Proposal (148) to South American Classification Committee
Change linear sequence of families in
Charadriiformes
Effect on South American CL: This would make minor changes in
the placement of five families to make our sequence reflect recent genetic
data.
Background: Our current sequence of families in the
Charadriiformes is a conventional one, with "kind-of-rail-like"
families first (Jacanidae + Rostratulidae), followed by the "shorebird"
families, and ending with the "gull-like" families. Oddballs like
Thinocoridae and Chionidae are placed between "shorebirds" and
"gulls." Relationships among these families have been controversial
-- see references at our SACC site.
Our current sequence =
Jacanidae
Rostratulidae
Haematopodidae
Recurvirostridae
Burhinidae
Charadriidae
Pluvianellidae
Scolopacidae
Thinocoridae
Chionidae
Stercorariidae
Laridae
Rynchopidae
New information: Three recent data sets (Ericson
et al. 2003, Paton et al. 2003, Fain & Houde 2004) using DNA sequence data
have produced largely concordant results, which in turn are reasonably
consistent with the DNA hybridization data of Sibley & Ahlquist. The first
two data sets both use the RAG-1 gene, so are not really independent (but it's
comforting to see similar results); Ericson et al. (I have pdf if interested)
also used an intron of the myoglobin gene. The third (Fain & Houde 2004; I
have pdf if interested) used an intron of the beta-fibrinogen gene.
The results with decent bootstrap support that are consistent
among the three studies and relevant to our sequence are as follows:
(1) the Charadriiformes consists of
three major groups: (1) the Scolopaci [Scolopacidae, Thinocoridae,
Pedionomidae, Rostratulidae, and Jacanidae]; (2) the Charadrii [Charadriidae,
Recurvirostridae, Haematopodidae, Burhinidae, and Chionidae]; and (3) the Lari
[Laridae, Rynchopidae, Stercorariidae, Alcidae, and Glareolidae]. This is also
consistent with Sibley & Ahlquist (1990).
(2) Jacanidae and Rostratulidae are
sister families (consistent with our current sequence as well as Sibley &
Ahlquist).
(3) Thinocoridae is sister to
Jacanidae + Rostratulidae (Sibley & Ahlquist have it as sister to other
Scolopaci but still with Scolopaci)
(4) The Scolopacidae are sister to
the other Scolopaci.
(5) Haematopodidae and
Recurvirostridae are sister families (consistent with our current sequence as
well as Sibley & Ahlquist).
(6) Charadriidae is the sister to
Haematopodidae + Recurvirostridae (consistent with Sibley & Ahlquist).
(7) Stercorariidae must be ranked
as a family if Rynchopidae and Alcidae are also ranked as families;
Stercorariidae is not the sister to Laridae + Rynchopidae (in contrast to
Sibley & Ahlquist).
The following result is consistent
between Ericson et al. and Paton et al. but is unresolved in Fain & Houde:
(8) Chionidae and Burhinidae are
more closely related to each other than to any other charadriiform family
(except Pluvianellidae: see #9 below). Sibley & Ahlquist "almost"
found that relationship -- they found: Chionidae + (Burhinidae + [other
Scolopaci]). Ericson et al. also showed that this relationship was not just due
to RAG-1 but also was obtained from myoglobin alone, so in this case we can
treat this as evidence from two independent analyses.
The following result was obtained only by Paton et al. because the
others did not have Pluvianellus:
(9) Pluvianellidae and Chionidae
are sisters. This result received 100% bootstrap support, as did the node
uniting these two with four species of Burhinus.
[There are some additional minor points that I have incorporated
directly into our Notes.]
Of these 9 points, 5 (#1, #3, #6, #8, #9) are not reflected in our
linear sequence.
Analysis and Proposal: I am always impressed by
congruence among data sets. Even the conflicts with Sibley & Ahlquist are
relatively minor, involving single node shifts in each case. To make our
sequence reflect their combined phylogenetic hypotheses and to also cause
minimum disturbance, I propose the following (with the changes in red):
Charadriidae (moved to front to reflect basal position; has added
trivial benefit of having nominate family first)
Haematopodidae
Recurvirostridae
Burhinidae
Chionidae
Pluvianellidae
Scolopacidae
Thinocoridae
Jacanidae
Rostratulidae
Stercorariidae
Laridae
Rynchopidae
Recommendation: Because our linear sequence and
classification should reflect phylogenetic data, and because the data appear
solid, I will vote YES on this. Whatever problems there might be with this
sequence, it is grounded in phylogenetic hypotheses and data and is certainly
closer to the true phylogeny of the order than any other sequence currently in
use. If this passes, I'll submit another proposal to recognize formally as
suborders the three major groups.
References:
ERICSON,
P.G.P., I. ENVALL, M. IRESTEDT, AND J. A. NORMAN. 2003. Inter- familial
relationships of the shorebirds (Aves: Charadriiformes) based on nuclear DNA
sequence data. BMC Evolutionary Biology 3 (14 pp).
FAIN, M.
G., & P. HOUDE. 2004. Parallel radiations in the primary clades of birds.
Evolution 58: 2558-2573.
PATON, T.
A., A. J. BAKER, J. G. GROTH, AND G. F. BARROWCLOUGH. 2003. RAG-1 sequences
resolve phylogenetic relationships within charadriiform birds. Molecular
Phylogenetics Evolution 29: 268-278.
Van Remsen, December 2004
_____________________________________________________________________________________
Comments from Robbins: "YES. The data presented in
the three studies support the changes proposed by Van, so I vote
"yes" for the new linear family arrangement within the
Charadriiformes."
Comments from Jaramillo: "YES - impressed by the
congruence of data sets, and it makes a great deal of sense to me. I like
it!"
Comments from Stiles: "YES. Genetic data seem well
substantiated and the linear sequence should reflect phylogenetic patterns
insofar as possible."
Comments from Silva: "YES. The congruence among
the datasets is quite impressive."