Ecology is an important factor that should not be overlooked in accounts of language evolution and speciation. English in some extra-European parts of the world speciated into vernaculars called creoles because it was appropriated by non-Europeans under ethnographic conditions that favored extensive restructuring under substrate influence. Substrate influence was possible especially when those who appropriated the language used it not only to communicate with its original speakers but also, and perhaps mostly, to communicate among themselves.
Whether or not the dominated populations interacted regularly with the dominating populations is a more important ecological factor than the often-invoked low proportion of native speakers of the target relative to the learners--especially in exploitation colonies, where most Natives were not acquiring the colonizer's language. Let us, however, illustrate this point with African-American vernacular English (AAVE).
The development of African-American vernacular English
The creators of AAVE were generally minorities relative to the European populations. AAVE shares many features with White nonstandard vernaculars in North America, because, despite the social reality of discrimination against them, African Americans shared over two hundred years of regular interaction with speakers of those other vernaculars since the early seventeenth century.
With the passage of the Jim Crow laws in the late nineteenth century, race segregation was institutionalized in the American hinterlands and this factor favored the divergence of White and Black vernaculars. The extent
of divergence between the different ethnolects is thus inversely correlated with the degree of interaction between the ethnic groups and the time when segregation was instituted in their evolution. The post-Civil Rights Movements' perpetuation of de facto segregation in American society appears to have favored the preservation of distinct African- and European-American vernaculars, leaving it only to African-American children in integrated residential communities to assimilate White middle class linguistic characteristics.Segregation as an ethnographic factor undermines claims that AAVE has been converging with white American varieties of English by loss of some "creole basilectal features." The fact that African Americans have developed and preserved a host of other cultural peculiarities supports this counter-observation.
For instance, they have different prayer and religious celebration styles, different music and dance styles, different cooking and catering styles, and different dress styles, which all converge to mark a different ethnic identity. This is not to deny that the sources of some of these features may well be shared with some cultural features of white communities. Nonetheless, some African-American linguistic and nonlinguistic characteristics are different enough to consider them as diverging from the White traditions and having autonomized in ways specific to the ethnic group.
Settlement patterns and language variation
A careful examination of settlement patterns in North America also shows that variation in ethnographic-ecological conditions of the founder population accounts for differences among (nonstandard) dialects of white Americans. According to Bernard Bailyn and David Hackett Fischer, homestead communities of early colonial New England more or less preserved ways of East Anglia, from which the vast majority of them had migrated in conservative and financially self-supporting family units.
Interacting primarily among themselves in the farm communities which they developed, they preserved most of their motherland's speech ways, restructuring them only minimally into a new English variety. One may understand why New England English is assumed to be the American variety that is the closest to British English.
On the other hand, colonies of the Chesapeake Bay (Virginia, Delaware, and Pennsylvania) were settled by fewer family units, consisted of a large proportion of indentured labor (50-75 percent according to one estimate), and were dialectally more heterogeneous. Although a large proportion came from the London area, London was itself a contact setting to which jobless peasants and artisans had migrated from different parts of the British Isles, including the frontier regions of Ireland and Scotland. Part of the indentured labor also came from continental Europe, especially Germany. Competition and selection of structural features produced an English variety different from that of New England and even more different from British dialects, although specific features have been traced to different parts of the United Kingdom.
Communities such as in the Appalachian mountains with larger proportions of Scots-Irish founder populations developed varieties of their own. Linguists J.K. Chambers and Sandra Clarke report similar things about varieties of English in rural Canada, where an Irish element is identifiable.
One may propose similar explanations for the development of Italian English, Jewish English, and the like, assuming a social integration parameter which would favor more divergence from other socially less marked varieties. The varieties spoken by populations that were socially isolated, or excluded, from the mainstream have diverged in significant ways from the varieties considered more "normal," such as educated white middle class English.
Where segregation was implemented in the strongest form, the strengths of factors bearing on feature selection were shifted more dramatically, even if the lexifying input was more or less the same, so that Celtic, or German, or Dutch influence would be stronger in some communities than in others. This is consistent with the interpretation of influence from outside the lexifier as the role which any such language must have played even only in favoring the selection of a particular structural feature over other alternatives in the lexifier itself. Thus, the selections made in the different varieties would not be identical. Where they are now almost identical, such as between AAVE and white American Southern English, rules do not apply in exactly the same ways.
An ecological model for linguistic evolution
There are many more similarities than have been admitted in part of the literature on the subject matter. Such considerations are one more reason for arguing that there are many more similarities in the restructuring processes that produced all these varieties.
The distinction between internally and externally motivated changes sheds no significant light on how restructuring itself proceeds. It provides no rationale for some varieties among the new Englishes to be treated as children out of wedlock. Instead, the ecological model makes it possible to account for differences where they exist, even if these are only statistical. Such differences matter to the extent that they reflect various ways in which competing alternatives may be weighted in different communities, favoring one or another variant.
