The birth of a new species observed

[Elessarina]

http://www.wired.com/wiredscience/2009/ ... d/index%20(Wired:%20Index%203%20(Top%20Stories%202


On one of the Galapagos islands whose finches shaped the theories of a young Charles Darwin, biologists have witnessed that elusive moment when a single species splits in two.

In many ways, the split followed predictable patterns, requiring a hybrid newcomer who’d already taken baby steps down a new evolutionary path. But playing an unexpected part was chance, and the newcomer singing his own special song.

This miniature evolutionary saga is described in a paper published Monday in the Proceedings of the National Academy of Sciences. It’s authored by Peter and Rosemary Grant, a husband-and-wife team who have spent much of the last 36 years studying a group of bird species known collectively as Darwin’s finches.

The finches — or, technically, tanagers — have adapted to the conditions of each island in the Galapagos, and they provided Darwin with a clear snapshot of evolutionary divergence when he sailed there on the HMS Beagle. The Grants have pushed that work further, with decades of painstaking observations providing a real-time record of evolution in action. In the PNAS paper, they describe something Darwin could only have dreamed of watching: the birth of a new species.

The species’ forefather was a medium ground finch, or Geospiza fortis, who flew from a neighboring island to the Grants’ island of Daphne Major, and into their nets, in 1981. He “was unusually large, especially in beak width, sang an unusual song” and had a few gene variants that could be traced to another finch species, they wrote. This exotic stranger soon found a mate, who also happened to have a few hybrid genes. The happy couple had five sons.

In the tradition of finches, for whom songs are passed from father to son and used to serenade potential mates, the sons learned their immigrant father’s tunes. But their father’s vocalizations were strange: he’d tried to mimick the natives, but accidentally introduced new notes and inflections, like a person who learns a song in a language he doesn’t understand.

These tunes set the sons apart, as did their unusual size. Though they found mates, it may only have taken a couple generations for the new lineage to ignore — or be ignored by — local finches, and breed only with each other. The Grants couldn’t tell for certain when this started, but they were certain after four generations, when a drought struck the island, killing all but a single brother and sister. They mated with each other, and their children did the same.

No exact rule exists for deciding when a group of animals constitutes a separate species. That question “is rarely if ever asked,” as speciation isn’t something that scientists have been fortunate enough to watch at the precise moment of divergence, except in bacteria and other simple creatures. But after at least three generations of reproductive isolation, the Grants felt comfortable in designating the new lineage as an incipient species.

The future of the species is far from certain. It’s possible that they’ll be out-competed by other finches on the island. Their initial gene pool may contain flaws that will be magnified with time. A chance disaster could wipe them out. The birds might even return to the fold of their parent species, and merge with them through interbreeding.

But whatever happens, their legacy will remain: New species can emerge very quickly — and sometimes all it takes is a song.

[Animavore]

Its still a finch though. It not like a pig popped out of the egg.

[Elessarina]

Its still a finch though. It not like a pig popped out of the egg.

[klr]

Its still a finch though. It not like a pig popped out of the egg.

Rapture Ready has claimed its first victim.

[devogue]

Its still a finch though. It not like a pig popped out of the egg.

[Elessarina]

Its still a finch though. It not like a pig popped out of the egg.

But which came first... the pig or the egg?

[Gawdzilla Sama]

Moved to Science and Tech.

[Animavore]

Its still a finch though. It not like a pig popped out of the egg.

But which came first... the pig or the egg?

God created all the animals fully formed. How would babies be able to look after themselves? They would all perish rather quickly and scupper God's plans. Jesus Christ! Its written in the FUCKING BIBLE. Why is this so difficult for some people to comprehend?

[Drewish]

So how long until the Amish become their own species?

[Bella Fortuna]

So how long until the Amish become their own species?

When they can hatch a pig out of an egg without electricity.

[Feck]

The fundies are going to say that they are the same type of bird, just as they have tried to explain Noah's Arc in terms of types of animal .

[Calilasseia]

The fundies are going to say that they are the same type of bird, just as they have tried to explain Noah's Arc in terms of types of animal .

Good luck to them with that one, given that no creationist has ever defined "kinds" in a manner that bears even the most tenuous of connections with taxonomic reality.

[Gawdzilla Sama]

The fundies are going to say that they are the same type of bird, just as they have tried to explain Noah's Arc in terms of types of animal .

Good luck to them with that one, given that no creationist has ever defined "kinds" in a manner that bears even the most tenuous of connections with taxonomic reality.

'Scuse me, but what does reality have to do with it?

[Calilasseia]

The fundies are going to say that they are the same type of bird, just as they have tried to explain Noah's Arc in terms of types of animal .

Good luck to them with that one, given that no creationist has ever defined "kinds" in a manner that bears even the most tenuous of connections with taxonomic reality.

'Scuse me, but what does reality have to do with it?

With creationists, nothing. But then that's why creationism is a crock of shit - it's based upon mythological blind assertion instead of diligent observation of reality.

[angrychimp]

Brother and Sister mated?


Jerry!

Jerry!

Jerry!