James Pagatpat
The global Flood account requires that the present diversity of land plants re-established after roughly one year of inundation. Seed plants have an obvious survival route, since they can persist and travel as seeds, and the ark narrative concerns food, which Genesis elsewhere identifies with seed-bearing plants (Genesis 1:11-12; 1:29; 6:21). Ferns, however, are seedless. They reproduce through wind-dispersed spores and a small, free-living gametophyte, and if they were not carried as propagules in the manner of seed plants, their persistence through the Flood must have depended on spores surviving in the water column, in bottom sediments, or on floating debris. I examine this requirement against the only experimental study to test fern spore survival under prolonged saline and freshwater inundation (de Groot and During, 2013). That study found that immersion in freshwater alone was tolerated by most tested species, but that salt progressively reduced germination, and that gametophytes grown from spores held for a year in saline water were smaller and far less viable. Critically, real marine sediments yielded no viable fern spores, and freshwater sediments yielded only two gametophytes, both of which died before maturity. Because a global Flood would be predominantly marine and more saline than the conditions tested, and because it would leave no dry refugia from which fresh spores could re-seed the drained land, sediment-based fern survival appears far from optimal. I then set this against the paleobotanical record, which shows a long and continuous fern diversification with no signature of a recent global bottleneck. I conclude that the survival of ferns is a genuine difficulty for a literal global year-long Flood.