Table 2 Evolutionary reasoning pattern: themes, definitions, and examples

Evolution term

Mention of evolution terms

Evolved, Darwin(ian), survival of the fittest, and common ancestor

VIST term

Mention of VIST terms

Variation, inheritance, selection, and time

Variation

Differences among individuals in a population

… a variant of the pre-existing algae; a sort-of-genetic uniqueness to the different fly variations

Inheritance

Traits (genes) are inherited and passed on to the next generation

(Diatom) so it simply carried on those traits as it split off or reproduced

Common descent

Reference to common ancestors (implication that they were a different species)

… the original algae were a type found in many other lakes …; it came from one fly; … originally the whale derived from a land animal or mammal

(Natural) selection

Organisms with adaptive traits are more likely to survive

(Whale) … because of the features that were selected that favored their ability to live on land

… those diatoms that had offspring that had characteristics that were more adapted to the new environment were more successful than those who did not

Time

There had to be enough time for Natural selection to occur

When you think of something happening over tens of millions of years, it’s kind of mind-boggling; … it changed over time

Sexual Selection

Any reference to sexual selection

The male flies evolved to have those things on their legs; (fly) some of the characteristics would have appealed to the girls

Ecological pressure

Mention of ecological pressures as a causal agent in diversification or change

… the algae responded to various climate changes; (fly) … because they were on different islands … the foods … the weather and stuff …