首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   91篇
  免费   0篇
安全科学   2篇
环保管理   9篇
基础理论   78篇
灾害及防治   2篇
  2014年   9篇
  2013年   5篇
  2012年   1篇
  2011年   8篇
  2010年   9篇
  2009年   10篇
  2008年   5篇
  2007年   7篇
  2006年   3篇
  2005年   9篇
  2004年   5篇
  2003年   3篇
  2002年   1篇
  2001年   2篇
  1997年   3篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1991年   4篇
  1987年   1篇
  1986年   1篇
  1984年   1篇
  1983年   1篇
排序方式: 共有91条查询结果,搜索用时 15 毫秒
91.
Abstract: There are few empirical studies of the effects of human-induced fragmentation and bottlenecks on the genetic structure of field populations. Assessment of these effects is necessary to evaluate the relevance of predictions obtained from simulation and theoretical models to the management of wild populations. The genetic structure of populations of the Wild Turkey (Meleagris gallopavo), which have been heavily influenced by human activities, was examined using allozyme electrophoresis Allele frequencies at four polymorphic loci were estimated for 27 localities using 461 turkeys The estimated proportion of genetic variation resulting from differences among populations (Fst= 0.102) was one of the highest reported for any avian species and was also much higher than that observed between turkey populations that had not passed through known bottlenecks Almost all of the variation (89%) among populations was accounted for by differences between groups of populations with different histories of manipulation Fragmented distributions and population bottlenecks due to human activities appear to have increased genetic differentiation among populations of wild turkeys. This observation agrees with theoretical predictions concerning the effects of isolation and bottlenecks on the genetic structure of field populations.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号