Hello Tweets (particularly those following this discussion) -

as someone freshly out of the long
sleepless nights spent in contemplation of evolutionary tenants (having
finished my undergrad last June with a strong focus on vertebrate evolution)
I've really enjoyed this entire discussion. I've intended to read the
papers mentioned here because I find cladistics fascinating (and because
this is partially the direction I want to go) but work has not yet given me
that time. But I'd like to add a few things off the cuff.

Everyone has mentioned their chagrin at some of these conclusions of
relationship. I'm unsure who has actually spent time dealing with
collaborating lab scientists (the people who do all the tear jerking of
extraction, Polymer Chain Reaction - PCR, and finally analysis of DNA) and
field biologists (the people potentially collecting data in the form of
blood samples, behavioral information, etc.) but there are some important
misunderstandings that can come out of such a relationship. I happily have
fallen on both sides of the work thus far in my college career and have a
bit of insight.

I'd like to preface this with a note that I don't hold *any* data as
confidently better than another. In my readings, musing, etc. I've come to
the conclusion that DNA doesn't always trump morphological or fossil
evidence and vice versa. Few organisms (if any) are that simple and
especially with birds there is so much more to consider. A holistic
approach is required in the fanatical pursuit of classification, both the
phylogenetic and biological species concepts both have important
components.

And I don't want to offend any lab rats out there - but there is certainly a
breed that is blissfully unaware of the habits of their species of concern.
I really think that you can read as much as you want about a bird and listen
to a field expert's gesticulations but until you've gone out and seen it in
a natural setting, those words don't add up to a whole lot. That of course
is just an opinion: but having participated in a project with Satin
Bowerbirds where a PhD candidate whom for *SIX YEARS* had been working with
their DNA but had not been into the field with the birds and knew little
about their behavior (or really was well versed in basic bird behavior
anyway) I can see how something like this can happen. It's easy to spend
your entire college career only reading about an organism of which you have
been so dutifully teasing apart its molecular makeup. There are ever so
many ways for misunderstandings to get caught before being published (i.e.
the peer review process, your PhD advisor smacking you over the head with
your mistakes) but I simply want to highlight that not all scientists in the
lab are as familiar with their species out of the lab. (I truly hope that
doesn't come off as an attack on those who spend their days working in a
laboratory setting because I have spent plenty of my time there and I think
it is very valuable work).

Anyway - in so many words I just think that there can be discord between
genetic analysis and a natural history understanding of a species (DUH).
I've spent several months of my life trying to determine the relationships
of several species of ants via DNA extraction, PCR, and analysis of the
sequences received. I can honestly say I only knew the most basic facts
about these ants and could have come to rather strange conclusions about
their relationships. I had no one to blame but myself for not knowing all
the facets of their natural histories because I never fully sought them out
(however, they also were newly described species from Central America....so
I had some leeway).

I have a hard time seeing Willets and Lesser Yellowlegs being more closely
related than Greater and Lesser simply because of the years I've been
watching birds. The gull discussion is a bit more complicated but I also
don't quite follow through in my evolutionary thinking of how the
"understood" phylogeny could have arisen even with the support of DNA
analysis (mainly the Western/Glaucous-winged discussion). Whether one is
looking at mitochondrial or nuclear DNA in analysis even makes a difference
in the conclusions found but you'd hope someone studying molecular genetics
would take that into account. This stuff is fascinating folks and if you
aren't familiar with all this nonsense I suggest you take a stab at
understanding some of it because it can really flesh out your knowledge and
appreciation of organisms, let alone birds.

BUT phylogentics is a giant whirlwind of information and however valuable,
interesting, and magical it's still based on our inherent need to endlessly
classify "things." Sometimes it's just more fun to go out and enjoy a bird
or two.

Sorry for being so long winded (in hindsight I could have just read the
papers by now and kept quiet).

-Brendan McGarry
Seattle, WA
mcgbre04 at gmail.com

On Tue, Feb 24, 2009 at 5:53 PM, Dennis Paulson
<dennispaulson at comcast.net>wrote:

> Hello, tweets.
>
> I hoped I could steal away into the night without having to deal with this
> confusing situation, but I'll try to write something about the relationship
> of the tringine sandpipers, as Gene said I would. You should delete if
> you're not into this stuff.
>
> Here is the paper I'm discussing: Multiple gene evidence for parallel
> evolution and retention of ancestral morphological states in the shanks
> (Charadriiformes: Scolopacidae), by S?rgio Luiz Pereira and Allan J. Baker,
> 2005. Condor 107 (3): 514-526.
>
> I will try to do justice to the authors' conclusions, but I'll also say why
> I'm not convinced about all of them.
>
> They analyze mitochondrial DNA, nuclear DNA, and morphological characters
> of the group we call the tribe Tringini. This includes yellowlegs,
> greenshanks, redshanks, Marsh Sandpiper, Wood Sandpiper, Green Sandpiper,
> Solitary Sandpiper, Willet, Spotted and Common Sandpipers, Terek Sandpiper,
> and the two species of tattlers. The very rare Nordmann's Greenshank wasn't
> analyzed, as they had no DNA from it.
>
> First of all, the Terek Sandpiper (*Xenus cinereus*) and *Actitis*sandpipers (Common,
> *A. hypoleucos*, and Spotted, *A. macularius*) fall out as separate from
> the other species and distinct from each other, and I won't say anything
> more about them. The authors consider everything else to be in the genus *
> Tringa*. All data show the Green and Solitary Sandpipers to be closely
> related, and they are very likely sister species, one for each hemisphere,
> with very similar appearance and life style. The Wood Sandpiper is
> superficially similar, but it doesn't group with them.
>
> The mitochondrial DNA data put the Lesser Yellowlegs in a group with
> Willet, Wood Sandpiper, Marsh Sandpiper, and Common Redshank, while Greater
> Yellowlegs is grouped with Common Greenshank and Spotted Redshank. Analysis
> of nuclear DNA doesn't resolve very much, although it indicates Wandering
> and Gray-tailed Tattler being in different clades, which isn't very
> believable, and Marsh Sandpiper separate from the Lesser Yellowlegs group.
> But clearly this method won't resolve the phylogeny of this group, so the
> authors must have depended much more on mitochondrial DNA for their
> molecular phylogenetic tree on p. 520, which basically grouped them as
> follows:
>
> 1) Green and Solitary a sister group to all other *Tringa*; 2) within the
> remaining group, the two tattlers a sister group to all the others; 3)
> within the remaining group, Greater Yellowlegs, Common Greenshank, and
> Spotted Redshank a sister group to all the others, and the yellowlegs and
> greenshank more closely related than either is to the redshank; 4) within
> the remaining group, Lesser Yellowlegs and Willet a sister group to another
> group containing Wood Sandpiper, Common Redshank, and Marsh Sandpiper.
> Within the latter group, Wood Sandpiper and Spotted Redshank more closely
> related than either is to the Marsh.
>
> They seemed to pay little attention to the morphological dataset, which
> clearly separates the Willet from the classical long-legged shanks. But
> morphology may not be too important to show relationships in a group in
> which there is strong selection on all sorts of shape variation for
> different foraging niches. DNA work on Dunlin, if I recall correctly, shows
> that changes in morphology evolve quite rapidly, differentiating populations
> that show little genetic difference.
>
> The paper states as one of its conclusions, "*Our analysis indicated that
> T. melanoleuca [Greater Yellowlegs] is more closely related to the
> Greenshank (T. nebularia), as previously suggested by Mayr and Short (1970)
> and T. flavipes [Lesser Yellowlegs] is more closely related to
> Catoptrophorus [Willet]. Indeed, body structure, color of bare parts, and
> call notes are more similar between these two species than between the two
> yellowlegs (Hayman et al. 1986)."*
> **
> I guess the authors are talking about Greater Yellowlegs and Common
> Greenshank here. I agree that these two are quite similar, but notice they
> didn't have anything to say about the purported relationship between Lesser
> Yellowlegs and WIllet, the latter dramatically different from both
> yellowlegs. They never did address why they were willing to accept a close
> relationship between these two species.
>
> The authors also state, about the yellowlegs, "They can be distinguished
> by call notes, shape of bill, and body size but these species may overlap in
> size, which confounds species identification (Hayman et al. 1986)." I
> hadn't realized Hayman et al. had said the two yellowlegs overlap in size,
> but that is quite false, and their acceptance of that makes me wonder how
> well the authors know these birds.
>
> It has been stated that perhaps the Greater Yellowlegs is a mimic of the
> Lesser, thus their extreme similarity. I'd probably call it convergence
> rather than mimicry, and the same situation with the extremely similar
> (differing in size, bill size, and call note, just like the yellowlegs)
> Common Greenshank and Marsh Sandpiper. All four species are what I call
> "sentinel" shorebirds, which I wrote about in Birding a few years ago. Other
> shorebirds such as Stilt Sandpiper and Wilson's Phalarope might mimic the
> similar-sized Lesser Yellowlegs to associate with it for protection from
> predators, but I'm not all convinced that it would be good evolutionary
> strategy for the larger species (GRYE) to mimic the smaller (LEYE).
>
> The fine details of plumage are pretty much identical within the species
> pairs of the two yellowlegs and the greenshank/Marsh Sandpiper, but the two
> Eurasian species are very different from the yellowlegs, and this more than
> anything causes me to question the phylogenetic conclusions in this paper. I
> see no reason in any mimicry/convergence scenario for the minute details of
> plumage to become that similar. The plumage of Stilt Sandpipers and Wilson's
> Phalaropes have not become similar to that of the yellowlegs, if indeed they
> are mimicking the flight patterns of the Lesser Yellowlegs. Nor have Red
> Knots become similar in plumage to Black-bellied Plovers, if they are
> mimicking their flight pattern. I think if there truly is mimicry, as I
> speculated in the Birding article, it is only in flight pattern, not in all
> aspects of plumage.
>
> The authors separate the two species of redshanks phylogenetically and
> write as if that is surprising. But I have never considered Spotted Redshank
> and Common Redshank closely related just because they both have red legs.
> There are many more differences between them than there are between the
> yellowlegs or between greenshank and Marsh Sandpiper. The winter ranges of
> the two redshanks don't overlap as much as the yellowlegs winter ranges, so
> I'm even more skeptical of mimicry/convergence in this pair.
>
> Finally, how do you get a Willet from a Lesser Yellowlegs? That's a lot
> harder than solving a problem like Maria. Moving from foraging in the water
> to foraging on mudflats could lead to the evolution of shorter legs. Perhaps
> there is more competition from smaller shorebirds on the mudflats, which
> could lead to the evolution of larger size. I can't explain why the flashy
> wing pattern of a Willet would evolve from the plain pattern of a
> yellowlegs, nor why all of their vocalizations would be so different. Note
> that the two dowitcher species have quite different flight calls, but their
> songs are almost identical, and the two yellowlegs have much more similar
> songs than either does to a Willet. Even if the flight calls of the
> yellowlegs converged to facilitate their association in winter flocks, there
> is no reason for their songs to have converged. I'm still not convinced of
> the validity of all parts of this phylogeny.
>
> NOTE: I am in no way belittling the use of molecular tools to study
> relationships of organisms. I think we are very fortunate that we have these
> tools available, and they have given us tremendous insight. They probably
> don't answer all the questions.
>
> So take a closer look at those yellowlegs and their relatives next time you
> encounter them.
>
> Dennis
> -----
> Dennis Paulson
> 1724 NE 98 St.
> Seattle, WA 98115
> 206-528-1382
> dennispaulson at comcast.net
>
>
>
>
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