New Twist On Population Growth.

 The other day, I read an article on some math students who took the time to figure out how long it would take for Tribbles to completely fill the Enterprise.

For those of you who have never watched the original Star Trek, people ended up visiting a place where a trader was selling these cute little purring creatures but a problem arose when Uhura brought one back to the ship.  The creature began reproducing so fast, it was born pregnant.  Soon, they were finding Tribbles all over the place including in the grain they were transporting to Sherman's Planet.  The only good thing about the situation was the tribbles died letting the captain know the grain had been poisoned and it helped them find the undercover Klingon agent who infiltrated the area.

These three undergraduates from the University of Leicester published the paper back in November 2018 in the Journal of Special Topics.  They used information from the television series which was given by Spock.  He stated that tribbles had liters of 10 offspring every 12 hours so they students used the equation -  NT = 11t/tr. to describe the growth of the tribbles where t represents the time spent breeding and tr is the time it takes to breed. After three days, there were 1,771,561 tribbles running all over the ship and within 4.5 days before the tribbles filled the ship from top to bottom, stem to stern.

The reason the tribbles grew so rapidly was they had been removed from their natural environment so they no longer had any predators to curb their growth.  Consequently, they had nothing to slow down their growth.  This is similar to at least two other situations people has experienced in real life.

1.  Australia did not have any rabbits until they were brought over in 1788 by the First Fleet.  The First Fleet released 24 wild European rabbits into the countryside in Victoria so they could hunt rabbits just like they did in Europe.  These 24 rabbits reproduces so well that by 1900, rabbits had made it to pretty much every place in Australia, including Western Australia.

In fact, the Australian government built three rabbit proof fences around the country but they were too late to stop the animals expansion.  It is estimated the rabbit population in the 1920's had reached 10 billion creatures.  Consequently, the government began using other methods from poisoning, to hunting, to releasing a virus to eliminate rabbits but it was not fully successful. The rabbit population is estimated at 200 million in 2018.

Currently, rabbits compete with livestock for pastures, with farmers for produce, and these wild rabbits are damaging the environment.  Another species showing a huge increase is the White Tailed Deer in the United States.

Back in the 1930's the White Tailed deer had an estimated population of 300,000 but since then it is estimated the population is estimated to be around 30 million.  This has occurred for several reasons but one major one is their enemies such as wolves, grizzlies, and cougars have disappeared so the young, sick, and old are no longer dying and live out to a ripe old age.  Then it has been found that as forests are cut down, this helps the deer because they do well in edge type areas.  These are the places between freeways, newly planted lawns, areas around airports, etc.

In addition, the number of animals being killed by hunters is decreasing due to the decrease of hunters.  It is estimated that 6 million deer were killed in 2014 but in ideal situations, the deer population will double every year.  They also compete with farmers for produce, destroy landscaped yards, and cause accidents when they step into the road.

These are three examples of real life population growth where the components that keep the numbers under control go away and allow for explosive growth.  There is enough information to have students determine rates of growth for all three groups.  Let me know what you think, I'd love to hear.  Have a great day.