Accipitridae (2 Viewers)

[Kirk Roth]

Meaning that it is theoretically the same species

Well, it depends on the theory you subscribe to.

Generally, Galapagos Hawk is considered distinct enough to have speciated - genetic distance or not. Under Biological Species Concept, it would be difficult to lump these birds with a species that is, (in contrast) migratory, has a distinct breeding/mating season, nesting habits, and pairing behavior.

But if someone's theory of speciation does not include paraphyly or close genetic distance, then sure - lump all these island species.

Remember that speciation is a measure of difference, not necessarily genetic or temporal distance. A taxon can technically speciate under concepts such as the BSC in two generations.

But another thing to consider in this particular case - Galapagos Hawks are one of the most inbred of bird species. This may be due to their recent divergence/colonization... and/or may be a factor in making it appear to be a younger species than it really is.

 

[Jim LeNomenclatoriste]

Well, it depends on the theory you subscribe to.

Generally, Galapagos Hawk is considered distinct enough to have speciated - genetic distance or not. Under Biological Species Concept, it would be difficult to lump these birds with a species that is, (in contrast) migratory, has a distinct breeding/mating season, nesting habits, and pairing behavior.

But if someone's theory of speciation does not include paraphyly or close genetic distance, then sure - lump all these island species.

Remember that speciation is a measure of difference, not necessarily genetic or temporal distance. A taxon can technically speciate under concepts such as the BSC in two generations.

But another thing to consider in this particular case - Galapagos Hawks are one of the most inbred of bird species. This may be due to their recent divergence/colonization... and/or may be a factor in making it appear to be a younger species than it really is.

Are there other species in this same situation?

 

[Jacana]

Are there other species in this same situation?

Dozens probably. Most waiting confirmation via genetic data.

Off the top of my head and without any prior research, I bet species such as Scottish Crossbill, MacKay's Bunting, Socotra Buzzard, Cape Verde Buzzard would be in a similar situation.

 

[Mysticete]

Meaning that it is theoretically the same species

I don't believe any of the major species concepts applied to birds is predicated on age of divergence. It can serve as a proxy for reproductive isolation/separation of lineages of course. But a young age still doesn't rule out something being a different species under either the biological, phylogenetic, or evolutionary species concepts.

 

[Mysticete]

Well, it depends on the theory you subscribe to.

Generally, Galapagos Hawk is considered distinct enough to have speciated - genetic distance or not. Under Biological Species Concept, it would be difficult to lump these birds with a species that is, (in contrast) migratory, has a distinct breeding/mating season, nesting habits, and pairing behavior.

But if someone's theory of speciation does not include paraphyly or close genetic distance, then sure - lump all these island species.

Remember that speciation is a measure of difference, not necessarily genetic or temporal distance. A taxon can technically speciate under concepts such as the BSC in two generations.

But another thing to consider in this particular case - Galapagos Hawks are one of the most inbred of bird species. This may be due to their recent divergence/colonization... and/or may be a factor in making it appear to be a younger species than it really is.

Also the study you cited just looked at the mitochondrial control region, a relatively small segment of DNA. It's probable that adding in additional genetic markers might provide better and different resolution.

 

[cajanuma]

I’ve always been intrigued by this possibility but didn’t actually expect it to be this result. Will be curious to see what genetics of the Cen American highlands birds look like too.

In their really fantastic little booklet "The Peterson Guide to Bird Identification in 12 Steps", Steve Howell and Brian Sullivan use a photo of Rufous-tailed Hawk to illustrate their second of the 12 steps, using location to assist with ID. Like just about every other reader I suspect, I simply assumed they were Red-tails before reading the caption, which ends with the thought: "Why isn't Rufous-tailed Hawk an isolated race of Red-tailed Hawk? From Step 1 [taxonomy] you know the answer - it's simply an opinion"

 

[Kirk Roth]

Dozens probably. Most waiting confirmation via genetic data.

Off the top of my head and without any prior research, I bet species such as Scottish Crossbill, MacKay's Bunting, Socotra Buzzard, Cape Verde Buzzard would be in a similar situation.

Certainly, Cassia Crossbill is both paraphyletic and young. Red Grouse, several of the newly-split "House Wrens" in the Caribbean I believe. Lots of island rails, especially in the "Black Rail" complex and the Porphyrio swamphens, and lots of the new world grebes that are limited to single lakes.

I would expect many among Pacific Island endemics - especially doves, reed warblers, white-eyes, and all those high diversity/low dispersal capacity taxa.

 

[Jacana]

Certainly, Cassia Crossbill is both paraphyletic and young. Red Grouse, several of the newly-split "House Wrens" in the Caribbean I believe. Lots of island rails, especially in the "Black Rail" complex and the Porphyrio swamphens, and lots of the new world grebes that are limited to single lakes.

I would expect many among Pacific Island endemics - especially doves, reed warblers, white-eyes, and all those high diversity/low dispersal capacity taxa.

Yes, I was forgetting Red Grouse. I think this is probably the best current example that is backed up with genomic data.

 

[Ruff-Leg]

Interesting presentation by the researcher:

He gets into the genetics starting around 31:00.

Thanks for the link, b2000. It was fascinating,