Collecting Animals: How did Noah and company collect a pair of every animal of every kind from everywhere on the Earth (and seven pairs of the clean animals)? Although kind is variously identified, it evidently corresponds approximately to the modern term species, which is loosely defined as: Kind or sort; and more properly defined as, a category of biological classification ranking immediately below the genus or subgenus, comprising related organisms or populations potentially capable of interbreeding, [to which should be added: and producing fertile offspring]
Thus, horse and donkey are different kinds because they cannot produce fertile offspring while dogs, wolves and coyotes, etc constitute one kind because they can successfully interbreed and produce fertile offspring.
Even using kind in a broad sense, the task of collecting animals worldwide suggests an impossible task. Even with modern transportation and thousands of people the task of collecting EVERY kind of animal would at least be immensely difficult.
For eight (or any number of) people to accomplish the task with nothing more than rudimentary transportation defies credibility. They would have had to gather animals from pole to pole and from every continent and according to the Bible they did it in seven days!
Many animals exist in only very small, very specific habitats, some only on one island. Yet a pair of each must, if the biblical account is accurate, have been collected and put aboard the ark or they would not exist today.
Every kind of insect, worm, bird, monkey, snake, tortoise, etc that is alive today would have had to be aboard the ark. Insects alone exist in hundreds of thousands of discrete species in every conceivable habitat. Were they all collected? They must have been if they were to survive.
100% survival is required: Every individual animal of every pair would be absolutely required to survive and reproduce or the species would become extinct immediately. In reality, when the population of any species declines to a few breeding pairs or a few hundred pairs the species is known to be on its way to extinction. Yet according to the ark story one pair was sufficient, every presently existing species survived starting from a single pair.
Animal feed must have been quite a problem. Large herbivores require great amounts of vegetative matter daily. Some are quite specific what vegetation they eat. Many of the Earths animals are carnivorous they eat other animals exclusively. What did they eat for weeks or months?
Some animals will die rather than eat anything other than a specific food. The koala bear (an Australian marsupial), for example, feeds exclusively on eucalyptus leaves. Many species eat exclusively decaying organic matter, others feed only upon fresh fruit or vegetation. Were all the necessary specific foods collected for each animal, preserved in required condition and stored on the ark? Would eight people be sufficient to feed animals on schedule some, like hummingbirds, which must eat very frequently?
Animal Habitat. Polar bears do not survive well in the tropics. Many desert animals do not survive well in humid climates. Some animals require a moist environment, others require a specific soil. How could all these habitat requirements be met aboard a single ship for weeks or months with a crew of eight, limited space and no climate control systems?
Microscopic life forms must also have been taken aboard since they obviously survived. Disease causing microorganism must have been preserved from destruction also. How was this accomplished by people without knowledge of microorganisms and without microscopes?
