Units 5 & 6 Flashcards
Scientists & Vocabulary
R.A. Fisher
- British statistician published a paper that established the field of population genetics.
- formed the basis of what came to be called the Modern Evolutionary Synthesis (along with Sewall Wright and J.B.S. Haldane)
Theodosius Dobzhansky
published “Genetics and the Origin of Species”, summarizing developments from the Modern Synthesis and bringing together the new field of genetics and Darwin’s natural selection into a coherent whole
Peter and Mary Grant
husband and wife researchers who demonstrated evolution in one population of finches on one of the Galapagos Islands
Niles Eldridge and Stephen Gould
“punctuated equilibrium” — proposed that jumps in fossil records are normal (more common than Darwin’s phyletic gradualism)
Willi Hennig
devised a more rigorous methodology to deal with the problem of convergence (developed cladistics)
Richard Dawkins
- “the selfish gene” (1976)
- coined “designed” (falcons are “designed” for high-speed flight) after William Paley proposed that living organisms are designed by a creator (natural theology)
Gene flow
movement of alleles from one population to another
Pleiotropy
The ability of a single gene to have multiple effects
Anagenesis
species formation without branching of the evolutionary line of descent
Population genetics
the study of how populations change genetically over time
Clade
A group of species that includes an ancestral species and all its descendants
Sister taxa
groups that share an immediate common ancestor
Primitive
Like the ancestor (does NOT mean older or less favorable)
Genetic drift
random change in allele frequencies that occurs in small populations
Phyletic gradualism
a theory that species evolve by the accumulation of many small changes over a long time period
Polygenic trait
trait controlled by two or more genes
Taxonomy
science of classification
Natural group
groups of organisms that possess a shared evolutionary history
Taxon
a group of organisms in a classification system
Derived
different from the ancestor (does NOT mean newer or more favorable)
Founder effect
genetic drift that occurs after a small number of individuals colonize a new area
Codominant
A heterozygote in which both alleles are fully expressed
Systematics
the science of naming and grouping organisms
Type
classification
Cladistics
A phylogenetic classification system that uses shared derived characters and ancestry for grouping taxa
Character
A heritable feature that varies among individuals
Ancestral
of/belonging to/inherited from ancestor or ancestors
Bottleneck
genetic drift in which a large population declines in number, then rebounds
Cladogenesis
evolution through the branching of a species or a lineage
Microevolution
Change in allele frequencies in a population over generations
Typology
the study of types, assigning objects/artifacts in categories according to physical attributes or characteristics
Node
the point where sister taxa meet (hypothetical place on their history where the common ancestor is)
Character state
distinguishable forms of a character, such as the presence or absence of a feature in a species
Biological species concept
A species is a group of populations whose members have the potential to produce fertile offspring
Sex-linked trait
Traits controlled by genes located on sex chromosomes
Punctuated equilibrium
A pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change
Macroevolution
Evolutionary change above the species level
Convergence
Similarity due to adaptations to the environment and not based on ancestry
Synapomorphy
shared derived character
Cladogram
A diagram that shows the evolutionary relationships among a group of organisms
