Equilibrium Introduction

Sooooo… to lesson your stress …. Story time … LISTEN ..pencils down

• Back in the fifties, people in a region of Borneo were having trouble with Malaria.

• In an attempt to save lives, the World Health Organization (WHO) decided to use DDT to kill off the mosquitoes that were known to transmit the disease

• The mosquito population was drastically reduced and the number of villagers contracting Malaria declined. …. Sounds good … right????

Once upon a time……

Side note on DDT……

• Over time, the thatched roofs of the villagers began to collapse as DDT killed a parasitic wasp that kept a thatch eating caterpillar in check.

• In addition, other insect eating organisms, geckoes, were affected as DDT moved through the food chain.

• Eventually the cats that kept the rat population in check also died. As the rat population increased so did the incidence of rat born illnesses, typhus and sylvatic plague (which are passed on by rats).

• Now the villagers were dying of other diseases in a town overrun by rats and no roofs over their heads.

• By now the cure had become worse than the initial disease, so the World Health Organization did what any self-respecting world health organization would do: they parachuted a bunch of live cats into Borneo.

• World Health Organization developed a plan they called Operation Cat Drop and parachuted live cats into the village to control the rat population to prevent the villagers from dying.

• The WHO had failed to consider the full implications of their actions on the delicate ecology of the region. Because they lacked understanding of the basic effects of DDT (now banned in the United States), such as the relationships among the animals of the area, they ended up making things worse rather than better - and a high cost was paid for this mistake.

• By considering only the straightforward, first-level relationship between mosquitoes as carriers of malaria and humans as recipients of malaria, the WHO unrealistically assumed that this relationship could be investigated or acted upon independently of any other variables or relationships. They considered one tiny aspect of the system, rather than the entire thing (the entire ecology).

Story time over…. Pick up those pencils … wipe off

the drool….

Basic vocab….

homeostasis Maintaining stable internal environment

Think …. STAY at HOME temperature