1 In this book, I will only use mestiçagem when referring specifically to Brazil.
2 La raza in Latin Amer i ca can refer to “a people” conceived as a biocultural unity;
for example, la raza colombiana means “the Colombian people,” understood to
share biology, history, and culture. This book title therefore can mean “the prob
lems of race in Colombia” but also “the problems facing la raza colombiana.”
3 See Wade (2010, 2015:ch. 6), Sanchez and Bryan (2003), Psacharopoulos and Pa-
trinos (1994), Telles and Project on Ethnicity and Race in Latin America (2014).
On Mexico specifically, see also Moreno Figueroa (2010, 2012), and Sue (2013).
4 For details about rgmla, see the preface.
chapter 1 · Purity and Mixture in Human Population Genetics
1 Lateral gene transfer occurs when ge ne t ic variants are transferred horizontally
between genealogically distinct lineages (common among microbes); hybrid spe-
cies are created when two different species breed to produce a new fertile species
(which contradicts the standard definition of a species); a polygenomic organism
is one that hosts different genomes, whether from the same species (e.g., a chi-
mera) or different species (e.g., the ratio of microbial to h uman cells in a h uman
body was widely reported to be 10:1, although this figure has recently been re-
vised down to 1:1 [Campbell 2016]).
2 In gwas, it is important to make sure that cases and controls are matched for bga
(i.e., population stratification is controlled for). If people with a high proportion
of a given bga are overrepresented among cases, genetic variants that are associ-
ated with that bga will show up as candidate genes, even if they have no influence
on the disease.
3 See Paz’s analysis of this well- k nown Mexican phrase, which is usually translated
as “son of a bitch/whore,” but r eally means “son of the act of fucking up/over”
4 In 2009, I participated with colleagues in a research group in the esrc Centre
for the Research on Socio-Cultural Change (cresc), hosted by the University of
Manchester and the Open University. We discussed the concept of topology at
some length, and I am indebted to these discussions.