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Therefore, the fluorine content test results reported by Day and Molleson remain consistent with (but are not proof of) an early Middle pleistocene age of about 800,000 years for the anatomically modern human trinil femurs.

A nitrogen content test was also performed on the trinil bones. dubois had boiled the skullcap and the first femur in glue. Day and Molleson (1973, p. 147) attempted to correct for this by “pre-treating the samples in order to remove soluble nitrogen before analysis.” Results showed that all of the trinil bones listed in table 7.1 had very little nitrogen left in them. this is consistent with all of the bones being of the same early Middle pleistocene age, although day and Molleson (1973, p. 148) did report that nitrogen in bone is lost so rapidly in Java that even Holocene bones often have no nitrogen. the uranium contents of the Trinil hominid bones and fauna were all almost zero, again consistent with (although not proof of ) their being of the same early Middle pleistocene age.

this data is from day and Molleson (1973, pp. 147–148). the figures represent the ratio of fluorine (F) to phosphate (P2O5) in the bones.

7.5.3 Uranium Content Testing of the Sangiran Fossils

In our discussion of the Sangiran hominid finds reported by von Koenigswald (Section 7.3) and later researchers (Section 7.4), we learned that almost all occurred on the surface. We suggested that this made their real age uncertain.

Some might infer a Middle or early pleistocene date for the Sangiran fossils on the basis of their equivalent U3O8 (uranium oxide) content. For example, the S1a upper jaw discovered in 1936 has an equivalent uranium content of 25 parts per million (ppm), somewhat less than that of 63 ppm for a Cervus (deer) antler from the same general region (Oakley et al. 1975, p. 109).

Sangiran 1a (S1a) was found on the surface, and von Koenigswald simply assumed it weathered out of the putjangan formation. therefore, we are not able to measure the concentration of uranium, either in the groundwater or in other fossils, at the precise location where Sangiran 1a, if in fact from the putjangan formation, lay buried. if we were able to compare the uranium contents of the S1a jaw and other bones from the same spot and found them similar, that would be consistent with, although not proof of, the view that they were of the same age.

But lacking such evidence, the reported uranium content for the S1a jaw itself gives little reason to suggest that the S1a jaw is as old as the putjangan formation. We cannot exclude the possibility that Sangiran 1a is a very young bone that was originally situated in a stratum through which uranium-rich waters percolated.

day and Molleson (1973, p. 148) reported that two Late pleistocene bones from Ngandong had uranium contents of 25 and 30 ppm. These figures are not directly comparable with the uranium content of 25 ppm for the supposedly early Pleistocene Sangiran 1a jaw, but they do demonstrate the difficulty in interpreting the kind of uranium content data reported by Oakley et al. (1975).

the above line of reasoning is also applicable to the other Sangiran hominid fossils, since they were also found on the surface or in other dubious ways.

7.6 Misleading Presentations of The Java Man Evidence

Most books dealing with the subject of human evolution present what appears at first glance to be an impressive weight of evidence for Homo erectus in Java between 0.5 and 2.0 million years ago. One such book is The Fossil Evidence for Human Evolution (1978), by W. e. Le Gros clark, professor of anatomy at Oxford University, and Bernard G. campbell, adjunct professor of anthropology at the University of california at Los Angeles. An impressive table showing discoveries of Homo erectus is presented in their book ( Le Gros clark and campbell 1978, p. 94). these discoveries (table 7.2, p. 498) have been used widely to support the belief that man has evolved from an apelike being.

t3 is the femur found by dubois at a distance of 45 feet from the