Chapters 22-25 Study Guide Flashcards
Natural selection
Differential success in the reproduction of different phenotypes resulting from the interaction of organisms with their environment. Evolution occurs when natural selection causes changes in relative frequencies of alleles in the gene pool.
Evolution
All the changes that have transformed life on Earth from its earliest beginnings to the diversity that characterizes it today.
Taxonomy
Ordered division of organisms into categories based on a set of characteristics used to assess similarities and differences, leading to a classification scheme; the branch of biology concerned with naming and classifying the diverse froms of life.
Artificial selection
The selective breeding of domesticated plants and animals to encourage the occurence of desirable traits.
Homologous structures
Structures in different species that are similar because of common ancestry
Analogous structures
Structures that are similar due to convergent evolution rather than to descent from a common ancestor with the same trait.
Vestigial structures
Structures of marginal if any importance to an organism. They are structures that are historical remnants of structures that had importance in ancestors.
Gene pool
The total aggregate of genes in a population at any one time.
Genetic drift
Unpredictable fluctuations in allele frequencies from one generation to the next because of a population’s finite size.
Bottleneck effect
Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer representative of the original population.
Founder’s effect
Genetic drift that occurs when a few individuals become isolated from a larger population, with the result that the new population’s gene pool is not reflective of the original population.
Gene flow
Genetic additions or subtractions from a population resulting from the movement of fertile individuals or gametes
Fitness
The contribution an individual makes to the gene pool of the next generation reflective to the contributions of other individuals
Sexual selection
Natural selection for mating success
Speciation
The origin of a new species in evolution
Heterozygote advantage
Greater reproductive success of heterozygote individuals compared to homozygotes; tends to preserve variation in gene pools
Taxon (plural taxa)
The named taxonomic unit at any given level of classification
Phylogenetic tree
A branching diagram that represents a hypothesis about evolutionary relationships
Cladogram
A diagram depicting patterns of shared characteristics among species.
Directional selection
natural selection that favors variants of one extreme
Disruptive selection
natural selection that favors individuals on both extremes of a phenotypic range over intermediate phenotypes
Stabalizing selection
natural selection that favors intermediate variants by acting against extreme phenotypes
Reproductive isolation
the exsistence of biological features (barriers) that impede members of two species from producing viable, fertile offspring
Habitat Isolation
Two species that occupy different habitats within the same area may encounter each other rarely even though they are not isolated by obvious physical barriers such as mountain ranges.
Temporal Isolation
Species that breed during different times of the day, different seasons, or different years cannot mix their gametes
Behavioral Isolation
Courtship rituals that attract mates and other behaviors unique to a species are effective reproductive barriers, even between closely related species
Mechanical Isolation
Morphological differences can prevent successful mating
Gametic Isoltation
Sperm of one species may not be able to fertilize the eggs of another species. MAny mechanisms can produce this isolation
What is the heirarchial classification starting from Domain and ending with Speices?
Domain Kingdom Phylum Class Order Family Genus Species
What are the 5 conditions for Hardy-weinberg equilibrium?
- Population must be very large
- No mutations
- Random mating
- No natural selection
- No immigration or emigration
What is the smallest unit of evolution?
A population
What type of population does the Hardy-Weinberg theorem describe?
A non-evolving population
Where does the variation that makes evolution possible come from?
Mutations, gene flow, and sexual reproduction
Allopatric speciation
a mode of speciation induced when an ancestral population becomes segregated by a geographic barrier or is itself divided into two or more geographically isolated subpopulations
Sympatric Speciation
a mode of speciation that occurs as a result of a radical change in the genome of a subpopulation, reproductively isolating the subpopulation from the parent population
Adaptive radiation
The emergence of numerous species from a common ancestor introduced into an environment that presents a diversity of new opportunities and challenges
Punctuated equilibrium
In evolutionary theory, long periods of apparent stasis (no change) interrupted by relatively short periods of sudden change.
Parallel Evolution
the development, through natural selection, of similar characteristics (morphology, behavior) in two unrelated species subjected to similar environmental conditions
Convergent evolution
process by which unrelated species become more similar as they adapt to the same kind of environment
Divergent evolution
when two or more biological characteristics have a common evolutionary origin but have diverged over evolutionary time. This is also known as adaptation or adaptive evolution.
Co-evolution
recoiprocal genetic change in two or more species resulting from interactions among them; in other words, species evolve in response to each other
Dichotomous key
a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish. Keys consist of a series of choices that lead the user to the correct name of a given item.
What are the characteristics of the class mammalia?
- mammals have hair covering their skin
- mammals produce with internal fertilization and have live birth
- mammals nourish their young with milk
- mammals have a four chambered heart
- mammals are warm blooded
What are the characteristics of the kingdom animalia?
- Animals are multicellular
- animals are heterotrophs
- animals undergo a period of embryonic development
- animals move at some point in their lives
- the dominant generation is diploid
What are the three domains?
Bacteria, archaea, and eukarya
What are the four kingdoms in eukarya?
Protista, fungi, plantae, and animalia
What are some of the characteristics of the domain bacteria?
- Unicellular
- cell walls with peptidoglycan
- prokaryotes
What are some of the characterisics of the domain archaea?
- prokaryotes
- unicellular
- cell walls without peptidoglycan
What are some of the characterisics of the domain eukarya?
- eukaryotes
- unicellular or multicellular
- consists of protista, fungi, plantae, and animalia
