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.”