[d_k_f]

How did your guide get there the first time?

[Jailbird]

It's guides, all the way down.

[otikik]

Isla Muerta is a piece of continental earth which has been slowly drifting away from the continent for generations. The guide's ancestry has lived there since before the island was an island.

[woof]

He was born there?

[snorkel]

He was hatched by the first chicken.

[TeMPOraL]

How did his parents get to the island? Were they born there as well? If so, how did the first settler found it? Or is this island the origin of life on Earth?

[chipgap98]

It doesn't say the the island was always findable only by those who already know where it is. This could have changed at some point.

[rational-future]

True. Also most islands are younger then life on Earth, so the island could just appear under the first guide.