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Species ()

Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily

[plant taxonomy 植物分類学|Engler's syllabus エングラー体系]
[alga 藻類|mosses 蘚苔類|fungi 菌類]

Species richness (種数)

The divergence of modern taxonomical groups (mostly divisions), based on the assumption of the origin of common ancestor.
    Angiospermae  2-300,000 spp. (12,000 gen.)
    Gymnospermae        800
    Ferns            11,000
    Mosses           24,000
    Lichens          20,000
    Fungi            36,000
    Bacteria          2,000

Variety: region - size



Table 3. Flora and fauna in East Asia. spp = number of species. end = percentages of endemic species. rpr = number of reproductive species. (World Resouces 2000-2001, WRI, 2001)
× 104 km2
islands or
Sri Lanka6islands33%8817%25010%14453%3951%3,31427%
North Korea12continent50%--1151%1911%1414%2,8984%
South Korea10continent80%490%1120%254%140%2,8988%
Russian Federation1,689continent45%2698%6282%580%410%--
Europe (reference)

Species ()

Biological and taxonomic species

Table. Relationship between classification units and applicable sphere (Cain 1954, Simpson 1961)
Units being classifiedSphere in which applicable
Taxonomic species (分類学的種)Taxa; groups of morphologically similar individualsGroups with morphological differences that are useful in formal classification
Biological species (生物学的種)Sexually reproducing population systemsSexual organisms on a single time level
Successional species (遷移種)Phyletic lineagesUniparental organisms, including asexual and parasexual organisms
Biosystematic species (系統学的種)Fertility groupsSexual plant groups which have been artificially hybridized in the experimental garden
Good species (良い種)
One taxonomic species = one biological species
Several taxonomic species = one biological species
Several taxonomic species = syngameon (sunsu Grant 1981)
Table. Biological species and stage of diversgence. Local race Population level, or variety
  Geographical race              Subspecies or variety
  Allopatric semispecies         Taxonomic species
  Sympatric semispecies          Taxonomic species
      of hybrid origin           Taxonomic species
  Allopatric biological species  Taxonomic species
  Sympatric biological species   Taxonomic species
  Species gorup                  Series
  Syngameon                      Series, or section

Character (形質)

phylogeny (= natural classification)

genetics – micro-evolution
taxonomy – macro-evolution

(Maekawa 1950)

Characters in multifaceted nature (多面性の形質)
= characters that reflect the phylesis
1. structure of flaggella (鞭毛構造)

Ex. Phycomycetes (藻菌類)

Basidiomycetes (担子菌): basidiospore, dicaryon
Ascomycetes (子嚢菌): ascospore, monocaryon
Phycomycetes: coenocyte (多核体)

Chytridiales (ツボカビ類): uniflagellate flaggella (単毛)
Oomycetes (卵菌類): two comb-shaped flaggella
Zygomycetes (接合菌): conjugation (接合)

→ the common character in Phycomycetes is only noncellular structrue

2. chemical structural components in cell wall
3. assimilatory pigment → assimilates
4. formation mode and behavior of reproductive cells

Ex. Rhizophydium (Zygomycetes)________♀: transfer of cell contents
______________________________♂: active reproductive behavior
Ex. Pyronema (Ascomycetes)

ascogonium (造嚢器) / antheridium (造卵器) → trichogyne (受精毛) → ascogenous hypha (造嚢糸), forming 2n → forming ascus (担子器)
→ oomycetes is phylogenetically different from the other phycomycetes → establishing Dichotomycetes (二毛菌) (Maekawa 1947)

5. biosynthetic pathway

Ex. biosynthesis of lysin – two pathways (Vögel 1960)

AAA-pathway: α-KG acid + CH3COO-Coenzyme A → L-α-aminoadaphic δ-semialdehyde → lysin

bacteria, cyanophyta, green algae, dichonomycetes

DAP-pathway: L-asparatic-α-semialdehyde + pyruvic acid → L-α-ε-diamino pimelic acid → lysin

Phycomycetes, ascomycetes, basidiomycetes

→ dichonomycetes is essentially different from the other fungal taxa

Characters in tendency (偏向性の形質)
1. number of flagella (鞭毛数)
2. life phase (生活相)

Ex. life phase (Maekawa 1947) – considered as interfacial film

1. virus phase
2. amoeboid phase
3. monadoid phase (鞭毛相) - primitive
4. cystoid phase (包膜相) – cell wall present = high environmental adaptation
5. gymnoid phase (裸出相) – specific for animals


Speciation (種分化)

Character displacement (形質置換)

Fig. Character displacement inferred from character states in sympatry (同所) and allopatry (異所) (Grant 1972).

Ex. Drosophilla pavlistrum complex

allopatry ___________sympatry
_____________________premating isolation
_____________________(the mechanisms unknown)

Ex. Litoria ewingii vs L. verreauxi

differences in sounds (or calls)

Ex. Phlox

____________allopatry sympatry
Phlox pilosa___pink______white
P. globerrina___pink______pink

Varation (変異)

1942 Mayer E: Geographycal race (≈ ecotype)

relationships of distribution between relative species: sympatric vs allopatric

1949, 1963 Anderson E: Introgressive hybridization

Introgression = immigration or penetration

introgressive genes to different race(s) in allopatric region(s), due to geological factors, etc.

1963 Anderson 1963: Introgression = hybridization of habitats
individuals [genes] → local population (forma) [genes, chromosome] → ecotype (variety) [genes, chromosome] → ecospecies (species) → coenospecies (species) → comparium (species or genus)
ramet (ラメート): all shoots have the same genotype

Ex. populations propagated by division = one clone

Evolutional entities (or units)
      ↓        ↓
    ramets    biotype: many heterogenous genotypes
              (genotype) - the same genotypes
    clones      ↓
                 closely remoted, related

Race (レース)

Geographical races
continuous geographical race – inappropriate because race is discontinuous
disjunctive gegographical race

Ex. Gilia latifolia (continuous distribution), G. leptantha (disjunctive) – sympatric = can breed between the races

ecological (geograpical) race

Ex. savanna, slope of alpine zone
Ex. Gilia achilleaefolia

Sun races: large flower – pollinator = insect
Shade races: small flower – self-crossing

(Huxley 1938)

Cline (クライン)

Ex. Chenopodium rubrum (Cumming 1963)
    34.3°N     50.2deg;N    60.8deg;N    62.8deg;N
    California  Suskatchwan  Yukon        Yukon
    Short-day                Quantitatic  Mostly ventral
    short-day →→→→→→→→→→→→→→ long-day

also observed on cultivated plants
likely reversed pattern shown by plants of southern elements

Selection factors on race formation
1922 Turesson: race is classified into two types:

1. adaptation to major environmental factors in a given habitat
2. replacement between species

Ex. Geum, Potentilla, Campanula, etc. → edaphic factor / biotic factor

Isolation mechanisms (隔離機構)

Table 2.1. classification of isolation types
1 Geographical isolation (地理的隔離)
2 Ecological isolation (生態的隔離)
3 Reproductive isolation (生殖的隔離)

a) Seasonal isolation
b) Diurnal isolation
c) Floral isolation
d) Incompatibility (不和合性)
e) Hybrid inviability or weakness
f) Hybrid sterility
g) Self fertilization

1-3c: External isolation or premating isolation
3d-g: Internal isolation or postmating isolation

*: mechanical isolation, ethological isolation

Semi-species (半種)
1. progressive branching (漸進的分岐) Ex. Catalpa bignoides (USA), C. ovata (China)
Ex. Pleatnus racemosa (California), P. wrightii (Arizona)

→ convenient when treated as taxonomic species
= not good biological species

Overlapping rings (重複環)

rings Fig. Overlapping rings
representative species groups that show overlapping rings: Gilia capitata group, Ipomopsis aggregata group, Aquilegia carysantha group, Mimulus longiflorus group, Pinus ponderosa group

2. natural hybridization (自然交雑)
a. hybridized group

semi-sepcies drived by semi-species: Ex. Geum rivale × G. urbanum, Aquilegia formosa × A. pubescens
Fig. 18.4. Laeves of Quercus alba and two of its hybrids (Hardin 1975)

b. permeable cross population (浸透性交雑個体群)

Iris hexagona var. giganticaerulea × I. fulva
→ conducted permeable cross after ecological isolation occurred (need revisit)

Ecological species (生態種)

Ecotype (エコタイプ) ≈ ecospecies (生態種)

Same species with different characters along environmental gradient


Product arising as a result of the response of the genotype of an organism to the particular habitat in which it lives. For example, Plantago maritima has a height of about 17.5 cm in waterlogged mud and 56 cm in fertile meadow. Cf. phenotpye plasticity

Ecocline (エコクライン)

consisting of ecotypes that exhibit gradual phenotypic and/or genetic differences along environmental gradients