Unit 5 Evolution

Biological Evolution All of the changes that have transformed life on Earth from the earliest beginnings to the diversity of organisms in the world today

Microevolution Change in a single, small population

Macroevolution Change in many large populations

Natural Selection States that the organisms that are fit to adapt to a changing environment will survive and pass those traits on to their offspring; but the organisms that cannot adapt will die

Overproduction of Offspring When too many offspring are produced that the environment will support

Variation A change in the offspring that is different from the parents

Inherited Traits Traits that are passed down from the parents to the offspring

Adaptation When organisms change to survive in an environment

Fitness Desired traits that allow the organism to survive

Survival of the Fittest Natural Selection that states that the organism that can adapt to a changing environment will survive and others will die

Descent with Modification When acquired traits are passed down to offspring

Species Organisms that are similar and can interbreed with one another

Gene Pool All genes in a population

Genetic Variability When a new generation results in individuals with unique genotypes and phenotypes

Genetic Drift The random change in the frequency of alleles of a population over time

Gene Flow The movement of genes into or out of a population

Non-Random Mating When mates are selected from a specific group within the species

Genetic Equilibrium (Hardy-Weinberg Principle) When there is no change in the allele frequencies within a species

Speciation The process of forming a new species by biological evolution from a preexisting species

Patterns of Evolution Describes the changes in evolution

Gradualism Gradual changes of a species in a particular way over long periods of time

Punctuated Equilibrium Periods of abrupt changes in a species after long periods of little change within the species over time, such as sudden change in species size or shape due to environmental factors

Adaptive Radiation/divergent Evolution When a number of different species split-off from a common ancestor

Convergent Evolution Evolution among different groups of organisms living in similar environments produces species that are similar in appearance and behavior (analogous structures)

Coevolution When two or more species living in close proximity change in response to each other

Gradual Extinction Extinction that occurs at a slow rate and may be due to other organisms, changes in climate, or natural disasters

Mass Extinction Extinction that occurs when a catastrophic event changes the environment very suddenly (such as a massive volcanic eruption, or a meteor hitting the earth causing massive climatic changes)

Anatomy The study of the structures of organisms

Homologous Structures Similar characteristics resulting from common ancestry

Vestigial Organs Structures with little or no function to the organism that are remnants of structures that had important functions in ancestors of the species

Embryology The study of the embryonic development of organisms

Biochemistry The study of the chemical processes in organisms

Paleontology The study of prehistoric life

Phylogeny Evolutionary history of a species or a group of related species

Convergence Structures that become more similar with time, which occurs when organisms with different evolutionary histories adapt to similar environments

Evolutionary Data Information derived from studying prehistoric remains

Transitional Fossils Fossils that show links in traits between groups of organisms and used to document intermediate stages in the evolution of a species

Phylogenetic Tree A scientific diagram that biologists use to represent the evolutionary history of organisms

Taxa Groups that are based on evolutionary relationships