The Bottleneck Theory In Cheetahs

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 ‘ideal’ 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
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.,
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,