Science Daily

• Earth's first animals barely evolved until sex changed everything

  Earth’s earliest animals may have held evolution back because they reproduced asexually, creating low-competition communities that changed very little over time. When environmental pressures pushed them toward sexual reproduction, biodiversity exploded and evolution accelerated dramatically.

• An invisible forever chemical rain is falling across the planet

  A surprising study suggests that chemicals introduced to protect the ozone layer may have unintentionally created a growing global pollution problem. Researchers found that refrigerants and certain anesthetic gases have generated more than 335,000 tonnes of trifluoroacetic acid (TFA), a highly persistent "forever chemical," that has been deposited across Earth's surface since 2000. The pollutant is now showing up everywhere from rainwater to remote Arctic ice, and scientists expect levels to keep rising.

• Stonehenge's most mysterious stone traveled 700 kilometers across Britain

  Scientists have uncovered new evidence that Stonehenge’s six-ton Altar Stone was deliberately transported hundreds of kilometers from Scotland by ancient people. The feat would have required extraordinary planning, teamwork, and determination, revealing a surprisingly sophisticated level of organization thousands of years ago.

• Scientists may have debunked one of humanity's oldest habits

  Ancient grooves on human teeth, once hailed as evidence of tooth-picking, may simply be the result of natural wear, according to a new study of wild primates. The research also revealed that a common modern dental defect appears to be uniquely human, hinting that today's lifestyles may be reshaping our teeth in unexpected ways.

• South Australia’s koala boom could end in mass starvation

  South Australia’s koala population has grown so large that it may be heading toward a self-made disaster, with forests struggling to support the animals. Researchers say targeted fertility control could prevent widespread starvation and habitat collapse before it’s too late.