Posted 13 November 2025
Scientists studying the fat-tailed dunnart, a tiny Australian marsupial, have uncovered genetic clues that explain how different mammals develop their facial features.
Marsupials like the dunnart are born extremely early and must quickly develop the muscles and senses needed to crawl into their mother’s pouch, while placental mammals, such as humans and mice, complete most of their development before birth.
“Such studies can provide functional insights into how regulatory elements in the genome control craniofacial development across mammals, and consequently the evolutionary changes that have driven divergent growth patterns in marsupials and placentals,” said Laura Cook, who led the research as a PhD student at the University of Melbourne.
Cook’s team compared gene activity in newborn dunnarts with existing data from mice and found that while the key facial-development genes were similar, the DNA regions that regulate them differed significantly.
“The recurrence of genes related to the development of the dunnarts’ sensory systems highlights a unique aspect of early pouch life in marsupials – the challenge of reaching it!” explained SVI’s Associate Professor Irene Gallego Romero.
“Newborn marsupial young need their sensory systems, especially their sense of smell, to be highly developed so they can follow the cues that guide them to their mother’s pouch.”
The findings suggest that marsupials evolved unique genetic “enhancers” to speed up facial and sensory development after birth — offering new insight into how faces evolved across mammals.
The study was published in eLife in which the editors describe it as important work with compelling data, including a new dunnart genome assembly, which they say provide an “invaluable reference” for future mammalian evolution studies.
Read the findings