| what is the effect of overexploitation on populations | they can be reduced to a low level but may still recover |
| what type of genetic diversity do some species naturally have | naturally low genetic diversity in their population and yet remain viable |
| what is the effect of overexploitation on small populations | they may lose the genetic variation necessary to enable evolutionary responses to environmental change |
| what is the bottleneck effect | when in small populations, the loss of genetic diversity due to overexploitation is critical for many species, as inbreeding results in poor reproductive rate |
| what does the clearing of habitats lead to | habitat fragmentation |
| what does degradation of the edges of habitat fragments result in | increased competition between species as the fragment becomes smaller, leading to a decrease in biodiversity |
| what kind of species diversity do more isolated and smaller fragments exhibit | lower species diversity |
| how can widespread habitat fragmentation be remedied | isolated fragments can be linked with habitat corridors |
| what do habitat corridors allow | the movement of animals between fragments, increasing access to food and choice of mate |
| what do the use of habitat corridors lead to | recolonisation of small fragments after local extinctions |
| what are introduced species | those that humans have moved either intentionally or accidentally to new geographic locations |
| what are naturalised species | those that have become established within wild communities |
| what are invasive species | naturalised species that spread rapidly and eliminate native species, therefore reducing species diversity |
| why do invasive species outcompete native species | they are free of predators, parasites, pathogens and competitors that limit their population in their native habitat |
| what do invasive species to do native species | prey on them, outcompete them for resources or hybridise with them |
