Species Variations and Brine Shrimp

Mr. Quick brought a bunch of "illegally gathered" shell and asked us to sort them. My group decided to sort them according to their shape. There are two kinds of shapes. Some of them are pointy, and others are flat. After that, Quick asked us to sort them in a different way, so we sort the shells according to their sizes. We had a pile of big ones, a pile of small ones and a pile of medium size ones.
The reason why each specie has so many variations is that it develops characteristics which enable itself to survive. Species develop different sizes, colors and shapes. Some of these mutations are positive, some are negative and some are neutral. All of the mutations that survived will be passed down to the next generation.

Now, about brine shrimp.

We prepared 0%, 0.5%, 1%, 1.5% and 2% salt water and put brine shrimp eggs into salt water.

We went back to count the number of brine shrimp that hatched after 24hrs and 48hrs. In the end, the hatching viability for 0% salt water is 0%, for 0.5% is 25.81%, for 1% is 11.11%, for 1.5% is 16% and for 2% is 39.39%.

(My lab partner)