Evolutionary implications of acidification: a frog’s eye view

Understanding the diversity of life is one of the main aims of evolutionary biology, and requires knowledge of the occurrence and causes of adaptive genetic differentiation among geographically distinct populations. Environmental stress caused by acidity may cause strong directional selection in nat...

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Bibliographic Details
Main Author: Räsänen, Katja
Format: Doctoral Thesis
Language:English
Published: Uppsala universitet, Populationsbiologi 2002
Subjects:
Online Access:http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-2873
http://nbn-resolving.de/urn:isbn:91-554-5441-0
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spelling ndltd-UPSALLA1-oai-DiVA.org-uu-28732013-01-08T13:03:39ZEvolutionary implications of acidification: a frog’s eye viewengRäsänen, KatjaUppsala universitet, PopulationsbiologiUppsala : Acta Universitatis Upsaliensis2002Biologyacid stressamphibianslocal adaptationmaternal effectsmaternal investmentBiologiBiologyBiologiUnderstanding the diversity of life is one of the main aims of evolutionary biology, and requires knowledge of the occurrence and causes of adaptive genetic differentiation among geographically distinct populations. Environmental stress caused by acidity may cause strong directional selection in natural populations, but is little explored from an evolutionary perspective. In this thesis, a series of laboratory experiments and field data was used to study evolutionary and ecological responses of amphibians to environmental acidity. Local adaptation to acid stress was studied in the moor frog (Rana arvalis).The results show that acid origin populations have higher acid stress tolerance during the embryonic stages than neutral origin populations, and that acid and neutral origin populations have diverged in embryonic and larval life-histories. The mechanisms underlying adaptive differentiation are partially mediated by maternal effects related to extra-embryonic membranes and egg size. Acid origin females invest in larger eggs and have a stronger egg size-fecundity trade-off than females from neutral areas, likely reflecting adaptive differentiation in maternal investment patterns. Potential carry-over effects of low pH, and the effects of UV-b/pH interaction were investigated in the common frog (R. temporaria). The results suggest that amphibian larvae are able to compensate for the negative effects of acidity experienced early in life, if conditions later turn beneficial. R. temporaria populations differed in their sensitivity to synergistic effects of low pH/UV-B, indicating variation in population responses to environmental stress. In conclusion, these results suggest rapid evolution in response to human induced environmental change, much of which may be mediated via adaptive maternal effects. Acidification may be a powerful selective force shaping life-history evolution. Doctoral thesis, comprehensive summaryinfo:eu-repo/semantics/doctoralThesistexthttp://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-2873urn:isbn:91-554-5441-0Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1104-232X ; 764application/pdfinfo:eu-repo/semantics/openAccess
collection NDLTD
language English
format Doctoral Thesis
sources NDLTD
topic Biology
acid stress
amphibians
local adaptation
maternal effects
maternal investment
Biologi
Biology
Biologi
spellingShingle Biology
acid stress
amphibians
local adaptation
maternal effects
maternal investment
Biologi
Biology
Biologi
Räsänen, Katja
Evolutionary implications of acidification: a frog’s eye view
description Understanding the diversity of life is one of the main aims of evolutionary biology, and requires knowledge of the occurrence and causes of adaptive genetic differentiation among geographically distinct populations. Environmental stress caused by acidity may cause strong directional selection in natural populations, but is little explored from an evolutionary perspective. In this thesis, a series of laboratory experiments and field data was used to study evolutionary and ecological responses of amphibians to environmental acidity. Local adaptation to acid stress was studied in the moor frog (Rana arvalis).The results show that acid origin populations have higher acid stress tolerance during the embryonic stages than neutral origin populations, and that acid and neutral origin populations have diverged in embryonic and larval life-histories. The mechanisms underlying adaptive differentiation are partially mediated by maternal effects related to extra-embryonic membranes and egg size. Acid origin females invest in larger eggs and have a stronger egg size-fecundity trade-off than females from neutral areas, likely reflecting adaptive differentiation in maternal investment patterns. Potential carry-over effects of low pH, and the effects of UV-b/pH interaction were investigated in the common frog (R. temporaria). The results suggest that amphibian larvae are able to compensate for the negative effects of acidity experienced early in life, if conditions later turn beneficial. R. temporaria populations differed in their sensitivity to synergistic effects of low pH/UV-B, indicating variation in population responses to environmental stress. In conclusion, these results suggest rapid evolution in response to human induced environmental change, much of which may be mediated via adaptive maternal effects. Acidification may be a powerful selective force shaping life-history evolution.
author Räsänen, Katja
author_facet Räsänen, Katja
author_sort Räsänen, Katja
title Evolutionary implications of acidification: a frog’s eye view
title_short Evolutionary implications of acidification: a frog’s eye view
title_full Evolutionary implications of acidification: a frog’s eye view
title_fullStr Evolutionary implications of acidification: a frog’s eye view
title_full_unstemmed Evolutionary implications of acidification: a frog’s eye view
title_sort evolutionary implications of acidification: a frog’s eye view
publisher Uppsala universitet, Populationsbiologi
publishDate 2002
url http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-2873
http://nbn-resolving.de/urn:isbn:91-554-5441-0
work_keys_str_mv AT rasanenkatja evolutionaryimplicationsofacidificationafrogseyeview
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