Lab Exam Study Guide - Evolution and Genetics

These flashcards cover key concepts from the lab exam study guide, including topics on population genetics, evolutionary mechanisms, and species definitions.

What is allele frequency?

The proportion of a particular allele in a population.

What formula is used to calculate allele frequency?

p = number of copies of allele A / total number of alleles.

What is genotypic frequency?

The proportion of individuals with a particular genotype in a population.

List the three possible genotypes for a gene with two alleles A and a.

AAAA (homozygous dominant), Aa (heterozygous), aaaa (homozygous recessive).

What is the Hardy-Weinberg equilibrium?

A model for population genetics stating allele and genotype frequencies remain constant unless influenced by evolutionary forces.

Name one assumption of the Hardy-Weinberg principle.

No mutation, no genetic drift, large population, random mating, and no selection.

What is genetic drift?

Random changes in allele frequencies, particularly in small populations.

How does natural selection contribute to evolution?

Individuals with advantageous traits are more likely to survive and reproduce.

Define microevolution.

Small-scale evolutionary changes within a population or species, observable over generations.

What is a gene pool?

The complete set of genetic material (alleles) available in a population.

What is a biological species according to the Biological Species Concept?

A group of organisms that can interbreed and produce fertile offspring under natural conditions.

What does the phylogenetic species concept focus on?

Evolutionary history and unique genetic markers of organisms.

What is hybridization in terms of species?

The interbreeding of individuals from different species or populations.

Define a monophyletic group.

A group that includes a common ancestor and all descendants.

Name one benefit of genetic diversity in species conservation.

Increased resilience to environmental stressors.

What is the critical value in hypothesis testing?

The threshold against which the calculated value is compared to determine if the null hypothesis should be rejected.

What is taxis?

Directed movement of an organism toward or away from a stimulus.

What does kinesis refer to?

Non-directional random movement of an organism in response to a stimulus.

What are the defining characteristics of Phylum Arthropoda?

Bilateral symmetry, segmented bodies, exoskeleton made of chitin, jointed appendages.

Give an example of a coelomate organism.

Humans.

What is the significance of the null hypothesis?

It is a statement that suggests there is no effect or difference, which researchers attempt to test and reject.

Phylogenetics

The study of evolutionary relationships among species or groups of organisms.

Cladistics

A method used in phylogenetic analysis that groups organisms based on shared derived characteristics to define evolutionary relationships.

Phylogeny

The evolutionary history and relationships of an organism or group of organisms.

Apomorphy

A derived trait or feature that is different from the ancestral state

Synapomorphy 

A shared derived trait that is present in two or more taxa and their most recent common ancestor

Plesiomorphy

An ancestral trait that is present in the common ancestor of a group but is not unique to that group.

Symplesiomorphy

A shared ancestral trait between two or more taxa that is inherited from a distant ancestor.

Parsimony

In phylogenetics,____ the principle that the simplest explanation, with the fewest evolutionary changes, is the most likely.

Paraphyletic

A group that includes a common ancestor but not all of its descendants.

Polyphyletic

A group that includes organisms from different evolutionary lines but does not include their common ancestor

Homology

The similarity between traits due to shared ancestry

Homoplasy 

The similarity between traits due to independent evolution (think convergent evolution)