Marmots Can Lose Up to Half Their Body Weight During Hibernation

A landmark 2013 study from the University of Pennsylvania found that, on average, female brains have stronger connections between the left and right hemispheres, while male brains tend to have stronger connections within each hemisphere. This may explain observed differences in performance: women consistently outperform men in memory and social cognition tests, while men tend to perform better on spatial perception tasks. However, most neuroscientists caution that individual variation is far greater than group differences.

Women outlive men by an average of 4–6 years globally, a gap observed in nearly every country in the world. In Japan, average female life expectancy exceeds 87 years. Scientists point to biological factors including two X chromosomes (which may buffer genetic defects), higher estrogen levels that protect cardiovascular health, and lower rates of risk-taking behavior. Social factors such as lower rates of smoking and alcohol consumption also contribute.

In 1952, British chemist Rosalind Franklin produced Photo 51 — a landmark X-ray diffraction image of DNA that revealed its helical structure. Her colleague Maurice Wilkins showed it without her permission to James Watson, who used it as a key piece of evidence in the Watson-Crick DNA model. Watson and Crick — along with Wilkins — received the 1962 Nobel Prize for the discovery. Franklin had died of cancer in 1958 and Nobel Prizes are not awarded posthumously. Her contribution went largely unacknowledged for decades.

The Olympic marmot (Marmota olympus) is endemic to the Olympic Peninsula in Washington State, USA — it exists nowhere else on Earth. Found only above 1,500 meters in the subalpine meadows of Olympic National Park, this species has one of the most restricted ranges of any North American mammal. Climate change is shrinking its alpine habitat, and the species is considered vulnerable by conservation scientists.