The most obvious would be the Paradoxical Frog, Pseudis paradoxa, found in Trinidad and the Amazon. As a tadpole, it can be as long as 10 inches (25.4cm); but as an adult is only 2.4 inches (6cm). I can't think of any others, but I have no doubt some other contributor will know more!
yes
Food, space, and water
Food, space, and water most directly affect the amount of people a region can support over time.
Fossils Further evidence is derived from living organisms Bones
That depends on which period of time you are talking about - a lot of things changed over Rome's three millennia history.
An ice cube melting, a candle burning down, and a balloon deflating are examples of things that get smaller as time passes.
smaller and alot have died
Rocks erode from mainly wind and water over time.
Because the tooth become smaller we use it all the time
Paper, leaves, and tissues are some examples of items that disintegrate easily, breaking down quickly into smaller pieces or decomposing over time.
smaller quantities over time trust me im a 330 with 1780 mafia and 80 tnts
time is the answer