island effect: the remaining areas of habitat are seperated from each other to form "islands"
edge effect: edges suffer from the effects of sun, wind, temperature changes and intruders
geologists have confirmed how many meteorite impacts on earth?
Geologists have suspected how many meteorite impacts on earth?
in 1991, the 170 kilometer (100 mile) diameter Chicxulub crater in Yucatan, Mexico.
KT= Cretaceous-Tertiary mass extinction
5 kilometers/3 miles
ten million years