Module 1 - Introduction to the Study of Organismic Biology Flashcards
Systematics
study of diversification
Phylogenetics
study of evolutionary relationships
Phylogenies
hypotheses of evolutionary relationships that are based on data
What does a node represent on a phylogenetic tree?
inferred common ancestors
Sister species
species that share a more recent common ancestry with each other than other species
Homoplasy
shared traits irrespective of common ancestry that arise through convergent evolution - organisms that aren’t related yet share the same traits
Monophyletic groups
an ancestral group and all of its descendants aka natural groups
Paraphyletic groups
ancestral species and miss some of its descendants aka unnatural groups
Polyphyletic groups
unrelated taxa
Alpha taxonomy
goal to correctly identify the species - it deals with the tips of the phylogeny
Species
smallest evolutionary unit
What causes a change in species?
Reproductive isolation, mutation, natural selection, gene flow, and genetic drift
Ecotype
species genetically altered to fit its environment
Morphological Species Concept
groups organisms based on physical characteristics - however there are too many traits to consider, it can be subjective, and cryptic species man not be recognized
Phylogenetic Species Concept
groups organisms based on the smallest monophyletic group - which relies on genetic divergence among groups of organisms, it could also inflate the number of species
Biological Species Concept
groups organisms based on reprodutive isolation - organisms may look related physically but that doesn’t mean they can breed together
Evolutionary Lineage Species Concept
groups organisms based on their immediate ancestral species
Ecological Species Concept
groups organisms based on their ecological niche
Reproductive Isolation
cannot successfully breed with each other
Prezygotic isolating mechanisms
prevents zygote from forming - species never contact each other, mate at different times, or have different mating behaviours
Postzygotic isolating mechanisms
prevents the growth of a zygote after fertilization - the egg cannot develop, offspring is fertile, or offspring have genetic abnormalities
Mechanical Isolation
species genitalia is not compatible
Gametic Isolation
species gametes are not compatible
Ring Species
reproductive isolation between interconnected populations
Cladogenesis
divergence of a species into two or more different species
What is a common way for cladogenesis to occur?
Allopatric speciation
Allopatric Speciation
species that diverge due to being geographically isolated
Adaptive Radiation
a single ancestral species has developed multiple different species based on their habitat, form, or behavior - different beaks on a finch based on where they live/their food
Sympatric Speciation
a species that diverges into two or more species even when they are in the same area
Polyploidy
when an organism has more than two sets of chromosomes
Gradualism
each news species evolves over a long period time
Punctuated Equilibrium
a concept that evolution is more sporadic than gradual
Heterochromy
differences among species in the rate or timing of developmental events
Evolutionary Developmental Biology
compares the development between different organism that bring about evolutionary change
Pattern Formation
process that results in a plant or animal with a particular structure
Hox genes
homeotic genes which determine the fate of a particular segment or region of the body
Taxonomy
a formal system of naming species
Hierarchies of Life
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
What are the 3 Domains?
Bacteria, Archaea, and Eukarya
Binomial Nomenclature
Genus + Species, scientific names are italicized
Taxonomy vs. Nomenclature
Taxonomy: study of naming and classifying organisms
Nomenclature: rules for choosing names
Evolution
heritable change between a population’s generations - it’s a THEORY
Microevolution
change in a single gene or in allele frequeneies
Processes of microevolution
Mutations, genetic drift, and nonrandom mating
Macroevolution
formation of a new species or groups of related species
Empirical Thought
using an observation to form a hypothesis rather than trying to rely on nonphysical or spiritual views
Perpetual Change
organismic diversity not constant over time
Common Descent
all organisms derived from a single ancestor
Natural Selection
adaptations that are favored and more likely to be passed down because they aid the survival of an organism in that environment
Five Evolutionary Theories
Perpetual change, common descent, multiplication of species, natural selection, and gradualism
Catastrophism
only catastrophic events change the Earth’s structure
Uniformitarianism
recurring events changes Earth’s structure (erosion)
Biogeography
unique species found on islands are a cause of reproductive isolation
Convergent Evolution
two different species from different lineages start to look similar because they occupy similar environments
Selective Breeding
programs and procedures made to modify traits in domestic species
Homologous Structures
structures that are anatomically similar because they evolved from a structure from a common ancestor
Vestigial structures
structures that have no function but resemble structures of a presumed ancestor
Ortholog
homologous genes found in different species
Paralog
homologous genes found in the same species
Vertical Evoution
genetic changes occur in a series of related species that form a lineage (parent to offspring)
Horizontal Gene Transfer
an organism incorporates genetic material from another organism without being it’s offspring