The sky becomes dark. The entire planet is
covered in one gigantic rainstorm that will last for 40 days and 40 nights. This superstorm
is a punishment from God and will wipe out every living thing on the planet. That is unless
one man can build an Ark and save the world. Many people believe this actually
happened, and the crazy thing is, they might be right. Could two of each animal
repopulate the planet? What crazy problems would Noah run into? And was it even possible
to build an ark big enough? Let’s find out. Recently researchers have re-examined the story
of Noah’s Ark and were surprised to find aspects of it could have saved the world. But would it be
enough to repopulate the entire planet if only two of every land species remained? This is where we
will start our journey into this biblical story. First, we will address the biggest
and grossest problem with restarting every animal population with just two individuals. The first generation that is born will
all end up all being brothers and sisters. This is uncomfortable to think about and would
cause some serious problems when trying to bring populations back up to stable levels. In order for
each species to continue to grow, the brothers and sisters would need to reproduce with one another,
and then the following generation would all need to reproduce with either their parent, a
sibling, a cousin, or an aunt or uncle. There would be no good choices for mates and
all options are a little icky. By the third generation of offspring, there are slightly
better options in terms of being less taboo, but it would take several more generations
before an organism could be relatively sure it wasn’t reproducing with a close relative. But reproducing with cousins is not all that
uncommon in the animal kingdom so it could be done. However, there is a bigger problem than
just the uncomfortable thought of organisms reproducing with their relatives in this scenario.
We are about to get into genetics but don’t worry; we’ll keep it much more straightforward than
your biology class. We know biology is complex and there are always exceptions to every
rule, but for the purposes of understanding if Noah’s Ark could have restarted
the world, we will keep things simple. Starting with just two individuals means
that every member of the species from there on out could only have the traits of those two
animals. This is because each offspring will get half of its DNA from mom and half from dad.
And since there are only two individuals left, they are the only ones having babies. This
means that there would be very low variation, or differences, in the members of every species. Low
diversity in any species is a big problem because the environment is always changing. The lack of
different characteristics can lead to populations being unable to adapt to a new environment.
When this happens, the species goes extinct. If this were to happen, all of Noah’s hard
work trying to save the animals of the planet would have been for nothing. Even
a slight shift in the environment like warmer temperatures could wipe out
entire species with low genetic diversity. Let’s think of it in simpler terms. Say before
the Great Flood rabbits came in all different colors. This would be beneficial to the rabbits
as a species because if their environment changed from a cold, snowy environment to a warmer,
woodland environment, there would likely be a group of brown rabbits that could thrive in the
new habitat, allowing the species to continue on. What would happen if the two rabbits
brought onto the ark were both white? After Noah released them back into the wild and
happily hopped into their new snowy habitat, they would reproduce and make more bunnies. The
whole population of bunnies after many generations would most likely still be white, unless there
was a mutation in the DNA of an individual that caused its fur to turn a different
color like brown. And if this brown rabbit was killed before it could reproduce, then
the brown fur trait would die with him. So, now Noah’s new white rabbit population
finds themselves on a warming planet where there is less snow and more brown
leaves and trees in their habitat. They stick out like a sore thumb,
and all of the wolves eat them because they are easy to spot. The rabbit
species goes extinct because there weren’t enough variations in their traits to allow
the species to survive in the new environment. This would happen with species after species
as the amount of genetic variation required for a population to be able to survive in
an ever-changing environment needs to be high. Therefore, years after Noah thought he
had saved all of the animals on the planet, most of them would already have gone extinct
or at least would still be very close to it. There is also a more immediate problem with only
having a limited number of genes in a species, especially when these individuals
start breeding with each other. When there is a small number of individuals
in a population—and two is as small as it can get before extinction—there tends to
be an accumulation of harmful genes that can lead to deadly diseases. This process
can actually be seen around the world today due to small populations being isolated
for one reason or another. The crazy thing is that these populations are
larger than just two individuals, and they are still having genetic problems
associated with their limited population size. Small populations are so dangerous when
it comes to reproduction because there is a good chance some of the individuals
are carrying a gene that could be harmful or even deadly. Scientists actually estimate
that in humans alone every single person has one or two genes in their DNA that could be
harmful if passed on to future generations. Now it is important to note that these genes
may be recessive, meaning that an individual may only have one copy of the harmful gene instead of
two. This would mean the harmful trait would not be expressed in that individual. But if mom has
the harmful gene, and dad has the harmful gene, they could both pass it on to their offspring
giving their baby two copies of the harmful gene. The percentage of harmful traits increases in
small populations because there is a greater chance of offspring being born with at least
one copy of that trait. Let’s imagine the two elephants that were on Noah’s Ark both had a copy
of a harmful gene that causes an elephant’s tusks to fall off. Since they both only have one copy,
their tusks stay on and are not harmed at all. However, when the two elephants get off the Ark
and begin repopulating the elephant species, three out of every four of their offspring would
be born with at least one of the harmful genes. Only one of these babies would end up with both
copies of the harmful gene and lose their tusks, but the other two would still be carriers of
the harmful gene. You can see how a trait like this could quickly become a problem and
would not be going away any time soon. 75% of the first generation would have
at least one gene for the harmful trait. Eventually, having such a small population
of elephants could lead to harmful mutations developing and accumulating in the species. A
mutation is a random change in the DNA that can be good, bad, or have no effect at all. The
problem with inbreeding in small populations is that harmful mutations can
spread rapidly in each generation, leaving the entire species vulnerable to
being wiped out by their own harmful genes. Some examples of this can be seen
in Noah’s very own descendants. Which would be all of us because the only
humans to survive the flood were Noah’s family. There have been instances of humans in
different parts of the world inbreeding due to limited population size. This happened
in parts of Czechoslovakia in the early 1900s. A study found that individuals who had
parents that were first-degree relatives had high instances of severe genetic
disorders. And of those people, around 14% died as a direct result of those
harmful genes that resulted from inbreeding. Another clear example of a harmful trait making
its way through a population can be seen in Pingelap. Pingelap is an isolated island in
Polynesia. The island’s entire population was wiped out during a typhoon, leaving only
20 individuals to repopulate. Unfortunately, one survivor carried a gene for achromatopsia. Achromatopsia is another name for colorblindness.
After the population on Pingelap began to increase from the 20 individuals reproducing, this
gene spread quickly through the island. Even though there are now thousands of people
on the Pingelap, around 10% are color blind, which is much higher than would be
expected with a more diverse gene pool. This just goes to show that starting with a small
population of individuals and being restricted to only a few combinations of genes can lead
to an increase in non-beneficial traits. In the Noah’s Ark story, the animals would
only have two sets of genes to build the entire species that we see today off of.
If this were the case, it would be highly unlikely many of the animals that inhabit
the planet today would be around right now. At this point, you may be wondering how any
species at all could have made it to the present even without Noah’s Ark since every species
starts with just one individual. Evolution is complicated, but we have to remember
that members of closely related species tend to be able to reproduce with one another.
We know humans and Neanderthals mated in the past because everyone—except for people with
lineages that never left Africa—has a little bit of Neanderthal DNA in them. So, when a new species evolves, they can still
reproduce with the species they evolved from, which offers a more diverse gene pool.
This means that when a new species evolves, they never start with just one
or two potential mates. Instead, they have the ability to mate with
other closely related species. What it comes down to is that almost all of the
species aboard Noah’s Ark would end up going extinct after one or two generations. This is due
to a lack of genetic diversity and inbreeding. What might be the most surprising thing
of all, however, are the species that could have actually made it after leaving
the Ark. There are some animals with very special abilities that would have allowed them to
repopulate the planet even if only two remained. Tree lobsters were almost completely wiped out
by humanity not too long ago. Their population plummeted to the point that scientists thought
the species had gone extinct. The scientists were surprised to find several tree lobsters
still alive high up on the rockface of a cliff where they were protected from predators. Out of
the tree lobsters discovered, two breeding pairs were used to restart the entire species. This
scenario provides a perfect case study for what could have happened with Noah’s Ark as today there
is a healthy tree lobster community in the wild. But how did they do it? How were the tree lobsters
able to overcome all of the hurdles of gene pool degradation and reproducing in a changing
environment? The answer will blow your mind. The tree lobster was able to survive and
overcome all odds due to a rare ability called parthenogenesis. What this means is that
the female tree lobster could reproduce without mating with the male. Sexual reproduction is
the main way that tree lobsters reproduce, and this is good for the species because it leads
to genetic diversity, but in dire situations, a female tree lobster can produce viable
offspring that are clones of herself. This obviously doesn’t help
with genetic diversity, but if those offspring go on to
mate with other tree lobsters, the gene pool can become more diverse much faster
than only using sexual reproduction. Therefore, if the tree lobster was on Noah’s Ark, it
would most likely have been able to survive and proliferate across the planet as they have
somewhat of a cheat code built into their DNA. Other animals would also be totally fine and
could repopulate their entire species after getting off the ark. Many lizards and insects
have the ability to reproduce asexually. What this means is that when two asexually
reproducing organisms step off of the Ark, they could go their separate ways and start
reproducing on their own. Their offspring would do the same, and before you knew it, the entire
planet would be swarming with lizards and insects. The downside to asexual reproduction
is that the genetic diversity of these species would be incredibly low. However,
the ability to reproduce quickly could mean that these species may end up creating
offspring with beneficial mutations. This could help the species survive
better in their environment. So the question is: how many
of each species would Noah need to put on the Ark in order
to repopulate the world? In the game of life, the magic numbers are 50 and
500. In order to avoid the problems of inbreeding and reduce the number of genetic disorders
from a build-up of harmful recessive genes, there needs to be at least 50 individuals
in a population. Therefore, Noah needed to round up 50 of every species, not just
two of every species. This probably would have taken a very long time, so hopefully, he
would get some help for the big guy upstairs. Unfortunately, there is some bad news for Noah.
The 50 individuals would make it possible for the animals to breed without the risk of harmful
genes killing off the entire species. However, this number would not be enough to ensure
a population would be able to adapt to environmental change. Basically, 50 individuals
are needed to save them from themselves, but many more are needed to save them
from the changes in the world around them. In order for a species to be able to survive
long term in the wild a minimum number of 500 individuals is required. The optimal percentage
of males to females would not be 50/50, but closer to 75/25 with the majority being
females. This is because in terms of reproduction, females tend to be much more important than males.
A male can impregnate multiple females, but the females of the species must bring the offspring
to term. They also have much more invested in the offspring and can only get pregnant
when they are not already carrying a baby. But the main reason there needs to be 500
individuals in a species to ensure success in the wild is because they must have a large amount
of variation in an ever-changing environment. With 500 unique individuals containing a plethora
of different traits and gene combinations, the species could continue to grow in numbers
while not losing their evolutionary potential. This would be the minimum number
of individuals for each species on the Ark in order for it to be
successful in restarting the world. It is also worth mentioning that in the Noah’s
Ark scenario all marine animals would have been fine. It would just be another day in the
ocean for them. Perhaps after the great flood, the new world would have been repopulated
similarly to how land animals first came about on our planet. Over millions of years,
fish would slowly make their way out of the oceans onto the land. Therefore, even if all
of the animals on Noah’s Ark died due to low genetic diversity and the proliferation
of harmful genes, life would continue on. Could Noah’s Ark actually have
restarted the world? It could have, except it would be a very different world
than we have today. There would be no humans, and there would likely be no mammals at all
because of the reasons mentioned before. Another more practical matter needs to
be addressed when examining if Noah’s Ark could have restarted the world.
Could the boat have even held two of every animal on the planet? And if so,
would the Ark have been able to float? The answers to these questions are shocking. Using the Bible as a reference guide, a group
of young scientists from the University of Leicester utilized modeling programs and
calculations to figure out whether Noah’s Ark would have been able to hold two of every
animal and float. According to the Bible, the Ark was built to be 300 cubits long, 50
cubits wide, and 30 cubits high. Since a cubit is a measurement from the fingers to the elbow,
these dimensions are up to some interpretation. The scientists took an average and concluded a
cubit would be approximately 48.2 centimeters. This meant that the Ark would have been
about 144.6 meters long, 24.1 meters wide, and 14.46 meters high, which is about the size
of a small cargo ship. The Bible says it was made out of Gopher wood which is hypothesized
to be similar to pine, cedar, or cypress trees. As long as a master craftsman had the time to plan
and the help of many people to build the vessel, it seems possible the Ark could have been
constructed using the dimensions in the Bible. But would a ship that size actually
fit two of every animal on the planet? This was another problem that was
solved by crunching some numbers. Animals vary widely in size and weight.
Luckily, aquatic animals didn’t need to be put on the Ark as two blue whales
would just end up sinking the ship. There are around 1.7 million
species on the planet today. Although some scientists argue the number is
much higher. But for the sake of argument, we are going to assume that Noah only needed to
fit around 1.7 million species onto his craft. The researchers determined that since huge animals
like elephants and rhinos would be offset by creatures like mice and lizards that an average
size animal would be the best to use for their calculation. It was decided that the average
size and weight of a goat would be adequate. This means that the Ark would need to be able
to hold approximately 3.4 million goats. So, is the Ark the Noah built capable of such a feat? According to the researchers’ calculations,
the Ark would weigh around 2,600,000 pounds or just over 1,300 tons. The surface area of the
Ark would give it a decent amount of buoyancy, only causing the hull to sink about a
foot into the saltwater of the oceans. So, using the dimensions of the Ark from the
Bible would create a ship that could float, but what would happen if you
loaded all of the animals onto it? It is argued that although there are
millions of species, many are aquatic, and Noah could have gotten away with only putting
one pair of animals from closely related species onto the ark. For example, since practically any
two species of wolf—or dogs for that matter—can interbreed, Noah would only need to put two on
the ark instead of the hundreds of variations. When you take away the closely
related species, aquatic animals, and microbes—which were probably not rounded
up to be put on the Ark—the number of animals would be around 50,000. If you consider the
average size and weight of 50,000 sheep, the Ark is a viable option for keeping
the animals afloat during the great flood. However, the amount of food and water that would
also need to be included on the ship for 40 days and 40 nights, would most likely put the Ark
over its weight limit and cause it to sink. Also, to be fair, even if God was angry it is
hard to believe he wouldn’t want to save both African and Asian elephants or all the
different species of cute bunnies. So, the number of animals on the ark would
probably be in the hundreds of thousands, which would be way too much
weight for the ship to handle. What is important to take away from the
Noah’s Ark story as told in Genesis is that it may have worked as long as
the number of animals was kept down. However, once they got off the ark and started
to reproduce, the lack of genetic diversity and mating options would almost immediately
cause the entire species to go extinct. So, when it comes down to it, science
says Noah’s Ark would not have been able to restart the world after all land
plants and animals were wiped out. But that is the thing about faith and religion.
An all-powerful God can do anything he, or she, wants. So, perhaps due to a series of miracles,
the animals on Noah’s Ark defied biology and repopulated the planet like
it is described in Genesis. But, the story of Noah’s Ark is likely just meant
to be poetic, not to be taken literally. The human species can learn a lot from
examining what needs to be changed in the Noah’s Ark story for our own future. Our
planet is quickly becoming overpopulated, and with climate change causing natural disasters
to happen more and more frequently, along with sea levels rising, it might be a real possibility
that animals will need to be relocated via ship. This might take the form of moving polar
bears into different parts of the arctic where the ice is thicker. Or maybe as coastal
environments are destroyed by intense hurricanes, species who are in danger of being
washed away will be brought further away from the equator to more stable ecosystems. These types of relocation strategies will require
a big vessel, perhaps something like Noah’s Ark, to move large numbers of animals to safety.
But there may be even more important reasons for understanding the mistakes that Noah
made when trying to restart the world. If we need to abandon the planet because of a
global catastrophe such as a runaway greenhouse effect or a gigantic asteroid that cannot be
deflected, we may need to know how to restart somewhere else. In this case, the Ark might be a
spaceship carrying plants, animals, and humans to the stars to colonize a new planet. Obviously, the
type of ship required will not be made of wood and will not need to float, but will need to travel
millions of miles through the vastness of space. If we don’t bring the right number of
animals to restart the world properly, then all would be lost. Humans will
need to figure out a way to build a space ark that could transport at
least 500 individuals of each species if we are to follow the advice of
scientists on how to restart a population. Luckily we may not need to bring 500 whole
blue whales, buffalos, and sequoia trees, but instead, we might be able to just carry
along 500 different genomes of every species, which is much more manageable. The way
that the biotech industry is headed the future of an Ark like Noah’s will
be based around saving a variety of DNA and then growing the animals in a
lab once we get to our final destination. Noah’s Ark would have been surprisingly successful
at saving and storing the animals of the world during the Great Flood. But without understanding
the science behind genetics and evolution, Noah’s plan to only bring two of each
species would have ended in disaster, as the world could not have been restarted
with so few individuals. Then again, maybe Noah had help from additional
shipbuilders and there were 250 other Arks with two of each animal on them;
then his plan could actually have worked. Now watch “This is How the World Ends.” Or check
out “Could 2 People Actually Repopulate Earth.”
