Aldabra rail: The bird that came back from the dead by evolving twice

[admin]

The flightless Aldabra rail went extinct 136,000 years ago when its atoll home sank beneath the waves. Then it evolved again.

Aldabra rail: The bird that came back from the dead by evolving twice : Read more

 

[PlumHunter]

"It wasn't as if it were two different species colonizing and becoming flightless. This was the very same ancestral bird." Does "very same" mean identical? So same DNA?

 

[TAGRUDZIEN]

"It wasn't as if it were two different species colonizing and becoming flightless. This was the very same ancestral bird." Does "very same" mean identical? So same DNA?

The first species (Aldabra Rail) became extinct. It's genetic lineage ended. A second rail species, a different genetic lineage colonized the reemerged island and became flightless probably due to Natura l selection. The Aldabra rail did not secondarily evolve. The new flightless rail represents a separate lineage evolving similar traits from similar selection regimes. This article misrepresents biological evolution.

 

[Jamellica]

"It wasn't as if it were two different species colonizing and becoming flightless. This was the very same ancestral bird." Does "very same" mean identical? So same DNA?

The 2 flightless rails that evolved were different species, but they both evolved from the same species (Dryolimnas cuvieri). The title is misleading since the second flightless rail is not exactly the same as the first, it didn't come back from the dead. But the part you're quoting is correct, the ancestor of both was the same. Iterative evolution is when 2 similar species evolve in the same group, but in this case, they weren't just both in the rail family, they both came from the same rail species.