Biology and anthropology of plant invasions - Invasive Plants: Ecological and Agricultural Aspects - page 219

The most important current agricultural plant invasion is the introduction of
transgenic crops, often on a vast scale (e.g., glyphosate-resistant crops).
Introduction of any trans-gene into the crop cultivars of these wild-crop-weed
complexes increases the chances of introgression into its related non-cultivat-
ed weedy and wild phenotypes (e.g., 5). The development of these biotech-
nologies in wild-crop-weed complexes fulfill the conjecture provided in the
introduction: a critical interaction of disturbance, dispersal and plant traits
adapted for the resultant opportunity space. The introduction of such biotech-
nologies as herbicide-resistant crops provides a mixture of environmental and
economic benefit and harm which makes implementation of public policy as
defined by US Federal policy [9, 15] somewhat problematic and highlights the
complex interaction of biology and human values.
Conclusions
“With the present tremendous population explosion the most common habitat
has become man-made, and it may not be many centuries before this will be
the only habitat available. With the disappearance of stable habitats, truly wild
species will be the first to become extinct. Wild colonizers may survive as long
as habitats remain that are only sporadically disturbed by man. Eventually
these must also disappear and Homo sapiens , the ultimate of all weeds, will
lord it over the domain he has created for himself, his companion weeds, his
crops and domesticated animals.” JMJ de Wet, 1966 [11]
The human role in creating opportunity space for plant invasion
Invasion biology is a reflection of the impact human populations have on the
earth's ecology. Public policy is currently focused on management and control
of specific species, but at the same time ignoring the fundamental and complex
sources of these changes in biological communities. Fundamentally the prob-
lem is human: human population size and collateral disturbance, human dis-
persal of invasive species propagules, heterogeneous human values about the
nature of harm and beauty, and the priorities of human scientific endeavors. In
all this there may be some benefit to humans by exploiting the very traits we
despise most for plant improvement.
Human population size
Human population size may be the primary cause of invasion biology and
changing community structure. With expanding populations are consequential
changes in land use and spatial organization, increasing direct and indirect dis-
turbance, increased resource use and loss, and other changes to habitats.