Unit A Section 2.1 Flashcards
Can all variation be seen:
No, some variation cannot be seen with a bare eye.
For example, humans have different blood types
Some jack pines can resist drought more than other jack pines.
How do scientist understand variation:
scientists may explore which characteristics species pass along from generation to generation, and how these characteristics show up in individuals.
Also, examine the role of the environment in variation.
Heritable characteristics
are passed on from generation to generation
ex. eye color, height, skin color
Non-heritable characteristics
they are not passed on to other generations.
ex. piano skills and some disease or scars
What are the two types of variations
Discrete and Continuous
Discrete variation
refers to differences in characteristics that have a defined form. You can think of discrete variation as being the “either/or” form of a characteristic
Continuous variation
refers to differences in characteristics that have a range of forms. They are not one form or another. For example, the height of adult humans can range from 1.2 m to 2.1 m. In squirrels, mass can range anywhere between 133 g and 249 g.
Can variation also result from interactions
Yes.
Some variations in individual organisms result from interactions with the environment.
Height is a heritable characteristic. But height can be affected by diet