Sunday, October 21, 2007

Population Growth

Hey Period 8+9, this is what Friday’s lesson was all about:

Basically what we were learning dealt with growth of populations on Earth and the effect population growths have on our planet. First, we dealt with what is called the Logistic rate of growth in which we learned that population, which can grow exponentially cannot always continue to grow because it is impossible. For example, if you refer back to the graph (which showed exponential growth) on the PowerPoint slide from Friday, (K) is the variable that stands for the Carrying Capacity of nature, while the other variable is (N), which stands for the number of individuals in a population. As one variable approaches the other, preferably (N) to (K) the effects of natural controls put its foot down and tries to alter this course. Without any natural control, the population would keep growing at an exponential rate and go over (K)’s limit. This would be an enormous problem in nature and on the ecosystem because the resources of that area are sure to run out do to its constant usage from the large population. Luckily nature always takes action in some way or form.

Now, going back to Carrying Capacity. (K) is the maximum size of a population that nature is able to support without reducing the quality or degrading the habitat. The Carrying Capacity can be altered with changes in resources of an environment. Again going back to the graph from PowerPoint, we see that the plankton population, after an exponential growth, decreases at a certain point because the organism overshot the Carrying Capacity. Now before, I said that changes in the resources in the environment varies the Carrying Capacity. One such example is the population cycles or Predator – Prey interactions. Referring back to the slide with the Snowshoe Hare and the Lynx, years that Hare populations are high (probably a warmer winter where grass is an available food source), the lynx population also high.

Next we learned about Human Population growth on Earth. For example the slide that dealt with the population growth of humans shows that advances of science, technology and industry are what led to an increase in the human population after the Bubonic Plague in the 1400’s. Also, in 2005, there are over 6 Billion people on Earth and that 82 Million people are being born each year. China and India having enormous populations, (1.3 Million People and 1.1 Million People). Could Humans be reaching Carrying Capacity? I truly believe so.

So what has been causing this sharp population increase? Well, countries that are still developing seem to have a higher fertility rate than that of developed countries (90% of births are in these developing countries). Also that the populations in these developing countries can either have a high, medium or low fertility rate in the future. Low fertility would be a better idea that having a medium or high fertility because we really don’t know what (K) is for the Human race, maybe 10 Million, maybe 15. A major factor that could aid in a better future for the world would be the education and income of people. If people were more educated and had more money problems like this wouldn’t happen. This could ultimately effect fertility rates and lead to a much lower population scenario in the years to come, benefiting Planet Earth.

Humans leave an ecological footprint. I feel that Humans are over-consuming resources on Earth and that we are destroying it as well. In the slide referring to Ecological footprints, the US uses so much land to support its population while India, whose population is much larger uses lesser land. The World is located on the deficit rather than the benefit side of its ecological footprint (which is a very bad thing people!), as well as our own nation because more wastes are being created from the consumption of resources such as land and water.

In the end, that’s pretty much all we learned on Friday. I think the Human race is heading onto a rough patch in the future. The Sherpa for Monday night will be Tom, (Your Welcome Tom). So that’s it, alright guys, Goodnight.
P.S, Sorry if its too Short or there arent enough pictures and such, I couldnt really find anything that could help illustrate the lesson. Sorry! :-)

1 comment:

Russ said...

The narrated slide show at might be of interest. It addresses human population growth, dynamic underpinnings, and ecological impact.