History Community ~ All Empires Homepage


This is the Archive on WORLD Historia, the old original forum.

 You cannot post here - you can only read.

 

Here is the link to the new forum:

  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Forum LockedMobility of early humans

 Post Reply Post Reply Page  <123
Author
gcle2003 View Drop Down
Immortal Guard
Immortal Guard
Avatar

Joined: 06-Dec-2004
Location: Luxembourg
Status: Offline
Points: 7011
Post Options Post Options   Thanks (0) Thanks(0)   Quote gcle2003 Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 14:57
Originally posted by calvo calvo wrote:

According to DNA analysis, human beings did spread over a large distance over a few thousands years.
Let's say that human beings left Africa 65,000 years ago, and 50,000 years ago they were in Australia.
How many kilometres are there between the Horn of Africa and Australia if they travelled along beach? If you divide that between 15,000 years (with a margin of errror), we could more or less calcalute the standard migration rate.
Taking a kind of smooth semi-circular route across the gulf states to Pakistan then east and then south-east it's about 10,000 miles. Which would make about 2/3 of a mile a year, which is fairly typical. An average human can walk several thousand miles in a year.
Quote  
I'm still more inclined to believe that the migration was more likely caused by expansion. The individuals who left Africa were about 200 strong; let's say 50 moved on along the South Asian coast to Australia. When their numbers grew, new communities were formed to the east of the original clan.... and so on, so on, therefore leaving a chain of human settlements along the Asian coast all the way to Australia.
How long do you think it would take for a settlement of 50 people to get to be 200 strong and therefore feel the need to move on again?
 
Citizen of Ankh-Morpork
Never believe anything until it has been officially denied - Sir Humphrey Appleby, 1984.
Back to Top
Carcharodon View Drop Down
Baron
Baron


Joined: 04-May-2007
Location: Sweden
Status: Offline
Points: 479
Post Options Post Options   Thanks (0) Thanks(0)   Quote Carcharodon Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 15:07
Originally posted by gcle2003 gcle2003 wrote:

I can do that in my habitat. They can do it in theirs. It depends on where you grow up and what you learn. So?
 
Many of those people could backtrack even if leaving their habitat, that is something not so many of modern people can without technical backup.
 
Originally posted by gcle2003 gcle2003 wrote:

What would I think be blatantly wrong would be to assume that primitive peoples in general were necessarily either better or worse at certain physical feats than modern humans (ignoring diet and training). You'd expect them of course to evolve characteristics suitable for their environment but that would only happen if they stayed around for a long time in the same surroundings.
 
I can agree that it depends on training and diet.  If you take a little child from, let us say, New York and and let him be raised by a so called "primitive" people he will of course obtain the same knowlege, stamina and endurance as they have. What I mean is that people who are raised in a nature environment and who live as hunters and gathers or as seminomads or even as garden farmers have developed skills (by training and way of life) that few people in modern urban society have. And similar skills would also have been required long ago. That is a factor one has to take into consideration when discussing prehistoric mobility.
 


Edited by Carcharodon - 11-Jun-2009 at 15:08
Back to Top
fantasus View Drop Down
Samurai
Samurai
Avatar

Joined: 07-May-2009
Location: denmark
Status: Offline
Points: 111
Post Options Post Options   Thanks (0) Thanks(0)   Quote fantasus Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 15:20

Why this belief in the number 200? I cannot see another reason than exaggerated pretentions on the part of scientists that "they know". Probably they think there is "genetical evidence" of the numbers, and I admit my very limited knowledge about prehistoric genetics. The same can be said about this "average(or "standard") expansion rate" for how scarce is the evidence? For me such "standard" seems more like fiction.

And of course we cannot set a (true) "standard growth rate" for populations at that time either (in fact we even cannot for contemporary populations). But if we did it anyway, let say assumed an average doubling time each millenium, the initial 50 individuals would grow to more than 500000 in 15000 years, and to astronomical size by now. 
Back to Top
drgonzaga View Drop Down
Colonel
Colonel


Joined: 15-May-2005
Status: Offline
Points: 609
Post Options Post Options   Thanks (0) Thanks(0)   Quote drgonzaga Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 15:49
In reading through the thread, I was struck by the near Biblical tenor of assumptions and posits and the desire to instill a coherent "origins theory". Back in 1982 I attended a rather interesting symposium that led to the publication of a heady tome titled: Paleopathology at the Origins of Agriculture (Orlando: Academic Press, 1984). The editors of the publication, Mark Cohen and George Armelagos, compiled an excellent and succint summation of what the bones and artifacts tell us:

____During the upper Paleolithic stage, subsistence seems focused on relatively easily available foods of high nutritional value, such as large herd animals and migratory fish. Some plant foods seem to have been eaten, but they appear not to have been quantitatively important in the diet. Storage of foods appears early in many sequences, even during the Paleolithic, apparently to save seasonal surpluses for consumption during seasons of low productivity.
____As hunting and gathering economies evolve during the Mesolithic [period of transition between hunting/gathering and agriculture], subsistence is expanded by exploitation of increasing numbers of species and by increasingly heavy exploitation of the more abundant and productive plant species. The inclusion of significant amounts of plant food in prehistoric diets seems to correlate with increased use of food processing tools, apparently to improve their taste and digestibility. As [Dr. Mark Nathan] Cohen suggests, there is an increasing focus through time on a few starchy plants of high productivity and storability. This process of subsistence intensification occurs even in regions where native agriculture never developed. In California, for example, as hunting-gathering populations grew, subsistence changed from an early pattern of reliance on game and varied plant resources to to one with increasing emphasis on collection of a few species of starchy seeds and nuts.
____...As [Dr. Cohen] predicts, evolutionary change in prehistoric subsistence has moved in the direction of higher carrying capacity foods, not toward foods of higher-quality nutrition or greater reliability. Early nonagricultural diets appear to have been high in minerals, protein, vitamins, and trace nutrients, but relatively low in starch. In the development toward agriculture there is a growing emphasis on starchy, highly caloric food of high productivity and storability, changes that are not favorable to nutritional quality but that would have acted to increase carrying capacity, as Cohen's theory suggests.

Paleopathology, pp. 565-568.
The book is chock-full of startling observations not least of which is the association of agriculture with the decline of quality-of-life:
Most [studies] conclude that infection was a more common and more serious problem for farmers than for their hunting and gathering forebears; and most suggest that this resulted from some combination of increasing sedentism, larger population aggregates, and the well-established synergism between infection and malnutrition.
"Taken as a whole, these indicators fairly clearly suggest an overall decline in the quality-- and probably in the length-- of human life associated with the adoption of agriculture"  (Ibid., p. 568) . Paleolithic Man, the bones tell us, did not face chronic cycles of abundance and shortages in the food supply so characteristic of sedentary societies at the closing of the Neolithic and the rise of sedentarism. 
 
Could the development of agriculture be more an imposition from ecological marginality than any presupposed expansion of populations? Fertile soils abounded on the planet's surface, yet the sedentarism necessary for the rise of "urbanism" (and what we choose to call "civilization") takes place in riverine or tropical forest environments under ecological assault.
 
Of particular interest in the cited publication is Lawrence J. Angel. "Health as a Crucial Factor in the Changes from Hunting to Developed Farming in the easter Mediterranean". p. 51-73.
 


Edited by drgonzaga - 11-Jun-2009 at 15:52
Back to Top
drgonzaga View Drop Down
Colonel
Colonel


Joined: 15-May-2005
Status: Offline
Points: 609
Post Options Post Options   Thanks (0) Thanks(0)   Quote drgonzaga Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 16:02
Originally posted by fantasus fantasus wrote:

Why this belief in the number 200? I cannot see another reason than exaggerated pretentions on the part of scientists that "they know". Probably they think there is "genetical evidence" of the numbers, and I admit my very limited knowledge about prehistoric genetics. The same can be said about this "average(or "standard") expansion rate" for how scarce is the evidence? For me such "standard" seems more like fiction.

And of course we cannot set a (true) "standard growth rate" for populations at that time either (in fact we even cannot for contemporary populations). But if we did it anyway, let say assumed an average doubling time each millenium, the initial 50 individuals would grow to more than 500000 in 15000 years, and to astronomical size by now. 
 
How about this chart as summarized from the above cited Paleopathology: "Health as a Crucial Factor..."
 

HEALTH & LONGEVITY OF ANCIENT PEOPLES

Pelvic Inlet Depth Index
% (higher is better)

Average Adult Stature

Median
Lifespan (yrs)

Historical Time Period

Male
cm
(ft/in)

Female
cm
(ft/in)

Male

Fem.

30,000 to 9,000 B.C. ("Late Paleolithic" times, i.e., roughly 50/50 plant/animal diet--according to latest figures available elsewhere.)

97.7

177.1
(5'9.7)

166.5
(5'5.6)

35.4

30.0

9,000 to 7,000 B.C. ("Mesolithic" transition period from Paleolithic to some agricultural products.)

86.3

172.5
(5'7.9)

159.7
(5'2.9)

33.5

31.3

7,000 to 5,000 B.C. ("Early Neolithic," i.e., agriculture first spreads widely: As diet becomes more agricultural, it also becomes more vegetarian in character--relatively much less meat at roughly 10% of the diet, and much more plant food, much of which was grain-based.)

76.6

169.6
(5'6.8)

155.5
(5'1.2)

33.6

29.8

5,000 to 3,000 B.C. ("Late Neolithic," i.e., the transition is mostly complete.)

75.6(?)

161.3
(5'3.5)

154.3
(5'0.7)

33.1

29.2

3,000 to 2,000 B.C. ("Early Bronze" period)

85

166.3
(5'5.4)

152.9
(5'0.2)

33.6

29.4

2,000 B.C. and following ("Middle People")

78.8

166.1
(5'5.4)

153.5
(5'0.4)

36.5

31.4

Circa 1,450 B.C. ("Bronze Kings")

82.6(?)

172.5
(5'7.9)

160.1
(5'3.0)

35.9

36.1

1,450 to 1,150 B.C. ("Late Bronze")

79.5

166.8
(5'5.7)

154.5
(5'0.8)

39.6

32.6

1,150 to 650 B.C. ("Early Iron")

80.6

166.7
(5'5.6)

155.1
(5'1.1)

39.0

30.9

650 to 300 B.C. ("Classic")

83.5

170.5
(5'7.1)

156.2
(5'1.5)

44.1

36.8

300 B.C. to 120 A.D. ("Hellenistic")

86.6

171.9
(5'7.7)

156.4
(5'1.6)

41.9

38.0

120 to 600 A.D. ("Imperial Roman")

84.6

169.2
(5'6.6)

158.0
(5'2.2)

38.8

34.2

Medieval Greece

85.9

169.3
(5'6.7)

157.0
(5'1.8)

37.7

31.1

Byzantine Constantinople

87.9

169.8
(5'6.9)

154.9
(5'1.0)

46.2

37.3

1400 to 1800 A.D. ("Baroque")

84.0

172.2
(5'7.8)

158.0
(5'2.2)

33.9

28.5

1800 to 1920 A.D. ("Romantic")

82.9

170.1
(5'7.0)

157.6
(5'2.0)

40.0

38.4

"Modern U.S. White" (1980-ish presumably)

92.1

174.2
(5'8.6)

163.4
(5'4.3)

71.0

78.5

 
Expanding population pressures are modern phenomena in terms of overall numbers given the constricting qualities of infant mortality and disease.


Edited by drgonzaga - 11-Jun-2009 at 16:04
Back to Top
calvo View Drop Down
General
General


Joined: 20-May-2007
Location: Spain
Status: Offline
Points: 848
Post Options Post Options   Thanks (0) Thanks(0)   Quote calvo Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 16:23
the number 200 comes from the genes.
That the amount of genetic diversity among non-Africans today could be trace back to 150-200 people 70,000 years ago.
No one has any idea of the world population by the dawn of the Neolithic age (10,000 years ago); but considering that there are human settlements all over the world: Europe, Middle East, Central Asia India, East Asia, Africa, North and South America; the total numbers would be in the tens or hundreds of thousands, if not approaching a million.
Therefore, over 60,000 years human numbers outside of Africa had indeed expanded from a few hundred to a number hundreds of times greater.
I do agree that the expansion was not linear, there were probably population bottlenecks caused by natural disasters etc; yet an overgrowth of an existinting population would probably mean that certain members would have to break off and form a new colony. Considering that hunter-gatherers required a vast extension of land, the new colony would have to be located at least a tens of kilometres from the old one to avoid "stepping on each other's territories".
 
Regarding the table of life expectancy. What is the source? How did they do the calculations? Was infant-mortality taken into account?
 
I ask these questions because a survey of life expectancy made in Spain in the year 1900 yielded a number of 32: the average age at which people died. Not that nobody reached the age of 40, but rather that so many people died in childhood that the average was dragged down.
This number, however, does not seem to fit so well with the table.
 
 
 
Back to Top
gcle2003 View Drop Down
Immortal Guard
Immortal Guard
Avatar

Joined: 06-Dec-2004
Location: Luxembourg
Status: Offline
Points: 7011
Post Options Post Options   Thanks (0) Thanks(0)   Quote gcle2003 Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 18:43
Is there any reason to suppose that the variance in such statistics was any less in earlier periods than it is now? Especially in those periods where no geographical range is given.
 
In general though the figures are pretty much what one would expect.
Citizen of Ankh-Morpork
Never believe anything until it has been officially denied - Sir Humphrey Appleby, 1984.
Back to Top
Carcharodon View Drop Down
Baron
Baron


Joined: 04-May-2007
Location: Sweden
Status: Offline
Points: 479
Post Options Post Options   Thanks (0) Thanks(0)   Quote Carcharodon Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 18:55
The time span in the above shown tabel that is labeled early bronze age are roughly equivalent to the middle neolithic period in Scandinavia (aorund 3200 - 2300 BC). In this period we can in the southern parts see three distinct archaeological cultures. We have the funnel beaker culture, a megalith grave culture, followed by the so called battleaxe culture. Both of these depended on agriculture and pastoralism (especially the later seems to depend heavily on pastoralism). And then we have at the same time the semi hunter gatherers along the coasts called the pitted ware culture. Norhtwards in Scandinavia we had also inland hunters and gatherers with another material culture. These peoples relations and eventual kinship to each other and their subsistence and mobilty are subject to several interesting research projects.

Edited by Carcharodon - 11-Jun-2009 at 22:32
Back to Top
fantasus View Drop Down
Samurai
Samurai
Avatar

Joined: 07-May-2009
Location: denmark
Status: Offline
Points: 111
Post Options Post Options   Thanks (0) Thanks(0)   Quote fantasus Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 19:59
Those numbers, with precice decimals and without any uncerntainties are nothing but absurd!
Of course no scientist of today have that knowledge. Historians of very much more recent days would not take such data seriously, if they read about them (let us say from first modern statistics, even from 18.th century). And tell me if I am wrong, but how many data do we have for the "expansion" from Africa (65000years ago?) to Australia (50000years ago). Could it be we have not very much more than for two places?
to calvo: If we "for fun" accept a doubling rate each 1000 years from 65000 years, the resulting number would be mvery much more than You seem to realise(?) a number with twenty something zeros i think.
Back to Top
drgonzaga View Drop Down
Colonel
Colonel


Joined: 15-May-2005
Status: Offline
Points: 609
Post Options Post Options   Thanks (0) Thanks(0)   Quote drgonzaga Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 22:21
Originally posted by fantasus fantasus wrote:

Those numbers, with precice decimals and without any uncerntainties are nothing but absurd!
Of course no scientist of today have that knowledge. Historians of very much more recent days would not take such data seriously, if they read about them (let us say from first modern statistics, even from 18.th century). And tell me if I am wrong, but how many data do we have for the "expansion" from Africa (65000years ago?) to Australia (50000years ago). Could it be we have not very much more than for two places?
to calvo: If we "for fun" accept a doubling rate each 1000 years from 65000 years, the resulting number would be mvery much more than You seem to realise(?) a number with twenty something zeros i think.
 
How about reviewing the cited source before venturing out on the limb of the Poo Poo tree? If anything, archaeological discoveries since 1984 and refined forensic science have strengthened the conclusions for the Paleolithic. Even introductory courses on the topic certainly are more illustrative of "historians" today than your superficial dismissal of long and careful study: e.g.
 
 
Perhaps a refresher on what the bones "say" can calm all the negativity:
 
Abstract
Analysis of skeletal remains from humans living in the past forms an important complement to observational and experimental studies of living humans and animal models. Including earlier humans in such analyses increases the range of variation in both behavior and body size and shape that are represented, and can provide insights into the adaptive potential of the modern human skeleton. I review here a variety of studies of archaeological and paleontological remains that have investigated differences in skeletal structure from a mechanical perspective, focusing in particular on diaphyseal strength of the limb bones. Several conclusions can be drawn from these studies: 1) there has been a decline in overall skeletal strength relative to body size over the course of human evolution that has become progressively steeper in recent millennia, probably due to increased sedentism and technological advancement; 2) differences in pelvic structure and hip mechanical loadings affect femoral shape; 3) activity patterns affect overall strength and shape of both the lower and upper limb bones; and 4) responsiveness to changes in mechanical loading varies between skeletal features (e.g., articulations versus diaphyses) and by age.
 
 
As you can see the data is taken very seriously. And an answer to your own question on "sites" is as close as your labtop with abundant data from myriads of sites dating from 100,000 to 20,000 BC.
Back to Top
drgonzaga View Drop Down
Colonel
Colonel


Joined: 15-May-2005
Status: Offline
Points: 609
Post Options Post Options   Thanks (0) Thanks(0)   Quote drgonzaga Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 22:58
Calvo wrote:
 
"Regarding the table of life expectancy. What is the source? How did they do the calculations? Was infant-mortality taken into account?
I ask these questions because a survey of life expectancy made in Spain in the year 1900 yielded a number of 32: the average age at which people died. Not that nobody reached the age of 40, but rather that so many people died in childhood that the average was dragged down. This number, however, does not seem to fit so well with the table."
 
Placing aside the different patterns of population aging within countries, a factor that did affect life expectancy in Spain for the year 1900, one must always keep in mind morbidity rates. After all, it is not until the last few generations that pregnancy does not constitute a significant risk to life expectancy or that today ageing males are rapidly increasing and addressing the imbalance between sexes after age 65 generated by lower risks in child bearing. As for the issue of the table and high infant mortality, one might assume that factor as stable throughout the periods summarized given the role of Science since the 1920s. Infant and preadolescence mortality prior to 1900 was astronomical, but rather than embark upon detailed exposition, here is a good intro:
 

Prior to 1900, infant mortality rates of two and three hundred obtained throughout the world. The infant mortality rate would fluctute sharply according to the weather, the harvest, war, and epidemic disease. In severe times, a majority of infants would die within one year. In good times, perhaps two hundred per thousand would die. So great was the pre-modern loss of children's lives that anthropologists claim to have found groups that do not name children until they have survived a year. 

Back to Top
calvo View Drop Down
General
General


Joined: 20-May-2007
Location: Spain
Status: Offline
Points: 848
Post Options Post Options   Thanks (0) Thanks(0)   Quote calvo Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2009 at 22:58
Originally posted by fantasus fantasus wrote:

Those numbers, with precice decimals and without any uncerntainties are nothing but absurd!
Of course no scientist of today have that knowledge. Historians of very much more recent days would not take such data seriously, if they read about them (let us say from first modern statistics, even from 18.th century). And tell me if I am wrong, but how many data do we have for the "expansion" from Africa (65000years ago?) to Australia (50000years ago). Could it be we have not very much more than for two places?
to calvo: If we "for fun" accept a doubling rate each 1000 years from 65000 years, the resulting number would be mvery much more than You seem to realise(?) a number with twenty something zeros i think.
 
I suggest that you check out this website:
 
 
It belongs to an ongoing project into investigating the genetic origins of human beings today, and many academics from universities of all over the world participate in this project.
This website is very informative and explains with colloquial language the methods of genetic analysis of human beings.
I suggest that you read all the articles on this website before challenging my statements.
 
 
Back to Top
gcle2003 View Drop Down
Immortal Guard
Immortal Guard
Avatar

Joined: 06-Dec-2004
Location: Luxembourg
Status: Offline
Points: 7011
Post Options Post Options   Thanks (0) Thanks(0)   Quote gcle2003 Quote  Post ReplyReply Direct Link To This Post Posted: 12-Jun-2009 at 10:46
What would  be extra interesting would be some information on how far these variations are simply due to adaptation and lifestyle - i.e. are 'acquired characteristics' and how many represent genuine genetic evolution - i.e. are transmissible characteristics.
Citizen of Ankh-Morpork
Never believe anything until it has been officially denied - Sir Humphrey Appleby, 1984.
Back to Top
fantasus View Drop Down
Samurai
Samurai
Avatar

Joined: 07-May-2009
Location: denmark
Status: Offline
Points: 111
Post Options Post Options   Thanks (0) Thanks(0)   Quote fantasus Quote  Post ReplyReply Direct Link To This Post Posted: 12-Jun-2009 at 15:46
You can all bet I dismiss those numbers regarding palaeolithic age as long as I have seen no evidence at all there is enough material to conclude anything with such accuracy. And of course 20.th century statistics are an entirely different matter, though I suspect there may even be some uncertainty aboub contemporary demographic data in a lot of cases.
Back to Top
 Post Reply Post Reply Page  <123
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 11.10
Copyright ©2001-2017 Web Wiz Ltd.

This page was generated in 0.063 seconds.