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Species and Speciation
definitions and such
43
Biology
Undergraduate 4
02/22/2014

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Term
What does the word species in Latin?
Definition
Form or kind
Term
Darwin warned that no defintion for species would satisfy everyone, since it would be try to
Definition
define the un-definable
Term
what did Linnaeus orginate?
Definition
morphological species concept
Term
From where problems arise in the question "what is a species?"
Definition
  • males vs. female
  • young vs. adult
  • species which change depending on environment in which they are found.
  • species that change seasonally.
Term
in the 20th century biologists, what is the concept did they use?
Definition
Biological species
Term
according to the "Biological species concept", what can be assumed?
Definition
it can be assumed that species are separated by a "reproductive isolating mechanism"
Term
what is the best definition of species?
Definition
a group of actually or potentially interbreeding individuals that are reproductively isolated from all other kinds of organisms.
Term
under reproductive isolating mechanisms, what are two major types?
Definition
  1. Pre zygotic reproductive barriers
  2. post zygotic reproductive barriers
Term
list some reproductive isolating mechanisms:
Definition
  • habitat preferences
  • temporal isolation
  • mechanical isolation
  • behavioral isolation
  • gametic isolation
Term
from the lecture, what was said "habitat preferences"
Definition
soil type in species of Galium
Term
what is temporal isolation:
Definition
breeding at different times of day or times of year.
Term
what is mechanical isolation?
Definition
that is differences in sizes and shapes of reproductive organs that make mating between different species impossible
Term
what is behavioral isolation?
Definition

species may lack the proper signals (visual, olfactory, auditory, etc) that would encourage mating.

 

  • visual: butterflies
  • olfactory: moths
  • Auditory: frogs
  • visual signal: fireflies
Term
what is gametic isolation?
Definition
  • sperm of a species may not be able to generate the egg of a different species
  • no fertilization 
Term
list the three post zygotic barriers:
Definition
  • low hybrid zygote viability
  • low hybrid adult viability
  • hybrid infertility:
    • horses plus donkeys = mules (infertile)
Term
the resultant strengthening of pre zygotic barriers is known as what?
Definition
reinforcement
Term
the other definition for a species is based on what?
Definition
molecular studies
Term
a species is viewed as a: ____ ?
Definition
distinct cluster of genes
Term
Many organisms, however, which are generally agreed upon as distinct species are known to do what?
Definition
interbreed and produce hybrids
Term
which dog family is true the interbreed and produce hybrids?
Definition
Canidae
Term

The  dog is now known as what?

(hint: it's a scientific name)

Definition
Canis lupus familiaris
Term
What does the name Canis lupus familiaris mean then?
Definition
subspecies of the wolf
Term
Although horses and zebras can interbreed, though they would not do so in the wild due to what differences?
Definition
behavioral and habitat differences.
Term
List: The Allopatric Model of Speciation of Ernst Mayr
Definition
  1. a species is divided into two populations that are geographically isolated from each other (an allopatric distribution)
  2. there is no gene flow between the two populations
  3. each population, though derived from the same gene pool, is genetically distinct due to finite (often small) population sizes resulting in "sampling error"
  4. each population finds itself in a unique environment in which natural selection follows a slightly different course
  5. therefore, each population diverges genetically from the orginal gene pool. 
  6. the two populations are isolated for a long period of time. 
  7. eventually, enough genetic changes accumulate such that, if the two populations are brought back into contact with one another, they are no longer able to interbreed and produce viable offspring 
  8. at this point, they are recognized as two different "biological species"
Term
when and how can the word "subspecies" be applied?
Definition
when speciation is ongoing particularly if the geographical isolation is not complete, the populations may become classified by biologists as "subspecies"
Term
what is an example of sympatric speciation?
Definition
maggot flies (Rhagoletis pononella) in North America.
Term
how do insects that are like flies select their food?
Definition
odor
Term
what is autopolyloidy?
Definition
polyploidy can arise either through chromosomes duplication of entire sets of chromosomes in a single species OR it can come from the combining of chromosomes of two different species
Term
how are tetraploid and diploid individuals of the same species reproduce?
Definition
reproductively isolated
Term
what is special about tetraploids and give an example of species that illustrate that:
Definition
tetraploids are able to self fertilize, which happens in many plants
Term
what is the estimated numbers that botanists came up for flowering plants and fern for polyploidy?
Definition

70% flowering plants

95% fern species

Term
what is an ecotype?
Definition
  1. a genetically differentiated population within a species, the differences having ecological significance 
  2. a genetically distinct population of the same species
  3. a genotypic response, through natural selection, to the environment. 
Term
what are two types of ecotypes? (i guess that's why they are)
Definition
Adaptaion and Acclimation
Term
describe adaptation:
Definition

A) A genetically determined characteristic that enhances the ability of an individual to cope with its environment 

B)An evolutionary process by which organisms become better suited to their enivronments. 

Term
describe acclimation:
Definition
a phenotypic response to the environment often a reversible charge in the morphology or physiology of an organism in response to an environmental charge
Term
What is phenotypic plasticity?
Definition
a single genotype can produce different phenotypes in different environments
Term
the phenomenon of phenotypic plasticity is well known for which species?
Definition
  • plants
Term
what are the implications of phenotypic plasticity?
Definition
  • differences among populations may not indicate adaptation (that is genetically based differences)
  • selection may not lead to evolutionary change if the variation within the populations is not genetically based
Term
please mention some important things about phenotypic plasticity
Definition
  • plasticity itself is a genetically based trait that is subject to selection and can evolve.
  • species that can occur in highly variable environments may evolve a great capacity for plasticity
Term
what is convergent evolution?
Definition
Under similar environmental conditions, species starting with different phylogenetic backgrounds can evolve similar adaptations
Term
What is Evolutionary Radiations?
Definition
Rapid proliferation of species into a variety of environments or niches
Term
again, what is convergent evolution?
Definition
Independently evolved traits subjected to similar selection pressures cause species that are not related to have similar traits
Term
In convergent evolution what can organisms can be?
Definition
sympatric
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