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CT Scan from Mijares

Definitely the Callao man is a human.  However,  proof is still needed to show that he is a MODERN human (Homo sapiens).  Unless there is that proof, the Tabon man is still the oldest Filipino.

But perhaps more than what’s written above, this find is very important in the study of early humans and their pattern of migration.

Philippine history says that our earliest ancestors traveled to the islands via a land bridge from Southeast Asia.  The discovery of the Tabon man supported this hypothesis being the oldest known modern human in the country.  There seems to be no questions before about this hypothesis since Palawan where Tabon is located, is indeed connected to mainland Asia.

In an article of A. Mijares et. al. which appeared in the Journal of  Human Evolution [1],  they studied a sample of a metatarsal (a foot bone) in Callao.  Two things are interesting about the find:

1) The bone is older than the Tabon man; and 2) That the bone was dug in an area known to be not connected with mainland Asia.

The Callao right metatarsal III from Mijares

How old?

Using direct dating via U-series ablation (a form of radiactive dating), the minimum age estimate obtained was 67,000 +/- 1000 years old.  This is older than the Tabon man (47,000 +/- 11,000). As for the age of the individual when it died, they estimated that it belongs to a young adult (adult) based on CT scans.

How’d they know it’s Human?

They compared the morphology of the bone to the same bone of the Philippine negrito (Homo sapiens),  a Homo habilis and three other primates.  The bone closely resembles the Philippine negrito but are much smaller leading the author to allude a connection with Homo floresiensis found in Flores, Indonesia.   The authors did not conclude about the taxonomic placement of the bone but definitively said that it belongs to a Homo.

From left to right: Callao man, H. sapiens, H. habilis, and the other primates from Mijares

How’d they get there?

The islands of the Philippines except for Palawan,  is geographical isolated even at the peak of the lowest ocean height.  There is no way to get to Callao unless using a boat or a raft.  This means that these humans can travel open seas.  This is strong support to the hypothesis that early humans are also seafarers.

plus a rather interesting comment from the authors…

The discoveries at Callao Cave also raise some other important questions about the cultural behavior of these early colonizers of the Philippine archipelago.  For example, even though there is evidence of butchery in the animal bone assemblage, not a single stone implement was recovered, suggesting perhaps the use of an alternative technology.

What could have been this technology?  More excavation is still necessary according to the authors.


Armand Salvador Mijares and Philip Piper are from UP Diliman; Florent Détroit and Guillaume Champion are from CNRS, France;  Rainer Grün, Peter Bellwood, and Maxime Aubert are from the ANU, Australia;  Nida Cuevas, Alexandra De Leon, and Eusebio Dizon are from the National Museum of the Philippines.


[1] A.S. Mijares et al. , Journal of Human Evolution 59 (2010) 123-132.  DOI:10.1016/j.jhevol.2010.04.008