It is in fact typically a closed system.
When we think of decoding the genome, we typically think in terms of the human genome.
The longest-known genus and the one containing the largest species is Anchitherium, typically from the Middle Miocene of Europe, but also represented by one species from the Upper Miocene of North America.
Pietersen was also fortunate during a typically belligerent conversation that Flintoff would have a declaration to mull over.
Typically there are many caveats required by the different political parties.