers inland, then flaked stone and ground hematite in a precursor ritual to self immolation (which mussel lighted the pyre?) is just a touch far-fetched.

My point?

Early man - choose your species, any species - had a hell of a lot more on the ball a hell of a lot earlier than "the proof" would indicate.

Given the paucity of physical evidence, I find this exercise far more akin to tracking wild game, or "reading sign" than some "absolute" mitochondrial proof of an african eve.

The existence of any of the Homo species, from the day to the millenium, has never been static, as far as I can tell. Why then should Science attempt to prove or disprove this process by static analysis? Smacks of the politics of position rather than the hard-won grace of understanding, to me.


Hoka Hey

John

[Minimalist]

I don't know. I can't remember.

[Rokcet Scientist]

Lemme guess: a Gonzalez quote?

[Beagle]

http://www.sciencenews.org/articles/20071103/bob9.asp

Fifty years ago, British anatomist Wilfrid Le Gros Clark explained in a lecture why evolutionary scientists argue so vehemently about how ancient apelike and humanlike creatures eventually gave way to modern humans. "Every fossil relic which appears to throw light on connecting links in man's ancestry always has, and always will, arouse controversy," he stated, "and it is right that this should be so, for it is very true that the sparks of controversy often illuminate the way to truth."

This article seems almost tailor made for this thread. While these theories change almost overnight it seems, this is about the latest thinking regarding our evolution.

[Rokcet Scientist]

Great article.
Here's a thought: how about rating articles according to the the number of bible quotations it can elicit from Arch and Stephen trying to refute it?

[Rokcet Scientist]

Here, this is cute: this article suggests the genome is much more volatile to change in some places than in others. This could severely upset the assumptions underlying the currently accepted DNA-modelling.

Ars Technica reports on a new study that suggests not only that certain areas of the mouse genome undergo more changes, but that changes to those areas are more tolerable by the organism than changes in other areas. Recently published in Nature Genetics, the study examined the certain copy number variations of the C57Bl/6 strain in mice that have been diverging for less than 1,000 generations. The results were a surprising number of variations. While the study does not address it, Ars Technica goes on to recount suggestions that genomes evolved to the point where they work well with evolution.

Go to the article: http://arstechnica.com/journals/science ... nstability.

[Minimalist]

Doesn't it seem that some genetic mutations might be off limits? By that I mean, let's say for example that the gene which controls the creation of hemoglobin stops functioning due to a mutation. Would that organism survive birth? However, a mutation for red-hair or blue eyes would have no immediate detrimental effect on the organism and so would be inconsequential enough to make it into the gene pool.

One wonders what the genetic overlap between humans and mice may be? Or humans and crocodiles?