Heinz-Ulrich Reyer’s research while affiliated with University of Zurich and other places

Josh van Buskirk (Photo 1) died on 20 August 2021 at the age of 61, after a two year long struggle with cancer, which included treatments in Switzerland and the USA, saw medical ups and downs and came with emotional fluctuations between hope and despair. He leaves behind a beloved family: his wife, two sons, his mother, and two sisters. He also leaves behind many people who were privileged to call Josh a dear friend, and he leaves behind a large community of evolutionary ecologists who saw Josh as a great researcher, admired for his pioneering and groundbreaking studies within the field of ecology and phenotypic plasticity in amphibians. The quotes in this obituary are a clear testimony to the enormous esteem in which Josh was held as a person and scientist.

Im Jahr 1912 veröffentlichte der für seine Sherlock-Holmes-Krimis bekannte britische Schriftsteller Sir Arthur Conan Doyle den Roman «The Lost World». Darin erreicht eine englische Expedition in Südamerika einen Tafelberg, der sich aus der Landschaft des Amazonas-Urwaldes erhebt. Er erweist sich als ein prähistorisches Reservat mit uralten Saurier-, Vogel- und Säugetierarten, die auf dem isolierten Plateau dem Aussterben entkommen sind. Kurz: eine andernorts verlorengegangene Welt. Obwohl eindeutig als Fantasiegeschichte zu erkennen, hat das Buch die Frage aufgeworfen, ob manche urzeitliche Tiere bis heute irgendwo überlebt haben könnten – woraus sich in der Folgezeit eine eigene biologische Disziplin entwickelte: die Kryptozoologie. Deren Ziele, Methoden und Ergebnisse werden in diesem Beitrag kurz vorgestellt.

For those of us who knew about his two-year struggle against cancer, the news should not have come as a total surprise; yet the message that Josh Van Buskirk (Fig. 1) had succumbed to the disease has deeply shaken us. We had never given up the hope that Josh would recover. We refused to believe that this friendly, enthusiastic, energetic, and brilliant man would have to go at the age of 61 and leave behind his family, many friends, and colleagues. We were particularly thinking how unfair and painful his untimely passing would be for his wife, two sons, his mother, and two sisters. But our wishful thinking was in vain. On August 20, Josh lost his battle. One thing, however, has not gone with him: the memory of what he meant to many of us. The following text with photos and the subsequent quotes from friends and colleagues may help in keeping this memory alive.

Schon seit Urzeiten beschäftigen den Menschen Vorstellungen von fantastischen Wesen: Der Löwenmensch von der Schwäbischen Alb oder die Mensch-Tier-Götter aus dem alten Ägypten sind nur einige dieser Zeugnisse unserer Vorfahren. Reisende berichteten von der Antike bis in die Neuzeit von Drachen, Einhörnern und Basilisken, die angeblich in fernen Ländern heimisch waren. Mutmaßliche Sichtungen von Werwölfen, Nessie oder Bigfoot ziehen sich bis in die Gegenwart hinein. In unzählbaren Bildern, Skulpturen und Erzählungen wurden diese seltsamen Kreaturen über alle Kontinente hinweg verewigt.Was steckt hinter diesen Fabeltieren und fantastischen Geschöpfen? Entspringen diese seltsamen Wesen bloß unserer Fantasie? Der Zoologe Heinz-Ulrich Reyer wirft einen biologischen Blick auf die Kulturgeschichte der Fabelwesen und zeigt, dass viele Fabelwesen überraschend reale Vorbilder haben. Eine bildgewaltige Spurensuche zwischen Mythos und Realität. Wie real sind Drache, Einhorn und andere fantastische Geschöpfe? Entspringen diese seltsamen Wesen bloß unserer Fantasie? Der Zoologe Heinz-Ulrich Reyer wirft einen biologischen Blick auf Fabelwesen aus aller Welt und zeigt, dass viele fantastische Kreaturen überraschend reale Vorbilder haben. Eine bildgewaltige Spurensuche zwischen Mythos und Realität.

Background: Sexual parasites offer unique insights into the reproduction of unisexual and sexual populations. Because unisexuality is almost exclusively linked to the female sex, most studies addressed host-parasite dynamics in populations where sperm-dependent females dominate. Pelophylax water frogs from Central Europe include hybrids of both sexes, collectively named P. esculentus. They live syntopically with their parental species P. lessonae and/or P. ridibundus. Some hybrid lineages consist of all males providing a chance to understand the origin and perpetuation of a host-parasite (egg-dependent) system compared to sperm-dependent parthenogenesis. Methods: We focused on P. ridibundus-P. esculentus populations where P. ridibundus of both sexes lives together with only diploid P. esculentus males. Based on 17 microsatellite markers and six allozyme loci, we analyzed (i) the variability of individual genomes, (ii) the reproductive mode(s) of all-male hybrids, and (iii) the genealogical relationships between the hybrid and parental genomes. Results: Our microsatellite data revealed that P. esculentus males bear Mendelian-inherited ridibundus genomes while the lessonae genome represents a single clone. Our data indicate that this clone did not recently originate from adjacent P. lessonae populations, suggesting an older in situ or ex situ origin. Conclusions: Our results confirm that also males can perpetuate over many generations as the unisexual lineage and successfully compete with P. ridibundus males for eggs provided by P. ridibundus females. Natural persistence of such sex-specific hybrid populations allows to studying the similarities and differences between male and female reproductive parasitism in many biological settings.