We can combine Noah's flood, Peleg's tectonics and knowledge of the process of devolution to help us clear up what level of variability is represented by the Biblical word KIND.
How Much Variability is in a Kind?
Distribution of Biodiversity
There were two horses on Noah’s ark but now there are at least seven species in genus Equus. That's speciation or macro-evolution. It's not a problem because the process of evolution has a scriptural context.
Species Concepts
Understanding how the process of evolution incorporates into the creation narrative solves a lot of issues, not the least of which is the potential space problem on Noah's ark.