BY APRIL, the human genome will be in the can – spelled out to almost the last letter, polished and completely wrapped up. A scientific triumph for sure, but one that will leave a yawning void. The vast sequencing factories, built to chew through those 3 billion letters of DNA faster than anyone thought possible, will still be hungry. What genome should we feed them next?
There is no shortage of candidates, but surprisingly few clear answers. Biologists cannot reach agreement about which organisms are most deserving. “This has come up quickly on all of us, because we’ve all been focusing on the human genome for a number of years and have deferred thinking much beyond that,” says George Weinstock, co-director of one of the world’s largest sequencing centres, at Baylor College of Medicine in Houston, Texas. Senior officials at other sequencing centres echo his uncertainty about what to do next.
So which species should be first in line? The obvious answers – the lab workhorses mouse, fruit fly, nematode worm, thale cress, yeast, rat, African clawed frog, pufferfish and zebra fish – have already been completed or soon will be. And while hundreds of microbial genomes are crying out to be sequenced, the world’s powerhouses also want some meatier projects.
Ask any group of biologists, and you will find there is no shortage of candidates. Ornithologists tend to rally behind the chicken. Livestock researchers support the cow. Biomedical types throw their weight behind the chimp or the dog. Developmental biologists champion the sea urchin, behaviourists the honeybee, agrobiologists maize. Comparative geneticists, meanwhile, support any representative of a group that has not been…
![Astronomers have long known that understanding how star clusters come to be is key to unlocking other secrets of galactic evolution. Stars form in clusters, created when clouds of gas collapse under gravity. As more and more stars are born in a collapsing cloud, strong stellar winds, harsh ultraviolet radiation and the supernova explosions of massive stars eventually disperse the cloud, and their light can bear down on other star-forming regions in the galaxy. This process is called stellar feedback, and it means that most of the gas in a galaxy never gets used for star formation. Researching how star clusters develop can answer questions about star formation at a galactic scale. Now, the state of the art has been further developed with both Hubble and Webb working together to provide a broad-spectrum view of thousands of young star clusters. An international team of astronomers has pored over images of four nearby galaxies from the FEAST observing programme (#1783), trying to solve this mystery. Their results show that it is the most massive star clusters that clear away their gaseous shroud the fastest, and begin lighting their galaxy the earliest. The team identified nearly 9000 star clusters in the four galaxies in different evolutionary stages: young clusters just starting to emerge from their natal clouds of gas, clusters that had partially dispersed the gas (both from Webb images), and fully unobstructed clusters visible in optical light (found in Hubble images). With Webb???s ability to peer inside the gas clouds, they were able to then estimate the mass and age of each cluster from its light spectrum. This image shows a section of one of the spiral arms of Messier 51 (M51), one of the four galaxies studied in this work, as seen by Webb???s Near-Infrared Camera (NIRCam). The thick clumps of star-forming gas are shown here in red and orange, representing infrared light emitted by ionised gas, dust grains, and complex molecules such as polycyclic aromatic hydrocarbons (PAHs). Within these gas complexes, each tens or hundreds of light years across, Webb reveals the dense, extremely bright clusters of massive stars that have just recently formed. The countless stars strewn across the arm of the galaxy, many of which would be invisible to our eyes behind layers of dust, are also laid bare in infrared light. [Image description: A large, long portion of one of the spiral arms in galaxy M51. Red-orange, clumpy filaments of gas and dust that stretch in a chain from left to right comprise the arm. Shining cyan bubbles light up parts of the gas clouds from within, and gaps expose bright star clusters in these bubbles as glowing white dots. The whole image is dotted with small stars. A faint blue glow around the arm colours the otherwise dark background.]](https://images.newscientist.com/wp-content/uploads/2026/05/13114322/SEI_296271016.jpg)