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55 Cards in this Set

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alterations in the organism’s genotype (by mutation) which result in slight changes in the organism’s phenotype
Scala Natura
ladder of nature
Charles Darwin
most associated with “theory” of evolution
Alfred Wallace
living things were not “immutable” but could change and even evolve into new species
Jean Lamarck
environmental pressure and internal needs could bring about characteristics in a process called Evolution by “Acquired” Characteristics
Acquired Characteristics
permanent structural or functional changes in an animal or plant due to their environmental pressures and internal needs
Evolution which results in new varieties of the same species
a change in gene frequency
2 factors necessary for Evolution
mutation and environment that favors the mutation
Natural Selection
a process where features or traits which impart a survival advantage are selected by the environment, Darwin’s theory
Competitive Advantage
those who can survive and reproduce to pass on desireable traits to their offspring as a result of differences in phenotypes.
variation in certain features (structural, morphological, physiological, behavioral)
Cambrian Explosion
a mutation that occurred 540 million years ago resulting in an entirely new gene so that the animal possessing it contained a new protein in which bonded “loosely” with oxygen and carbon dioxide.
Stabilizing Selection
Selection pressure which favors the intermediate form of gene trait and eliminates the extremes
Disruptive Selection
Natural selection which favors the extremes and not the intermediate forms
Directional Selection
Selection that changes the frequency of an allele in a constant direction, either toward or away from fixation for that allele.
Sexual Selection
a trait possessed by the most “fit” individual that made it most “attractive” to the opposite sex
where a living thing is found and what it does there
Gene Flow
Flow of genetic information within and between species, transfer of genes from one population to another
Genetic Drift
Changes in gene frequencies caused by separation of a small group from a larger population
Reproductive Isolation
a process where speciation occurs and breeding cannot occur as a result of the sub-population evolving through enough genetic change
Founder Effect
Genetic differences between populations, genetically different individuals established the populations
Bottleneck Effect
a form of genetic drift that occurs when a population is drastically reduced in size.
Gene Pool
all the genes in a breeding population
The development of one or more species from an existing species.
Allopatric Speciation
The type of speciation that occurs when a sub-population is physically separated from the parent population
Sympatric Speciation
Speciation that occurs when there are no physical barriers
Evolutionary process that increases differences in initially similar organisms
Adaptive Radiation
process where one species gives rise to many species
Darwin’s belief where evolution occurred at slow, steady rate
Punctuated Equilibrium
belief that evolution can occur in rapid bursts
The evolution that occurs within a branch
evolution resulting from splits or divergences of branches
determines the evolutionary relationships of living things based on derived similarities. It forms the basis for most modern systems of classification, which seek to group organisms by evolutionary relationships
evolutionary relationship between organisms
the ceasing of existence of a species or group of taxons
Extinction Event
when the line or branch of a species suddenly terminates
K-T Extinction
a period of massive extinction of species, about 65.5 million years ago. corresponds to the end of the Cretaceous Period and the beginning of the Tertiary Period.
“Big Dying”
95% of all species became extinct at the end of the Permian Period
The process of identifying and sorting out the many lines of descent that connect all species
Fossil Record
the totality of artifacts and their placement in rock formations
This similarity between one or more body parts in different animals that descent from a common ancestor
Unrelated structures which serve the same purpose and/or look related
Morphological Divergence
process in homology where the structure modifies and, under different environmental selection pressures, evolves into something (wing, flipper, etc.)
Morphological Convergence
the evolution of basically dissimilar structures to serve a common function.
Molecular Clocks
process where the rate at which mutations occur within DNA, are used to determine when certain evolutionary events occurred
Mitochondrial Eve
determination where the likely point of origin of humans was one woman from East, central Africa
Hox Genes
groups of genes that occurred in an evolutionary jump from similar, related species to an entirely different class of organism as a result of repetitive mutations
a field of biology that compares the developmental processes of different animals in an attempt to determine the ancestral relationship between organisms and how developmental processes evolved
Number and variety of living organisms; includes genetic diversity, species diversity, and ecological diversity.
Age of Earth
4.55 billion years old
First Life
bacteria-like life identified in rocks from 3.5 billion years ago
Photosynthesizing - O2 releasing cells that appeared in fossils approx. 3.5 billion years ago as filamentous cyanobacteria, pumped large quantities of O2 into the atmosphere
the supposition that there is design, purpose, directive principle, or finality in the works and processes of nature, and the philosophical study of that purpose.
Intelligent Design
certain features of the universe and of living things are best explained by an intelligent designer, rather than an undirected process such as natural selection.