After the relative paucity of science news the previous month, I’ve been hit by an absolute deluge of important announcements in June.

• The most important of these concern the realization that the history of intelligent life on Earth may need to be completely rewritten. Homo naledi was a species of hominids who were much shorter than modern humans but had human-like hands and feet and more ape-like hips and shoulders similar to Australopithecus. They were first discovered in 2013 and due to the small size of their skulls and therefore their brains were not thought to be intelligent in the way humans are. Now researchers have found not only evidence of ceremonial burial but abstract geometrical patterns carved into cave walls that may be a form of primitive art. This has forced researchers to revise their opinions that such small brains could not be intelligent and to reevaluate the evidence of stone tools, cave art and remains of fires as hominids other than Homo sapiens and Neanderthals may have been responsible for them.
• Another important announcement is that a team has succeeded in creating synthetic models of human embryos by reprogramming stem cells without the need for human eggs or sperm at all. These model embryos are useful to study the earliest stages of human development and it is not clear that they ever have the potential to grow into living creatures. It is currently illegal to implant them into human wombs and animal versions of these models have failed to develop properly in animal wombs beyond a few days. Nevertheless it’s easy to see what a significant development this is and why there are so many ethical concerns over this announcement.
• The line ‘life finds a way’ is such a meme by now but it’s the best way to describe the case of a female American crocodile that laid a clutch of eggs by itself despite having being kept in complete isolation from other crocodiles throughout its life. This makes it a clear case of parthenogenesis in which female gametes develop without being fertilized. Of the 14 eggs laid, 7 appeared to be fertile and were artificially incubated. Unfortunately none hatched and only seemed to have a fully formed fetus inside. DNA analysis proved that the fetus was essentially a clone of the mother with no paternal alleles at all. In this instance, the clutch of eggs all failed and suggests that such eggs are inherently less healthy that properly fertilized ones. Nonetheless it makes for a fortuitous, unplanned experiment that demonstrates that the phenomenon is real.
• Then we have a paper that talks about using targeted neurostimulation to treat major depressive disorder (MDD). As the paper notes, patients with MDD are resistant to other forms of treatment and the condition itself is widely thought to be the result of disordered communication across the entire brain network. It shows that targeted neurostimulation can restore typical propagation patterns of signals within the brain and this could the mechanism by which the treatment works.
• Finally here is an article about the so-called study drugs that are popular in some circles. These include such brands as Adderall and Ritalin, taken because they are thought to boost brainpower. A double-blind study however found that those on these drugs spent more effort on completing cognitively demanding tasks yet performed worse on average. In fact, even those who did well after taking the placebo performed poorly under the effects of one of these drugs.