June 10, 2019
If I'm reading the headline of the first article right, a new study says that dads have bigger brains. Maybe I better read the article all the way through just to be sure. And so should you! Please, enjoy.
Learn about this and more interesting stories from the scientific community in today's issue.
*-- Mammals evolve bigger brains when dads take on parenting duties --*
The parents of mammals with larger brains tend to share parenting duties, according to a new study, with both mom and dad involved in raising offspring. Scientists also found mammals with greater reproductive success tend to have help from non-biological parents, or alloparents.
Researchers analyzed data on the parenting behaviors, brain size and fertility of 478 mammal species, including lions, mice, meerkats, monkeys and apes. The analysis showed different types of parental support aids different evolutionary advances.
"Both reproduction and brain tissue are energetically very expensive, and one way for females to reduce their cost is by distributing that cost over other individuals by sharing the burden of care," Sandra Heldstab, an anthropologist at the University of Zurich, said in a news release. "Unlike previous studies, we distinguished between paternal and alloparental care because we expected there to be a difference between how reliable they are and in the effect they may have on brain size and fertility."
The new research, published this week in the journal Behavioral Ecology and Sociobiology, is based on the "expensive brain hypothesis," which posits increases in brain size requires new energy sources for females to be stable and reliable.
Because male parenting support is likely to be more stable and reliable than alloparental help, which tends to fluctuate, it makes sense that helpful dads would be correlated with increased brain size.
"Additional care from individuals who are not the offspring's parents often fluctuates as they adjust their caring effort depending on both food availability and their own reproductive needs," Heldstab said. "This unpredictable type of care doesn't provide enough stable energy to affect brain size, but our findings suggest that the additional energy it does provide is associated with a significant increase in fertility, as females readily respond through litter size adjustments to variable amounts of energy inputs."
With both large brains and high reproductive output, humans are an outlier. Researchers suggest the impressive combination is likely made possibly by "multi-family cooperative parenting." Early in the evolutionary history of humans, moms benefited from stable and reliable help provided by both parents and alloparents.
Of course, parental help isn't the only way moms can find new sources of energy for evolutionary advances. Changes in diet, like the addition of freshwater crabs or other aqueous food sources, can also provide the added energy necessary to evolve larger brains.
*-- Study: Impacts of extreme weather on communities influences climate beliefs --*
New research suggests the impact of extreme weather on a person's neighbors and community has a greater influence on a person's climate change beliefs than individual losses.
"We found that damage at the zip-code level as measured by FEMA was positively associated with stronger climate change beliefs even three or four years after the extreme flooding event our study examined," Elizabeth A. Albright, an assistant professor of the practice of environmental science and policy methods at Duke University, said in a news release.
Albright and her colleagues sent surveys to a variety of communities impacted by heavy rains and flooding in Colorado. Researchers surveyed individuals that were directly impacted by flooding, as well as those that avoided individual property damages. Surveys were also sent to residents of communities spared from the worst of the flooding.
The questionnaires asked residents about their individual experiences and the effects of flooding on their broader communities, as well as their perception of future flooding risks and beliefs about climate change.
Survey results showed people who perceived flooding as having a broad and significant effect on their community were more likely to be concerned about climate change and the prospects of future floods, even three years after the floods. The findings, published this week in the journal Climatic Change, revealed the experience of individual damages had little impact on a person's long-term beliefs about climate change and the risk of severe flooding.
"These findings speak to the power of collective experiences and suggest that how the impacts from extreme weather are conceptualized, measured and shared matters greatly in terms of influencing individual beliefs," said Deserai Crow, associate professor of public affairs at the University of Colorado, Denver.