Noah was allowed two animals of each kind, however having only two animals creates a lack of genetic diversity. With that being said, some of these animals must have been ‘ideas to contain abundant genetic diversity to be passed on to future generations. So how did Noah know to choose the lion or the domestic house cat in deciding which genes were more important to pass down? According to many scientists, for a species to not be considered endangered there must be fifty of its kind for there to be enough genetic diversity, however the best results would occur if there were at least five hundred in a species (Freemon and Heron, 2007).
However, having only two animals would not be enough in order to sustain all of the genetic diversity for a population. This can also apply to humans as well. With the ark containing only Noah, his wife, and his sons and their wives, this means that all of the Earth’s descendants would typically not have very much variance in their genes. With that being said, if there was only Noah and his family, how could other skin colors and disease have arisen?
With little variation in a population, there could be changes in the environment that may not suit those genes, therefore, most animals and humans would die because they do not have the variation of genes where they are able to adapt to the environment (Freemon and Heron, 2007). Therefore, this leads to the topic of the bottleneck theory The bottleneck theory is described as starting a population with what is left in the existing population (Freemon and Heron, 2007). The reason why this happens is because something drastic must have happened in the population that results in many animals in a species to die (Freemon and Heron, 2007).
With less and less of a population, this creates less variation within a species. Therefore, more heterozygosity and alleles are lost because of less variation (Allendorf, 2005). In populations that are small, alleles can be lost due to fixation, which results in the loss of heterozygosity (Freemon and Heron, 2007). Even if a species contained fifty animals that mated randomly, at least one percent of heterozygosity would be lost each year (Freemon and Heron, 2007). An example of the bottleneck theory can be found in cheetahs.
Recently cheetahs have undergone a decrease in population size, resulting in less variation in genes. Scientists think that this decrease may have happened during the last ice age affecting today’s cheetahs ever since ( Menotti-Raymond and O’Brien, 1992). Scientists were able to discover this by looking at mitochondrial DNA as well as hypervariable nminisatellite loci in South African and East African cheetahs (Menotti-Raymond and O’Brien, 1992). By looking at these, they were able to tell that the Pleistocene bottleneck affected cheetahs and decreased cheetah’s variation of alleles (Menotti-Raymond and O’Brien, 1992).
Zoos have also had trouble breeding cheetahs in captivity due to such low variations and trying to make sure that inbreeding does not happen (Menotti-Raymond and O’Brien, 1992). Because many cheetahs are related to one another through inbreeding, zoos have to be extremely careful to make sure that they are not mating cheetahs with their relatives. Cousins always contain 1/8th of your genes, so scientists must be careful to take this into consideration (Freemon and Heron, 2007). Mating with relatives can also lead to infertile eggs not or too much similarity in genes (Nordell, S. E. and Valon, T. J. , 2014).
This can also lead to an inbreeding depression, resulting in a decrease in fitness as one mates with close relatives (Nordell, S. E. and Valon, T. J. , 2014). The bottleneck effect can also happen in humans as well. In a population of Pingelapese people, only twenty individuals survived after the destruction of typhoon and famine (Freemon and Heron, 2007). One of these individuals was carrying a mutation on one of their genes that affects normal eye vision (Freemon and Heron, 2007).
In other populations, this only occurs one in every twenty thousand people, but with such a small starting population, one in twenty people have this mutation (Freemon and Heron, 2007). As you can see, a population with only twenty individuals can cause for a rare mutation to commonly occur in a population. So with Noah having only his family and if they had mutations of any kind, this could be why we have viruses or diseases. These individuals must have been carrying all of the genetics and mutations for disease and viruses and passed them on to future generations (Moore, 1983). This is also true for parasites (Moore, 1983).
In order for parasites to survive, they need hosts that can be deadly to others, however they are still here today, meaning they must have survived the ark (Moore, 1983). For example, one of Noah’s family members must have had malaria during their time on or before the ark which is why we see organisms having malaria today (Moore, 1983). Because there were so many animals that Noah and his family had to find, they had to use different tactics. Some animals could have migrated to the ark because God commanded them to, but not all animals use migration as a common behavior (Moore, 1983).
Animals were found all over the world, so some kind of miracle must have happened, otherwise not all animals with the necessary genetic diversity would be on the ark. For example, how would giraffes or elephants or even animals from Australia be able to cross the ocean to get to the ark? There had to be some kind of miraculous event in order for this to occur. Another thing to keep in mind would be climatic zones (Moore, 1983). Most animals have to live in a specific environment so living on the ark for a year could be difficult (Moore, 1983).
Some animals are accustomed to live in caves or may need to live in extremely hot conditions to survive (Moore, 1983), so how would the ark accommodate their special needs? This also leads to the question on how they loaded the ark. Noah only had one week to load the ark and with almost 16,000 animals to load, that would mean that each animal would have had to be loaded on every thirty-eight seconds (Isaak, M. , 1998). This number seems impossible just to load one animal, especially if that said animal had to be on the third deck and would have had to climb the stairs to get there.
This number also is unreasonable because that means they must have had other ways to load slow or large animals that took longer strides. Some special needs could include the diet of the animals and where their waste materials went. Many animals require specials diets and must have a certain type of food to survive (2 Woodmorappe, J. , 1996). Some think that in order to not have specialty food items, like meat or specific plants, God commanded that all animals would be able to eat the same foods (Moore, R. A. , 1983). If this is the case, did animals just switch back in the blink of an eye to their regular diet after exiting the ark?
This could create dilemmas where as other animals were getting off the ark they could possibly be eaten before they spread their genes back into the environment. If these animals were eaten, then that would lead to an extinct species. Often, food that animals need are usually unique to them and could often go bad (2 Woodmorappe, J. , 1996). In order for food to not go bad, it must all be finished and cleaned every day (Moore, R. A. , 1983). This means that either the eight people had to go to every stall and make sure everything was clean and sanitary every day or the animals must have been able to do it themselves.