Table 3.
Categories of misconceptions, student quotes, and the frequency with which students employed these misconceptionsa
| Misconceptions | Student quotes | % of Total (n = 244) | % Before instructionb (n = 85) | % After instructionb (n = 122) | % Upper divisionc (n = 37) |
|---|---|---|---|---|---|
| Novice Genetics | 12.7 | 22.4 | 9.0 | 5.4 | |
| Genetic drift is… | |||||
| shared traits or genes. | “Genetic drift [is] when it's the same species but different characteristics.” | 7.4 | 14.1 | 4.9 | 0.0 |
| “Genetic drift because both species [have] distinctive commonalities.” | |||||
| gradual genetic change in a population. | “Genetic drift is where the amount of present alleles change[s] gradually over time.” | 4.1 | 5.9 | 3.3 | 5.4 |
| “Genetic drift is a change in genes over time.” | |||||
| when genes or traits are passed from one individual to another. | “Genetic drift is the passing down of traits while natural selection does not have anything to do with genetics.” | 1.2 | 2.4 | 0.8 | 0.0 |
| Novice Evolution | 20.9 | 31.8 | 14.7 | 13.5 | |
| Genetic drift is… | |||||
| acclimation to the environment that may result from a need to survive. | “It was probably genetic drift. As the butterflies adapted to their new habitat they had to physically change in order for survival.” | 15.6 | 25.9 | 11.5 | 2.7 |
| “The evolution of the two butterflies is genetic drift because they developed to their surroundings.” | |||||
| change resulting from mating between individuals from different species. | “[Genetic drift occurred when] certain butterflies with each gene and characteristics came together in a certain spot and they mated forming new types of butterflies.” | 4.5 | 5.9 | 1.6 | 10.8 |
| when natural selection cannot or is not occurring. | “[Genetic drift is] the genetic changes that occur when a population is not under selection.” | 0.8 | 0.0 | 1.6 | 0.0 |
| Associating Genetic Drift with Other Evolutionary Mechanisms | 18.8 | 13.0 | 13.1 | 48.6 | |
| Genetic drift is… | |||||
| random mutation. | “[Genetic drift occurs when] due to random mutations, genetic structure can change over time.” | 7.4 | 4.7 | 5.7 | 18.9 |
| “The definition of genetic drift is random chance mutation.” | |||||
| gene flow. | “The movement of genes from one population of a species to another or from one locality to another.” | 5.7 | 7.1 | 4.1 | 8.1 |
| “Genetic drift is a chance occurrence that brings genes into a population.” | |||||
| natural selection. | “Genetic drift occurs to eliminate the less adaptable trait that is not well suitable to the environment.” | 4.5 | 1.2 | 2.5 | 13.5 |
| any change in allele frequencies. | “[Genetic drift is] the process of changing allele frequencies within a population.” | 1.2 | 0.0 | 0.8 | 8.1 |
| Associating Genetic Drift with Population Boundaries | 32.8 | 33.0 | 36.1 | 21.6 | |
| Genetic drift is… | |||||
| migration with or without acclimation to the environment. | “Genetic drift is when the population moves to a location more suitable to its characteristics.” | 14.8 | 16.5 | 15.6 | 8.1 |
| “[Genetic drift occurred] as certain ancestral butterflies moved to different areas, they changed to better suit their new environment.” | |||||
| the separation of populations with or without acclimation to the environment. | “[Genetic drift occurs due to] isolation of a population or species by whatever means.” | 10.2 | 9.4 | 10.7 | 10.8 |
| “Genetic drift occurs when a sect of a species is separated from the other and changes to adapt to their new environment.” | |||||
| speciation. | “I believe [it was genetic drift] because I believe at one point both species were one, then separated.” | 7.8 | 7.1 | 9.8 | 2.7 |
| “It was genetic drift because some genes changed to create this new species.” | |||||
| Developing Genetic Drift Comprehension | 8.6 | 0.0 | 12.3 | 18.9 | |
| Genetic drift is… | |||||
| a change in genes caused by an isolated event, often a catastrophe. | “Genetic drift involves a natural disaster that dramatically changes the genes in that area.” | 4.5 | 0.0 | 8.2 | 2.7 |
| limited to small populations. | “Genetic drift is genetics in a smaller populations.” | 2.5 | 0.0 | 3.3 | 8.1 |
| when an allele is fixed in a population. | “This is when alleles from one population either die out or become the only allele present. It occurs because of random processes. The alleles just happen to die out or become the most prevalent because of chance.” | 1.6 | 0.0 | 0.8 | 8.1 |
aFrequencies are based on the subset of responses that addressed drift (n = 244), not the total number of responses (n = 356).
bResponses from the case study project.
cResponses from the concept inventory project.