Life on ancient Mars should not be surprising: there would have been transfer of life on impact debris back and forth among Earth and Mars (and possibly Venus).

The journal article referenced by the press release, titled "Does the Measured Abundance Suggest a Biological Origin for the Ancient Alkanes Preserved in a Martian Mudstone?" is at https://journals.sagepub.com/doi/epub/10.1177/15311074261417...