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Flashcards in Exam 1 Deck (32):

Who proposed the theory of evolution?

Charles Darwin and Alfred Russel Wallace


What is evolution?

The accumulation of genetic changes within a population over time.


What is Lamarkian Evolution?

Inheritance of acquired characteristics driven by inner need.... Theory is false


What is evidence for common ancestry? (7)

1. Fossil record-- TIME
2. Homology (structural similarities functions may vary)--ANATOMY
3. Vestigial structures (structures that are non-functional)--ANATOMY
4. Classification-- TRAITS
5. Hierarchal distrib. Of traits-- TRAITS
6. Agreement between gene trees-- TRAITS
7. 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