In many animals, males advertise to potential mates with showy traits, many of which are linked to testosterone levels. However, a new study suggests that, in fish, choosing a flashier mate may cause future generations to be more susceptible to pathogens.
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Baby's smell tamps down dad's testosterone levels
Does eau de infant make dad a better parent? It does, it seems, if you are a common marmoset, a New World monkey known for its collaborative approach to rearing offspring.
New study points to agriculture in frog sexual abnormalities
A farm irrigation canal would seem a healthier place for toads than a ditch by a supermarket parking lot. But University of Florida scientists have found the opposite is true. In a study with wide implications for a longstanding debate over whether agricultural chemicals pose a threat to amphibians, UF zoologists have found that toads in suburban areas are less likely to suffer from reproductive system abnormalities than toads near farms – where some had both testes and ovaries.
Pregnancy may help protect against bladder cancer
Pregnancy seems to confer some protection against bladder cancer in mice, scientists have found. Female mice that had never become pregnant had approximately 15 times as much cancer in their bladders as their counterparts that had become pregnant, according to new findings by investigators at the University of Rochester Medical Center.
For barn swallows, feathers make the man, says study
A new study led by the University of Colorado at Boulder has shown the testosterone of male North American barn swallows skyrocketed early in the breeding season when their breast colors were artificially enhanced by researchers, indicating the clothes -- or in this case, the feathers -- make the man.
Disabling mouse enzyme increases fertility
Changing the sugars attached to a hormone produced in the pituitary gland increased fertility levels in mice nearly 50 percent, a research group at Washington University School of Medicine in St. Louis has found. The change appears to alter a reproductive "thermostat," unveiling part of an intricate regulatory system that may one day be used to enhance human fertility.
Study finds biological link between pain and fatigue
A recent University of Iowa study reveals a biological link between pain and fatigue and may help explain why more women than men are diagnosed with chronic pain and fatigue conditions like fibromyalgia and chronic fatigue syndrome.
Research indicates testosterone could guard against eating disorders
Testosterone appears to protect people against eating disorders, providing further evidence that biological factors -- and not just social influences -- are linked to anorexia and bulimia, according to new research findings at Michigan State University.
Females decide whether ambitious males float or flounder
Aggression, testosterone and nepotism don’t necessarily help one climb the social ladder, but the support of a good female can, according to new research on the social habits of an unusual African species of fish.