Biol 108 midterm topics 1-8 Flashcards
Broad def of Evolution
Organisms decent from common ancestor by modification over generations.
Narrow def of Evolution
The different genetic composition over genderations
Adaptions
Refers to traits that organisms inherit that make them better fit to survive and reproduce with viable fertile offspring.
Fitness
individual’s ability to survive reproduce and pass on traits to the next generation
Evidence for common ancestor?
Genes, DNA
Character
Heritable feature of an organism
Trait
Condition or state of the character
Biodiversity
Variety of life on earth
Species
Population that is able to interbreed and produce fertile viable offspring
Genetic diversity
Various versions of genetic composition within a population of the same species
Population
Organisms that live in the same place at the same time and are able to reproduce and create fertile viable offspring
Ecosystem diversity
Variety of habitats and the relationships between them. Predator-prey
Ecosystem
The environment where species live
Developmental diversity and form and function diversity
1.-variety in how embryos develop
2.-various anatomy and physiology and behaviours member of a pop species or higher unit of taxonomy
Benefits of biodiversity
-maintain ecosystem.
-supply materials water, dirt, oxygen, food
-regulate materials such as regulating climate
-Supporting systems, recycling of materials
-cultural services
Extinction
The last individual of a species is dead or is cannot be considered beyond reasonable doubts
Extant species
at least on individual is still living
Extirpation
A population of a species is gone but you can find the population elsewhere
Endangered
threat to go extinct
4 threats to biodiversity
-Habitat loss
-invasive species
-overexploitation-over harvesting plants or animals faster then they can keep up
-Global cimate change
Evolutionary theory
Body of knowledge that guides our understanding of biodiversity
theory
set of broad comprehensive and systematic explanation of the natural world based on evidence and experiments.
hypothesis
explanation of the natural world based on evidence that leads to experiments
Inductive reasoning
reaching a conclusion from synthesizing observations
Deductive reasoning
reaching a conclusion based off things that are already assumed to be true.
Correlation
smoking and getting lung cancer. could be corelated but there could be other reasons
Causation
change in one thing leads to another. Cause and effect
Taxonomy
Discipline of naming organisms and putting into containers of classification
Nomenclature
System of rules for naming
Linnaean system
Classification system where organism are grouped based off similarity
Binomial nomenclature
In italics Genus species Not in italics (date, name of person)
Domain
Kingdom
Phylum
class
order
family
genus
species
Taxon or taxonomic unit
unit of classification at any rank
Limitation of linnaean
At high ranks groups and family’s are not always comparable
does not depict evolutionary relationship between taxa at multiple levels
Systematic
Discipline of classifying organisms based on there evolutionary relationships and history
Phylogenetic
Field of systematics based on organisms evolutionary relationships relationships
Phylogenetics
Field of systematics based on evolutionary relationships among organisms
Phylogenetic tree
evolutionary hypothesis about the evolutionary relationship among biologically related taxa
Root
Base of phylogeny
Tip
terminals of phylogeny
Node (branch point)
internal and external
point where branches meet and hypothetical place where species share a common ancestor
internal node and node
external is node and a tip
Branch or clade
Lines connecting nodes roots and tips
In-group
the group under study
out group
least connected outside clade of interest
Sister taxa
two most closely related branches from a node
Basal taxa
diverges early
Derived taxa
diverges later
Phylogram vs cladogram
Phylogram includes measure of time and evolutionary relationship
cladogram does not include time and includes only taxa relationships
monophyletic group
common ancestors and all of their descendants
paraphyletic group
ancestor and some descendants
polyphyletics group
some descendents and no common ancestor
dichotomy
only two diverge from common ancestor
polytomy
more than two branches
soft polytomy
represents uncertainty among taxa nodes most related to eachother
hard polytomy
represents hypothesis between more then two taxa arose from same common ancestor
morphological traits
anatomical features
molecular data
genomic protein structure
Character state
specific state or condition of a character
homology
traits that evolved from a common ancestor
analogy
character traits independently evolve on their own. wings bird and wings of a bug
synapomorphy
derived feature found only in one taxa
automorphy
derived feature found in only one taxa
symplesiomorphy
ancestral feature shared by at least some members of a taxonomic group
Character states coded
out groups 0
state 1,2 represent derived groups
ancestral to derived 0-1
derived to ancestral 1-0
Parsimony
all possible cladograms for a certain taxa. Most likely is the one with the least amount of changes
Maximum likelihood and bayesian inference
Just need to know these are two methods not details to choose phylogenies
Embryonic development von baers law
the more general basal characteristics appear earlier in development more special derived characteristics appear later
Gradualism
geological features in rock are formed by slow continuous processes
Uniformitarianism
same natural laws govern the natural process in modern day and throughout the history of earth
natural selection
mechanism for descent by modification
Unity
similar traits among organism due to descent from a shared
diversity
different in traits due to changes of heritable traits
Speciation
origin of new species diverged from ancestral species
selective agents
environmental factors acting on the population to influence the survival and or reproduction of individuals in the population
natural selection
process by which traits that enhance survival and reproduction become more common in successive generations
macroevolution
evolutionary change above the species level
direct observations
evolutionary changes documented by overwhelming amounts of biological studies especially from organisms with short lifespans
Morphological homology
comparative embryology
comparative anatomy
Comparative embryology- demonstrate homologous features visible during embryonic development
comparative anatomy- demonstrates homologous features visible after birth
Molecular homology
demonstrates by similarities in genetic makeup inherited from common ancestors
Biogeography
study of past and present geographic distribution of species
endemic species
biological taxa that are native to specific area and not found in other regions experience selective pressures differently
microevolution
evolution below the species level change in allele frequencies in a population over generations
chromosome
cellular structure carrying genetic material
Gene pool
copies of every type of allele at a loci in every individual in a population. Individuals within a population share allele’s by reproducing and producing fertile offspring
gene discrete unit of hereditary information consisting of specific nucleotide sequence in DNA
Alleles
alternative versions to genes that correspond to different combination of nucleotides in each version
Point mutation, insertion deletion and large structural changes
Point- single change in a nucleotide base
insertion/deletion- addition or removal of one or small number of nucleotide bases
Large structural changes- major alteration in DNA(damages)
Mutation
random changes in the nucleotide sequence in an organisms genetic makeup, can be beneficial, nuetral or deleterious. Create new alleles. only be creating tgrough gamete producing cells.
Gene Duplication
copies of nucleotide sequence if an organisms genetic makeup
types of duplication small segments, gene duplication, whole genome duplication
Small segments copy of dna segments that effect multiple genes
Gene duplication- copy of entire gene
Whole genome duplication- doubling entire genome
Gene recombination
shuffling of existing alleles into new combinations during sexual reproduction
Meiosis
Cross over
independent assortment
radnom fertilization
type of cell division sexual reproduction to produce gametes with 1/2 the genetic material
cross over- reciprocal exchange of homologous genetic material
independent assortment-different genes are independent from each other
directional selection
natural selection in whush individuals on one side of the phenotype range reproduce and survive better then others.
-new phenotype with higher relative fitness
-frequency distribution of phenotype variation shifts towards adapted traits
-genotype variation assumed to reduce
disruptive selection
individual’s at both ends of the phenotype range survive or reproduce better then other individuals
-intermediate phenotypes are less adapted then ones on either end
-genotype variation lead to more then one phenotype with higher relative fitness
-frequency of intermediate trait decline over time
stabilising selection
Natural selection in which individuals at intermediate or common variants of phenotype range survive or reproduce more successfully than others
-conserve genotype and phenotype traits against the extremes
-the mean of the trait stays the same and the spread is reduced
Genetic drift
Random events that change allele frequency in a population
bottleneck effect
population size suddenly decreased due to changes in the environment which alter allele frequency and gene pool
founder effect
select few individuals become isolated from the population and become a new population. Carry a fraction of the gene pool from the original population
Gene flow
transfer of alleles between populations. Take place via movements of fertile individuals or gametes. reduces genetic variation and works against genetic drift. Can reduce of increase fitness adaptive traits introduced or deleterious traits introduced
Local adaption
populations become more adjusted to their local environment often gain adaptive traits that are absent in population from other locations
Balancing selection
type of natural selection that maintains genetic diversity within a population
Heterozygote advantage
individuals of two different alleles of a given gene are more adaptive to the environment compared to individuals with two identical copies of alleles
Frequency-dependent selection (pos and neg)
selection in which the fitness of a phenotype depends on how common the phenotype is in a population. often between species ( comp, predation, parasitism)
Positive- fitness of phenotype increases as it becomes more common
negative- fitness of phenotype decreases as it becomes more common.
Biological species concept
Pop. that can interbreed or have potential to interbreed with members of the same group in nature and produce viable fertile offspring
-breeding over generations
-gene flow throughout populations of the same species increases unity
Reproductive barrier
Biological factors that stops members of two species from creating viable fertile offspring
zygote
fertilized egg
hybrid
offspring from 2 different species
prezygotic barrier
reproductive barrier that impedes mating between species or hinders fertilization in interspecific mating is attempted
habitat isolation
diff habitat same location barely see eachother
temporal isolation
different breeding times
behavioural isolation
different ways to attract mates
mechanical isolation
different anatomy that stops mating
gametic isolation
sperms of one species cant fertilize egg of another
post-zygotic
barrier that prevents hybrids from from developing into viable orgnaisms able to reproduce
reduced hybrid viability
genes from parent of different species may interact and impair the hybrids developmental or survival
reduced hybrid fertility
hybrids may be sterile even if they survive
hybrid breakdown
reproductive failure that appears after the F2 generation of crosses between different species. Become worse and worse. Accumulation of deleterious genes
limitation of BSC
cant be applied to asexual organisms, cant be explained with fossils emphasis on the absence of gene flow, surviving hybrids exist in nature
morphological species concept
defines species in terms of anatomical features
ecological species concept
defines species by ecological niche niche is how species interacts with biotic and abiotic features in the environment
phylogenetic species concept
defines a species as the smallest group of individuals on a phylogeny. based on evolutionary history and shared ancestor
allopatric speciation
formation of new species in populations that are geographically isolated from each other
Allopatric- dispersal
movement of individuals away from pop expands geographical range
allopatric- vicariance
range of species is split by a change in the environment creating two subpopulations
Sympatric speciation
formation of new species from populations that live in the same area. Process: geographical barrier is absent but some individuals stop interbreeding with others in population. new populations are established when reproductive isolation is achieved
sympatric- polyploid speciation
establishment of reproductive barriers from having additional sets of chromosomes
sympatric-Hybrid speciation
offspring of two related species are reproductively isolated from either parent
polyploids
chromosomal alteration in which and organism posses more then two sets of chromosomes. Uncommon in animals lethal, common in plants. Continuous interbreeding is possible between individuals of the same polyploids.
allopolyploids
fertile individual with more then two sets of chromosomes derived from hybridization of different species. cause hybridization and doubling of chromosomes
autopolyploids
fertile individual with more then two chromosomal sets that is derived from a single species Cause error in meiotic division genetic material failed to seperate.
homoploids
result of hybridization without altering the number of chromosomes. when hybridization creates novel combinations of genes phenotypes of these genes increases fitness of hybrids
sympatric- habitat differentiation
subpopulations of the same species adapt to different environments leading to reproductive isolation
sympatric- sexual selection
individuals with certain inherited traits are more likely then others to obtain mates. Can be a form of natural selection
Hybrid zone
geographic region in which members of different species meet and mate producing offspring of mixed ancestry. often less fit but can lead to speciation. Partial overlap in range of species
outcomes of hybrid zones
reinforcement- hybrid offspring less fit then parents natural selection removes hybrids. strengthens reproductive barriers.
Fusion- offspring as fit as parents gene flow is maintained between hybrid and parent populations. reproductive barrier is weakened and eventually removed
stability- hybrid offspring are continuously formed by the parents gene flow can be maintained between the parent population can lead to fusion
