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Tuesday, January 4, 2011

Out of Africa and into America - H. erectus

 
Thinking about how our friend Homo erectus could have got in to America from his Old World home (the Bering route is very plausible but it is also cold and long), I wondered if H. erectus could have just come across the Atlantic Ocean from his original home in Africa.

I was aware of H. erectus sites along eastern Africa but did not know if there were any along the western coast of Africa (where they would have had to "set sail" for America). Well, the answer is yes, H. erectus did live in western Africa as shown in the map below: [1]

homo erectus dispersal
Above: Homo erectus occupation at 1 million years ago resulting from colonisation most consistent with the observed record of arrival (100%=black, 0%=white). From: [1]

You can see that they spanned Africa's Atlantic seaboard from Senegal to Angola. Could they have used simple log rafts to fish or move along the coast? Did a storm or sea currents drag them across the Atlantic?

A raft, wind and currents

The trade winds blow in a western direction in the Tropical Atlantic areas [2] and, the Southern Equatorial Current has a speed of about 1 meter / sec, which means that a raft would be pushed 86.4 km per day (53.7 miles/day) in a westerly direction. [2]

The current links the Gulf of Guinea and the easternmost point of Brazil (where the cities of Natal and Recife are located). The minimum distance between both continents is there, and is only 2,800 km (1,740) mi. Which at the speed given above would mean a voyage of about 32 days. Of course, the sea current does not traverse the Ocean at its narrowest point, so we could estimate a distance of about 5,000 km (3,107 mi) from the bottom of the Gulf of Guinea to Natal. This would take 58 days to cover.

The Atlantic has been crossed from the Canary Islands to the Caribbean by Dr. Hannes Lindeman in 1956, in 72 days, solo, in a kayak. So it is possible to cross the Ocean in flimsy craft and survive.[3]

See my post on the navigating abilities of H. erectus, who sailed across open stretches of sea in Indonesia some 800,000 years ago.


Additionally, the African Homo erectus, could explain the findings in Brazil (Lagoa Santa area) and Buenos Aires. The map below summarizes the route, the sites and the location:

homo erectus across the Atlantic
Homo erectus a possible route from Africa to America across the Atlantic Ocean.
Copyright 2011 by Austin Whittall

Now, to survive, reproduce and grow enough to expand and move across the continent towards Buenos Aires and north, to Mexico, the group must have had females, and should have been quite large. Perhaps it was not a chance event, perhaps they embarked on an expedition and the winds and currents pushed them west.

Actually, the discovery of Brazil by Portuguese sailors in 1500 is attributed to this same effect: Pedro Alvarez de Cabral was sailing to India when a storm drove him away from his route.

My next post will summarize and index all my previous posts on H. erectus to make a simple entry point to access all the information. Future posts will also be referenced there.

Still, I have not found any references to unusual Patagonian skulls or remains. I will keep on searching.

Sources.

[1] Paul Valdes, Bruce Sellwood, Steve Mithen, Sam Smith, Alan Haywood, Sarah Elton and Hannah O'Regan, Advanced computer modelling of hominin dispersal from Africa: integrating archaeological and palaeoclimatic simulations. The Environmental Factors in the Chronology of Human Evolution & Dispersal programme (EFCHED). Natural Environment Research Council.
[2] S. G. Philander, (2001). Atlantic Ocean Equatorial Currents
[3] Hannes Lindeman (1957). Alone at sea for 72 days. The true story of a German doctor who sails and paddles a 17 foot kayak across the Atlantic Ocean. NSW Sea Kayaker vol. 41. Citing a Life Magazine Article (July 22, 1957).


Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia
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2011 International Year of Forests Copyright 2009-2011 by Austin Whittall © 

2 comments:

  1. Why not the Behring Strait. Didn't bisons and possibly other animals make it across? Walking food? All that homo erectus had to do is follow them.

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  2. Actually yes, Behring Strait is definitively an option and I posted about it: http://patagoniamonsters.blogspot.com.ar/2010/12/erectus-in-america-journey-from-asiae.html
    This Transatlantic route is another possible way of getting to America from Africa.
    Thanks for posting.

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