How was a new species of fireweed formed?

Question

I know they doubled the chromosome count, but how did they do this and how exactly did that create a new species. Also, why hasn't this been done many times with other species and organisms?

Answer 1

Tetraploid expansions are common in plants.  They can be induced with the compound colchicine which prevents segregation of chromosomes during mitosis.  The cells wind up with twice as many genes in the same cell, creating the same balance on genes.  During replication, they are able to segregate their genes and function.  When crossed with their parent strain, they produce and infertile triploid plant which cannot segregate its chromosomes in a balanced fashion.  In general, this does not occur in animals.  Tetraploid cells will not develop in sequence.  There are a variety of factors involved.

It should be noted that some giant protozoa use a comparable strategy.  Paramecia produce copies of their reproductive nucleus (the micronucleus) that can produce enough RNA for the cell of that size from a working somatic nucleus (the macronucleus).  In comparison, the giant amoeba has thousands of chromosomes, many duplicates, to support the cell.