In a groundbreaking study published online on June 18 in iScience, researchers have found that female chimpanzees who were more socially integrated with other females before giving birth had a significantly higher chance of raising surviving offspring. This discovery sheds light on the crucial role of social connections among female chimps, particularly in the absence of close kin.

The study, led by Joseph Feldblum, assistant research professor of evolutionary anthropology at Duke University, analyzed three decades’ worth of behavioral data from 37 mothers and their 110 offspring. The researchers focused on association and grooming behavior – how often females spent time near each other or engaged in social grooming – in the year before birth.

The results showed that females who were more socially connected had a considerable better chance of raising their babies through to their first year, the period of highest infant mortality. In fact, a female with a sociality score twice the community average had a 95% chance her infant would survive the first year, while one who was halfway below average saw that chance drop to 75%. The effect persisted through age five, which is roughly the age of weaning.

Interestingly, the researchers found that having close female kin in the group – like a sister or mother – did not account for the survival benefit. Neither did having bonds with males, who could potentially offer protection. What mattered most was having social connections with other females, regardless of kinship.

“This tells us it’s not just about being born into a supportive family,” said Feldblum. “These are primarily social relationships with non-kin.”

The researchers propose several possibilities for the survival benefit, including:

* Social females receiving less harassment from other females
* More help defending food patches or protecting their young
* Offspring being less likely to be killed by another group member
* Social connections helping these females stay in better condition – maybe better fed and less stressed – through pregnancy, giving their offspring a better chance from the get-go.

Moreover, social females stayed social after their babies were born – a sign of stable relationships, not short-term alliances. “Our results don’t prove causation, but they point to the value of being surrounded by others who support you, or at least tolerate you,” said Feldblum.

This study has significant implications for understanding human evolution and cooperation. As Feldblum noted, “Human females who don’t have access to kin – for example because they moved to a new city or village – are still able to form strong bonds that can benefit them.” Studying these social dynamics in chimpanzees can help us understand how we evolved to be the social, cooperative species we are today.

The world of cats is fascinating, especially when it comes to their sleeping habits. Researchers from Italy, Germany, Canada, Switzerland, and Turkey have made an intriguing discovery – cats prefer to sleep on their left side. This bias towards one side might seem trivial at first, but the team behind this study believes it holds a significant evolutionary advantage.

Cats are notorious for spending around 12 to 16 hours a day snoozing. They often find elevated places to rest, making it difficult for predators to access them from below. The research team, led by Dr. Sevim Isparta and Professor Onur Güntürkün, aimed to understand the behavior behind this preference. They analyzed over 400 YouTube videos featuring cats sleeping on one side or the other.

The results showed that two-thirds of these videos had cats sleeping on their left side. So, what’s the explanation? According to the researchers, when a cat sleeps on its left side and wakes up, it perceives its surroundings with its left visual field. This visual information is processed in the right hemisphere of the brain, which specializes in spatial awareness and threat processing.

This might seem like an insignificant detail, but for cats, it’s a crucial aspect of survival. By sleeping on their left side, they can quickly respond to potential threats or prey upon waking up. The researchers conclude that this preference could be a key survival strategy for cats.

The study published in the journal Current Biology provides valuable insights into the fascinating world of cat behavior and evolution. As we continue to learn more about our feline friends, we might just uncover even more surprising advantages behind their seemingly ordinary habits.

The deep ocean can be a breathtaking sight to behold, resembling a real-life snow globe. As organic particles from plant and animal matter on the surface sink downward, they combine with dust and other material to create “marine snow,” a crucial component in cycling carbon and nutrients through the world’s oceans. However, researchers from Brown University and the University of North Carolina at Chapel Hill have recently uncovered surprising new insights into how these particles settle in the ocean.

In a study published in Proceedings of the National Academy of Sciences, they found that the speed at which particles sink is not solely determined by resistive drag forces from the fluid, but also by their ability to absorb salt relative to their volume. This discovery challenges conventional wisdom and could have significant implications for understanding natural carbon cycling and even engineering ways of speeding up carbon capture.

“It basically means that smaller particles can sink faster than bigger ones,” said Robert Hunt, a postdoctoral researcher in Brown’s School of Engineering who led the work. “That’s exactly the opposite of what you’d expect in a fluid with uniform density.”

The researchers created a linearly stratified body of water to test their model and found that particles with high porosity tended to sink faster than those with lower porosity, regardless of their size. This means that elongated particles actually sink faster than spherical ones of the same volume.

“We ended up with a pretty simple formula where you can plug in estimates for different parameters – the size of the particles or speed at which the liquid density changes – and get reasonable estimates of the sinking speed,” said Daniel Harris, an associate professor of engineering at Brown who oversaw the work. “There’s value in having predictive power that’s readily accessible.”

The study grew out of prior work by Hunt and Harris investigating neutrally buoyant particles, and their new findings have the potential to revolutionize our understanding of how particles settle in complex ecological settings.

“We’re not trying to replicate full oceanic conditions,” Harris said. “The approach in our lab is to boil things down to their simplest form and think about the fundamental physics involved in these complex phenomena. Then we can work back and forth with people measuring these things in the field to understand where these fundamentals are relevant.”

Harris hopes to connect with oceanographers and climate scientists to see what insights these new findings might provide, and other co-authors of the research were Roberto Camassa and Richard McLaughlin from UNC Chapel Hill. The research was funded by the National Science Foundation and the Office of Naval Research.