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Science 10 July 2009:
Vol. 325. no. 5937, p. 148
DOI: 10.1126/science.1167672
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Technical Comments

Response to Comment by Goldberg et al. on "DNA from Pre-Clovis Human Coprolites in Oregon, North America"

Morten Rasmussen1,*, Linda Scott Cummings2,*, M. Thomas P. Gilbert1, Vaughn Bryant3, Colin Smith4, Dennis L. Jenkins5 and Eske Willerslev1,{dagger}

1 Centre for Ancient Genetics, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
2 Paleo Research Institute, 2675 Youngfield Street, Golden, CO 80401, USA.
3 Palynology Laboratory, Department of Anthropology, Texas A&M University (TAMU 4352) College Station, TX 77843–4352, USA.
4 Max Planck Institute for Evolutionary Anthropology, Department of Human Evolution, 04103 Leipzig, Germany.
5 Museum of Natural and Cultural History, 1224 University of Oregon, Eugene, OR 97403–1224, USA.


Figure 1
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  		Fig. 1. Nubian coprolite from a child about 5 years of age, from an Early Christian cemetery (21-S-46), used between 500 and 750 C.E., located at Kulubnarti, on the Nile River in the Batn el Hajar of Sudanese Nubia. Wave numbers of infrared light are represented along the bottom, expressed as cm–1. Absorbance (amplitude) is represented on the left scale. Amplitude varies with preservation, as well as original presence of the compounds. CAP yields peaks at 610 and 566 wave numbers, as well as a broad peak between 1530 and 1400 wave numbers, representing the C-O stretching vibration and a peak at 878 wave numbers, representing the C-O out-of-plane vibration. These peaks are missing from this human coprolite, which yielded pollen, phytolith, macrofloral, and/or faunal evidence for dates, sorghum, and fish scales (3). Although Goldberg et al. (1) note the presence of silicates in the wave-number range of 450 to 1100, we highlight that peaks in the low 1000s can also represent carbohydrates and cellulose, whereas various polysaccharides (also carbohydrates) are denoted by numerous peaks between 800 and 1170 wave numbers. Goldberg et al. (1) also mention that wave numbers 1300 to 1400 represent organics, implying that this is the only portion of the spectrum that represents organic matter. However, there are many portions of the mid-infrared spectrum that are associated with organic matter, which include the above-mentioned carbohydrates and polysaccharides, fats/lipids/plant waxes between 3000 and 2800 wave numbers, aromatic and saturated esters at multiple locations (including 1705 to 1750 cm–1 and 1130 to 1030 cm–1), and proteins in multiple locations, including 1350 to 1490 cm–1, 1500 to 1600, and others (15).

 

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