New bird family tree

[mynah]

This new phylogeny of birds was published about two weeks ago. It was based on an analysis of 19 genes - quite a task! How likely is it to stand the test of time, seeing that it contains some rather interesting findings - parrots as the sister group of the passerines, and falcons being closer to sparrows (for instance) than to eagles and kites, etc.?

[freeztar]

This new phylogeny of birds was published about two weeks ago. It was based on an analysis of 19 genes - quite a task! How likely is it to stand the test of time, seeing that it contains some rather interesting findings - parrots as the sister group of the passerines, and falcons being closer to sparrows (for instance) than to eagles and kites, etc.?

 

As I don't know scientific names of birds off the top of my head, it's impossible to understand this cladogram. Perhaps you could point out the really interesting findings (with scientific name) so all us bird-ignorant folk can discuss this with you. :hihi:

[mynah]

Let me try... (BTW, by surprising I don't mean everything in it is brand new information. I'm just contrasting it with what was believed a few years ago.);)

 

Here it is:

 

Starting from the left, the first branch to split off (Q) is the ratites, or “primitive” flightless birds like ostriches, rheas, emus, kiwis, etc. This group also contains the tinamous, South American birds that can fly. The composition is not a surprise, but it is a surprise that the Australasian flightless birds are more closely related to tinamous than to non-Australasian ratites.

 

The second branch (P) contains the Anseriformes (“primitive” waterfowl such as ducks, geese, etc.) and the Galliformes (gamebirds, such as pheasants, guineafowl, etc.). No surprises there.

 

With the third branch and its two main branches (M and N) things get really messy (and has an ornithologist or two in a tizz). Columbiformes are pigeons, the next three families in N are mesites, sandgrouse and tropicbirds, and the last two orders are flamingos and grebes respectively. The relationship between the last two has long been suspected, as has that between pigeons and sandgrouse, but until recently no-one thought N formed a clade. Tropicbirds were thought to be related to pelicans, frigatebirds, gannets and other shorebirds (order Pelicaniformes) while mesites were placed in Gruiformes (see later).

 

In M the relationship between Apodiformes (swifts) and Caprimulgiformes (nightjars) was expected, though their placement and closeness to clade N was not until recently.

 

The two Gruiformes (traditionally consisting of cranes, crakes, rails, etc.) are the sunbittern and kagu. The Gruiformes has been gruesomely dismembered and its parts scattered all over the tree. (At least ornithologists were puzzled by the above two birds; some of the scatterlings they were not even thinking about.)

 

J has also raised eyebrows. Opisthocomus at the base of it is the hoatzin of South America, which has variously been considered a cuckoo, a chicken, a turaco, a rail, or a seriema. Truth is, taxonomists didn’t know what to do with it. (They still don’t.)

 

Group I, surprisingly, allies some of the Gruiformes (ones mentioned here include cranes, limpkins, finfoots and rails) with the cuckoos (Cuculiformes). Even more surprisingly, bustards (Otididae), groups with cuckoos, rather than with Gruiformes as expected.

 

H makes rather a mess of the waterbird orders. Shorebirds (Pelicaniformes) were thought to be quite distinct from waders (Ciconiiformes), although a relationship was suspected. The first 11 genera are: Anhingas, cormorants, gannets, frigatebirds, great herons, boatbilled herons, American white and scarlet ibises, shoebills, hamerkop, pelicans, and storks. Procellariiformes (tubenoses – marine birds such as albatrosses and petrels) seems to yield no surprises. A few years ago, however no-one would have thought their closest relatives were penguins (Sphenisciformes). Another surprise is that, at the base of this huge waterbird clade, are the distinctly terrestrial turacos (Musophagiformes), which were thought to be closer to cuckoos.

 

The long branch going to G is for convenience, not an indication that the next group is very distant from the first. The “higher” waterbirds order, Charadriformes (waders, gulls, auks, plovers, jacanas, etc.), remains fairly intact - though Turnix (buttonquails) and Pedionomus (plains wanderers) were once considered either Galliformes or Gruiformes.

 

The two families of E are (1) the eagles, kites, kestrels and (not usually included, but close, the secretarybird) and (2) the condors and New World vultures. The last were at one time thought to be related to storks.

 

Mousebirds (Coliiformes) end up as sisters to owls (Strigiformes), which is surprising – but, to be honest, no-one knew where they belonged anyway.

 

C contains the hornbills, hoopoes, toucans, woodpeckers, kingfishers, etc. The only mild surprise is that trogons seem to belong here.

 

The placement of Falconiformes (falcons) is surprising, as falcons were, until quite recently, considered members of the eagle family!

 

Psittaciformes (parrots) as sister group to the passerines is a huge surprise. Not too long ago it was thought that their closest relatives were pigeons, right at the other side of the tree.

 

The Passeriformes is by far the biggest order, and contains most of the dinosaurs in the average garden – finches, canaries, crows, etc. It is a natural order that goes undisputed. I just wonder what the poor rifleman (Acanthisitta – a very ordinary-looking little New Zealand bird) did to be cast out so far on a limb?

[mynah]

I've found a PDF copy of the original article here. It also contains a cladogram (though I notice it differs slightly from the one above) that is much more user-friendly, with all the common names given.

 

Pity it had to be after I'd done all that work...;)

[freeztar]

Pity it had to be after I'd done all that work...

 

All that work did not go unnoticed. Thank you very much for going above and beyond what I asked and giving a very thorough explanation. I found it very informative. :hyper:

[Mercedes Benzene]

Yes, thank you very much. Phylogenetic systematics was always one of my favorite parts of AP Biology. The information presented here is really interesting, and you put a lot of effort into what you've done.

 

As far as you can tell, are there any major implications of these new groupings? In other words, what affect will it have on our current understandings of evolution and phylogeny?

 

Thanks again.

[Thunderbird]

That was very helpful, thank you, you taxonomic tease, :doh: now I can the down load the pattern into my neuronal net.

[mynah]

Here I was thinking I was the only phylogeny weirdo in the world... Good to discover one isn't alone!

 

I'd say a major implication of the molecular genetics-based classification systems is that they are far more objective than earlier systems based on morphology alone. Although it is not an open door to perfect knowledge of evolution, its greatest value is that scientists can at last say, "We know species A and B are very probably related, so lets look at the way their common or different characteristics could have evolved," rather than, "A and B share the same thingummy, so they are probably related".

 

As for the birds, the research is too recent for all implications to be clear, but it does show the extent to which natural selection and similar environmental conditions may lead to similar characteristics being expressed in animals that are not nearly as closely related as had been thought.

 

I'm currently working on an article on Columbiformes (doves, dodo's, etc.) and had a feeling that the oft-repeated "pigeons are probably close to parrots" needed a second look. (No brilliantly original insight of mine, except that it has become clear that every page dealing with systematics that hasn't changed since one's last visit months ago is probably outdated. :phones:) The new family tree shows that, well, it's a good thing I looked...

[DougF]

mynah

This new phylogeny of birds was published about two weeks ago. It was based on an analysis of 19 genes - quite a task! How likely is it to stand the test of time' date=' seeing that it contains some rather interesting findings - parrots as the sister group of the passerines, and falcons being closer to sparrows (for instance) than to eagles and kites, etc.? [/quote']

I to would like to thank you for all the effort in giving a very thorough explanation. I found it very informative.

[Thunderbird]

I agree, morphology and anatomical similarities as a classification system are not the best way to build a historical tree, especially considering the amount of evolutionary convergence in the bird world. This will allow us to see bird as an adaptive history. I was wondering if they have found a species that could be described as an archetypal bird, like the Hoatzin.

 

Hoatzin: Guyana's Prehistoric Throwback

The Hoatzin is a strange primitive bird. The Hoatzin's plump body and reddish-brown feathers may not appear antediluvian, but the bird's blood-red eyes set in patches of bright blue skin and unruly crest of long feathers are throwbacks to another time. Hoatzins are also born with two prehistoric claws protruding from their wings, a characteristic that lead many to believe that it's a direct link to the Archaeopteryx, the first known bird. Hoatzins are found along rivers and creeks in the Upper Demerara River-Berbice area in Guyana, and are easily seen because they often live in large groups and rarely stray far from their principal locals, probably due to the fact that they're poor fliers. Indeed, Guyana's national bird is such a bizarre species that it was put in its own order, the Opisthocomidae.