Homo erectus the sailor: in previous posts I mentioned that H. erectus could have used watercraft to reach America, but I did not reference the statement. Today we will see what evidence supports the idea of a navigating erectus.
Flores island or crossing Wallace’s line
H. erectus after leaving Africa trekked along South Asia’s coast and reached what is now Indonesia. There he came to a dead end at Bali. The sea blocked any further advances towards the south.
However, a Dutch missionary named Theodor Verhoeven , an amateur archeologist who lived on Flores Island, discovered on that island, some man-made stone tools together with the remains of an extinct elephant (the Stegodon) which dated back to over 750,000 years ago. He concluded that the tools were as old as the bones and that the only humans of that period (H. erectus) had made the tools and, much more important, reached Flores Island.
Flores was not linked to the rest of South East Asia at that time, it was isolated by a strait of treacherous deep sea from the other land masses.
This was a formidable barrier, and actually divides the fauna of Asia (monkeys, rhinos, elephants) from that of Australia and New Guinea, confining marsupials to the latter. It is known as Wallace’s line (after biologist Russel Wallace who, independently from Charles Darwin, and at the same time, formulated a theory of evolution based on natural selection).
Animals could only island hop up to Wallace’s line. One one side was "Sundaland", which comprised the mainland and the large Indonesian Islands, which when the sea level was lower, formed a large land mass (Malay Peninsula, Sumatra, Java, Bali and Borneo).
On the other side, was "Sahul" which comprised Australia, Tasmania and New Guinea. In between was “Wallacea”, formed by the islands of Flores, Timor, Celebes (Sulawesi), Lombok and other lesser ones.
Homo erectus the sailor
So, to get to Flores Island, our distant ancestor had to master the art and craft of watercraft building, as well as that of navigating. Quite a feat, which until recently science did not consider possible (the oldest human navigators were believed to be the Homo sapiens who entered Australia some 50 to 60,000 years ago.
For this reason Verhoeven’s claim was ignored (and also because he was an amateur who published in German in an Anglo speaking scientific world).
In 1994 another Dutch group, headed by Paul Sondaar,  dated the soil using a paleomagnetic method at a site called Mata Menge to an age of 750,000 years.
Later dating by fission-track method confirm the date, and place it 800,000 years ago. This means that these primitive humans were not so primitive and had quite developed cognitive abilities, such as a language to ensure cooperation between sailors and ship-builders.
However there are skeptics: as only tools, not erectus bones have been found some some believe that these may be natural and not man-made artifacts.
There is more evidence to support the idea of erectus in Flores: the islands’ odd mix of giant komodo dragons and tortoises plus pygmy stegodon elephants all became extinct quite suddenly some 900,000 years ago. Did humans cause these extinctions?
The distance from Sumbawa Island to Flores is some 19 km (12 mi), and before that the straits between Sumbawa and Bali (25 km or 16 mi ) had to be crossed also. This could not be done by swimming. Furthermore, a stable population would have been required to produce the tools found at Flores and span such a long period of time.
The American link
Of course, the tall volcanoes of Indonesia’s islands would have let men see where they were going even if they did not see the coast of the islands. They knew where they were going.
If erectus had gone on towards Australia as some believe, he would have ventured into the unknown, and had to cross a longer stretch of open sea. To reach America along the northern coastal waters of Asia along Beringia and then down the Western coast of America would have been quite a feat, and would have needed sturdy, well built craft.
Perhaps H. erectus reached Melanesia, and when modern humans reached this region, mixed with them, sharing part of their genome with us: The DNA from H. erectus remains from Denisova, Siberia, shows current Melanesians share about 5 percent of their DNA with these Denisovans, a sign of ancient interbreeding.
At Flores, nearly one million years ago, they perhaps floated across on bundles of bamboo. They may have even undertaken the first voyage accidentally, pushed by the wind while fishing close to the shore. Perhaps they later learned to assemble their rafts to deliberately cross the sea in a safer way.
Until modern humans appeared in Africa some 170,000 years ago, and then moved out of Africa and displaced / replaced erectus there was a long span of time during which the more archaic humans could have moved on, from Asia and into America. Where they settled until modern humans moved in too less than 50,000 years ago.
Update. Jan. 21, 2011: Crude stone tools found in Crete, Greece dated to some 130 - 700,000 years ago indicate that H. erectus crossed at least 65 km (40 mi) of open sea to reach Crete from the mainland. (see my post on this find Homo erectus navigator reaches Crete).
 Verhoeven, Theodor, (1968). Vorgeschichtliche Forschungen auf Flores, Timor und Sumba. Athropica: Gedenkschrift zum 100. Geburtstag von P. W. Schmidt, Studia Instituti Anthropos No. 21, St. Augustin, pp. 393-403.
 Sondaar, P. Y., van den Bergh, G. D., Mub-roto, B., Aziz, F., de Vos, J., and Batu, U. L., (1994). Middle Pleistocene faunal turnover and colonization of Flo-res (Indonesia) by Homo erectus. Comptes Rendus de l'Academie des Sciences Paris 319: 1255-1262.
 Morwood, M,J., O'Sullivan, P.B., Aziz, F., & Raza, A. (1998). Fission-track ages of stone tools and fossils on the east Indonesian island of Flores. Nature, 392(6672):173-176.
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia2011 International Year of Forests Copyright 2009-2011 by Austin Whittall ©