Only a few problematic assumptions being made there:
First, the age
Can you elaborate more...
-Second, the habitat
-Third, the materials being available
The subject matter is about
MICROBIAL life not about elephants...
-Fourth, abiogenesis being possible
They don't pretend they know how microbial life emerged 4 billion years ago...like we don't know
how God created life...
The Beginnings of Life - The Physics of the Universe
The modern definition of abiogenesis, however, is concerned with the formation of the simplest forms of life from primordial chemicals,
rather than the old Aristotelian concept of abiogenesis, which postulated the formation of fully-formed complex organisms by spontaneous generation. It becomes, then, the search for some kind of molecule (along the lines of RNA or DNA) that is simple enough that it can be made by physical processes on the young Earth, yet complicated enough that it can take charge of making more of itself, which is probably what most people would recognize as constituting “life”.
The thing they said is
A sophistication of [MICROBIAL] life by 3,700 Ma is in accord with genetic molecular clock studies placing life’s origin in the Hadean eon (>4,000 Ma)
http://www.nature.com/nature/journal/v537/n7621/full/nature19355.html
''The presence of the ISB stromatolites demonstrates the establishment of shallow marine carbonate production with biotic CO2 sequestration by 3,700 million years ago (Ma), near the start of Earth’s sedimentary record.
A sophistication of life by 3,700 Ma is in accord with genetic molecular clock studies placing life’s origin in the Hadean eon (>4,000 Ma)