Choose the right word for each gap.

Lonesome George was a giant tortoise, the last of his species and thus, ... alone. Scientists tried to rescue his genes by ... him with another tortoise. The research team
... DNA from seven Pinta tortoises – six from the deceased museum ... and one from George himself – and compared it with blood ... from twenty-seven giant tortoises. Among these samples, they found one tortoise, about thirty years old, with clear signs of Pinta ... . Sadly, however, the newly discovered tortoise was not a suitable romantic partner for George: he was male! He was not ... either. In that case, there was a clear possibility of finding other Pinta individuals out there, maybe even a female. Unfortunately, all the ... failed.