Theme | Operational definition | Examples—current study |
---|---|---|
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 … |