Birds: Taxonomies; Cladistics; Categories

[CygnusRex]

Birds of a feather not related to each other

09:30 11 December 04

If it walks like a flamingo and looks like a flamingo, it is not necessarily a flamingo - or even a close relative. A controversial genetic study suggests we have completely misunderstood how the majority of birds are related, and that some species that look almost identical are not related at all.

The discovery comes from an analysis of the evolution of the bird gene beta-fibrinogen. It suggests that the Neoaves, a group that includes all modern bird species except waterfowl, landfowl and flightless birds, actually comprises two distinct lineages called the Metaves and Coronaves, and that many birds which look alike are not in the same lineage.

For instance, flamingos and roseate spoonbills - two pink, long-legged wading birds with similar-looking heads, wing shapes and plumage - are not related as previously thought. Flamingos, it turns out, belong to the Metaves, while spoonbills belong to the Coronaves.

Matthew Fain and Peter Houde at New Mexico State University in Las Cruces, US, analysed the number of different nucleotides found on beta-fibrinogen across some 150 bird families. From that the researchers constructed a new avian evolutionary tree.

They found two major lineages, each of which contains many examples of convergent evolution, the process by which two species that do not share a recent evolutionary history nevertheless end up looking alike and inhabiting a similar ecological niche.

Both lineages contain owl-like nocturnal predators, birds with long curvy beaks that live on nectar, broad-winged oceanic divers and birds that evolved splayed toes to help them live in trees. Using this classification, boobies and tropicbirds, two similar-looking types of seabird, now belong to Coronaves and Metaves, respectively.

“People have been trying to classify birds based on their appearance for hundreds of years. It is valuable at some levels, but when you get to really deep divergences, you just hit a wall,” Houde says.

But Joel Cracraft at the American Museum of Natural History in New York, US, is not convinced. “The base of modern birds is a very difficult problem to resolve. This is a welcome data set, but it’s not going to be this simple,” he says. Fain and Houde are working with 11 other genes to corroborate their results

Source

 

[Anonymous]

Good stuff. I've been trying to find something decent on avian cladistics for ages, now it seems they're about to rewrite the book. I've been trying to find out what is the sister group to parrots, can't find it anywhere.

 

[CygnusRex]

Good stuff. I've been trying to find something decent on avian cladistics for ages, now it seems they're about to rewrite the book. I've been trying to find out what is the sister group to parrots, can't find it anywhere.

I didn't think they had one, I thought they sat in a clade with passeres?
Taking into account I could be completely wrong, as its just a snippet of info that I plucked from the back of my mind

 

[Min Bannister]

Hmm. Very interesting. Guess it shows that the traits these birds have evolved are so useful nature has done it twice!

 

[Anonymous]

Tis called convergence.

It's why fish, cetaceans and icthyosaurs look so similar.

 

[Thirtysixth_Bee]

Can someone tell me the difference between landfowl and flightless birds, please? Are landfowl birds that nest on the ground, but able to fly?

 

[Anonymous]

lil' OT but is it true that crocodiles and alligators are actually closer related to geese than they are to lizards. If so its another example of convergence.