FINAL EXAM Flashcards
Survivorship Curves: Type I
low death rates during early and middle life and an increase in death rates among older age groups.
Survivorship Curves: Type II
a constant death rate over the organism’s life span
Survivorship Curves: Type III
high death rates for the young and a lower death rate for survivors
Exponential Growth
Idealized situation with no external limits on growth. Population’s growth rate (per capita increase) equals birth rate minus death rate.
Zero population growth
When the birth rate and death rate are equally the same.
Idealized population
has a intrinsic rate of increase with maximum rate of production. ( J-shaped curve)
Logistic growth
When a populations per capita growth rate decreases as population size approaches a maximum due to limited resources
Allele affect
When individuals have a harder time surviving or reproducing if the population size is too small
K-selection
selection for traits that are advantageous at high densities. It promotes the history life history traits that maximize reproduction.
r-selection
selection for traits that maximize reproductive success in uncrowded environments.
Predation
As a prey, population builds up, predators may feed preferentially on that species.
Phylogeny
Is the evolutionary history of a species or a group of related species
Taxonomy
Is the ordered division and naming of organisms
Cladistics
Organizes groups of organisms by common decent.
Clade
a group of species that includes an ancestral species and all its descendants.
Plesiomorphies
shared ancestral characters in an ancestor of the taxon
Apomorphies
shared derived characters is an evolutionary novelty unique to a particular group of related organisms
Subspecies
a taxonomic category that ranks below species, usually a fairly permanent geographically isolated race.
Phylogenetic tree
A branching diagram that represents a hypothesis about the evolutionary history of a group of organisms
Parsimony
the principle that, out of all possible explanations for a phenomenon, the simplest of the set is most likely to be correct
Sequence homology
the situation where nucleic acid or protein sequences are similar because they have a common evolutionary origin.
Monophyletic
Pertaining to a group of taxa that consists of a common ancestor and all of its descendants. A monophyletic taxon is equivalent to a clade.
What is a taxon?
a named taxonomic unit at any given level of classification.
Polyphyletic
Pertaining to a group of taxa that includes distantly related organisms but does not include their most recent common ancestor
Apomorphy
A derived trait or characteristic that identifies a species or a taxonomic group (taxon) from the ancestral trait. apo= “away from”+ morph= “shape”
Paralogous Genes (aka: paralogs)
Homologous genes that are found in the same genome as a result of gene duplication.
Orthologous genes (aka: orthologs)
Homologous genes that are found in different species because of speciation.
Homoplasy
A similar structure or molecular sequence that has evolved independently in two species.
Analogous
Having characteristics that are similar because of convergent evolution, not homology.
Covergent evolution
The evolution of similar features in independent evolutionary linages.
Interspecific competition
(-/-) interaction: occurs when species compete for resources in short supply
Intraspecific competition
a competition between individuals from the same species (cospecifics)
Competitive Exclusion
Two species competing for ALL the same limiting resource in short supply
Batesian Mimicry
One patable or harmless species mimics an unpalatable or species for survival.
Mullerian Mimicry
2+ unpatable or harmful species resemble each other.
Symbiosis
A relationship where two or more species live in direct and intimate contact with one another.
Parasitism
(+/-) one organism derives direct nourishment from another with the host harmed
Disease
(+/-) one organism (pathogen) exert harm on another organism by fulfilling part or all of their life cycle. Bother have similar effects on populations and communities.
Mutualism
(+/+) is an interspecific interaction benefiting both species.
Obligate
Where one species cannot survive without the other
Facultative
Where both species can survive alone.
Commensalism
(+/0) where one species benefits and other is neither harmed nor helped. Commensal interactions are hard to document in nature because any close association likely affects both species.
Facilitation
(+/+ or +/0) species have positive effects on other species without direct contact
Paraphyletic
Pertaining to a group of taxa that consists of a common ancestor and some, but not all, of its descendants.
