142 Before Agriculture
with cross-language communication in situations of contact. This extensive multi-
lingualism has been a key factor in the maintenance of linguistic diversity histori-
cally, countering the increasing effects of linguistic assimilation.
Linguists are only beginning to realize that there may be structure to such
linguistic diversity. The functional relationships that develop in space and time
among linguistic communities that communicate across language barriers have
been referred to as ‘linguistic ecologies’. An ecological theory of language takes as
its focus the diversity of languages per se, and investigates the functions of such
diversity in the history of humanity. It seeks to identify the mechanisms that sus-
tain a language ecology over time – which are, in fact, the very same mechanisms
that will be required to build a genuine multilingual and multicultural society in
today’s global world. Furthermore, the study of traditional linguistic ecologies
reveals that they encompass not only the linguistic and social environment, but
also the physical environment, within a worldview in which physical reality and
the description of that reality are not seen as separate phenomena, but instead as
interrelated parts of a whole.^7
Language and the Environment: the Inextricable Link
Overlap of linguistic and biological diversity
To understand how language and the environment may be seen as parts of the
same whole, let us first consider some striking correlations between linguistic and
biological diversity.^8 The majority of the smaller languages (which, as we have seen,
account for most of the world’s linguistic diversity) can be labelled as ‘endemic’, in
that they are spoken exclusively within this or that country’s borders. Comparing a
list of countries by number of endemic languages with the IUCN list of ‘megadiver-
sity’ countries, one finds that 10 out of the top 12 megadiversity countries (or
83 per cent) also figure among the top 25 countries for endemic languages
(Table 5.1).
A global cross-mapping of endemic languages and higher vertebrate species
brings out the remarkable overlap between linguistic and biological diversity
throughout the world. Similar results can be obtained by cross-mapping endemic
languages and flowering plant species.
Language, knowledge and human–environment coevolution
What may account for these correlations? Several geographical and environmental
factors have been suggested that may comparably affect both biological and lin-
guistic diversity, and especially endemism: (1) Extensive land masses with a variety
of terrains, climates and ecosystems (e.g. Brazil, China, India, Mexico, US); (2)
Island territories, especially with internal geophysical barriers (such as Australia,