Exam 1 Flashcards
What is evolution?
The accumulation of genetic changes within a population over time.
Who proposed the theory of evolution?
Charles Darwin and Alfred Russel Wallace
What is Lamarkian Evolution?
Inheritance of acquired characteristics driven by inner need…. Theory is false
What is evidence for common ancestry? (7)
- Fossil record– TIME
- Homology (structural similarities functions may vary)–ANATOMY
- Vestigial structures (structures that are non-functional)–ANATOMY
- Classification– TRAITS
- Hierarchal distrib. Of traits– TRAITS
- Agreement between gene trees– TRAITS
- Evolution during domestication– HUMAN INTERFERENCE
What is population genetics?
The study of genetic variability within a population
What is a gene pool?
All the alleles for all the loci present in the population
What is genetic equilibrium?
A population whose allele or genotypic frequencies do not undergo evolutionary change over time.
What is the Hardy- Weinberg principle and what is its formula?
Using phenotypic frequencies to calculate expected genotypic frequencies and Allele frequencies in sexually reproducing organisms.
p^2 + 2pq + q^2 = 1
What are the conditions of genetic equilibrium?
- random mating
- no net mutations
- large population size
- no migration
- no natural selection
What is microevolution?
Small generation to generation changes in allele or genotypic frequencies within a population
What are the five micro evolutionary processes?
- non-random mating
- mutation
- genetic drift
- gene flow
- natural selection
What are the three kinds of natural selection?
Stabilizing- middle thrives, extremes die off
Directional- shifting of the curve to one side, changing the average
Disruptive- middle (avg) dies out while extremes thrive
What are the three species concepts?
MORPHOLOGICAL- a species is determined by visible characteristics
BIOLOGICAL- one or more populations who interbreed to produce fertile offspring, reproductive barriers keep species genetically distinct, new species evolve when reproductively isolated from other members
PHYLOGENETIC- has undergone evolution long enough for significant differences in diagnostic traits to emerge by comparing gene sequence
What is speciation?
A population become reproductively isolated from other populations and their gene pools diverge.
What are the two forms of speciation and their definitions?
Allopatric- pupil actions becomes geographically isolated from other species
Sympatric- same geographic range, reproductive isolating mechanism evolves at the start of the speciation process.
What are prezygotic isolation barriers?
Temporal- reproducing at different TIMES
Habitat- reproducing in different HABITATS
Behavioral- having distinct courtship behaviors
Mechanical- different structured reproductive organs
Game tic- gametes are chemically incompatible
What are postzygotic isolation barriers?
Hybrid inviability- hybrid dies early in embryonic development
Hybrid sterility- hybrid survives into adulthood but unable to reproduce successfully
Hybrid Breakdown- offspring (gen 2) of hybrids are unable to reproduce
What are the two patterns of evolutionary change?
Punctuated equilibrium- long periods of STASIS are interrupted by short periods of rapid speciation
Phyletic gradualism- evolution occurs over time
What is macroevolution?
Large scale phenotypic changes in populations at the species level or higher
What is a preadaptation? Give example.
Evolutionary novelties that are variants of pre-resisting structures.
Example: scales changing to feathers
What is evolution and development? (EVO-DEVO)
Variation and mutation that is created through genetic reshuffling during meiosis that causes evolutionary jumps that appear in the fossil record…consists of two types
What are the two types of EVO-DEVO?
Homeotic - changes in placement of body parts or developmental programs
Allometric- organs having an unequal distribution of growth
What is adaptive radiation?
Rapid diversification and speciation from a common ancestor.. It happens for two reasons:
Innovation- new trait makes species highly competitive
Opportunity- wide range of available adaptive zones
What is extinction?
The permanent end of a lineage…occurs when the last individual of a species dies
How do we classify organisms?
Taxonomy- naming, describing and classifying organisms
Classification- arranging organisms into groups based on similarities
Systematics- study of diversity of organisms and their evolutionary relationships
What is a clade?
A group of organisms that share characteristics from a common ancestor
What is a synapomorphie?
A shared trait by all members in a population that evolved
What is convergent evolution?
When similar environmental conditions result in independent evolution of structures
What is homoplasy?
A characteristic that appears homologous but is acquired through convergent evolution
What is parsimony?
Simplest explanation to interpret data
What are evolutionary relationships?
Monophyletic- ancestral species and all descendants (shared derived characters)
Paraphyletic- common ancestor and some descendants but not all
Polyphyletic- several evolutionary lines that do not share the same common ancestor… Misrepresents evolutionary relationships
What is molecular systematics?
Using molecular structure to clarify evolutionary relationships
