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Titolo:
Fractals, sea-ice landscape and spatial patterns of polar bears
Autore:
Ferguson, SH; Taylor, MK; Born, EW; Messier, F;
Indirizzi:
Univ Saskatchewan, Dept Biol, Saskatoon, SK S7N 5E2, Canada Univ Saskatchewan Saskatoon SK Canada S7N 5E2 skatoon, SK S7N 5E2, Canada Dept Resources Wildlife & Econ Dev, Iqaluit, NT X0A 0H0, Canada Dept Resources Wildlife & Econ Dev Iqaluit NT Canada X0A 0H0 0H0, Canada Greenland Inst Nat Resources, DK-2200 Copenhagen, Denmark Greenland Inst Nat Resources Copenhagen Denmark DK-2200 enhagen, Denmark
Titolo Testata:
JOURNAL OF BIOGEOGRAPHY
fascicolo: 6, volume: 25, anno: 1998,
pagine: 1081 - 1092
SICI:
0305-0270(199811)25:6<1081:FSLASP>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
PHOCA-HISPIDA; RINGED SEAL; POPULATION-DYNAMICS; URSUS-MARITIMUS; MITOCHONDRIAL-DNA; BREEDING HABITAT; ANIMAL MOVEMENT; COMMUNITIES; VARIABILITY; PREDATION;
Keywords:
allopatric speciation; cluster analysis; evolution; metapopulation; movement pathway; Ursus maritimus;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
90
Recensione:
Indirizzi per estratti:
Indirizzo: Ferguson, SH Univ Saskatchewan, Dept Biol, 112 Sci Pl, Saskatoon, SK S7N 5E2, Canada Univ Saskatchewan 112 Sci Pl Saskatoon SK Canada S7N 5E2 nada
Citazione:
S.H. Ferguson et al., "Fractals, sea-ice landscape and spatial patterns of polar bears", J BIOGEOGR, 25(6), 1998, pp. 1081-1092

Abstract

Periodic landscape transformations can give rise to macroevolutionary changes such as speciation, whereas more constant microevolutionary differencescan lead to population differentiation within a species. The most recent major macroevolutionary change occurred 2.5 mya when an abrupt increase in the scale of glacial cycles in the northern hemisphere resulted in the formation of the arctic sea-ice ecosystem. An initial burst of diversity occurred and sometime later polar bears evolved from brown bears as a marine mammal predator of seals living among the sea ice landscape. We tested the hypothesis that the distribution of sea ice creates a spatial patterning in the present groupings of polar bears (i.e. populations). We compared the spatial attributes of sea ice and polar bear characteristics in the Canadian Arctic. The winter and spring seasons, before and during mating, respectively, best described groupings of polar bears based on separate cluster analyses of ice and bears. A relationship between polar bear fractal movement patterns and the fractal dimension of sea ice indicated a possible mechanism linking geography and population structure. Sea ice dominates as a structuring agent and the hierarchical spatial groupings of polar bears within a circumpolar metapopulation related to the fractal pattern of annual sea ice created by the interspersion of Arctic islands. Once a new sea-ice environment formed, directional selection resulted in allopatric speciation whereas stabilizing selection maintains present groupings due to exchanges among populations at the time of breeding.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/07/20 alle ore 11:46:32