Muscle spasms is the answer i belive because you dont have the control
Http://blogs.discovermagazine.com/seriouslyscience/2015/01/29/pandas-ancestors-ditch-meat-bamboo/
According to this study, it may have had to do with the deactivation (technically known as “pseudogenization”) of an umami taste receptor gene. Umami is the taste that makes things like meat, soy sauce, and mushrooms extra yummy. Apparently, at some point in panda evolution, the umami receptor became non-functional. Based on how much the gene has changed, the authors calculate that this happened around the same time that pandas started eating bamboo. Whether it’s cause or effect is unclear, although the authors think the switch to bamboo may have happened before the gene was lost. Regardless, the loss of the gene reinforced the panda’s vegetarian diet because it made meat less delicious to the bears.
Sorry it's a lot but hope it's useful
Lithosphere (or geosphere) describes all the rocks, minerals and molten magma found on or in the Earth
The hydrosphere describes all the water on Earth – including liquid water (oceans, etc.) and vapour (precipitation)
The atmosphere describes the layer of gases surrounding the Earth and is divided into sections (stratosphere, etc.)
The biosphere is composed of all the living organisms on the planet (including plants, animals, bacteria, etc.)
The four spheres are interconnected, so human impact on one sphere will potentially effect other spheres
The release of plastic pollution into the oceans (hydrosphere) will impact on marine life (biosphere)
The production and release of CFCs into the atmosphere will effect the impact of UV radiation on the biosphere
The Four Earth Spheres
Answer:
That'll be a "Long term change".
Goodluck with your test! :)