Re: How come New Zealand has so many of the most primitive plants in the world?

Complete Question:

I would like to know why New Zealand has so much primitive plant 
life, opposed to other countries where plants may have evolved more.

Reply:

First, are you sure that New Zealand has more primitive plants than other 
countries? One difficulty is that simple looking plants may not be that 
primitive. We aren't really certain whether some plants are primitive or 
actually highly evolved. An example is the very simple-looking whisk fern 
(Psilotum nudum) which is structurally like the earliest land plants. However, 
recent evidence suggest the whisk fern may not be that old but is more highly 
evolved and reduced from fern-like ancestors.  

If it is true that New Zealand has more primitive plants and less evolution, it 
may be because it is more isolated because it is an island. Also, it may have 
had a more stable, less harsh environment enabling a species well adapted to 
that environment to survive successfully for millions of years without change. 
A changing environment provides a selection pressure that can promote 
evolution. It also may just be chance that New Zealand would have more 
primitive species that other areas. 

Reference


Psilotum