excreationist
Married mouth-breather
From "Problems with a Global Flood, Second Edition."
How did diseases survive? Many diseases can't survive in hosts other than humans. Many others can only survive in humans and in short-lived arthropod vectors. The list includes typhus, measles, smallpox, polio, gonorrhea, syphilis. For these diseases to have survived the Flood, they must all have infected one or more of the eight people aboard the Ark.
Other animals aboard the ark must have suffered from multiple diseases, too, since there are other diseases specific to other animals, and the nonspecific diseases must have been somewhere.
Here are related counter-arguments from YEC sources:
https://creation.com/diseases-on-the-ark
https://answersingenesis.org/noahs-ark/how-did-infectious-diseases-get-on-the-ark/
The problem of inbreeding has to do with mutations that accumulate. I think the YEC belief that animals originally had no mutations makes sense...Why is inbreeding depression not a problem in most species? Harmful recessive alleles occur in significant numbers in most species. (Humans have, on average, 3 to 4 lethal recessive alleles each.) When close relatives breed, the offspring are more likely to be homozygous for these harmful alleles, to the detriment of the offspring. Such inbreeding depression still shows up in cheetahs; they have about 1/6th the number of motile spermatozoa as domestic cats, and of those, almost 80% show morphological abnormalities. [O'Brien et al, 1987] How could more than a handful of species survive the inbreeding depression that comes with establishing a population from a single mating pair?
The counter-arguments might not fully address the issues but the point is that YECs can easily find related counter-arguments and this makes them feel confident in their beliefs....