Final answer:
Exposure to mutagens can cause genetic changes in plant and animal life, potentially leading to harmful mutations or beneficial adaptations.
Step-by-step explanation:
When plant and animal life is exposed to mutagens on contaminated land, several genetic changes can occur. Mutagens, such as chemicals, radiation, or even genetically engineered (GE) crops, may damage DNA, leading to mutations that can impact cell division and overall organism health. This damage can result in genetic defects, potentially leading to cancer or other heritable diseases. While some mutations may be beneficial and drive evolution, others can be detrimental to the organisms and their ecosystems.
Interbreeding between GE crops and native species, for instance, could lead to the spread of engineered traits such as herbicide resistance, potentially creating 'super weeds' that are harmful to the environment. The environmental impacts of such crosses can be significant, as they may disrupt local wildlife and ecological balances. However, it is also worth considering that, according to some researchers, low levels of exposure to certain mutagens might induce hormesis, leading to adaptive and protective biological responses.
Harmful mutations can also affect biodiversity at an unprecedented pace, with some individuals being more capable than others of metabolizing contaminants and resisting their effects. This is an ongoing concern as many compounds can alter gene expression even at low levels, contributing to the genetic diversity shaped by environmental pressures.