"what evidence exists that some of the asteroids were geologically active in the distant past"

The geological activity of a celestial body like a planet, satellite or asteroid can be determined by looking at the surface features like the presence of a valley like terrain or plains or basins created by the lava flow. The presence of heavy elements like uranium, lead, iron and gold on the surface also indicate that the body once spewed out lava since these are found within the internal core of the body. Ceres, an asteroid has these elements present on its surface which hints at the presence of an active geological process in the past.

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.

explanation:

the universal gravitation equation. since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. if the mass of one of the objects is doubled, then the force of gravity between them is doubled.