Scientists for decades have clashed over whether evolution
takes place gradually or is driven by short spurts of intense
change. In the latest chapter in this debate, researchers
report that it appears that when new languages spin-off from
older one, there is an initial introductory burst of alterations
11
to vocabulary. Then, the language intends to settle and accumulate
12
gradual changes over a long period of time. The
team believes this discrete evolutionary pattern occurs when
a social group tries to forge a separate identification. Study
13
co-author Mark Pagel says that the latest study grew out of
an earlier finding in which he and colleagues determined
that about 20 percent of genetic changes among species occur
14
they first split off, whereas the rest happens gradually. "It
15
was very natural with us to wonder if a similar process of
16
evolution happens in cultural groups," Pagel says. "We treat
the words that the different languages use almost identically
so to the way we use genes: ... The more divergent two species
17
are, the less their genes have in common, just like the
18
more divergent two languages are, the less their words have
in common." The team focused on three of the world"s major
language families in its study: Bantu, Indo-European and
Austronesian. They constructed genealogical trees—similar
to those they had created previously in their 2006 species-related
study—albeit this time the trees traced existed
19
languages back to their common roots; the length of a
"branch" indicates the extent of word replacement that took
20
place as each old language morphed into its current form.