SYSTEMATICS

LEARNING OBJECTIVES 1.  Define systematics, taxonomy and phylogenetics 2.  Differentiate between taxonomy and phylogenetics 3.  Apply the dichotomous key for classification

4.  Interpret phylogenetic trees to describe evolutionary relationships among organisms

5.  Explain how taxonomy and phylogenetics complement each other

Campbell, Ch 26.1

LEARNING OBJECTIVES 1.  Define systematics, taxonomy and phylogenetics 2.  Differentiate between taxonomy and phylogenetics 3.  Apply the dichotomous key for classification

4.  Interpret phylogenetic trees to describe evolutionary relationships among organisms

5.  Explain how taxonomy and phylogenetics complement each other

Campbell, Ch 26.1

SYSTEMATICS

Organism

Taxonomy (diversity)

Phylogeny (relationships)

•  To which group of organisms does it belong?

•  How different is it from others?

•  How is it related to other organisms?

•  How did it evolve?

DEFINITION OF TERMS Systematics •  The study of the diversification of and the relationships

among organisms Taxonomy

•  The study of naming, describing, and classifying organisms

Phylogenetics

•  The study of evolutionary history, development, and relationships among groups of organisms

LEARNING OBJECTIVES 1.  Define systematics, taxonomy and phylogenetics 2.  Differentiate between taxonomy and phylogenetics 3.  Apply the dichotomous key for classification

4.  Interpret phylogenetic trees to describe evolutionary relationships among organisms

5.  Explain how taxonomy and phylogenetics complement each other

Campbell, Ch 26.1

TAXONOMY binomial nomenclature

DICHOTOMOUS KEY •  Tool for classifying and

identifying organisms •  Focuses on

morphological characteristics

•  Series of statements that branch into 2 choices

DICHOTOMOUS KEY: VERTEBRATE CLASSES

DICHOTOMOUS KEY: PLANT PHYLA

http://ib.bioninja.com.au/standard-level/topic-5-evolution-and-biodi/53-classification-of-biodiv/dichotomous-keys.html

DICHOTOMOUS KEY: INVERTEBRATE PHYLA

http://ib.bioninja.com.au/standard-level/topic-5-evolution-and-biodi/53-classification-of-biodiv/dichotomous-keys.html

EXERCISE Develop a dichotomous key for the 6 kingdoms.

LEARNING OBJECTIVES 1.  Define systematics, taxonomy and phylogenetics 2.  Differentiate between taxonomy and phylogenetics 3.  Apply the dichotomous key for classification

4.  Interpret phylogenetic trees to describe evolutionary relationships among organisms

5.  Explain how taxonomy and phylogenetics complement each other

Campbell, Ch 26.1

PHYLOGENETICS •  Tool for determining

relationships •  Usually focuses on

molecular characteristics

•  Composed of branches (descendants) and nodes (common ancestor)

PHYLOGENETIC TREE

HOW TO READ TREES

sister taxon

clade

Are B and C sister taxa? Are C and D sister taxa? Are D and E sister taxa?

Do A and B form a clade? Do C and D form a clade? Do D and E form a clade?

WHAT TREES DON’T SAY 1.  Trees show evolutionary

history, but not necessarily phenotypic similarity •  e.g. lizards, crocodiles and

birds 2.  Sequence of branching does

not indicate absolute ages •  e.g. crocodiles and birds

3.  Sister taxons did not evolve from each other •  e.g. ostriches and hawks

Nature 496, 311–316 (18 April 2013)

EXERCISE 1.  Name the organisms that form a clade with the dog. Write T if the statement is true or F is false. If false, rephrase the statement into its correct form: 2.  Turkey and zebra finch are sister taxa.

3.  The mouse looks more like an opossum, hence are more related to each other.

4.  The zebrafish evolved before Tilapia.

5.  The little skate evolved from the spotted catshark

LEARNING OBJECTIVES 1.  Define systematics, taxonomy and phylogenetics 2.  Differentiate between taxonomy and phylogenetics 3.  Apply the dichotomous key for classification

4.  Interpret phylogenetic trees to describe evolutionary relationships among organisms

5.  Explain how taxonomy and phylogenetics complement each other

Campbell, Ch 26.1

TAXONOMY MEETS PHYLOGENY 1690 [Vol. 89AMERICAN JOURNAL OF BOTANY

Fig. 11. One of 980 equally parsimonious trees of the combined analysis of the Zingiberaceae in which monophyletic genera have been collapsed into asingle branch for clarity. Branch lengths (above the line) and bootstrap values (below the line if $50%) are shown for clades encompassing two or more genera.Asterisks indicate nodes that collapse in the strict consensus tree. Subfamilies and tribes of the new classification of the family are indicated (see Fig. 10 andTables 2–4).

1682

American Journal of Botany 89(11): 1682–1696. 2002.

THE PHYLOGENY AND A NEW CLASSIFICATION OF THEGINGERS (ZINGIBERACEAE): EVIDENCE FROM

MOLECULAR DATA1

W. JOHN KRESS,2,5 LINDA M. PRINCE,2,4 AND KYLE J. WILLIAMS3

2Botany, MRC-166, United States National Herbarium, National Museum of Natural History, Smithsonian Institution, P.O. Box37012, Washington, D.C. 20013-7012 USA; 3Department of Biology, Duke University, Durham, North Carolina 27708 USA

The pantropical Zingiberaceae is the largest family in the order Zingiberales with 53 genera and over 1200 species. Classificationsof the family first proposed in 1889 and refined by others since that time recognize four tribes (Globbeae, Hedychieae, Alpinieae, andZingibereae) based on morphological features, such as number of locules and placentation in the ovary, development of staminodia,modifications of the fertile anther, and rhizome-shoot-leaf orientation. New phylogenetic analyses based on DNA sequences of thenuclear internal transcribed spacer (ITS) and plastid matK regions suggest that at least some of these morphological traits are homo-plasious and three of the tribes are paraphyletic. The African genus Siphonochilus and Bornean genus Tamijia are basal clades. Theformer Alpinieae and Hedychieae for the most part are monophyletic taxa with the Globbeae and Zingibereae included within thelatter. The results of these phylogenetic investigations are used to propose a new classification of the Zingiberaceae that recognizesfour subfamilies and four tribes: Siphonochiloideae (Siphonochileae), Tamijioideae (Tamijieae), Alpinioideae (Alpinieae, Riedelieae),and Zingiberoideae (Zingibereae, Globbeae). Morphological features congruent with this classification and the taxonomic status ofvarious monotypic genera are discussed.

Key words: classification; gingers; ITS; matK; phylogeny; tropical; Zingiberaceae; Zingiberales.

The primarily tropical Zingiberales are phylogenetically em-bedded within the derived eumonocots (Arecales, Commelin-ales, Poales) and include many conspicuous taxa, such as thebananas (Musaceae), birds of paradise (Strelitziaceae), heli-conias (Heliconiaceae), and gingers (Zingiberaceae). With 53genera and over 1200 species, the Zingiberaceae is the largestof the eight families of the order (Kress, 1990). In earlier clas-sifications (e.g., Petersen, 1889; Schumann, 1904) the familyCostaceae (Fig. 1) was included in the Zingiberaceae, but witha number of distinctive characters (e.g., lack of aromatic oils,branched aerial stems, and spiral monostichous phyllotaxy;Specht et al., 2001) it is now accepted as the sister clade tothe gingers (Kress, 1990, 1995; Kress et al., 2001). The Zin-giberaceae is distributed pantropically with one genus (Re-nealmia) found in the Neotropics, four genera (Aframomum,Aulotandra, Siphonochilus, and Renealmia) found in Africa,and the rest of the genera distributed in east Asia and thePacific Islands. The family is still poorly known taxonomicallywith many species (Theilade and Mood, 1997; Sakai and Na-gamasu, 1998; Poulsen, Mood, and Ibrahim, 1999; Williams,Kress, and Thet Tun, 2002) and even genera (Newman, 1995;Mood and Larsen, 1997; Larsen and Mood, 1998; Sakai and

1 Manuscript received 15 February 2002; revision accepted 3 May 2002.The authors thank Ray Baker, Josef Bogner, Mike Bordelon, Alan Carle,

Mark Collins, David Harris, Yin Yin Kyi, Kai Larsen, Qing-Jun Li, Jing-PingLiao, Ida Lopez, Paul Manos, John Mood, Mark Newman, Chatchai Ngam-riabsakul, Dan Nicolson, David Orr, Louise Pedersen, Kai Rangsiruji, ShokoSakai, Henk van der Werf, Tom Wood, Qi-Gen Wu, and Yong-Mei Xia fordiscussion, assistance, and tissue samples that made this investigation possi-ble. The comments of two anonymous reviewers significantly improved themanuscript. This work was funded by the Smithsonian Scholarly Studies Pro-gram, the Biotic Surveys and Inventories Program of the National Museumof Natural History, and the A.W. Mellon Training Grant for Plant Systematicsto Duke University.

4 Current address: Rancho Santa Ana Botanic Garden, 1500 North CollegeAvenue, Claremont, California 91711-3157 USA.

5 Author for reprint requests (phone: 202-357-2534; FAX: 202-786-2563;e-mail: kress.john@nmnh.si.edu).

Nagamasu, 2000; Kress and Larsen, 2001; Larsen and Jenjit-tikul, 2001) newly described in the last several years.The currently accepted classification of the Zingiberaceae

(Petersen, 1889; Schumann, 1904; Holttum, 1950; Burtt andSmith, 1972; Larsen et al., 1998) includes four tribes (Hedy-chieae: 22 genera, Figs. 2–3; Alpinieae: 25 genera, Fig. 4;Zingibereae: one genus, Fig. 5; and Globbeae: four genera,Fig. 6) and is based on both vegetative and floral character-istics (Table 1). Although a number of morphological featureshave been used to distinguish the four tribes, in most casesthe defining characters are either not unique to any one tribeor are not universal for all taxa within any tribe (Table 1). Forexample, the plane of distichy of the leaves is perpendicularto the rhizome in the Alpinieae (except in the genera Rhyn-chanthus and Pommereschea) and is parallel to the rhizome inthe other three tribes (except for Siliquamomum in the Hedy-chieae). Similarly, the ovary is unilocular in all members ofthe Globbeae, but trilocular in the other three tribes with someexceptions, e.g., unilocular in Tamijia and partially unilocularin Caulokaempferia, Paracautleya, Scaphochlamys, Siphono-chilus, and Riedelia (Larsen et al., 1998; Sakai and Nagamasu,2000). The lateral staminodes are well developed in Hedy-chieae, Globbeae, and Zingibereae (Figs. 2–3, 5–7) and gen-erally absent in the Alpinieae (Fig. 4; but all five staminodesare absent in Rhynchanthus). The fusion of the lateral stami-nodes to the central labellum (Fig. 7) in Siphonochilus (He-dychieae; Fig. 2) and Zingiber (Zingibereae; Fig. 5) has nowbeen reported in the narrow endemic Tamijia (Alpinieae) fromBorneo (Sakai and Nagamasu, 2000). Most of the charactersthat are used to define the tribes are often inconsistent andvariable.The circumscription of various genera of the Zingiberaceae

has also been debated by investigators (e.g., Etlingera: Burttand Smith, 1986; Curcumorpha: Larsen, 1997; Paramomum:Wu, 1997), and a consensus has not been reached on the actualnumber of genera in the family. Nearly one-quarter of the gen-