Not many articles this month and most of them are about medicine. I didn’t realize that until I sat down to write this post.

• Starting with the non-medical science article first, this is piece about how each distinct community of sperm whales may have their own unique culture. The researchers studied groups of the whales in the Carribean, using microphones to record the sounds they make and track their interactions. They found that each clan has their own dialect that family members explicitly teach to new calves but there are also codas, or words, that they share in common with sperm whales of other clans.
• This next article talks about the medical mystery of how incidences of major diseases in many wealthy countries seem to be dramatically dropping for no discernible reason. These include colon cancer, heart disease, dementia, hip fractures and so forth, each seemingly unconnected with another. One obvious cause is that better technology and practices should result in better diagnosis and treatment but the researchers found that the rates are still down after controlling for these factors. No one knows what other explanation there could be but I guess people are just in general living more healthily now in rich countries, contrary to the popular impression that humans are becoming ever more unhealthy.
• Readers of this blog should probably already know that mitochondrial DNA, which comes only from the mother, is different from nuclear DNA, which comes from both parents. Nevertheless it is thought that they have co-evolved together through generations and therefore DNA from the same lineage should work better together. Current cloning technology however mixes mitochondrial DNA with nuclear DNA of two different and presumably distantly related donors. The surprise is, as this article explains, that the resulting organisms seem to live longer rather than shorter as you might expect. The current guess is that some small amount of adversity, in this case caused by the two types of DNA being not completely compatible, is sometimes beneficial to the organism, and how true this is remains yet unknown.
• Usually when we see advertisements or click-bait headlines like oil companies don’t want you to know this energy-saving secret it’s either a scam or crazy conspiracy bullshit. So this bit of news about how mainstream dentists are hindering the widespread adoption of a treatment for cavities that doesn’t require any drilling looks suspect. Except that this comes from a reputable source and the treatment, an antimicrobial fluid called silver diamine fluoride, has already been cleared as being safe by the FDA in the US and has been used for decades in Japan. The fluid can’t save teeth that has already been too damaged but it can prevent cavities from becoming worse and prevent new ones from occurring. The only downside is that it may blacken portions of teeth that have already been damaged by cavities. The upside however is that its cheap, quick to apply and requires no surgery.