Anthropology.net

Mark Aldenderfer, from the anthropology department at the University of Arizona in Tucson, has just published a paper with several other authors which made the cover of the PNAS. The cover features a gold and turquoise necklace found from excavations of burials in Jiskairumoko, a site near Lake Titicaca in Peru. The significance of this find is that it is the oldest known gold object made in the Americas and shows us that status symbols like jewelery began before the appearance of more complex societies in the Andes.

So, just how old is it? Radiocarbon dating for the burials indicate the artifact is 3,776 to 3,690 old and was alongside the jawbone of an elderly female adult skull in a burial pit next to primitive pithouses. During this time hunter-gatherers occupied the area. Markings on the necklace indicate that gold nuggets had been flattened with a stone hammer. They were skillfully crafted around a hard cylindrical object to form tubular beads.

Mark Aldenferfer interprets the find as an, “emerging social role for gold beyond simple decoration.” He told BBC News:

“The gold reflects a universal tendency for human beings to strive for prestige and status.

The gold reflects that process in people living in a simple society which is in the process of becoming more complex.

[and were] not at all different to today… This reflects a lot more than just a lovely object… This is a major piece of how people lived their lives and how they competed for status in the past.”

The paper was published yesterday. Here’s the title and link, “Four-thousand-year-old gold artifacts from the Lake Titicaca basin, southern Peru.”

Amongst people who do not fully understand evolutionary biology, there’s this big misconstrued concept that human evolution has slowed down or even that humans have stopped evolving. If you don’t believe me check out the following links which are in chronological order from 1992 to 2006.

1. Has Human Evolution Ended?
2. Is human evolution finally over?
3. Are we still evolving?

Some think that evolution has stopped because humans, and other higher organisms, are so complex, that the shear number pleiotropic interactions impedes on the rate evolution change. In a new Nature paper, Günter Wagner and crew have studied pleiotropy in mice. They investigated the quantitative trait loci (QTLs) that affect skeletal characters. They conclude that,

“most QTLs affect a relatively small subset of traits and that a substitution at a QTL has an effect on each trait that increases with the total number of traits affected. This suggests that evolution of higher organisms does not suffer a ‘cost of complexity’ because most mutations affect few traits and the size of the effects does not decrease with pleiotropy.”

Here’s the title and link to the paper, “Pleiotropic scaling of gene effects and the ‘cost of complexity’.” This paper is not only significant in clearing up this misunderstanding, but also enlightening in showing us how mutations simultaneously affect multiple phenotypic characters.

Wagner, G.P., Kenney-Hunt, J.P., Pavlicev, M., Peck, J.R., Waxman, D., Cheverud, J.M. (2008). Pleiotropic scaling of gene effects and the ‘cost of complexity’. Nature, 452(7186), 470-472. DOI: 10.1038/nature06756