Birth of New Species Witnessed By Scientists

[The Accomplice]

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.

Read the rest of the article here: http://www.wired.com/wiredscience/2009/11/speciation-in-action/?npu=1&mbid=yhp


Darwin would cream his pants if he were still alive and witnessed this! Neat stuff in my opinion.

[Axle]

This is really, really interesting. We could go a thousand years or more without seeing something like this again.



...I'm also wondering how long its going to take before I start hearing creationists call this a hoax.

[Jimmie Higgins]

Maybe I missed it in the article, but why did the other finches die-out in the drought while this kind survived - is it just chance or were its slight variations something that actually helped and led to its survival?

[turquino]

Excuse my ignorance, but how are new species born? I thought a species was a group of organisms that could only reproduce with others of their kind. At what point does the genetic diversity from a mutation become enough for an organism to no longer be the same species as its ancestors?

[Luisrah]

Excuse my ignorance, but how are new species born? I thought a species was a group of organisms that could only reproduce with others of their kind. At what point does the genetic diversity from a mutation become enough for an organism to no longer be the same species as its ancestors?

As you could see from the article, it's difficult to say when you can consider 2 species.

But the thing isn't being able to mate, but being able to generate fertile offspring.
If a horse and a donkey mate, a mule is born, but she isn't fertile.
Horses and donkeys can mate, but they aren't of the same species, and that's why the offspring is non fertile. Their genes are just similar enough to generate viable offspring, but those can't mate.

[MarxSchmarx]

The authors of the article unfairly dismiss previous experimental work on speciation as

something that scientists have (not) been fortunate enough to watch at the precise moment of divergence, except in bacteria and other simple creatures.

This is rather misleading. The mechanism of isolation in sexually reproducing organisms actually has been found in some detail in, e.g., fruit flies, no less complex than birds.

http://scholar.google.com/scholar?hl=en&client=firefox-a&rls=com.ubuntu:en-US:unofficial&hs=1AD&q=author:%22Rice%22+intitle:%22Laboratory+experime nts+on+speciation:+what+have+we+...%22+&um=1&ie=UTF-8&oi=scholarr

Speciation stuff has been done to death in the laboratory. It's nice that the Grants found this semi-plausible example in nature. I suspect that there is a real potential for inbreeding depression making the offspring severely less fit, as Luisrah points out.


Maybe I missed it in the article, but why did the other finches die-out in the drought while this kind survived - is it just chance or were its slight variations something that actually helped and led to its survival?


It appears to be largely chance. There wasn't a very high population to begin with, so any attempts to attribute it to specific causal factors would probably be too untenable.

[Rosa Lichtenstein]

And yet the article says this:


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.

So, we still do not know of this is a new species or not.

[Dr Mindbender]

excellent news, another blow to creationism.

[MarxSchmarx]

And yet the article says this:

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.



So, we still do not know of this is a new species or not.

Hmmm...I guess the journalists did do some of their homework after all.

Actually, though, I think the species question is so intractable, at best it is a matter of semantics and at worst it is just ridiculous the amount of resources that are thrown at this pseudo-question. It's rare that philosophy has lessons for natural science instead of vice versa, but this is a good example. Biologists are expecting too much for this question in hoping to delineate a hard and fast rule for what constitutes a species. I suspect this has a lot to do with the utter naivete of biologists on philosophy and the humanities more generally, as aluded to in another thread on SJ Gould.

[Rosa Lichtenstein]

Maybe so, but if this is just a semantic issue, can we say that we know any more about the origin of the species than Darwin did? If we can't say what a species is, how can be account for their origin? On the other hand, if this is just semantics, then what exactly, in the real world, are we explaining?