The cladistic race concept: race and biological reality

Andreasen, R. O. (2000). “Race: biological reality or social construct?” Philosophy of Science 67: S653-666.

Andreasen, R. O. (2004). “The cladistic race concept: a defense.” Biology and Philosophy 19: 425-442.

In these two publications, Andreason argues that human race is biologically real and cladistic concept explains the human biological race.  Cladistic races are “ancestor-descendent sequences of breeding populations that share a common origin” (2004:430) and she views cladistic races as “geographically circumscribed breeding populations” (2004:436), or subspecies.  While there are similarities between cladistic race and common sense race (for example, shared ancestry), there are significant differences as well.  Common sense racial classification is based on similarities in physical characteristics, but two individuals who have similar physical characteristics can belong to different cladistic racial groups. 

She believes that phylogenetic trees of human populations accurately represent evolutionary relationships between different human populations and objectively categorize people into racial groups using cladistic approach.  She cites Cavalli-Sforza and Nei, and says

…many evolutionalists agree that it is possible to accurately represent human evolution as a branching pattern.  As long as this is possible it is possible to define race cladistically (2004:427).

She is a philosopher of science, but it seems that she is not familiar with more recent human population genetics literatures that discuss how the gene flow and admixture have shaped the genetic variation of many human populations.  She does not address the issues raised by anthropological geneticists, how the phylogenetic trees do not accurately represent the evolutionary relationship of human populations.

Following Cavalli-Sforza, she also assumes that human populations are relatively reproductively isolated due to geographic barriers and socio-cultural factors.

A ‘breeding population’ is a set of local populations that exchange genetic material through reproduction and are reasonably reproductively isolated from other such sets.  For example, a tribe of bushmen might constitute a local population….Separation often results from the introduction of geographic barriers; however, in the case of humans it can also be due to socio-cultural differences.

These statements clearly suggest that she has modernist, colonialist, racial/typological thinking and in her publications, she tries to defend this view.

4 thoughts on “The cladistic race concept: race and biological reality

  1. If the races qua Clades were not reasonably isolated, they would not have genetic similarity. They have genetic similarity (a Fst above 0), therefore they were reasonably isolated. By the way, could you cite the more recent literature which shows that populations were not reasonably isolated enough to form Clades.

    • My arguement here is that if we include only isolated populations for analysis, you can find distinct clades. In reality, human populations are not reproductively isolated, with a few exceptions, so if we include as many population samples as possible, you will not see clear clustering of populations, especially clustering of populations based on race. Human populations are basically genetically similar to each other (small Fst), especially compared to other species (so these species should have large Fst).
      I wrote about Tishkoff et al. They found genetic structure within Africa more than outside of Africa and they found clear evidence of gene flow between sub-Saharan Africans and the Middle Easterns (note Europeans are genetically very similar to the Middle Easterns).

      Lynn Jorde and his colleagues have analyzed genetic variation of Indians. They found that Indians are intermediate between East Asians and the Middle Easterns/Europeans, so cline rather than clustering can explain the genetic variation of Eurasia.

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