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Evolution and Biodiversity flashcards

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What is a fossil?Evidence for Common Ancestry
A preserved trace or remain of past life.
What is relative dating?Evidence for Common Ancestry
Determining which layers or events are older or younger.
What is radiometric dating?Evidence for Common Ancestry
Estimating age from radioactive decay in suitable material.
What is a transitional feature?Evidence for Common Ancestry
A trait combination informative about change among lineages.
What is homology?Evidence for Common Ancestry
Similarity inherited from a common ancestor.
What is analogy in evolution?Evidence for Common Ancestry
Similarity due to independent evolution rather than shared origin of that feature.
What is convergent evolution?Evidence for Common Ancestry
Independent evolution of similar features in different lineages.
What does vestigial mean?Evidence for Common Ancestry
An inherited feature with a reduced or altered ancestral role.
What is molecular evidence for ancestry?Evidence for Common Ancestry
Shared informative patterns in homologous DNA or proteins.
What is biogeography?Evidence for Common Ancestry
Study of organism distributions across space and time.
What is a homologous sequence?Evidence for Common Ancestry
A sequence related to another through shared ancestry.
Does one sequence have a universal mutation rate?Evidence for Common Ancestry
No; rates vary across genes and lineages.
What is natural selection?Natural Selection
Change in heritable variants associated with differential reproductive success.
What is heritable variation?Natural Selection
Differences that can be transmitted genetically.
What is differential reproduction?Natural Selection
Some variants leave more descendants than others in a context.
Does an individual genetically evolve during a lifetime?Natural Selection
No; evolution refers to populations across generations.
What is evolutionary fitness?Natural Selection
Relative contribution to later generations in a specified environment.
What is an adaptation?Natural Selection
A heritable feature shaped by selection in its historical context.
What is a tradeoff?Natural Selection
An advantage paired with a cost under some conditions.
Is evolution a ladder toward perfection?Natural Selection
No; it is branching change under constraints.
What does an allele-frequency graph track?Natural Selection
The proportion of copies of a specified allele over time or groups.
What is a selection hypothesis?Natural Selection
A proposed link between heritable variation and reproductive differences.
Why use controls?Natural Selection
To distinguish a proposed effect from alternatives.
Does a frequency trend alone prove selection?Natural Selection
No; multiple mechanisms may produce trends.
What is allele frequency?Population Change
The share of sampled gene copies bearing a specified allele.
What is genotype frequency?Population Change
The share of individuals with a specified allele combination.
In a diploid sample of N, how many autosomal gene copies are counted?Population Change
2N under the standard model.
What does p + q equal for two alleles?Population Change
1.
What is genetic drift?Population Change
Random change in allele frequency from finite sampling.
What is a founder effect?Population Change
Frequency change when a small subset establishes a new population.
What is a bottleneck?Population Change
A sharp reduction in population size affecting genetic composition.
What is gene flow?Population Change
Transfer of alleles between populations through reproduction.
What is Hardy-Weinberg equilibrium?Population Change
A baseline genotype-frequency model under stated simplifying assumptions.
What is expected heterozygote frequency?Population Change
2pq in a two-allele Hardy-Weinberg model.
What is expected aa frequency?Population Change
q² in that model.
Does deviation identify one mechanism?Population Change
No; several causes can produce deviation.
What is speciation?Speciation and Phylogeny
The formation of distinct evolutionary lineages.
What is gene-flow reduction?Speciation and Phylogeny
Less exchange of alleles between populations.
What is reproductive isolation?Speciation and Phylogeny
Barriers limiting successful genetic exchange between lineages.
What is a species concept?Speciation and Phylogeny
A defined set of criteria for grouping organisms into species.
What is a phylogenetic node?Speciation and Phylogeny
A modeled common ancestor at a branching point.
What are sister groups?Speciation and Phylogeny
Lineages sharing an immediate common ancestor in a tree.
What is an outgroup?Speciation and Phylogeny
A lineage used to help root a tree.
When does branch length carry a quantity?Speciation and Phylogeny
When a scale for time or change is specified.
What is a clade?Speciation and Phylogeny
An ancestor and all descendants in a tree.
What is a shared derived trait?Speciation and Phylogeny
A homologous feature arising in an ancestor and inherited by descendants.
What can convergence do to a tree?Speciation and Phylogeny
Make unrelated lineages appear close when using one trait.
Why can gene trees differ from species trees?Speciation and Phylogeny
Different genes can have different histories.
What is taxonomy?Classifying Biodiversity
The naming and organization of biological groups.
What is binomial nomenclature?Classifying Biodiversity
A two-part species name using genus and specific epithet.
What is a genus?Classifying Biodiversity
A named group containing one or more species.
Are taxonomic ranks equal units of time?Classifying Biodiversity
No.
What are the three commonly taught domains?Classifying Biodiversity
Bacteria, Archaea, and Eukarya.
What is a prokaryote?Classifying Biodiversity
An organism whose cells lack a nucleus.
What is a eukaryote?Classifying Biodiversity
An organism whose cells have a nucleus.
What is endosymbiosis?Classifying Biodiversity
A long-term cellular association implicated in origins of some organelles.
What is species richness?Classifying Biodiversity
The number of species in a defined area and sample.
What is evenness?Classifying Biodiversity
How evenly individuals are distributed among species.
What is genetic diversity?Classifying Biodiversity
Variation in genetic material within a group.
What is phylogenetic diversity?Classifying Biodiversity
Breadth of evolutionary history represented by lineages.