Hypothesis Testing in Palaeoanthropology

Abstract

Hypothesis testing is used to guide scientific research by narrowing down possible explanations for a phenomenon, using the principle of elimination of alternative scenarios. Thus, scientists test hypotheses by attempting to falsify them. A hypothesis is deduced from observed patterns and aims at linking those patterns to the factors proposed to have caused it. Hypothesis testing is frequently accompanied by statistical tests of null hypotheses, focusing on the inferential analysis of sample properties such as the mean and the variance. For instance, if there is less than a 5% chance that two samples are drawn from the same entity, we reject the null hypothesis and claim that these samples are significantly different. A salient point to keep in mind when testing hypotheses is that a successful evaluation of a hypothesis depends critically on the manner in which it was formulated. Hypotheses pertaining to the origin of modern humans are reviewed and evaluated.

Key Concepts

  • A hypothesis links observed patterns to the factors proposed to have caused it.
  • Scientists do not attempt to prove that a hypothesis is true.
  • Hypothesis testing guides scientific research by narrowing down possible explanations for a phenomenon, using the principle of elimination of alternative scenarios.
  • Statistical tests assess the probability that a hypothesis is true or false.
  • It is important for hypotheses to specify testable predictions.
  • Several hypotheses have been proposed to explain the origin of modern humans.
  • Hypotheses explaining modern human origins each make several predictions, some of which can be readily tested using paleontological and genetic data.

Keywords: hypothesis; deductive thinking; statistical significance; origin of modern humans; replacement; multiregional

Figure 1. Diagrams illustrating several of the major hypotheses for the origin of modern humans. A) Strict Replacement hypothesis; B) Replacement with Hybridization hypothesis; C) Assimilation hypothesis; D) Diffusion Wave hypothesis; E) Recurrent African Expansion hypothesis; F) Multiregional Evolution hypothesis. The Diffusion wave hypothesis is depicted in a way similar to the Assimilation model. However, in the former case, the arrows would represent gene flow between adjacent populations, while in latter case, the arrows would represent gene exchange between migrants and indigenous populations. Black color in the big arrows indicates anatomically modern . Modelled from Aiello (). Reproduced with permission from Joanna Cameron.
close

References

Aiello LC (1993) The fossil evidence for modern human origins in Africa: a revised view. American Anthropologist, New Series 95: 73–96.

Ball IR (1976) Nature and formulation of biogeographical hypotheses. Systematic Zoology 24: 407–430.

Bräuer G (1992) Africa's place in the evolution of Homo sapiens. In: Bräuer G and Smith FH (eds) Continuity or replacement: controversies in Homo sapiens evolution, pp. 83–98. Rotterdam: AA Balkema.

Cann RL, Stoneking M and Wilson AC (1987) Mitochondrial DNA and human evolution. Nature 325: 31–36.

Cann RL (1988) DNA and human origins. Annual Review of Anthropology 17: 127–143.

Crisp MD, Trewick SA and Cook LG (2011) Hypothesis testing in biogeography. Trends in Ecology and Evolution 26: 66–72.

Eswaran V (2002) A diffusion wave out of Africa: the mechanism of the modern human revolution? Current Anthropology 43: 749–774.

Green RE, Krause J, Briggs AW, et al. (2010) A draft sequence of the Neandertal genome. Science 328: 710–722.

Henn BM, Gignoux CR, Jobin M, et al. (2011) Hunter‐gatherer genomic diversity suggests a southern African origin for modern humans. Proceedings of the National Academy of Sciences 108: 5154–5162.

Li JZ, Absher DM, Tang H, et al. (2008) Worldwide human relationships inferred from genome‐wide patterns of variation. Science 319: 1100–1104.

McDougall I, Brown FH and Fleagle JG (2005) Stratigraphic placement and age of modern humans from Kibish, Ethiopia. Nature 433: 733–736.

Popper KR (1959) The Logic of Scientific Discovery. London: Routledge.

Reich D, Green RE, et al. (2010) Genetic history of an archaic hominin group from Denisova Cave in Siberia. Nature 468: 1053–1060.

Relethford JH and Harpending HC (1994) Craniometric variation, genetic theory, and modern human origins. American Journal of Physical Anthropology 95: 249–270.

Seielstad M, Bekele E, Ibrahim M, et al. (1999) A view of modern human origins from Y chromosome microsatellite variation. Genome Research 9: 558–567.

Smith FH (1985) Continuity and change in the origin of modern Homo sapiens. Zeitschrift ftir Morphologie und Anthropologie 75: 197–222.

Smith FH (1992) The role of continuity in modern human origins. In: Braüer G and Smith FH (eds) Continuity or Replacement: Controversies in Homo sapiens Evolution, pp. 145–156. Rotterdam: Balkema.

Stringer CB, Hublin J‐J and Vandermeersch B (1984) The origin of anatomically modern humans in western Europe. In: Smith FH and Spencer F (eds) The Origins of Modern Humans: A World Survey of the Fossil Evidence, pp. 51–135. New York: Alan R. Liss.

Stringer CB and Andrews P (1988) Genetic and fossil evidence for the origin of modern humans. Science 239: 1263–1268.

Templeton AR (2002) Out of Africa again and again. Nature 416: 45–51.

Thorne AG and Wolpoff MH (1981) Regional continuity in Australasian Pleistocene hominid evolution. American Journal of Physical Anthropology 55: 337–349.

Tishkoff SA, Dietzsch E, Speed W, et al. (1996) Global patterns of linkage disequilibrium at the CD4 locus and modern human origins. Science 271: 1380–1387.

Tishkoff SA, Pakstis AJ, Stoneking M, et al. (2000) Short tandem‐repeat polymorphism/Alu haplotype variation at the PLAT locus: implications for modern human origins. American Journal of Human Genetics 67: 901–925.

Waters JM and Craw D (2006) Goodbye Gondwana? New Zealand biogeography, geology, and the problem of circularity. Systematic Biology 55: 351–356.

Wolpoff MH, Wu X and Thorne AG (1984) Modern Homo sapiens origins: a general theory of hominid evolution involving the fossil evidence from East Asia. In: Smith FH and Spencer F (eds) The Origins of Modern Humans: A World Survey of the Fossil Evidence, pp. 441–483. New York: Alan R. Liss.

Wolpoff MH (1989) Multiregional evolution: the fossil alternative to Eden. In: Mellars P and Stringer C (eds) The Human Revolution, pp. 62–108. Princeton: Princeton University Press.

Wright S (1943) Isolation by distance. Genetics, 28: 139–156.

Further Reading

Ellison AM, Gotelli NJ, Inouye BD, et al. (2014) P values, hypothesis testing, and model selection: it's déjà vu all over again. Ecology 95 (3): 609–610.

Sedgwick P (2014a) Pitfalls of statistical hypothesis testing: multiple testing. BMJ 349: g5310.

Sedgwick P (2014b) Understanding statistical hypothesis testing. BMJ 348: g3557.

Sedgwick P (2014c) Pitfalls of statistical hypothesis testing: type I and type II errors. BMJ 349: g4287.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Makedonska, Jana A, and Strait, David S(Jul 2015) Hypothesis Testing in Palaeoanthropology. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0026160]