New Delhi: Do women really live longer than men? In a new paper published in the Science Advances journal on 1 October, German anthropologists from the Max Planck Institute looked across mammals and birds to find the answer.
Globally, on average, women do live longer, which is consistently true across countries, and throughout history. Additionally, females in other mammalian and even some bird species live longer than their male counterparts, and the Max Planck scientists wanted to see why.
The answer lies in a couple of factors, to do with evolutionary and genetic history. One of the main theories propounded is that women have two X chromosomes, meaning they’re homogametic, while men have one X and one Y chromosome. Among mammals, this is seen as a survival advantage for women because it protects females from harmful mutations. The study found this repeated in almost all mammals, and even in birds.
In some birds, however, the opposite is true—females have X and Y chromosomes while males have two Xs. Consistently, the males live longer in those species.
Another reason found for women living longer is the role of sexual selection and caregiving. Most males across species develop sexual selection traits, like having colourful plumage, antlers or even larger sizes. While great for attracting mates, these traits might be an overall disadvantage for lifespan. Finally, since females are the caregivers in most species, the study consistently found that they are more likely to stay alive longer, at least until their offspring is fully mature.
Wildfires are good news for Sierra Nevada’s birds
Not all forest fires are bad news, especially for birds in California’s Sierra Nevada. Some moderate-severity fires can even boost bird populations, and these benefits can last for decades. Researchers from UCLA, in a new study published in Fire Ecology journal on 9 October, analysed 20 years of bird monitoring data across Yosemite, Sequoia and Kings Canyon National Parks, alongside fire records of 35 years.
Their findings show that 28 of 42 bird species monitored were more abundant in areas that had been burned by wildfires. For 11 of those species, the fire’s positive effects on population size lasted at least 35 years. The reason is described in the paper, too.
When forest fires happen, they leave behind a much richer landscape, with some burnt open forests and other wooded enclaves. This supports a more diverse group of animals. Also, fires leave behind snags and twigs that are perfect for nests, and the new growth of grass and shrubs after a forest fire can attract new insects, which are great for birds to feed on.
If you thought forest fires brought about only devastation, think again. Controlled, low-intensity fires are actually beneficial to the biodiversity of many forests and green regions.
Gut microbes can survive space travel, microgravity
A test-tube full of microbes was just sent to space and back! In a first-of-its-kind experiment, a group of scientists from Australia’s RMIT University sent samples of a bacterium called Bacillus subtilis up to space in a rocket. This experiment, the results of which are described in a paper in NPJ Microgravity journal, was to see whether bacteria essential for human survival could manage the harsh conditions and forces of space launches.
The results were indeed positive, as the samples reached altitudes of up to 260 kilometres above Earth and returned to the ground unharmed. The bacteria are essential for immunity, gut health and blood circulation. It was launched on a sounding rocket and experienced up to 13 times Earth’s gravity on ascent.
The authors said these findings expand our understanding of how life copes with spaceflight. It also demonstrates that microbes crucial for sustaining human life are more resilient than expected.
Mars, the windy planet
Scientists from the University of Bern in Switzerland have found that Mars is much windier than once believed—a finding that can reshape how we understand the planet’s weather and climate, and even how we conduct future explorations on Mars. A new study published in Science Advances journal on 8 October lays out the research project.
The scientists analysed more than 50,000 satellite images from European Mars missions, tracking thousands of dust devils—swirling columns of dust across the red planet. The team measured dust devils racing across the Martian surface at speeds of up to 160 km/h, far exceeding earlier estimates.
This study marks the first time wind activity has been mapped on the planet so deeply, and these findings have implications for future Mars missions. They are going to enable scientists to better model the planet’s atmosphere, and prepare landers and rovers for harsh surface conditions.
(Edited by Mannat Chugh)
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