Show relations among organisms
An example of a long food chain from the animal world. . .
Here's a simplified food chain with six links. You could add humans on to the end if you apply us to the term 'animal world' too.
Phytoplankton
The changing of the structure of a gene
The gravitational forces are what pull the interstellar dust and gas to form a protostar. The gravity force is strong enough to hold the dusts together to form clouds which later become big enough to be called protostars. However there are some clouds that are too small to become clouds and are called brown dwarfs.