| Mutagenic damage can produce significant
consequences not only in the individual in which it is detected,
but also in the whole population. Somatic cell effects which impact on
individual reproductive effectiveness can produce indirect
multigenerational genetic effects through selection for adaptation to
the contaminant stressor. Germ cell effects can cause direct impacts
through mutations passed on to the next generation that may ultimately
become fixed in the gene pool of the population in future generations.
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Somatic Cells
- Significantly higher frequency of cell
death
- Level 2 genetic damage can trigger
premature cell death. This higher turnover in
cells will place increased energy demands on the
animal or plant. During periods of food scarcity
(i.e. in winter), this could result in an
increase in juvenile mortality.
- Disruption, alteration or loss of cell
function
- impairment of immune function in
damaged white blood cells
- greater lifetime
susceptibility to effects of endemic
pathogens
- causes differential
fitness within the population
- Possible impairment of oxygen
transport by red blood cells
- Greater risk of Cancer
- The risk is especially high during
the rapid growth of the juvenile stage.
- Symptoms of the disease may occur
4 to 6 months after exposure.
- Adaptive selection in response to effects
on fitness.
- Reduction of useful genotype
variation.
- Reduced ability of the
population to genetically respond to new
selection pressures (i.e. effects of global warming).
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Germ Cells
- Increase in the background mutation rate
(possibly compounded over generations).
- Increased genetic variation
because of greater mutation rate
- Decreased useful genetic
variability (similar to inbreeding) prevents
population adaptation to novel environmental
stressors.
- Greater susceptibility to cancer
and carcinogens.
- Decreased effectiveness of the
immune system;
- Decrease in fertility;
- Greater frequency of
defective sperm
- Higher frequency of
post-zygotic and embryonic mortality
- Increase in Recombinational Load
- Break-up of favourable gene
combinations that are normally tightly linked.
- Alteration of optimum pre-adapted
genotype frequencies.
- reduced potential for
pre-adaptation to environmental extremes
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