Dissertation Research: Evolution and Development of         Alternative Amphibian Morphologies
{'Code': '08010207', 'Directorate': {'Abbreviation': 'BIO', 'LongName': 'Direct For Biological Sciences'}, 'Division': {'Abbreviation': 'DEB', 'LongName': 'Division Of Environmental Biology'}}
{'SignBlockName': 'Joann P. Roskoski', 'PO_EMAI': None, 'PO_PHON': None}
Under the concept of natural selection, individuals should                      respond to their environment in such a way as to increase their                 genetic fitness.  Individuals in a population may respond                       differently, however, to identical environmental conditions;                    there are often alternative, equally adaptive responses to                      selection pressure.  The proposed research will study spadefoot                 tadpoles which occur as two discrete phenotypes:  a large,                      rapidly developing carnivore morph and a smaller, slower                        developing omnivore morph.  This system provides a unique                       opportunity to examine how an animal's ecology can profoundly                   affect its development.  The system poses interesting problems on               the population level as well.                                                                                                                                   The first goal of this study will be to ascertain how the                       dimorphism is maintained evolutionarily.  Carnivores appear to do               better in highly ephemeral pools (because of their more rapid                   development), but omnivores may do better in more permanent ponds               (because of their greater postmetamorphic survivorship and                      reduced susceptibility to carnivore predation).  The hypothesis                 that these fitness trade-offs balance will be tested by examining               whether survivorship (both pre- and postmetamorphic) of the two                 morphs is equal within a given pond.  If this experiment shows                  that the two morphs do equally well, this would provide the                     opportunity to analyze the strategies of development.                                                                                                           The second goal is to explain what factors favor the spread of                  this and other similar dimorphisms.  Research will be done on the               extent to which this variability represents genetic adaptation to               different environmental conditions at opposite ends of the                      species' range as opposed to environmentally induced phenotypic                 variation.                                                                                                                                                      The third goal is to explain the physiological basis of morph                   determination.  Whether the ingestion of naturally occurring                    thyroxine (the endocrine "trigger" of amphibian differentiation                 at metamorphosis) causes young tadpoles to develop into                         carnivores will be examined. If thyroxine is the trigger of morph               differentiation, the underlying physiological mechanisms will be                studied.                                                                                                                                                        This study will provide much needed information, at both the                    proximate and ultimate levels, concerning how alternative                       strategies of development can persist in a population.                          Scaphiopus with its dimorphic tadpole is an excellent model                     animal for studying the evolution of developmental plasticity.                  The results of this study may have potential applications.                      Tadpoles have long been used in the study of animal development                 and spadefoots may provide developmental biologists with a unique               opportunity to study large scale facultative shifts in                          development in a vertebrate.  Finally, the carnivore's ability to               switch to omnivory has already interested a German scientist                    attempting to increase yields in commercial fish hatcheries,                    where fish are typically fed a more expensive carnivorous diet.
[{'FirstName': 'James', 'LastName': 'Bull', 'PI_MID_INIT': 'J', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'James J Bull', 'EmailAddress': 'jbull@uidaho.edu', 'NSF_ID': '000339367', 'StartDate': '06/15/1988', 'EndDate': None, 'RoleCode': 'Co-Principal Investigator'}, {'FirstName': 'David', 'LastName': 'Pfennig', 'PI_MID_INIT': 'W', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'David W Pfennig', 'EmailAddress': 'dpfennig@unc.edu', 'NSF_ID': '000367125', 'StartDate': '06/15/1988', 'EndDate': None, 'RoleCode': 'Co-Principal Investigator'}, {'FirstName': 'Mark', 'LastName': 'Kirkpatrick', 'PI_MID_INIT': None, 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Mark Kirkpatrick', 'EmailAddress': 'kirkp@mail.utexas.edu', 'NSF_ID': '000194828', 'StartDate': '06/15/1988', 'EndDate': None, 'RoleCode': 'Principal Investigator'}]
{'Name': 'University of Texas at Austin', 'CityName': 'AUSTIN', 'ZipCode': '787121139', 'PhoneNumber': '5124716424', 'StreetAddress': '110 INNER CAMPUS DR', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Texas', 'StateCode': 'TX', 'CONGRESSDISTRICT': '25', 'CONGRESS_DISTRICT_ORG': 'TX25', 'ORG_UEI_NUM': 'V6AFQPN18437', 'ORG_LGL_BUS_NAME': 'UNIVERSITY OF TEXAS AT AUSTIN', 'ORG_PRNT_UEI_NUM': None}
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{'Code': '112700', 'Text': 'Evolutionary Processes'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1988&All=true', 'xml': '8800986.xml'}