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Julia Giehr

Fakultät für Biologie und Vorklinische Medizin
Institut für Zoologie
Lehrstuhl für Zoologie / Evolutionsbiologie
Julia Giehr

Julia Giehr 1 Julia Giehr

Zoology/Evolutionary Biology
University of  Regensburg
Biology I
Institute of Evolution, Behavior and Genetics

Julia Giehr 2

PhD Projekt:

The importance of direct fitness for helpers in advanced insect societies

The evolution of insect societies and especially the division of reproductive labor has puzzled generations of scientists. Hamilton’s theory of inclusive fitness shows that helpers can benefit from their apparent altruism by increasing the number of copies of their own genes by helping a relative to produce offspring. In addition to this indirect fitness component, helpers in societies of “primitively eusocial” insects and group-living vertebrates may also have the option to obtain direct fitness benefits by reproduction. How important direct fitness is in advanced eusocial insects has rarely been quantified.

Workers of the monogynous ant Temnothorax crassispinus are capable of producing males from unfertilized eggs. Workers usually refrain from reproduction in queenright colonies due to worker policing and therefore do not gain direct fitness. However, after the death of the queen, workers form a hierarchy and the high-ranking workers gain direct fitness by producing sons. Preliminary studies revealed a considerable percentage of queenless colonies with reproductive workers under natural conditions. We currently determine worker reproduction and quantify the percentage of worker-produced males in queenright and queenless colonies in the field.

Julia Giehr 4

Previous projects:

·        Reproductive biology in the genus Cardiocondyla (Master thesis, see Dr. A. Schrempf):

1.      “Influence of queen and worker age composition on colony fitness in C. obscurior”

2.      “Genetic variability and reproductive strategies in C. elegans”

3.      “The ant C. elegans as host of the enigmatic endoparasitic fungus M. durum”

·        Stresstoleranz und terminales Investment in C. obscurior (Bachelor thesis, see Dr. A. Schrempf)



Giehr J., Heinze J. 2018 "Queens stay, workers leave: caste-specific responses to fatal infections in an ant." BMC Evolutionary Biology, Vol 18, 202
Giehr J., Heinze J., Schrempf A. 2017 "Group demography affects ant colony performance and individual speed of queen and worker aging." BMC Evolutionary Biology, Vol 17, 173
Giehr J., Grasse A. V., Cremer S., Heinze J., Schrempf A. 2017 "Ant queens increase their reproductive efforts after pathogen infection." Royal Society Open Science, Vol 4, 1705457
Schrempf A., Giehr J., Röhrl R., Steigleder S., Heinze J. 2017 "Royal Darwinian Demons: enforced changes in reproductive efforts do not affect the life expectancy of ant queens." The American Naturalist, Vol 189, 436-442

Giehr J., Heinze J., Schrempf A. 2015 “The ant Cardiocondyla elegans as host of the enigmatic endoparasitic fungus Myrmicinosporidium durum.” Psyche, Vol 2015, Article ID 364967


Julia Giehr 3a

  1. Fakultäten
  2. Fakultät für Biologie und Vorklinische Medizin