Such geographic analysis works best in the absence of recent large-scale, rapid migrations.

The most recent migration could have taken place around 12,000 years ago, with the earliest period remaining a matter of some unresolved contention.

The report said many of Delhi's environmental problems could be traced to recent migrations from the countryside to the city.

There have also been recent large migrations of Hondurans and Nicaraguans.

But the most recent migration, which gathered steam about five years ago, is bringing many poorer, mostly illegal Mexican immigrants.

The town is home to the Luo, but recent migration has introduced a significant number of Maragolis.

In El Salvador it is spoken by 12,000 as a result of recent migrations.

Riots swept the nation in waves, usually in urban areas where there had been recent migration of blacks from the South.

This excludes the Austronesian languages, which have been established as associated with a more recent migration of peoples.

A more recent migration ensued in the 1950s, when Belize was still a British colony.