Hydrocarbon fuels can now be produced with sunlight and air, making them carbon-neutral; the hole in the ozone layer was shrinking; and the first successful climate model of the early Eocene showed that temperatures are increasingly sensitive to additional CO2 as its atmospheric concentration rises. The cooling effect of fragrant terpene aerosols from coniferous boreal forests was decreasing, and aeolian accumulations of dust on the Loess Plateau indicated that human existence did not coincide with a high-carbon atmosphere until 1965. British scientists urged the government to support breastfeeding in order to reduce the carbon imprint of baby formula, Iron Age infant graves were found to contain ceramic bottles for feeding babies animal milk, and Japanese researchers deciphered the characteristic odor of newborn babies’ heads. As mammals grow more sophisticated, the proportions of their skulls approach the Golden Ratio.
Biologists who counted the warts on the heads of octopuses in the Pacific found more warts on those who live in deeper waters. Baltic marine predators were losing weight, and washing machines’ delicate cycles were contributing more microplastics to the oceans than were regular cycles. High levels of toxins, some of which are heritable, were discovered in bottlenose dolphins in the Normano-Breton Gulf, and antibiotic resistance continued to rise among bottlenose dolphins in Florida’s Indian River Lagoon. Nose swabs of 188 dead hedgehogs submitted by members of the Danish public resulted in positive tests for MRSA. Overweight Danes are likelier to have overweight dogs, which researchers blamed on those owners’ tendency to use snacks not as training incentives but as “hygge candy,” to create an atmosphere of cozy conviviality. Pine martens were reintroduced to the Forest of Dean, and authorities in New South Wales were evacuating fish from the Darling River ahead of the austral summer. The completion of genomic sequencing for all living species of penguins was announced by the Penguin Genome Consortium, and anthropologists warned of dwindling genetic diversity among the long-legged chicken landraces of the Horn of Africa. The United States and Canada were found to have lost 29 percent of their bird populations since 1970. Eastern gray squirrels eavesdrop on birds.
Formerly inexplicable high global rates of gonorrhea can be explained by kissing, and H.I.V. resistance may be promoted by repeated vaginal exposure to semen. During sex, male honeybees inject queens with a toxin that temporarily blinds them, presumably to make it more dangerous for them to fly off and mate with other males. Some cancer cells eat one another to survive chemotherapy. Exosome therapy proved better than both retinol and stem cells at treating nude mice with sun-damaged skin. Darker male giraffes are less sociable. A researcher who found that wolves break their teeth more often when prey is scarce suggested that her findings would also apply to lions, tigers, and bears. British doctors reported a case of transient Brexit-induced psychosis. Impostor syndrome is more widespread than previously estimated. A meta-meta-analysis of autism studies showed that those diagnosed with the disorder were becoming increasingly hard to distinguish from the population at large. A species of tumbleweed has defied projections of its inevitable extinction and is now thriving.