Fred W. Allendorf, W. Chris Funk, Sally N. Aitken, Margaret Byrne, and Gordon Luikart
- Published in print:
- 2022
- Published Online:
- April 2022
- ISBN:
- 9780198856566
- eISBN:
- 9780191889912
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198856566.003.0006
- Subject:
- Biology, Biodiversity / Conservation Biology, Evolutionary Biology / Genetics
All populations are finite in size so that genetic drift will occur in all natural and managed populations. Genetic drift causes both changes in allele frequencies and the loss of genetic variation. ...
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All populations are finite in size so that genetic drift will occur in all natural and managed populations. Genetic drift causes both changes in allele frequencies and the loss of genetic variation. Loss of heterozygosity and loss of alleles are t^ghe two primary measures of the loss of genetic variation in populations. Matings between related individuals (i.e., inbreeding) is more common in small populations, and this will lead to inbreeding depression in small populations. Understanding the effects of genetic drift is especially important for conservation because loss of genetic variation and inbreeding depression can reduce the probability of population persistence.Less
All populations are finite in size so that genetic drift will occur in all natural and managed populations. Genetic drift causes both changes in allele frequencies and the loss of genetic variation. Loss of heterozygosity and loss of alleles are t^ghe two primary measures of the loss of genetic variation in populations. Matings between related individuals (i.e., inbreeding) is more common in small populations, and this will lead to inbreeding depression in small populations. Understanding the effects of genetic drift is especially important for conservation because loss of genetic variation and inbreeding depression can reduce the probability of population persistence.
Sergio Balari and Guillermo Lorenzo
- Published in print:
- 2012
- Published Online:
- January 2013
- ISBN:
- 9780199665464
- eISBN:
- 9780191746116
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199665464.003.0002
- Subject:
- Linguistics, Psycholinguistics / Neurolinguistics / Cognitive Linguistics, Historical Linguistics
The main theme of the chapter revolves around the notion of “monster,” both in its biological and social dimensions, in order to explain the processes that eventually brought about the appearance of ...
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The main theme of the chapter revolves around the notion of “monster,” both in its biological and social dimensions, in order to explain the processes that eventually brought about the appearance of modern humans, conceptualized in two basic steps. The first step would correspond to the appearance and subsequent consolidation of a developmental monstrosity in the mind/brain of a subpopulation of hominids. Such a monstrosity, just a would-be FL at this stage, would initially have had a negative impact by turning these individuals into social monsters in the eyes of their conspecifics, with the effect of generating a reproductive barrier and thus opening the way to a process of speciation. The process would only culminate with the advent of a number of environmental circumstances giving rise to a population bottleneck, altering the genetic makeup of the population, and favoring the preservation of the original developmental monstrosity.Less
The main theme of the chapter revolves around the notion of “monster,” both in its biological and social dimensions, in order to explain the processes that eventually brought about the appearance of modern humans, conceptualized in two basic steps. The first step would correspond to the appearance and subsequent consolidation of a developmental monstrosity in the mind/brain of a subpopulation of hominids. Such a monstrosity, just a would-be FL at this stage, would initially have had a negative impact by turning these individuals into social monsters in the eyes of their conspecifics, with the effect of generating a reproductive barrier and thus opening the way to a process of speciation. The process would only culminate with the advent of a number of environmental circumstances giving rise to a population bottleneck, altering the genetic makeup of the population, and favoring the preservation of the original developmental monstrosity.
Rodney B. Pierce
- Published in print:
- 2012
- Published Online:
- August 2015
- ISBN:
- 9780816679546
- eISBN:
- 9781452947761
- Item type:
- chapter
- Publisher:
- University of Minnesota Press
- DOI:
- 10.5749/minnesota/9780816679546.003.0001
- Subject:
- Biology, Ecology
This chapter discusses the ecology of northern pike including variability, habitat, reproduction, feeding, and other behaviors. The pike’s relatively low genetic variability compared to other fish ...
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This chapter discusses the ecology of northern pike including variability, habitat, reproduction, feeding, and other behaviors. The pike’s relatively low genetic variability compared to other fish stems from low effective population sizes and population bottlenecks, which can be traced back to earlier glacial periods when the geographic range of pike was limited. Northern pike can tolerate a broad range of environmental conditions but thrive in moderately productive mesotrophic to eutrophic freshwater lakes and rivers. With regard to gender and reproduction, the sex of northern pike can be identified accurately via the external appearance of their urogenital areas, where eggs and milt are expelled.Less
This chapter discusses the ecology of northern pike including variability, habitat, reproduction, feeding, and other behaviors. The pike’s relatively low genetic variability compared to other fish stems from low effective population sizes and population bottlenecks, which can be traced back to earlier glacial periods when the geographic range of pike was limited. Northern pike can tolerate a broad range of environmental conditions but thrive in moderately productive mesotrophic to eutrophic freshwater lakes and rivers. With regard to gender and reproduction, the sex of northern pike can be identified accurately via the external appearance of their urogenital areas, where eggs and milt are expelled.
