Our understanding of sexual selection has greatly improved during the last decades. The focus is no longer solely on males, but also on how female competition and male mate choice shape ornamentation and other sexuall...Our understanding of sexual selection has greatly improved during the last decades. The focus is no longer solely on males, but also on how female competition and male mate choice shape ornamentation and other sexually selected traits in females. At the same time, the focus has shifted from documenting sexual selection to exploring variation and spatiotemporal dynamics of sexual selection, and their evolutionary consequences. Here, I review insights from a model system with exceptionally dynamic sexual selection, the two-spotted goby fish Gobiusculus flavescens. The species displays a complete reversal of sex roles over a 3-month breeding season. The reversal is driven by a dramatic change in the operational sex ratio, which is heavily male-biased at the start of the season and heavily female-biased late in the season. Early in the season, breeding-ready males outnumber mature females, causing males to be highly competitive, and leading to sexual selection on males. Late in the season, mating-ready females are in excess, engage more in courtship and aggression than males, and rarely reject mating opportunities. With typically many females simultaneously courting available males late in the season, males become selective and prefer more colorful females. This variable sexual selection regime likely explains why both male and female G. flavescens have ornamental colors. The G. flavescens model system reveals that sexual behavior and sexual selection can be astonishingly dynamic in response to short-term fluctuations in mating competition. Future work should explore whether sexual selection is equally dynamic on a spatial scale, and related spatiotemporal dynamics.展开更多
The little fire ant Wasmannia auropunctata(Roger)is a major invasive species that seriously threatens the biodiversity of invaded areas.W.auropunctata was first reported in Chinese mainland in 2022 and its impact on n...The little fire ant Wasmannia auropunctata(Roger)is a major invasive species that seriously threatens the biodiversity of invaded areas.W.auropunctata was first reported in Chinese mainland in 2022 and its impact on native species is still unknown.To evaluate the impact of W.auropunctata invasion on the ant communities in southern China,a series of interspecific competition experiments were conducted in this study.The individual aggression index and group aggression experiments showed the advantage of W.auropunctata in competition with 5 resident ants under equal worker numbers.When encountering Anoplolepis gracilipes,Camponotus nicobarensis,Tetramorium bicarinatum,Polyrhachis dives,and Solenopsis invicta,W.auropunctata gradually gained a competitive advantage with an increase in its number of workers.In the group aggression experiments with equal worker numbers,there was a negative correlation between the body length and mortality rate of resident ants.The results of the foraging behavior experiments showed that W.auropunctata was able to dominate food resources under competition with Carebara diversa,which also displayed weak competition in the group aggression bioassay.In addition,the abilities to recruit workers and retrieve food were inhibited under competition with S.invicta and T.bicarinatum.The results of the nesting behavior experiments showed that in the 24-h bout of space resource competition,W.auropunctata was dominant over C.diversa,S.invicta,and T.bicarinatum.The results of this study show that W.auropunctata has certain advantages in competition for food and space resources over resident ants in southern China,and some resident ant species may be replaced in the future.展开更多
基金The work on which this review article is based has been funded by grants from the Research Council of Norway [Gram Nos. 133553, 146744, 166596, and 178444], the Norwegian University of Science and Technology, the Norwegian Academy of Science and Letters, the Royal Swedish Academy of Sciences, the Nordic Marine Academy, the EU Transnational Access to Research Infrastructures Scheme, the Nordic Council program NORDFORSK, and the National Science Foundation [USA, Grant No. OISE/0701086].
文摘Our understanding of sexual selection has greatly improved during the last decades. The focus is no longer solely on males, but also on how female competition and male mate choice shape ornamentation and other sexually selected traits in females. At the same time, the focus has shifted from documenting sexual selection to exploring variation and spatiotemporal dynamics of sexual selection, and their evolutionary consequences. Here, I review insights from a model system with exceptionally dynamic sexual selection, the two-spotted goby fish Gobiusculus flavescens. The species displays a complete reversal of sex roles over a 3-month breeding season. The reversal is driven by a dramatic change in the operational sex ratio, which is heavily male-biased at the start of the season and heavily female-biased late in the season. Early in the season, breeding-ready males outnumber mature females, causing males to be highly competitive, and leading to sexual selection on males. Late in the season, mating-ready females are in excess, engage more in courtship and aggression than males, and rarely reject mating opportunities. With typically many females simultaneously courting available males late in the season, males become selective and prefer more colorful females. This variable sexual selection regime likely explains why both male and female G. flavescens have ornamental colors. The G. flavescens model system reveals that sexual behavior and sexual selection can be astonishingly dynamic in response to short-term fluctuations in mating competition. Future work should explore whether sexual selection is equally dynamic on a spatial scale, and related spatiotemporal dynamics.
基金supported by the National Key Research and Development Program of China(2021YFC 2600404).
文摘The little fire ant Wasmannia auropunctata(Roger)is a major invasive species that seriously threatens the biodiversity of invaded areas.W.auropunctata was first reported in Chinese mainland in 2022 and its impact on native species is still unknown.To evaluate the impact of W.auropunctata invasion on the ant communities in southern China,a series of interspecific competition experiments were conducted in this study.The individual aggression index and group aggression experiments showed the advantage of W.auropunctata in competition with 5 resident ants under equal worker numbers.When encountering Anoplolepis gracilipes,Camponotus nicobarensis,Tetramorium bicarinatum,Polyrhachis dives,and Solenopsis invicta,W.auropunctata gradually gained a competitive advantage with an increase in its number of workers.In the group aggression experiments with equal worker numbers,there was a negative correlation between the body length and mortality rate of resident ants.The results of the foraging behavior experiments showed that W.auropunctata was able to dominate food resources under competition with Carebara diversa,which also displayed weak competition in the group aggression bioassay.In addition,the abilities to recruit workers and retrieve food were inhibited under competition with S.invicta and T.bicarinatum.The results of the nesting behavior experiments showed that in the 24-h bout of space resource competition,W.auropunctata was dominant over C.diversa,S.invicta,and T.bicarinatum.The results of this study show that W.auropunctata has certain advantages in competition for food and space resources over resident ants in southern China,and some resident ant species may be replaced in the future.
