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Table 2 Coding rubric for the Dino Problem

From: Using Avida-ED for Teaching and Learning About Evolution in Undergraduate Introductory Biology Courses

 

Score

Principle

0

1—novice

2—expert

Variation within a population [V]

No mention or misconception

Variation between individuals is only described in one of the populations—trees or animalsa

There is a clear reference to the different phenotypes existing, at the same time, within the animal and the tree populations

Origin of variation [O]

No mention or misconception

Phenotypic differences are the result of “mutations”b

Variation within populations has genetic origin (is caused by random genetic mutation, resulting in different alleles)

Inheritance [I]

No mention or misconception

Traits are inherited by offspringc

The genes responsible for phenotypic traits are inherited by offspring

Fitness [F]

No mention or misconception

Individuals whose characteristics are favored by the environment are more likely to survived

Individuals whose characteristics are favored by the environment are likely to reproduce more and produce more viable offspring

Change in populations [P]

No mention or misconception

Populations change over time, and shift from a variety of phenotypes to selected phenotypes becoming predominant

Allele frequencies change in populations over time

  1. Possible alternative conceptions that would earn a score of zero for a given conceptual category: [V]—individual trees/animals become taller over time, there are no differences between individuals; [O]—organisms need or want to change/adapt in response to the environment, genes mutate in order to achieve a desirable phenotype, mutation is a consequence of the selective pressure posed by the environment; [I]—traits acquired during the lifetime of an individual are inherited; [F]—fitness refers to features other than survival and reproduction; [P]—change occurs in individuals (rather than in populations)
  2. aOften, students recognized the existence of variation among animals, but did not mention variation among trees, or simply said trees “grow taller over time” ([V] score = 1)
  3. bStudent responses earned only a score of one in the [O] category if they mentioned mutation, but their overall explanation did not convey a clear understanding that mutations occur in DNA/genes. Examples: “a long neck would be a mutation that took place within the organism” or “over time, mutations occurred in the trees, resulting in them becoming taller”
  4. cSome answers did not explicitly mention inheritance, but still earned a score of one because the idea of inheritance was implicit in the context of correct statements about both fitness (individuals with certain traits reproduce more) and change in the population (these traits become predominant in the population)
  5. dStudents often expressed the idea of differential survival as: “the short trees (or animals) die out,” implying survival of the tall ones
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Evolution: Education and Outreach

ISSN: 1936-6434

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