Don't worry, Ralph, I read them too.
Yes, some seeds would die depending on the concentration of salt water. Yes, some plant species became extinct during the Flood. The experiment you mention, however, did not include the apple being buried by a landslide due to geologic upheaval that would give it temporary protection from salt water.
Geologic upheaval DID alter the Earth's rotation, including the tilt. Seasons are not mentioned until after the Flood.
Concerning DNA, when God created the biosphere, everything in it was perfect, including DNA. God ordered all species to multiply while remaining separate species, which would include diversity within a species. Again, once the water canopy was removed, UV rays bombarded DNA like never before and all genetic defects known today took hold of the biosphere. DNA was no longer perfect, and the Second Law of Thermodynamics took hold of it.
Concerning dinosaurs and the space within the ark: read the link Ralph posted, as it explains that better than I can. Dinosaurs died out shortly after the Flood because the biosphere could no longer support them. And, note, that a lot of ancient civilizations make references to "dragons" or similar creatures. The Aztec-Mayan quetzalcóatl-kukulkán predates the Aztec and Mayan civilizations by 1,000 years, as it is mentioned in Olmec records.
As to whether the Flood was worldwide or not, if it wasn't, then the local event must have been more catastrophic than one can imagine, since ancient civilizations have some mention of people surviving a flood in a boat, including the Aztecs and the Mayans.
The website posted has better explanations for the points presented here, so I now defer questions to that site.
See, people? We can have a debate concerning a Biblical event without resorting to flaming, name calling, or locking threads.
Until next time, remember:
J.A.M. (a.k.a. Numbuh i. "Just because I'm imaginary doesn't mean I don't exist")