The Tasmanian tiger was declared extinct in the 1980s, but now a team of scientists from the US and Australia want to bring it back to life – launching an ambitious multimillion-dollar project, with the backing of investors and celebrities like Chris Hemsworth. However, some in the scientific community question whether this project is worthwhile and scientifically possible. The Guardian Australia climate and environment editor Adam Morton speaks to Laura Murphy-Oates about the science behind bringing back the Tasmanian tiger and what this project could mean for the broader extinction crisis