First, a physical property just identifies it's state, how it looks, color, and that stuff. Let's work on finding that.
⇔ Ability to rust wouldn't work as a physical property. That one changes the substance, making it a chemical change. So, we know that this can certainly be our answer!
The most likely cause of the beak variation is the food source of the finch, the break size and shape was adapted to most likely have easier and better access to food. <span />
Answer: Immune system
Explanation:
Lymphocytes are a class of white blood cells (leukocytes) involved in immune response when activated by the a foreign molecule (an antigen). B lymphocytes develop in the bone marrow of mammals and are responsible for the production of circulating antibodies.
Thus, lymphocytes are associated with the immune system.
The correct answer is: "coevolution" .
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