Cerebral controversies in brain science

Scientists have long known structural differences exist between the brains of males and females. But for the first time, researchers have discovered differences in the brain anatomy of men and women that appear directly linked to sex chromosomes. Though the study—published in Proceedings of the National Academy of Sciences on Aug. 4—does not prove sex chromosomes cause differences in brain structure, it does suggest some differences may come hardwired at birth.

Armin Raznahan and his research team did not set out to study the differences between men and women. They were exploring why people with sex chromosome abnormalities have a greater risk of certain developmental disorders. “If we can understand the biology of sex better, maybe those pathways are going to help us understand what is happening to put a person at risk of manifesting symptoms of autism spectrum disorder, for example,” Raznahan told Wired magazine.

The researchers studied brain scans of more than 1,000 people from the United States and the United Kingdom. They found men tend to have more gray matter in parts of the occipital lobe, associated with vision, and in the amygdala and hippocampus, which are connected to emotion and memory. Women had more gray matter in parts of the prefrontal cortex associated with decision making and self-control, as well as a region associated with functions such as emotion and taste.

As with most studies that explore sex differences in brain anatomy, Raznahan’s research sparked controversy. Lise Eliot, a professor of neuroscience at Rosalind Franklin University, believes brain differences between men and women are a myth. She fears research like this will “validate the fixed, hardwired, God-given—however you want to put it—differences between the sexes so that we can get over this idea of real equality,” she told Wired.

Eliot claims that a correlation between sex chromosomes and the sizes of various brain structures does not mean the chromosomes caused those differences. She suggested environmental factors such as societal gender expectations and different psychological stressors could cause the changes.

Raznahan’s team said it’s unclear whether these brain differences mean anything in terms of psychology or behavior, but they think an environmental explanation is unlikely.

William Struthers, a neuroscience professor at Wheaton College, noted that the book of Genesis says God made humans in His image, male and female. He said that indicates God created men and women as biologically different, but it doesn’t have to mean they don’t have equal value: “We should celebrate the differences between men and women rather than denigrate them.”

Our biology, the environment in which we live, and the choices we make all play a role in the anatomy of our brain, Struthers added, noting that the brain “is an organ, so it does have a physical, hardwired nature to it. But it is also the organ that is engaging with the culture and is designed to adapt and change.”

Mars missions

Three countries last month launched separate missions to our closest planetary neighbor. The July blastoffs put the spacecraft on a trajectory to reach Mars on its closest approach to Earth, which only happens once every 26 months. Each mission will cover about 300 million miles on its seven-month trip.

The United Arab Emirates on July 19 launched the Hope satellite from Japan. The UAE formed a partnership with the University of Colorado–Boulder; the University of California, Berkeley; and Arizona State University for the project. The satellite will orbit Mars and collect data on the red planet’s weather patterns. Scientists hope it can shed light on why oxygen and hydrogen leached out of the Martian atmosphere long ago, Live Science reported.

China’s Tianwen-1 spacecraft, consisting of an orbiter, a lander, and a golf cart–sized rover, took off on July 23.

A week later, NASA launched the massive Perseverance rover, scheduled to land in Mars’ Jezero crater on Feb. 18, 2021. The six-wheeled robot will search for signs of ancient life in the rocks of the 28-mile-wide crater, which scientists believe once contained a lake and river delta. NASA hopes to send another mission to Mars in 2026 to pick up soil samples from Perseverance and bring them to Earth by 2031 at the earliest.

An experimental helicopter, the Ingenuity, hitched a ride on the NASA mission, as well. If Ingenuity can successfully negotiate the thin Martian atmosphere, minus-130 degrees Fahrenheit temperatures, and frequent communication delays, it could pave the way for future robotic helicopters to provide high-definition images from a new perspective. It also could enable access to terrain too difficult for rovers to reach.

“We’ll be learning all along the way, and it will be the ultimate reward for our team to be able to add another dimension to the way we explore other worlds in the future,” said MiMi Aung, Ingenuity’s project manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. —J.B.

Wildlife Conservation Society apologizes for racist past

The Wildlife Conservation Society issued an apology on July 29 for two historic episodes of “unconscionable racial intolerance.”

In 1906, the organization put Ota Benga, a young African male from the present-day Democratic Republic of Congo, on display in a cage at the Bronx Zoo in New York. His captors displayed him as an example of a missing evolutionary link between humans and apes. An outcry from local African American ministers brought an end to Benga’s captivity, but he never returned to his home in Africa. He lived in an orphanage in Brooklyn and later moved to Virginia, where he worked in a tobacco factory until he committed suicide in 1916.

WCS also apologized for the racist writings and philosophies of founders Madison Grant and Henry Fairfield Osborn Sr. An attorney at the Nuremberg trials used Grant’s book, The Passing of the Great Race, to defend Nazi war criminals following World War II.

Grant and Osborn helped to found the American Eugenics Society in 1926. Rooted in evolutionary biology, eugenics sought to improve the human race by discouraging the reproduction of people it deemed inferior.

WCS vowed to be more transparent about its history and make all known records related to Ota Benga available online: “Today we challenge ourselves to do better and to never look away whenever and wherever injustice occurs.” —J.B.

Radiation-eating fungus

Scientists have discovered a fungus that can convert radioactive energy into chemical energy, posing a possible solution to one of the dangers astronauts face in space. Exposure to cosmic radiation can put space travelers at risk of health problems, including cancer. On a 360-day round trip to Mars, astronauts would suffer exposure to two-thirds of the maximum amount of radiation considered safe for an entire lifetime.

Cladosporium sphaerospermum can grow in highly radioactive environments like the cooling pools of the damaged Chernobyl nuclear power plant in Ukraine, Gizmodo reported. In research conducted on the International Space Station and published in the online preprint journal bioRxiv, scientists found the fungi could adapt to the microgravity of low-Earth orbit and thrive off incoming radiation.

The researchers believe a blanket of fungi 8.2 inches thick could neutralize as much radiation as a person would be exposed to during a year on the surface of Mars.

The fungus can live and replicate on very small doses of radiation and biomass. It also grows on various carbon sources such as organic waste. It does not pose any harm to humans, but scientists could minimize exposure by growing it within a double wall.

“While this is not enough to sufficiently protect astronauts, it is a starting point for the further development of a live radiation shield,” Nils Averesch, a co-author of the study and a scientist at NASA Ames Research Center in Mountain View, Calif., told Gizmodo. —J.B.