Definitions List 2 Flashcards
Who also developed the theory of evolution by Natural Selection?
Alfred Russel Wallace
Who first noted that, while populations have the ability to increase geometrically, this does not occur?
Thomas Malthus (1798)
What is Fitness?
A measure of the extent to which the individual genotype is represented in the next generation.
What is fixation of advantagous alleles?
The allele has a frequency of 1
What is positive selection?
Natural selection that increases the frequency of favourable alleles.
What is positive selection?
Natural selection that increases the frequency of favourable alleles.
What is natural selection that increases the frequency of favourable alleles?
Positive selection
Definition
Deleterious
Causing harm or damage.
What is negative selection?
Selection that decreases the frequency of a deleterious allele.
What is selection that decreases the frequency of a deleterious allele?
Negative selection
What is stabilizing selection?
It is selection that maintains the status quo and acts against extremes.
What is selection that maintains the status quo and acts against extremes?
Stabilizing selection
What is the majority of natural selection?
The majority of natural selection is deleterious mutation that are selected against.
What is ‘Direction Selection’?
Selection that leads to a change in a trait over time.
What is selection that leads to a change in a trait over time?
‘Direction Selection’
What is intersexual selection?
Selection driven by the interactions between females and males.
What is selection driven by the interactions between females and males?
Intersexual selection
What does a species represent?
A closed gene pool with alleles being shared among members of that species.
What is the Biological Species Concept?
Generally accepted definiton of a species.
Species are groups of actually or potentially interbreeding populations that are reproductivley isolated from other such groups.
Reproductive compatibility entails more than just the ability to produce offspring.
Who developed BSC?
The Biological Species Concept was developed by Ernst Mayr.
What is a major thing that Ernst Mayr is known for?
Developing the Biological Species Concept.
What is the Morphospecies Concept?
The concept that members of the same species usually look alike.
Morphospecies is not infallible.
What is the concept that members of the same species usually look alike?
The Morphospecies Concept
What is polymorphisms?
When members of the same species have different phenotypes.
What is it called when members of the same species have different phenotypes?
Polymorphisms
What are ring species?
Species with populations that are reproductively but not genetically isolated.
What are species with populations that are reproductively but not genetically isolated?
Ring Species
What is hybridization?
Interbreeding between species.
What is interbreeding between species?
Hybridization
What is an ecological niche?
Complete description of the role the species plays in its environment, it’s habitat requirements, its nutritional and water needs.
Two species can not exist in the exact same niche.
This leads to the idea of categorizing species by their niche.
What is the Ecological Species Concept? (ESC)
The idea that there is a one-to-one correspeondence between a species and its niche.
What is the idea that there is a one-to-one correspeondence between a species and its niche called?
The Ecological Species Concept. (ESC)
What is the Phylogenetic Species Concept (PSC)?
The idea that members of a species all share a common ancestry and a common trait.
What is the idea that members of a species all share a common ancestry and a common trait?
The Phylogenetic Species Concept (PSC)
What are Pre-zygotic Factors?
Factors that cause isolation before fertilization of an egg.
What are Post-zygotic Factors?
Factors that isolate after fertilization of an egg.
Most species are isolated by pre-zygotic factors.
What are factors that isolate after fertilization of an egg?
Post-zygotic Factors
What are factors that cause isolation before fertilization of an egg?
Pre-zygotic Factors
What does Behaviourally Isolated mean?
It means that individuals mate only with other individuals based on specific courtship rituals, songs or other behaviours.
How is it refered to when individuals mate only with other individuals based on specific courtship rituals, songs or other behaviours?
Behaviourally Isolated
What is gametic isolation?
Incompatabilities between the gametes of two different species.
What is mechanical incompatibility?
The reproductive organs are shaped in such a way that they are not compatible.
Mechanical incompatibility is common in insects.
What is temporal isolation?
Species mate or are active at different times so reproduction is not possible.
That is Geographic or Ecological isolation?
The species live separated from each other so reproduction is not possible.
What is genetic incompatability?
The genes make it impossible to reproduce.
I.e. Two organisms with a different number of chromosomes.
What is Speciation?
The development of reproductive isolation between populations.
What is the development of reproductive isolation between populations?
Speciation
What is partially reproductively isolated?
Where they are not yet separate species, but the genetic difference are extensive enough that offspring produced have reduced fertility.
What is allopatric speciation?
Speciation that results from the geographical separation of populations.
What is speciation that results from the geographical separation of populations?
Allopatric speciation
What is a subspecies?
Allopatric populations that have yet to evolve even partial reproductive isolation, but which have accumulated a few population specific traits.
What are allopatric populations, that have yet to evolve partial reproductive isolation, but which have accumulated a few population specific traits?
A subspecies
What is dispersal?
Where some individuals colonize a distant place such as an island far from the main source population.
What is vicariance?
Where a geographic barrier arises within a single population separating it into two or more isolated populations.
Core Term
Refers to where a geographic barrier arises within a single population separating it into two or more isolated populations.
Vicariance
What is the mainland population?
Central population of a species.
What is peripatric speciation?
A few individuals form a mainland population disperse to a new location remote from the original population and evolve separately.
What is it when a few individuals form a mainland population disperse to a new location remote from the original population and evolve separately?
Peripatric speciation.
What is an island population?
A population that lives on an ‘island’
In this case that may be a true island or simply a remote patch of habitat.
What is adaptive radiation?
A period of unusually rapid evolutionary diversification in which natural selection accelerates the rates of both speciation and adaption.
What is co-speciation?
A process in which two groups of organisms speciate in response to each other and at the same time
What does the term ‘Sympatric’ mean?
The term used to describe populations that are in the same geographic locations.
If disruptive selection is strong enough and sustained enough ti may eventually lead to sympatric speciation.
What is instantaneous speciation?
When the hybridization between two species’ offspring are reproductively isolated from both parents?
What are sister groups?
Groups that are more closely related to each other than either of them is to any other group.
What are taxon?
8 levels
All the species in some taxonomic entity under discussion.
- Domain
2. Kingdom
3. Phylum
4. Class
5. Order
6. Family
7. Genus
8. Species
What are the characters?
The anatomical physiological or molecular features that make up an organism.
What are character states?
Observed condition of a character (most have several)
What is synapomorphy?
Characteristics that are shared by some but not all of the members of the group under consideration.
What is cladistics?
Phylogenetic reconstrucion on the basis of synapomorphies.
What is Artificial selection?
A form of directional selection practiced by humans.
What is a form of directional selection practiced by humans?
Artificial selection
What is Sexual Selection?
Selection that promots traits that increase an individual’s access to reproductive opportunities.
What is selection that promots traits that increase an individual’s access to reproductive opportunities?
Sexual Selection
Outgroup phylogenetic tree
In cladistics or phylogenetics, an outgroup is a more distantly related group of organisms that serves as a reference group when determining the evolutionary relationships of the ingroup, the set of organisms under study, and is distinct from sociological outgroups.
