Tag Archives: female

Bonobo.

Bonobo mothers help their sons get dates — it makes them 3x as likely to become fathers

If you’re tired of your parents asking you when you’re getting married, tell them they could be more like bonobos and help you out.

Bonobo.

“You’re not going out groomed like that, young man!”
Image via Pixabay.

Many social animals share child-rearing duties among members of the group, but new research from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, found that one species takes this to the extreme: the bonobos. Mother bonobos, the team reports, take an active role in ensuring their sons father children. Sons who are aided by their mothers have three times the chance of becoming fathers compared to those who aren’t.

‘I gave your number to a cute girl’

“This is the first time that we can show the impact of the mother’s presence on a very important male fitness trait, which is their fertility,” says Martin Surbeck, a primatologist at the Max Planck Institute for Evolutionary Anthropology.

“We were surprised to see that the mothers have such a strong, direct influence on the number of grandchildren they get.”

Surbeck and his team worked with populations of wild bonobos in the Democratic Republic of Congo, as well as groups of wild chimpanzees in the Ivory Coast (Tanzania) and Uganda. Both chimpanzee and bonobo mothers would take the role of advocating for their sons in male-on-male conflicts, the team reports — but bonobo mothers also seem to aid their sons in romance.

Some of the behaviors they’ll use to this end include protecting their sons’ mating attempts from other males and intervening in other male’s mating attempts. Bonobo mothers will also leverage their rank in the group (bonobos have matriarchal societies) to give their sons access to popular spots within social groups in the community and help them achieve higher status — which increases their mating prospects. Chimp mothers also engage in such interactions, albeit rarely, the team notes. However, male chimpanzees hold a dominant position over females, socially, making their efforts much less effective than those of bonobo females.

Bonobo mothers don’t seem to extend the same kind of help to their daughters — either socially or romantically.

“In bonobo social systems, the daughters disperse from the native community and the sons stay,” Surbeck says.

“And for the few daughters that stay in the community, which we don’t have many examples of, we don’t see them receiving much help from their mothers.”

In the future, the team wants to understand why bonobo females engage in such behavior. Their working theory so far is that by helping their sons father children, they’re indirectly supporting the continuation of their own genes. This will require a long-term, collaborative effort, he says, to gather data on post-reproductive lifespans of females in chimp and bonobo communities.

“These [bonobo] females have found a way to increase their reproductive success without having more offspring themselves,” Surbeck says.

The team notes that a similar mechanism may have taken place in humans (the ‘grandmother hypothesis‘), listing the long stretch of the post-reproductive human female lifespan as well as the early-age at which human women can no longer bear children (menopause) as evidence in support of this.

The paper “Males with a mother living in their group have higher paternity success in bonobos but not chimpanzees” has been published in the journal Current Biology.

Credit: Biology Letters.

Cave insects that have female penises evolved independently

Credit: Biology Letters.

Credit: Biology Letters.

Inside caves in Brazil, researchers have come across two peculiar insect species whose sexual organs are reversed. Unlike almost every other animal, the females have penis-like appendages and males have vagina-like pouches. In a new study, an international team of researchers from Japan, Brazil, and Switzerland investigated the evolutionary history of the two species. To their surprise, they found that the sex reversal in these insects evolved independently from one another.

Reversed sexual selection

The researchers studied three insects (AfrotroglaNeotrogla, and Sensitibilla), all belonging to the same genera. Afrotrogla and Neotrogla are particularly noteworthy because the females have a penis-like organ, termed a gynosome. This organ is used to anchor male vagina-like genitalia in a species-specific manner for up to days at a time, during which “voluminous and probably nutritious semen is passed to the female,” the authors of the new study wrote in Biology Letters

Although Sensitibilla belongs to the same tribus as Afrotrogla and Neotrogla, these insects do not have reversed organs. By studying the sex organs of all three, the researchers came to the conclusion that sexual organ reversal in the two identified insect species had evolved independently, and not before the species diverged.

Genital traits differ between sexes due to conflicting mating strategies. In most species of animals, male reproductive success increases with the number of mates, whereas female fitness does not improve with the number of mates (and can even be detrimental due to limited ova). In response, some males developed traits in their genitalia that enable them coercively mate with females, such as claspers and spines. In response, females developed traits for resistance or tolerance, such as pouches that accommodate spines or anti-clasping projections.  

However, in the dry and resource-scarce caves where Afrotrogla and Neotrogla live, the environment seems to have forced an organ reversal. Because food is scarce, males appear to have invested more resources into securing nutrients than for mating. In retaliation, the female had to assume the traditional role of the male. What’s more, in order to prevent the male from escaping with his sperm, the females evolved a hook that latches onto the male. Predation in the cave ecosystem may also have played a role in the odd sexual organ differentiation seen in these insects.

Males generally have higher potential reproductive and optimal mating rates than females. Therefore, sexual selection acts strongly on males. But for Afrotrogla and Neotrogla, their genital adaptations have been driven by reversed sexual selection with females competing for sperm. Writing in another paper published last month in the journal eLife, the same team of researchers reported that “the ability to obtain greater amounts of semen thanks to the valve [a switching valve at the entrance of the semen-storage organ] has led to fierce competition over semen among females, facilitating the evolution of the female penis.” Nothing similar is known among sex-role-reversed animals.

Peggy Whitson becomes oldest female in space, shoots for longest-serving astronaut

NASA’s Peggy Whitson made history by becoming the oldest woman ever to go into space, at age 56. Currently deployed on the ISS, Whitson is also likely to once again gain the distinction of most-time-in-orbit U.S. astronaut.

Peggy Whitson, NASA portrait.

With a degree in biochemistry and her first trip to space in 2002, Peggy Whitson has spent more than a year of her life in space. She’s the agency’s most experienced female astronaut, and the first female commander the ISS has ever had. She will now embark on her third mission to the station, and will soon take command for the second time. By the time she touches back on Earth in the spring of 2017, her time in orbit will exceed that of Jeff Williams, who in September amassed 534 off-planet days, the most of any U.S. astronaut. And, before her mission is over, she will turn 57 aboard the ISS.

“The Iowa native completed two six-month tours of duty aboard the station for Expedition 5 in 2002, and as the station commander for Expedition 16 in 2008,” NASA describes her career.

“She has accumulated 377 days in space between the two missions, the most for any U.S. woman at the time of her return to Earth. Whitson has also performed six spacewalks, totaling 39 hours and 46 minutes.”

There will probably be a time when regular folk will spend way more than one year in space but the records pioneers like Whitson are setting today are vital to making it happen. So, three cheers for Peggy Whitson!

 

Deceptive Female Mantises Eat Males Even Without Having Sex

It has been known for quite some time that male praying mantises can get their heads ripped off while copulating with females. But a new study has shown that deceptive females can trick the males and eat them even without copulation; basically, they lure them in pretending to be full of eggs and eat them when they’re hungry.

“This is the first evidence in support of the Femme Fatale hypothesis, which posits that female mantids in poor condition might dishonestly entice males in order to eat them rather than mate with them,” said lead research Dr Kate Barry, of Macquarie University’s Department of Biological Sciences.

The study initially found that males are more attracted to starving females, despite the chance of being eaten during copulation.

mantis

Image via 5oclockam.

 

“We presume this attraction is due to an increase in the quality or quantity of pheromone emissions, which makes sense because very hungry females gain both survival and reproductive benefits from attracting and consuming a male.

They then observed that some females (which are much larger than the males) eat the males even without reproduction. They set up large large field enclosures on the Macquarie University campus to examine the potential for sexual deception in females.

They found that healthy, well fed females sometimes lure in males with no intention of reproducing, just to eat them. However, hungry females are much more likely to do this. To figure this out, researchers assigned 24 female to one of four feeding regimes: good, medium, poor, or very poor, for six weeks. The cages were covered with two layers of mesh so that you couldn’t see inside of them, but chemical signals could still be released. 78 virgin males were then released and out of them, 55 were found on female cages. The number of males found on specific cages was used as an indicator of female attractiveness.

This is the first time that females exploiting males has  been reported in nature… and it’s also the most extreme example of sexual manipulation ever found.

“There are many examples in the animal kingdom of males exploiting females to secure paternity, however in this instance, female praying mantids have turned the tables.”

 

Female models and their negative effect on men

scarlett johanssonWe all know that seeing female models can have a negative effect on how women think about themselves, but really, it seems hard to believe that they would have the same effect on men. Still, Jennifer Aubrey, a leading researcher of media effects on body image, completed three different studies that led to the same conclusion: it’s actually men that are more affected.

In the first study, she measured the male exposure to magazines such as Maxim, FHM, etc, and she found that the readers pick up two different messages: the visual (which of course, is of sexually sugestive nature) and the textual (which reffers to fashion, sex, technology, urban culture, etc). She then measured men’s self awareness about their bodies, and the appearance anxiety.

“We found that reading lad magazines was related to having body self-consciousness a year later,” said Aubrey. “This was surprising because if you look at the cover of these magazines, they are mainly images of women. We wondered why magazines that were dominated by sexual images of women were having an effect of men’s feelings about their own bodies.”

To conclude the test, they divided men into two groups. A group received pictures with great looking females while the second received the same pictures, only with average boyfriends added to them and explanations about how female models are attracted to average people.

“We found that the men who view the ads with the average-looking boyfriend in the picture reported less body self-consciousness than the men who saw the ads with just the model,” Aubrey said. “When the men felt that the model in the ad liked average-looking guys, it took the pressure off of them and made them less self-conscious about their own bodies.”