Darwin's idea of the survival of the fittest means that certain organisms are more likely to survive with they traits in particular environments. This is because some organisms are more fit to live in a given environment whether it be due to temperature, weather, or predators.
One example is that dark moths are more fit for survival than light moths in many areas because they are able to camouflage against dark tree bark.
Hope this helps.
Because it takes LOADS of feathers to make up 1kg and lead would be such a small amount, it could fit in a purse.
Many theories can never be proven.
Here are a few examples:
-- The moon orbits the Earth.
-- Gravity pulls all masses toward each other.
-- The Earth orbits the sun.
-- Everything is made of atoms and molecules.
-- Atoms are made of protons, neutrons, and electrons.
-- Electrons moving through a wire make electric current.
-- The center of the Earth is molten iron and nickel.
-- The source of the sun's energy is nuclear fusion in its core.
-- Almost all galaxies are moving away from us.
-- The universe is expanding.
None of these statements can be proven. That's why they're not called
Facts or Laws.
It also tells you that some pretty powerful stuff has been done with concepts
that can't be proven. If you want to make an idea look foolish, that doesn't
happen when you say "it's only a theory".
It is called the Milky Way because it appears as a milky band of light in the sky when you see it in a really dark area. Just as the Earth goes around the Sun, the Sun goes around the center of the Milky Way.
