Originally Gustafson and his colleagues dated the mastodon hunting at Manis to more than 13,500 years ago. This was nearly 1,000 years before the Clovis culture, long considered to be the first culture in the New World. Their research was heavily criticized, due to limitations in the radiocarbon methodology used for dating the archaeological findings. However a recent publication supported their finding; an international group of researchers led by Michael Waters of Texas A&M University used a refined radiocarbon dating methodology and DNA analyses to demonstrate that the projectile found at the site came from a mastodon bone shaped as a spear point, handcrafted 13,800 years ago.

After careful DNA extractions of the hunted mastodon rib and the bone projectile found, the researchers successfully amplified a 69 base pair DNA fragment from the mitochondrial control region. Both samples produced identical sequences to mastodon DNA obtained previously, but distinct from other proboscideans (mammoth or elephant) by nine single nucleotide polymorphisms (SNPs).

These findings support the hypothesis that humans had permanent settlements in the Americas earlier than the Clovis culture (11,500 years ago). The bone projectile also shows that humans actively hunted megafauna (i.e., animals bigger than 50 kg) in this region. In addition, it suggests that the slow process of extinction of the biggest mammals inhabiting the Americas after the last glacial period (approximately 15,000 years ago), such as mammoths and mastodons, may have begun earlier than the time of the Clovis people.

Find out more about all these fascinating discoveries:

• Gustafson, C. E., et al. (1979). The Manis mastodon site: early man on the Olympic Peninsula. Canadian Journal of Archaeology, 3: 157-164.
• Radiocarbon dating methodology:
  • www.c14dating.com
  • http://en.wikipedia.org/wiki/Radiocarbon_dating
• Waters, M. R., et al. (2011). Pre-Clovis mastodon hunting 13,800 years ago at the Manis Site, Washington. Science 334, 6054: 351-353.
• Waters, M. R. et al. (2011). The Buttermilk Creek complex and the Origins of the Clovis at the Debra L. Friedkin Site, Texas. Science, 331, 6024: 1599-1603.

Affectionately known as “Ardi”, some of her features were distinctive. Due to her location in the ancient Ethiopian strata, she was dated to 4.4 million years ago, pre-dating “Lucy” (Australopithecus afarensis) by over a million years. Her brain size was much smaller than Lucy’s but was similar to that of a modern chimpanzee.  According to the form of her limbs and pelvis, she was able to walk upright, yet she had a grasping hallux (big toe) on each foot, which suggests that she had an arboreal lifestyle.  This theory was supported by the fossils discovered locally near Ardi’s resting place.  This “woodland” lifestyle came as a surprise to scientists because Ardi’s descendant, Australopithecus afarensis (“Lucy”), lived on the savannah.  Now thoughts on the evolution of bipedalism must be re-threaded.  

To date, Ardi (Ardipithecus ramidus) has replaced Lucy (Australopithecus afarensis) as the oldest hominid fossil.  Genetically, the common ancestor between humans and chimps was estimated to exist 6 million years ago.  “Ardi” takes us one step closer to that ancestor.

For more on Ardi, see our interview with researcher, Tim White, at the DNALC website here.

Ardi sketch redirected from The Guardian.