Evolutionary Biology Lab
Evolutionary Biology Lab - Related Videos
07:32
Evolutionary Relationships - Student Protocol
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2019
Forming an Evolutionary Hypothesis ExpandNOTE: A cladogram is an important tool for forming an evolutionary hypothesis. A cladogram is a tree-shaped chart used to depict the hypothetical genealogical relationships between species. The tips or leaves of the chart represent specific species and the branches of the tree are different lengths. The different lengths represent the degree of change between each of the species. The common ancestor of all of the species that a specific line branches...
01:02
Evolutionary Relationships - Instructor Prep
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2019
Using BLAST to Test Evolutionary Hypotheses ExpandOpen the BLAST website on each computer that the students will be using. https://blast.ncbi.nlm.nih.gov/Blast.cgi Navigate to the provided link to find the chicken, alligator, and zebra finch gene sequences. https://github.com/EvolutionGenes/Evolutionary-Relationships-Genes NOTE: These gene sequences will be used as the living relative DNA samples for the mystery fossil. Click on the first sequence to familiarize yourself with it. Return to the...
05:21
Evolutionary Relationships - Concepts
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2019
Humans have been attempting to properly classify living things since Aristotle made the first attempt during the 4th century BC. Aristotle’s system was improved upon during the Renaissance and then, subsequently, by Carolus Linnaeus in the mid 1700’s. These more formal classification and organization systems grouped species by their physical similarity to one another. For example, all vertebrates have a backbone, but invertebrates do not. Traits like the backbone are called synapomorphies,...
02:35
What is Evolutionary History?
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2026
Scientists record evolutionary history by analyzing fossil, morphological, and genetic data. The fossil record documents the history of life on Earth and provides evidence for evolution. However, both fossil and living organisms offer evidence that outlines Earth’s evolutionary history.Phylogenetic trees illustrate the evolutionary relationships among these organisms. Scientists infer organisms’ common ancestry by evaluating shared morphological and genetic characteristics. Together, the fossil...
01:20
Evolutionary Psychology
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2024
Evolutionary psychology explores the origins of human behavior and mental processes by framing them within the context of natural selection, a theory famously propounded by Charles Darwin. This field asserts that many behaviors common across human societies — ranging from instinctive fear reactions to complex social interactions — arose as evolutionary adaptations. These adaptations enhanced the survival and reproductive success of our ancestors, thereby becoming embedded in the human psyche...
FAQs
Natural selection can be evaluated by tracking whether heritable traits are associated with different reproductive success across generations. If the representation of related alleles changes in the population data, the result provides measurable evidence of selection rather than merely documenting differences among individuals. Laboratory designs therefore connect observed traits, inheritance, reproduction, and changing allele frequencies.
These mechanisms provide different explanations for changes in allele frequencies. Mutation introduces genetic variation, genetic drift represents a population-level mechanism that can alter frequencies, and gene flow connects populations by moving genetic variation between them. Comparing these mechanisms helps investigators interpret whether observed evolutionary change reflects selection or another process.
A trait must be connected to inheritance for differences in reproductive success to contribute to evolutionary change across generations. Evolutionary Biology Lab investigations therefore examine genetic variation alongside trait measurements and population outcomes. This combination helps distinguish a temporary difference among organisms from a pattern that can persist through inheritance and influence allele frequencies.
Comparative analyses examine similarities and differences among organisms or their biological data to evaluate evolutionary relationships. In a laboratory context, these analyses complement direct population experiments by using patterns of variation to reconstruct relatedness. They are especially useful when investigators want to connect observed diversity with broader hypotheses about how lineages and biological traits changed over time.
Investigators may work with model organisms, population data, simulations, or comparative analyses, depending on the question and available evidence. A study can measure traits and reproductive outcomes, analyze changes in allele frequencies, or model evolutionary mechanisms. Selecting the approach requires matching the evidence collected to the mechanism or relationship being evaluated.
Useful evidence includes measurements of genetic variation, heritable traits, differential reproductive success, allele frequencies, population patterns, and comparative relationships. These data can be gathered from organisms, existing population information, or simulations. Analysis then tests how well the observed patterns support mechanisms such as natural selection, mutation, genetic drift, or gene flow.
The same experimental and analytical framework connects evolutionary biology with ecology, conservation, medicine, and genomics. Population measurements can help examine biological diversity, while comparative and genetic analyses provide context for relationships and change. These applications also strengthen practical skills in experimental design, data analysis, and scientific reasoning, which are central to interpreting biological evidence.