All Stories

  1. Competitive gametic traits and their coevolution with strong and slight anisogamy

    Article • Evolution, October 2025, Oxford University Press (OUP)

    Professor Geoff A. Parker

  2. Optimality Theory

    Article • January 2025, Elsevier

    Professor Geoff A. Parker

  3. The logic of conventional and reversed Bateman gradients

    Article • Proceedings of the Royal Society B Biological Sciences, November 2024, Royal Society Publishing

    Professor Geoff A. Parker

  4. An ulvophycean marine green alga produces large parthenogenetic isogametes as predicted by the gamete dynamics model for the evolution of anisogamy

    Article • Biology Letters, October 2024, Royal Society Publishing

    Professor Geoff A. Parker

  5. The correlation between anisogamy and sexual selection intensity—the broad theoretical predictions

    Article • Evolution Letters, July 2024, Oxford University Press (OUP)

    Professor Geoff A. Parker

  6. Mitochondrial uniparental inheritance achieved after fertilization challenges the nuclear–cytoplasmic conflict hypothesis for anisogamy evolution

    Article • Biology Letters, September 2023, Royal Society Publishing

    Professor Geoff A. Parker

  7. The early rise and spread of evolutionary game theory: perspectives based on recollections of early workers

    Article • Philosophical Transactions of the Royal Society B Biological Sciences, March 2023, Royal Society Publishing

    Professor Geoff A. Parker

  8. Maximum gonad investment of the sexes of the broadcast-spawning sea cucumber Holothuria (Halodeima) inornata (Echinodermata: Holothuroidea)

    Article • Journal of the Marine Biological Association of the United Kingdom, February 2022, Cambridge University Press

    Professor Geoff A. Parker

  9. Complex life-cycles in trophically transmitted helminths: Do the benefits of increased growth and transmission outweigh generalism and complexity costs?

    Article • Current Research in Parasitology and Vector-Borne Diseases, January 2022, Elsevier

    Professor Geoff A. Parker

  10. Evolution of Anisogamy in Organisms with Parthenogenetic Gametes

    Article • The American Naturalist, September 2021, University of Chicago Press

    Professor Geoff A. Parker

  11. The devil is in the details: a comment on Shuker and Kvarnemo

    Article • Behavioral Ecology, August 2021, Oxford University Press (OUP)

    Professor Geoff A. Parker

  12. Life‐cycle complexity in helminths: What are the benefits?

    Article • Evolution, July 2021, Wiley

    Professor Geoff A. Parker

  13. A comparative test of the gamete dynamics theory for the evolution of anisogamy in Bryopsidales green algae

    Article • Royal Society Open Science, March 2021, Royal Society Publishing

    Professor Geoff A. Parker

  14. How Soon Hath Time… A History of Two “Seminal” Publications

    Article • Cells, February 2021, MDPI AG

    Professor Geoff A. Parker

  15. Conceptual developments in sperm competition: a very brief synopsis

    Article • Philosophical Transactions of the Royal Society B Biological Sciences, October 2020, Royal Society Publishing

    Professor Geoff A. Parker

  16. Evolutionary insight from a humble fly: sperm competition and the yellow dungfly

    Article • Philosophical Transactions of the Royal Society B Biological Sciences, October 2020, Royal Society Publishing

    Professor Geoff A. Parker

  17. Ungulate Helminth Transmission and Two Evolutionary Puzzles

    Article • Trends in Parasitology, January 2020, Elsevier

    Professor Geoff A. Parker

  18. So we all choose our own assessment rules?: a comment on Chapin et al

    Article • Behavioral Ecology, July 2019, Oxford University Press (OUP)

    Professor Geoff A. Parker

  19. Evolution of the Two Sexes under Internal Fertilization and Alternative Evolutionary Pathways

    Article • The American Naturalist, May 2019, University of Chicago Press

    Professor Geoff A. Parker

  20. What do isogamous organisms teach us about sex and the two sexes?

    Article • Philosophical Transactions of the Royal Society B Biological Sciences, October 2016, Royal Society Publishing

    Professor Geoff A. Parker

  21. Why anisogamy drives ancestral sex roles

    Article • Evolution, May 2016, Wiley

    Professor Geoff A. Parker

  22. The evolution of expenditure on testes

    Article • Journal of Zoology, January 2016, Wiley

    Professor Geoff A. Parker

  23. Evolution of complex life cycles in trophically transmitted helminths. I. Host incorporation and trophic ascent

    Article • Journal of Evolutionary Biology, January 2015, Wiley

    Professor Geoff A. Parker

  24. Evolution of complex life cycles in trophically transmitted helminths. II. How do life-history stages adapt to their hosts?

    Article • Journal of Evolutionary Biology, January 2015, Wiley

    Professor Geoff A. Parker

  25. Gamete competition, gamete limitation, and the evolution of the two sexes

    Article • Molecular Human Reproduction, October 2014, Oxford University Press (OUP)

    Professor Geoff A. Parker

  26. The Sexual Cascade and the Rise of Pre-Ejaculatory (Darwinian) Sexual Selection, Sex Roles, and Sexual Conflict

    Article • Cold Spring Harbor Perspectives in Biology, August 2014, Cold Spring Harbor Laboratory Press

    Professor Geoff A. Parker

  27. Gamete evolution and sperm numbers: sperm competition versus sperm limitation

    Article • Proceedings of the Royal Society B Biological Sciences, August 2014, Royal Society Publishing

    Professor Geoff A. Parker

  28. The asymmetric incubation game: a prospective model and a house sparrow investigation

    Article • Animal Behaviour, July 2014, Elsevier

    Professor Geoff A. Parker

  29. Foreword

    Article • May 2013, Cambridge University Press

    Professor Geoff A. Parker

  30. Polyandry: the history of a revolution

    Article • Philosophical Transactions of the Royal Society B Biological Sciences, January 2013, Royal Society Publishing

    Professor Geoff A. Parker

  31. Complex Life Cycles: Why Refrain from Growth before Reproduction in the Adult Niche?

    Article • The American Naturalist, January 2013, University of Chicago Press

    Professor Geoff A. Parker, Daniel Benesh

  32. SPERM COMPETITION GAMES: A GENERAL MODEL FOR PRECOPULATORY MALE-MALE COMPETITION

    Article • Evolution, August 2012, Oxford University Press (OUP)

    Professor Geoff A. Parker

  33. Correction for Immler et al., Resolving variation in the reproductive tradeoff between sperm size and number

    Article • Proceedings of the National Academy of Sciences, April 2011, Proceedings of the National Academy of Sciences

    Professor Geoff A. Parker

  34. EXPLOITATION OF THE SAME TROPHIC LINK FAVORS CONVERGENCE OF LARVAL LIFE-HISTORY STRATEGIES IN COMPLEX LIFE CYCLE HELMINTHS

    Article • Evolution, April 2011, Oxford University Press (OUP)

    Professor Geoff A. Parker, Daniel Benesh

  35. The origin and maintenance of two sexes (anisogamy), and their gamete sizes by gamete competition

    Article • April 2011, Cambridge University Press

    Professor Geoff A. Parker

  36. Resolving variation in the reproductive tradeoff between sperm size and number

    Article • Proceedings of the National Academy of Sciences, March 2011, Proceedings of the National Academy of Sciences

    Professor Geoff A. Parker

  37. Inclusive fitness theory and eusociality

    Article • Nature, March 2011, Nature

    Dr Charles W Fox, Professor Geoff A. Parker

  38. Sperm competition and ejaculate economics

    Article • Biological Reviews, June 2010, Wiley

    Professor Geoff A. Parker

  39. Sperm competition games: Sperm size (mass) and number under raffle and displacement, and the evolution of P2

    Article • Journal of Theoretical Biology, June 2010, Elsevier

    Professor Geoff A. Parker

  40. Maternal effects on offspring size and packaging constraints in the whelk

    Article • Journal of Zoology, May 2010, Wiley

    Professor Geoff A. Parker

  41. Living in intermediate hosts: evolutionary adaptations in larval helminths

    Article • Trends in Parasitology, February 2010, Elsevier

    Professor Geoff A. Parker

  42. Why do larval helminths avoid the gut of intermediate hosts?

    Article • Journal of Theoretical Biology, October 2009, Elsevier

    Professor Geoff A. Parker

  43. WHEN TO GO: OPTIMIZATION OF HOST SWITCHING IN PARASITES WITH COMPLEX LIFE CYCLES

    Article • Evolution, August 2009, Oxford University Press (OUP)

    Professor Geoff A. Parker

  44. To grow or not to grow? Intermediate and paratenic hosts as helminth life cycle strategies

    Article • Journal of Theoretical Biology, May 2009, Elsevier

    Professor Geoff A. Parker

  45. WHEN SHOULD A TROPHICALLY TRANSMITTED PARASITE MANIPULATE ITS HOST?

    Article • Evolution, February 2009, Wiley

    Professor Geoff A. Parker

  46. Sperm competition and sperm phenotype

    Article • January 2009, Elsevier

    Professor Geoff A. Parker

  47. The evolution of complex life cycles when parasite mortality is size- or time-dependent

    Article • Journal of Theoretical Biology, July 2008, Elsevier

    Professor Geoff A. Parker

  48. Geoff A. Parker

    Article • Current Biology, February 2007, Elsevier

    Professor Geoff A. Parker

  49. Sperm competition games: the risk model can generate higher sperm allocation to virgin females

    Article • Journal of Evolutionary Biology, October 2006, Oxford University Press (OUP)

    Professor Geoff A. Parker

  50. Consequences of biparental care for begging and growth in zebra finches, Taeniopygia guttata

    Article • Animal Behaviour, July 2006, Elsevier

    Professor Geoff A. Parker

  51. Sexual conflict over mating and fertilization: an overview

    Article • Philosophical Transactions of the Royal Society B Biological Sciences, February 2006, Royal Society Publishing

    Professor Geoff A. Parker

  52. Competitive Growth Strategies in Intermediate Hosts: Experimental Tests of a Parasite life-History Model Using the Cestode, Schistocephalus solidus

    Article • Evolutionary Ecology, January 2006, Springer Science + Business Media

    Professor Geoff A. Parker

  53. Sperm competition and the evolution of male reproductive anatomy in rodents

    Article • Proceedings of the Royal Society B Biological Sciences, May 2005, Royal Society Publishing

    Professor Geoff A. Parker, Dr Steven A Ramm

  54. Sperm competition, mating rate and the evolution of testis and ejaculate sizes: a population model

    Article • Proceedings of the Royal Society B Biological Sciences, May 2005, Royal Society Publishing

    Professor Geoff A. Parker

  55. Trinucleotide microsatellite loci in the yellow dung fly Scathophaga stercoraria (Diptera: Scathophagidae)

    Article • Molecular Ecology Notes, November 2004, Wiley

    Professor Geoff A. Parker

  56. Parental investment and family dynamics: interactions between theory and empirical tests

    Article • Population Ecology, September 2004, Wiley

    Professor Geoff A. Parker

  57. Spermatozoal Traits and Sperm Competition in Atlantic Salmon

    Article • Current Biology, January 2004, Elsevier

    Professor Geoff A. Parker

  58. Evolution of complex life cycles in helminth parasites

    Article • October 2003

    Professor Geoff A. Parker

  59. Sperm competition games: sperm selection by females

    Article • Journal of Theoretical Biology, September 2003, Elsevier

    Professor Geoff A. Parker

  60. Correction for Bulmer and Parker, The evolution of anisogamy: a game-theoretic approach

    Article • Proceedings of the Royal Society B Biological Sciences, December 2002, Royal Society Publishing

    Professor Geoff A. Parker

  61. Relationships between sperm morphometry and sperm motility in the Atlantic salmon

    Article • Journal of Fish Biology, December 2002, Wiley

    Professor Geoff A. Parker

  62. The evolution of anisogamy: a game-theoretic approach

    Article • Proceedings of the Royal Society B Biological Sciences, November 2002, Royal Society Publishing

    Professor Geoff A. Parker

  63. Begging for control: when are offspring solicitation behaviours honest?

    Article • Trends in Ecology & Evolution, September 2002, Elsevier

    Professor Geoff A. Parker

  64. Survival and anisogamy

    Article • Trends in Ecology & Evolution, August 2002, Elsevier

    Professor Geoff A. Parker

  65. Sperm competition, male prudence and sperm-limited females

    Article • Trends in Ecology & Evolution, July 2002, Elsevier

    Professor Geoff A. Parker

  66. Sexual conflict reduces offspring fitness in zebra finches

    Article • Nature, April 2002, Springer Science + Business Media

    Professor Geoff A. Parker

  67. Begging scrambles with unequal chicks: interactions between need and competitive ability

    Article • Ecology Letters, March 2002, Wiley

    Professor Geoff A. Parker

  68. Sperm Competition Games: A Comparison of Loaded Raffle Models and their Biological Implications

    Article • Journal of Theoretical Biology, October 2000, Elsevier

    Professor Geoff A. Parker

  69. Sperm competition games between related males

    Article • Proceedings of the Royal Society B Biological Sciences, May 2000, Royal Society Publishing

    Professor Geoff A. Parker

  70. The link between interference and continuous input models

    Article • Animal Behaviour, May 1999, Elsevier

    Professor Geoff A. Parker

  71. Sperm Displacement in the Yellow Dung Fly, Scatophaga stercoraria : An Investigation of Male and Female Processes

    Article • The American Naturalist, March 1999, University of Chicago Press

    Professor Geoff A. Parker

  72. Coercion

    Article • January 1999, Springer Science + Business Media

    Professor Geoff A. Parker

  73. Sperm Competition Games: a General Approach to Risk Assessment

    Article • Journal of Theoretical Biology, September 1998, Elsevier

    Professor Geoff A. Parker

  74. Sexual conflict and speciation

    Article • Philosophical Transactions of the Royal Society B Biological Sciences, February 1998, Royal Society Publishing

    Professor Geoff A. Parker

  75. Sperm Competition and the Evolution of Ejaculates: Towards a Theory Base

    Article • January 1998, Elsevier

    Professor Geoff A. Parker

  76. Sperm competition games: a prospective analysis of risk assessment

    Article • Proceedings of the Royal Society B Biological Sciences, December 1997, Royal Society Publishing

    Professor Geoff A. Parker

  77. Evolutionary sperm wars

    Article • Journal of Biological Education, September 1997, Taylor & Francis

    Professor Geoff A. Parker

  78. Sperm Competition Games: Inter- and Intra-species Results of a Continuous External Fertilization Model

    Article • Journal of Theoretical Biology, June 1997, Elsevier

    Professor Geoff A. Parker

  79. Sperm Competition in Fishes: The Evolution of Testis Size and Ejaculate Characteristics

    Article • The American Naturalist, May 1997, University of Chicago Press

    Professor Geoff A. Parker

  80. Giant female or dwarf male spiders?

    Article • Nature, February 1997, Springer Science + Business Media

    Professor Geoff A. Parker

  81. Sperm Competition Games: Individual Assessment of Sperm Competition Intensity by Group Spawners

    Article • Proceedings of the Royal Society B Biological Sciences, October 1996, Royal Society Publishing

    Professor Geoff A. Parker

  82. Sperm Competition Games: External Fertilization and “Adapative” Infertility

    Article • Journal of Theoretical Biology, May 1996, Elsevier

    Professor Geoff A. Parker

  83. Sperm competition or sperm selection: no evidence for female influence over paternity in yellow dung flies Scatophaga stercoraria

    Article • Behavioral Ecology and Sociobiology, March 1996, Springer Science + Business Media

    Professor Geoff A. Parker

  84. Interference and the ideal free distribution: models and tests

    Article • Behavioral Ecology, January 1996, Oxford University Press (OUP)

    Professor Geoff A. Parker

  85. Interference and the ideal free distribution: oviposition in a parasitoid wasp

    Article • Behavioral Ecology, January 1996, Oxford University Press (OUP)

    Professor Geoff A. Parker

  86. Sperm Competition Games: Sperm Size and Sperm Number under Adult Control

    Article • Proceedings of the Royal Society B Biological Sciences, September 1993, Royal Society Publishing

    Professor Geoff A. Parker

  87. Sperm Competition Games: Sperm Size and Number under Gametic Control

    Article • Proceedings of the Royal Society B Biological Sciences, September 1993, Royal Society Publishing

    Professor Geoff A. Parker

  88. Sexual dimorphism and distorted sex ratios in spiders

    Article • Nature, November 1992, Springer Science + Business Media

    Professor Geoff A. Parker

  89. Individual Variation in Sperm Competition Success of Yellow Dung Flies, Scatophaga stercoraria

    Article • Evolution, April 1992, JSTOR

    Professor Geoff A. Parker

  90. A Model of Constant Random Sperm Displacement during Mating: Evidence from Scatophaga

    Article • Proceedings of the Royal Society B Biological Sciences, November 1991, Royal Society Publishing

    Professor Geoff A. Parker

  91. Sperm Competition Games: Raffles and Roles

    Article • Proceedings of the Royal Society B Biological Sciences, November 1990, Royal Society Publishing

    Professor Geoff A. Parker

  92. Sperm Competition Games: Sneaks and Extra-Pair Copulations

    Article • Proceedings of the Royal Society B Biological Sciences, November 1990, Royal Society Publishing

    Professor Geoff A. Parker

  93. Male mate choice as predicted by sperm competition in thirteen-lined ground squirrels

    Article • Nature, November 1990, Springer Science + Business Media

    Professor Geoff A. Parker

  94. Analysing sperm competition data: simple models for predicting mechanisms

    Article • Behavioral Ecology and Sociobiology, July 1990, Springer Science + Business Media

    Professor Geoff A. Parker

  95. Hamilton's rule and conditionality

    Article • Ethology Ecology & Evolution, October 1989, Taylor & Francis

    Professor Geoff A. Parker

  96. The Distribution of Stay Times in Scatophaga: Reply to Curtsinger

    Article • The American Naturalist, April 1987, University of Chicago Press

    Professor Geoff A. Parker

  97. Parent-offspring conflict over clutch size

    Article • Evolutionary Ecology, April 1987, Springer Science + Business Media

    Professor Geoff A. Parker

  98. Why are there so many tiny sperm? Sperm competition and the maintenance of two sexes

    Article • Journal of Theoretical Biology, May 1982, Elsevier

    Professor Geoff A. Parker

  99. Selection on non-random fusion of gametes during the evolution of anisogamy

    Article • Journal of Theoretical Biology, July 1978, Elsevier

    Professor Geoff A. Parker

  100. Sperm (ejaculate) competition in Drosophila melanogaster , and the reproductive value of females to males in relation to female age and mating status

    Article • Ecological Entomology, August 1976, Wiley

    Professor Geoff A. Parker

  101. Sperm competition and the evolution of the precopulatory passive phase behaviour in Locusta migratoria migratorioides

    Article • Journal of Entomology Series A General Entomology, March 1975, Wiley

    Professor Geoff A. Parker

  102. The reproductive behaviour and the nature of sexual selection in Scatophaga stercoraria L. (Diptera: Scatophagidae).

    Article • Journal of Entomology Series A General Entomology, May 1974, Wiley

    Professor Geoff A. Parker

  103. The Reproductive Behaviour and the Nature of Sexual Selection in Scatophaga stercoraria L. (Diptera: Scatophagidae). IX. Spatial Distribution of Fertilization Rates and Evolution of Male Search Strategy Within the Reproductive Area

    Article • Evolution, March 1974, JSTOR

    Professor Geoff A. Parker

  104. The Reproductive Behaviour and the Nature of Sexual Selection in Scatophaga stercoraria L. (Diptera:Scatophagidae)

    Article • Journal of Animal Ecology, February 1971, JSTOR

    Professor Geoff A. Parker

  105. The Reproductive Behavior and the Nature of Sexual Selection in Scatophaga stercoraria L. (Diptera: Scatophagidae). VII. The Origin and Evolution of the Passive Phase

    Article • Evolution, December 1970, JSTOR

    Professor Geoff A. Parker

  106. SPERM COMPETITION AND ITS EVOLUTIONARY CONSEQUENCES IN THE INSECTS

    Article • Biological Reviews, November 1970, Wiley

    Professor Geoff A. Parker

  107. Sperm competition and its evolutionary effect on copula duration in the fly Scatophaga stercoraria

    Article • Journal of Insect Physiology, July 1970, Elsevier

    Professor Geoff A. Parker

  108. The Reproductive Behaviour and the Nature of Sexual Selection in Scatophaga stercoraria L. (Diptera: Scatophagidae): II. The Fertilization Rate and the Spatial and Temporal Relationships of Each Sex Around the Site of Mating and Oviposition

    Article • Journal of Animal Ecology, February 1970, JSTOR

    Professor Geoff A. Parker

  109. The Reproductive Behaviour and the Nature of Sexual Selection in Scatophaga stercoraria L. (Diptera: Scatophagidae): I. Diurnal and Seasonal Changes in Population Density Around the Site of Mating and Oviposition

    Article • Journal of Animal Ecology, February 1970, JSTOR

    Professor Geoff A. Parker

  110. The Reproductive Behaviour and the Nature of Sexual Selection in Scatophaga Stercoraria L. (Diptera : Scatophagidae)

    Article • Behaviour, January 1970, De Gruyter

    Professor Geoff A. Parker

  111. The Reproductive Behaviour and the Nature of Sexual Selection in Scatophaga Stercorarial. (Diptera: Scatophagidae)

    Article • Behaviour, January 1970, De Gruyter

    Professor Geoff A. Parker

  112. The reproductive behaviour and the nature of sexual selection in Scatophaga stercoraria L. (Diptera: Scatophagidae)—III* Apparent intersex individuals and their evolutionary cost to normal, searching males

    Article • Transactions of the Royal Entomological Society of London, December 1969, Wiley

    Professor Geoff A. Parker

  113. Profile: In celebration of questions, past, present and future

    Article • Cambridge University Press

    Professor Geoff A. Parker

  114. Why are there so many tiny sperm? sperm competition and the maintenance of two sexes (1982)

    Article • Springer Science + Business Media

    Professor Geoff A. Parker

  115. Sperm competition, male prudence, and sperm-limited females (2002)

    Article • Springer Science + Business Media

    Professor Geoff A. Parker

  116. Information about sperm competition and the economics of sperm allocation

    Article • Cambridge University Press

    Professor Geoff A. Parker