Genetic consequences of habitat fragmentation and loss: the case of the Florida black bear (Ursus americanus floridanus)

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• 作者：Jeremy D. Dixon ; Madan K. Oli ; Michael C. Wooten ; Thomas H. Eason ; J. Walter McCown and Mark W. Cunningham
• 关键词：Florida black bears ; Genetic variation ; Gene flow ; Habitat fragmentation ; Microsatellites ; Ursus americanus floridanus
• 刊名：Conservation Genetics
• 出版年：2007
• 出版时间：April, 2007
• 年：2007
• 卷：8
• 期：2
• 页码：455-464
• 全文大小：275 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Biomedicine
  Human Genetics
  Animal Anatomy, Morphology and Histology
  Plant Sciences
  Evolutionary Biology
  
• 出版者：Springer Netherlands
• ISSN：1572-9737

文摘

Habitat loss and fragmentation can influence the genetic structure of biological populations. We studied the genetic consequences of habitat fragmentation in Florida black bear (Ursus americanus floridanus) populations. Genetic samples were collected from 339 bears, representing nine populations. Bears were genotyped for 12 microsatellite loci to estimate genetic variation and to characterize genetic structure. None of the nine study populations deviated from Hardy–Weinberg equilibrium. Genetic variation, quantified by mean expected heterozygosity (H _E), ranged from 0.27 to 0.71 and was substantially lower in smaller and less connected populations. High levels of genetic differentiation among populations (global F _ST = 0.224; global R _ST = 0.245) suggest that fragmentation of once contiguous habitat has resulted in genetically distinct populations. There was no isolation-by-distance relationship among Florida black bear populations, likely because of barriers to gene flow created by habitat fragmentation and other anthropogenic disturbances. These factors resulted in genetic differentiation among populations, even those that were geographically close. Population assignment tests indicated that most individuals were genetically assigned to the population where they were sampled. Habitat fragmentation and anthropogenic barriers to movement appear to have limited the dispersal capabilities of the Florida black bear, thereby reducing gene flow among populations. Regional corridors or translocation of bears may be needed to restore historical levels of genetic variation. Our results suggest that management actions to mitigate genetic consequences of habitat fragmentation are needed to ensure long-term persistence of the Florida black bear.