Appendix 5. Textual analysis of Curr-Bio 205
Appendix 5. Textual analysis of Curr-Bio All the academic words in the following text (Kittler / Kayser / Stoneking 2003) are highlighted in italics and the assignment of each academic word occurrence to one of six functional categories is indicated by the appearance of the following symbols immediately before each word. Symbol Functional category Metatextual Extratextual Intratextual Scholarly process States of affairs Relations between entities # Attitudinal Summary The human head louse (Pediculus humanus capitis) and body louse (P humanus corporis or P. h. humanus) are strict, obligate human ectoparasites that differ mainly in their habitat on the host [1, 2]: the head louse lives and feeds exclusively on the scalp, whereas the body louse feeds on the body but lives in clothing. This ecological differentiation probably arose when humans adopted frequent use of clothing, an important event in human evolution for which there is no direct archaeological evidence. We therefore used a molecular clock approach to date the origin of body lice, assuming that this should correspond with the frequent use of clothing. Sequences were obtained from two mtDNA and two nuclear DNA segments from a global sample of 40 head and body lice, and from a chimpanzee louse to use as an outgroup. The results indicate greater diversity in African than non-African lice, suggesting an African origin of human lice. A molecular clock analysis indicates that body lice originated not more than about 72,000 ± 42,00 years ago; the mtDNA sequences also indicate a demographic expansion of...
You are not authenticated to view the full text of this chapter or article.
This site requires a subscription or purchase to access the full text of books or journals.
Do you have any questions? Contact us.Or login to access all content.