Evolution Study Guide

Evolution

The process through which species change over time through variations in traits, driven by mechanisms such as natural selection, genetic drift, and mutation.

Homology

Refers to the similarity in structure or genetic makeup between different species due to shared ancestry.

Paleontology

The scientific study of the history of life on Earth through the examination of fossilized remains.

Fossil Record

Coverage of gradual changes in species over time, documenting transitional forms that highlight evolutionary pathways.

Comparative Anatomy

The study of similarity and differences in the anatomy of different species, indicating evolutionary relationships.

Genetics

The branch of biology that studies heredity and variation in organisms, revealing relationships between species.

Biogeography

The study of the geographic distribution of species, supporting evolution through patterns of isolation and adaptation.

Direct Observation

Instances of rapid evolution observed in real-time, such as antibiotic resistance in bacteria.

Embryology

The study of the development of embryos, showing similarities that indicate common ancestry among different organisms.

Molecular Biology

The study of the molecular basis of biological activity, including patterns of similarity in proteins and genes between species.

Natural Selection

The process in evolutionary biology where organisms better adapted to their environment tend to survive and produce more offspring.

Directional Selection

A type of natural selection that favors one extreme phenotype over others, causing a shift in a population's trait distribution.

Stabilizing Selection

A type of natural selection that favors intermediate phenotypes and reduces variation in a trait.

Disruptive Selection

A type of natural selection that favors extreme phenotypes over intermediate phenotypes, potentially leading to speciation.

Artificial Selection

The process by which humans intentionally breed plants or animals for specific traits.

Sexual Selection

A form of natural selection where individuals with certain traits are more likely to attract mates and reproduce.

Convergence

The process where unrelated organisms develop similar traits or adaptations due to similar environmental pressures.

Analogous Structures

Traits that arise from convergent evolution, serving similar functions but having different evolutionary origins.

Genes

Segments of DNA that encode instructions for building proteins and determining traits.

Chromosomes

Structures made of DNA and proteins that carry genetic information, with humans having 23 pairs.

Meiosis

The process of cell division that reduces chromosome numbers by half to form gametes.

Mutation

A change in the DNA sequence of an organism's genome that can lead to new traits.

Gene Flow

The transfer of genetic material between populations through the movement of individuals or their gametes.

Genetic Drift

Random changes in allele frequencies in a population, especially in small populations, due to chance events.

Bottleneck Effect

A significant reduction in population size due to an event, resulting in a loss of genetic diversity.

Founder Effect

When a small group of individuals establishes a new population, influencing future gene pool.

Binomial Nomenclature

The formal system of naming species, consisting of a two-part name (genus and species).

Taxonomic Hierarchy

A hierarchical classification system used to organize living organisms based on shared characteristics.

Encephalization Factor (EF)

A measure used to estimate the relative brain size compared to what would be expected for an animal of a given body size.

Protracted Development

The extended period of brain maturation occurring in humans compared to other primates.

Social Brain Hypothesis

The idea that a larger cortex is necessary to manage complex social relationships.

What are the main stages of evolution and how do they occur in a sequential order?

The main stages of evolution include variation, natural selection, adaptation, and speciation. These occur in the following order: 1. Variation arises within a population. 2. Natural selection acts on the variations. 3. Adaptations develop over time. 4. Speciation occurs when populations diverge significantly.

What processes contribute to genetic variation in populations, and what is the order of their significance?

The processes contributing to genetic variation include: 1. Mutation (introduces new alleles), 2. Gene flow (adds genetic material from other populations), 3. Genetic drift (random changes, especially in small populations), 4. Sexual reproduction (combines alleles in new ways).

Describe the processes of natural selection and their effects in sequential terms. What are the types?

Natural selection occurs in the following steps: 1. Variation exists within a population. 2. Some variations are advantageous for survival and reproduction. 3. Individuals with advantageous traits are more likely to reproduce. 4. Over time, these advantageous traits become more common in the population. The types of natural selection include directional selection, stabilizing selection, and disruptive selection.

How does the fossil record document evolutionary history, and what are the key steps involved in its formation?

The fossil record documents evolutionary history through: 1. Organisms' remains being preserved in rocks. 2. Evidence of gradual changes through layers of sediment. 3. Discovery of transitional forms indicating speciation over time. 4. Analysis by paleontologists to establish evolutionary relationships and timelines.

What is the taxonomic hierarchy and how does it classify organisms in a systematic order?

The taxonomic hierarchy classifies organisms in the following order: Domain > Kingdom > Phylum > Class > Order > Family > Genus > Species. Each level represents increasingly specific classifications, allowing scientists to organize and study biodiversity.