In this activity, you will research the genetic diversity in two fish variants. The Mexican tetra (Astyanax mexicanus) has two notable variations: the surface variety and the blind cave fish variety. In this activity, you’ll use credible websites to find the following information about these two fish: What type of habitat does each fish live in?

How do their physical characteristics differ?

How are they similar?

Can the two types mate with each other?

Why are their characteristics advantageous to their environments?

When you’ve found the information, answer the following questions.

Part A :

What are the similarities and differences between the two fish varieties?

Part B:

Do you think these fish are an example of natural selection among two populations of the same species? Explain your answer.

Part C:

Explain how the characteristics of the two types of fish relate to the genetic diversity of the species.