London, A study of chicken bones dug up at
London archaeological sites shows how the bird we know today has
altered beyond recognition from its ancestors.
With around 23 billion chickens on the planet at any one time,
the bird is a symbol of the way we are shaping the environment, say
scientists.
Evolution usually takes place over a timescale of millions of years,
but the chicken has changed much more rapidly.
The rise of the supermarket chicken mirrors the decline in wild
birds.
“The sheer number of chickens is an order of magnitude higher than
any other bird species that’s alive today,” said Dr. Carys Bennett, a
geologist at the University of Leicester, who led the study.
The researchers used the archaeological record to look at how
chickens have changed over the years – and say they are a symbol of
this geological era.
We are entering the Anthropocene, the period during which
human activity has been the dominant influence on climate and the
environment.
“Human activities have altered the Earth’s landscapes, the oceans,
atmosphere and land surface,” said Dr. Bennett.
“As the most numerous terrestrial vertebrate species on the planet,
with a biology shaped by humans, modern chickens are a symbol of
our changed biosphere.”
She said when future generations examine rocks from our time,
they will probably see “tin cans, glass bottles, and bits of material that
were once plastic, and amongst that will be bones of chickens”.
Domesticated animals now make up the majority of animal
species on land, shaping the natural world.
The domestic chicken is descended from the red jungle fowl,
which is native to tropical South East Asia. The bird was first
domesticated around 8,000 years ago, and rapidly spread around the
world, to be used for meat and eggs.
In the 1950s the “chicken-of-tomorrow programme” was launched
to produce bigger birds. Since then, the bird has undergone
extraordinary changes.
It has been selectively bred to put on weight fast, which is
evident from its body and the chemistry and genetics of its bones.
Meanwhile, roast chicken has gone from being an occasional
treat to a global food enterprise, the BBC news reported.
Source: Oman News Agency