[philcrump]

From the subtley linked 'Husbandry Manual': http://www.aszk.org.au/docs/lhisi.pdf

Section 3.2 (p8)

The population at Melbourne Zoo, being descended from a single pair, appeared to experience increasing symptoms of inbreeding over two generations until four adult males were introduced, descended from a second pair held at Insektus in Sydney, and their genes began to have an influence.

After new males were introduced, no further abnormalities were observed...

[PhasmaFelis]

That was still pretty interesting, I think. The Melbourne Zoo population ballooned after the four new males arrived: " the population at Melbourne Zoo, which hovered around 20 individuals at any time during the first three years of captive management, rose to 600 within 12 months of the males’ genes taking effect." Even though the four males were all descended from a single (different) pair. That means they got a stable breeding population out of only two breeding pairs! I really wouldn't have thought introducing a single extra pair of ancestors would have fixed everything so dramatically.

[thaumasiotes]

I don't know; a 100% increase in whatever you've got is generally thought of as significant.