Why fruit fly sperm are giant
Researchers found that larger males with more sperm are favored by females, driving the evolution of longer sperm. This study provides the first explanation for the development of giant sperm in fruit flies.
Sexual Selection
Articles tagged with Sexual Selection
Too much sex causes genitals to change shape, beetle study shows
A University of Exeter study on burying beetles shows that excessive mating can cause males to evolve longer penis-like organs and females to develop larger 'claws' on their genitalia within ten generations. This co-evolutionary process highlights the importance of sexual conflict in shaping biodiversity.
Deep male voices not so much sexy as intimidating
Research found that deep-pitched male voices are seen as dominant by other males but have a smaller impact on attracting females. Human male traits imply physical aggression and formidability, providing competitive advantages in fighting or threatening other men more than they help attract women.
Size not such a big thing for seed bugs
Researchers found that processus length is crucial during mating for seed bugs, particularly when a rival male is present, and bigger isn't always better. Males with medium-length processus are most likely to fertilise female eggs successfully.
New finding shows that males can drive creation of new species
Researchers show that intense male competition can lead to speciation, erasing boundaries between species and creating new ones. This process is independent of natural selection and has significant implications for understanding biodiversity.
First demonstration of sexual selection in dinosaurs identified
Researchers at Queen Mary University of London found that Protoceratops' large bony frill increased in size as the animal matured, suggesting it played a role in attracting mates. The study provides the first demonstration of sexual selection in dinosaurs and sheds light on the evolution of ornamental structures.
Frogs' irrational choices could reform understanding of animal mating
A study on túngara frogs reveals the 'decoy' effect, where females choose less attractive mates over more appealing options when a third, inferior mate is introduced. This challenges rational choice models used in sexual selection theory and highlights the influence of context on mating decisions.
Population benefits of sexual selection explain the existence of males
A new study published in Nature reveals that sexual selection improves population health by removing harmful genetic mutations, allowing species to flourish and avoid extinction. This finding provides direct support for the idea that sex persists as a dominant mode of reproduction due to its role in maintaining genetic diversity.
Sexual selection isn't the last word on bird plumage, UWM study shows
A new study by University of Wisconsin-Milwaukee researchers found that bird plumage color is influenced more by natural selection than sexual selection. The study analyzed nearly 1,000 species of birds and discovered that the sexes have become closer in color over time to blend into their surroundings and hide from predators.
Research finds clue to why females live longer than males
A study found that female flies live longer than males when subjected to mate competition and juvenile survival pressures. The research suggests that the sexes respond differently to selection regimes, with males being more affected by natural and sexual selection on their lifespan.
Males of great bustard self-medicate to appear more attractive to females
Researchers found that male great bustards consume toxic blister beetles to eliminate parasites and look healthier. This behavior is a mechanism of sexual selection, where males use cantharidin to show females their resistance to toxicity, potentially increasing reproductive success.
Secret wing colors attract female fruit flies
New study reveals that females choose mates based on hidden wing colours, important for female choice in fruit flies. Researchers found that the transparent wings shimmer with beautiful colours due to thin-film interference.
Sexual preference for masculine men and feminine women is an urban habit
A groundbreaking study led by Brunel University London found that in modern, urbanized societies, people prefer highly feminine women and highly masculine men. The research challenged the theory of social and sexual selection, suggesting that this preference is an urban habit rather than a long-standing tradition.
New 'tree of life' traces evolution of mysterious cotinga birds
A comprehensive new evolutionary 'tree of life' for the tropical cotinga family has been generated, providing insight into the evolution of over 60 species. The study reveals that sexual selection appears to have played a role in the evolution of non-plumage gender differences in some cotinga species.
Biologists link sexual selection and placenta formation
Researchers found that species with placentas tend to have smaller males with reduced bright colors and courtship displays. This discovery links sexual selection and placenta formation, suggesting that the evolution of complex organs like placentas is influenced by mating strategies.
Darwin: It's not all sexual (selection)
A team of researchers found that 71% of surveyed birds had female song, contradicting the long-held assumption that bird song is an exclusively male trait resulting from sexual selection. The study suggests that social selection may have played a role in the evolution of bird song, with both males and females competing for resources.
Fish genital shape linked to predation
Male Bahamas mosquitofish develop longer, more elongated gonopodium tips when living with predators, suggesting an adaptation for efficient sperm transfer during rapid copulations. This study highlights the importance of ecological variation in generating genital diversity.
Biologists confirm role of sperm competition in formation of new species
Researchers at Syracuse University's College of Arts and Sciences have confirmed that diversifying sperm competition is a critical step in the formation of new species. The study, published in Current Biology, reveals how postcopulatory sexual selection drives rapid evolutionary changes in ejaculate and female reproductive tract traits.
New study finds females play active, pivotal role in postcopulatory processes
A new study by Syracuse University researchers found that female Drosophila melanogaster flies actively influence sperm competition, allowing them to choose between different male sperm for fertilization. This discovery has major implications for the study of sexual selection and coevolution in animals.
Dartmouth researchers find there is no single sexy chin
Dartmouth researchers found significant geographic differences in male and female chin shapes, contradicting the notion of a single 'sexy' chin. The study tested the universal facial attractiveness hypothesis across nine regions, challenging Darwin's theory on the evolution of physical characteristics.
The evolutionary consequences of infidelity
Research reveals that social relationships and pair bonds play a crucial role in shaping the traits of male birds, with extra-pair mating having limited effects on sexual selection. The findings suggest that infidelity may even slow the evolution of sexual dimorphism.
'Trust' provides answer to handaxe enigma
Research suggests that the fine crafting of handaxes by Homo erectus/ergaster in the Lower Palaeolithic period was driven by a desire to prove trustworthiness rather than physical fitness. The 'trustworthy handaxe theory' proposes that attention to detail is about demonstrating emotional reliability and capacity for strong relationships.
Romancing the firefly
Researchers at Tufts University found that female fireflies prefer males with larger nuptial gifts after mating, leading to higher reproductive success. This discovery challenges the conventional view that flash duration is the primary cue for female choice in firefly courtship.
UCSB researchers find that less is more, for female cowbirds
Brown-headed cowbird females are attracted to less intense wing spreading, feather puffing, and bowing during a display. This study reveals the opposite of what was previously predicted by sexual selection theory. The researchers used audiovisual recordings to investigate the female's response to male displays.
Darwinian selection continues to influence human evolution
A study analyzing church records of Finnish people from 1760-1849 found significant natural and sexual selection is still taking place in modern humans. The research suggests that men and women are not equally affected by Darwinian selection, with characteristics increasing mating success in men evolving faster.
European dung-fly females all aflutter for large males
In European dung flies, larger males are preferred by females for mating, leading to increased copulation frequency and potentially larger testes. This difference in mating behavior is attributed to female preference, but the underlying evolutionary cause remains unclear.
Manipulative mothers subdue show-off sons
A team of evolutionary biologists found that when mothers control offspring sex ratios, sexual selection collapses, and males lose their elaborate courtship displays to attract females. This twist adds unexpected complexity to Darwin's theory of sexual selection, suggesting that motherly control can override the need for showy males.
For peacocks, the eyespots don't lie
Research by Roz Dakin and Robert Montgomerie found that peacock tails with fewer eyespots are less successful in attracting mates, suggesting other characteristics like colour pattern may play a role. The study suggests females consider multiple factors during courtship, including tail size and health.
Polygamy hurt 19th century Mormon wives' evolutionary fitness
A study of 19th century Mormon polygamy found that more sister-wives led to fewer children per woman, due to a 'Bateman gradient' effect. The practice reduced the strength of sexual selection on males by 58%, bringing their reproductive success closer to women's.
The success of male bustards is measured by their 'beards'
A study shows that great bustard males use their 'beards' to signal their weight and age, avoiding bloody fights and increasing reproductive success. The study found that the heaviest males with well-developed plumage are more attractive to females and avoid confrontations.
Brain size and a trip to Disneyland
A new study suggests that human creativity may have evolved as a way for parents to bond with their children, passing on cultural knowledge and traditions. This theory challenges the idea that creativity emerged from courtship behaviors, proposing instead that it arose from parental influences.
SU biologists' work with 'glow-in-the-dark' sperm sheds light on sexual selection
Researchers genetically alter fruit flies to create fluorescent sperm, allowing them to observe in detail what happens to live sperm inside the female. The findings may have huge implications for understanding postcopulatory sexual selection and its role in evolutionary change.
Female birds -- acting just like the guys -- become sexual show-offs in cooperative breeding species
In cooperative breeding species, female birds show off sexually to compete with each other and with males. Researchers found that these females evolved traits such as colorful plumage and elaborate dances, comparable to those of males.
Ecological speciation by sexual selection on good genes
A mathematical model demonstrates that disruptive ecological selection can trigger positive feedback between mate choice and ecological diversification, ultimately eliminating gene flow between species. This process can lead to the evolution of specialized ecotypes without divergent mating preferences, a departure from previous studies...
Studies suggest males have more personality
Studies across various species reveal that males tend to exhibit more predictable behavior, particularly in parental care, aggression, and risk-taking. Females, on the other hand, are more likely to vary their behavior and respond to these traits, indicating a preference for mates with consistent personalities.
Why do we choose our mates? Ask Charles Darwin, prof says
Darwin's work has withstood decades of analysis, confirming that animals' mating choices can drive evolutionary change. Molecular markers have also been developed to study paternity and the driving forces behind sexual selection.
Changing fashions govern mating success in lark buntings, study finds
A new study reveals that female lark buntings show dynamic preferences for certain traits in males, which shift from year to year. This flexibility may help females adapt to changing environmental conditions and increase their nesting success.
Teens find the benefits of not having sex decline with age
Researchers found that teens who remained sexually inexperienced reported fewer positive benefits from refraining from sex, while those who were sexually experienced valued refraining more. The study suggests that adults should guide teens on coping with both positive and negative outcomes of sexual behaviors.
Brains reflect sex differences
Brain structures reflect sex differences due to varying pressures on males and females, with larger neocortex linked to female sociability. Greater male competition correlates with reduced septum size, suggesting less control over aggression.
More flight than fancy?
Females may be more astute at choosing a mate, favoring mates with longer tails that signal aerodynamic abilities rather than attractive ornaments. Tail length is linked to natural selection, not sexual selection.
Why some people are more attractive than others
Researchers found that genetic mutations affecting DNA repair kits cause greater variation in individuals, leading to increased physical diversity. This contradicts the 'lek paradox' argument that sexually-selecting species should have less individuality.
A little of what you fancy does you no good
Researchers found that high-fitness parents led to lower reproductive success for their offspring, particularly sons and daughters. This challenged the theory that females benefit from passing on good genes through sons.
Behavioural ecologists elucidated how peahens choose their mates, and why
A new study found that females prefer males with higher ocelli density but also those with shorter tails, suggesting they value the visual perception of a dense cluster. This preference is driven by both ocelli density and male displaying activity, providing peahens with information about male health.
Rare bird 'sings' with its feathers to attract a mate
The club-winged manakin, a rare species found in Ecuador's cloud forest, produces a unique sound by rubbing its inner feathers together. This adaptation is driven by sexual selection and makes the male more attractive to females.
Size matters: fish genitalia attractiveness vs. predatory escape value
A recent study found that male fish with larger gonopodia are more attractive to females for mating purposes, but simultaneously exhibit reduced swimming performance when trying to evade predators. The research suggests a trade-off between genetic size and predator escape value in certain fish species.
Size does matter when choosing a mate
Scientists analyzed mating behavior and body size of over 100 shorebird species to explain Rensch's rule. Larger shorebirds show competitive battles on the ground, where bigger males have an advantage, while smaller species feature aerial battles where agility is key.
More news in the battle between the sexes
Studies show that foreign males from conflict populations are more costly to females, but benefits of sexual selection may outweigh costs at intermediate levels of conflict. The findings highlight the potential cost of sexual selection and generate a fitness load.
Sex and gender scientists explore a revolution in evolution
Researchers are re-examining Darwin's sexual selection theory, finding it doesn't fit many species' behaviors. Scientists propose a more comprehensive approach incorporating social and reproductive roles in sexuality.
Male birds' ability to learn song affects female mating response
Researchers found that the quality of a male bird's learned song is linked to its attractiveness to females, who prefer well-copied wild-type songs. The study suggests that females use song-learning ability as an indicator of male quality and provides insight into the role of traits learned by males in sexual success.
For Fruit Flies, Finding The Right Mate May Mean Offspring With A Longer Life Span, According To New Study
A new study by geneticists at the University of Georgia shows that female fruit flies who have a choice between mates have offspring that live longer as adults. The research confirms the validity of the 'good genes' model, which proposes that females prefer males with certain traits because they indicate high genetic quality.