jim sims

Darwin in Southern South America

This year is the 200th anniversary of the birth of Charles Darwin, a man who changed our way of looking at the natural world in a profound way in the 19th century. You can watch Gary Williams, Ph.D. recount his youthful trip to Argentina and Chile, places where Darwin was able to get off the HMS Beagle and explore southern South America.

Expanding the American Identity

This post is a follow-up to the one I wrote previously on the American Identity near the holidays in December of 2006.  This week, an African American became the president-elect of the United States of America.  This development is nothing short of a paradigm shift in the political psyche of the nation, and a hopeful example to all nations and all peoples.  The American dream is surely alive in her people today. It does seem possible for a fairly broad cross section of the American people to judge others based on the content of their character, rather than the color of their skin, even when choosing the chief executive of the nation. 

I am old enough to have grown up in a racially segregated community in America with white only drinking fountains and white only bathrooms. About the only place whites and blacks saw each other up close in any numbers was at the movie theaters. Blacks climbed the stairs to sit in the balcony as required, while the whites sat downstairs.  It was a confusing thing for a young white boy to take in. As I graduated high school, the civil rights movement was in high gear.  I think Dr. Martin Luther King, Jr. would be smiling if he were here today, to see that African Americans can, and many have come down off the mountain, and they have walked with other Americans into that promised land, which is the full share in the American Dream.

Would it not be ironic, if this development found resonance in the hearts and minds of other oppressed and disenfranchised people, yearning to be be free, even unto those in the hills of Pakistan and Afghanistan?  Let it be so.

More evidence: earlier peopleing of the Americas

Tom D. Dillehay et al. report new analyzes of ancient hearth remains from the Monte Verde site in modern-day Chile, which indicate human presence at that site as early as 14,220 years B.P.  The analysis indicates the people of the area exploited several different ecosystems:  ocean-beach, river delta and inland locations.  In the same issue of Science is a paper by M. Thomas P. Gilbert et al. that reports on the recovery and sequencing of ancient human mtDNA from coprolites (feces) in Oregon in the Northwest of the United States.  They found mtDNA haplogroups A2 and B2. Their dating of the human samples is at least 1,000 years older than the Clovis toolkit dates.

Refs: Tom D. Dillehay et al., Monte Verde: Seaweed, Food, Medicine, and the Peopling of South America , Science 320:784-786 (2008) DOI: 10.1126/science.1156533

M. Thomas P. Gilbert, et al., DNA from Pre-Clovis Human Coprolites in Oregon, Science 320:786-788 (2008) DOI: 10.1126/science.1154116

mtDNA & a single pre-Clovis peopling of the Americas

In this very interesting research paper, the authors produce 86 complete human mtDNA sequences from natives of North, Meso and South America to reconstruct the time to most recent common ancestor for each of the native-specific haplogroups in the Americas (A2,B2,C, D1, X2a). As can be seen in the the top part of the figure at left, all of the haplogroups in the Americas appear to be converge on a date between 23,000 and 18,000 years ago (gray shaded area) suggesting this is the time humans first entered the Americas. This predates the Clovis toolkit, which appeared around 13,000 years ago.  The bottom half of the figure shows the estimated effective female population, which appears to be on the order of 1,000 individuals (center line). The authors say their data supports a single peopling event and argues against mutliple migration hypotheses.

Ref: Nelson J.R. Fagundes et al., Mitochondrial Population Genomics Supports a Single Pre-Clovis Origin with a Coastal Route for the Peopling of the Americas, Journal of Human Genetics 82, 583–592, March 2008