Biodiversity
Biodiversity is important for humans as a source of food, industrial materials and the potential for new medicines. This is why we must study and protect the biodiversity on Earth.
Population numbers of organisms are constantly To increase and decrease. due to:
- competition for resources
- The hunting of another animal for food.
- disease
- pollution
When scientists detect a constant decline in population numbers of a particular species it requires further investigation.
Alien species
In Australia in the 1930s farmers had a real problem with beetles and grubs eating the sugar cane they were trying to grow. It was decided that pesticides might also harm other native species so instead they decided to try The control of a pest by the introduction of a natural enemy or predator..
The cane toad from Hawaii was introduced to Queensland in the hope it would eat the beetle.
Unfortunately, the cane toad:
- was an A species which is not native to a particular region or country. to Australia - it had no natural predators to control its numbers and as a result its population exploded
- was a predator of a large variety of organisms (but not the cane beetle)
- was prey for many predators but it would exude a toxin which killed the predator
- carried diseases which the native species had no resistance to
This series of events led to a large reduction of biodiversity in the area reducing the population of the yellow-spotted monitor lizard by 90 per cent. To this day, Australia is struggling to control the spread of this A species whose numbers grow faster than native species and upset the ecological balance..
More guides on this topic
- Cell division and stem cells – WJEC
- DNA and inheritance – WJEC
- Variation – WJEC
- Mutation – WJEC
- Evolution – WJEC
- The nervous system – WJEC
- Homeostasis – WJEC
- The role of the kidneys in homeostasis – WJEC
- Micro-organisms and their applications – WJEC
- Disease, defence and treatment – WJEC
- Video playlist