Population bottlenecks are when population size reduces for a short period of time. Overpopulation may indicate any case in which the population of any species of animal may exceed the carrying capacity of its ecological niche.
The name zirconium comes from the mineral zircon, which is the most important source of the metal. The largest deposits of this mineral are found in Australia, Brazil, Russia, India, South Africa and the United States. Australia and South Africa are the largest miners of the mineral.
Just three of the very oldest zircons have been found, ones that date back to almost 4.4 billion years ago. Their extreme age always makes the dates suspect, because of possible radiation damage.