text: Top stories: Caterpillar wrestling, next-generation CRISPR, and the troubled James Webb Space Telescope
  
  Researchers have published what may be the largest family tree ever: a genealogy database stretching back 5 centuries that links 13 million people related by blood or marriage. The tree has already illuminated links between longevity and certain genes, and it has provided insight into why some of our ancestors married whom they did. And researchers say that’s just a start.
  
  You wouldn’t know it from the excitement generated by the revolutionary genome editing method known as CRISPR, but as practiced, it is far from perfect. Its standard components can find and cut DNA in only a limited fraction of the genome, and its molecular scissors are wobbly, leading to “off-target” mutations. Now, a team led by chemist David Liu at Harvard University has engineered a version of CRISPR that potentially is both more dexterous and more precise.
  
  Resilience is on many people’s minds these days. Hurricanes and fires regularly wallop communities, the risks of climate change loom large, and the horrors of war and the refugee crises it spawns show no signs of abating. It’s an unsettling time—made more so because we humans feel unable to control many of these human-influenced events. But even though hardship cripples some, others rebound. What can science teach us about how we might gird for future challenges and adapt to them? A package of stories in this week’s issue of Science explores what scientists are learning about resilience in a challenging world.
  
  NASA’s troubled James Webb Space Telescope—which is expected to revolutionize our knowledge of the early universe, planets around other stars, and much else in between—is heading for more choppy water, says a report from the U.S. Government Accountability Office released this week. Problems in testing the orbiting telescope’s components and integrating them together means further launch delays are likely. And the slips could mean the project will breach the $8 billion cost ceiling imposed by Congress in 2011.
  
  Soft, squishy caterpillars might seem like easy prey to a hungry predator, but one species doesn’t give up without a fight. Fully developed caterpillars of the hornworm moth use a mix of squeaks, strikes, and vomit to defend themselves from predators, according to a new study. Scientists tested how hornworm moth larvae fared in the presence of caterpillar-hunting beetles and found that none of the 25 beetles tested was successful in killing a single caterpillar.