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48 Cards in this Set

  • Front
  • Back
According to the "biological species" concept, what is a species?
a population that interbreeds and produces fertile offspring
Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species that lived side by side in parts of their ranges. However, recent books show them as eastern and western forms of a single species, the yellow-rumped warbler. Apparently, the myrtle warbler and Audubon's warbler _____.
successfully interbreed and produce fertile offspring
What is necessary for speciation to occur?
reproductive isolation
According to the "biological species" concept (that is, our definition of "species"), members of different species _____.
do not mate successfully under natural conditions
The biological species concept cannot be applied to organisms that _____.
reproduce only asexually
Three species of frogs—Rana pipiens, Rana clamitans, and Rana sylvatica—all mate in the same ponds, but they pair off correctly because they have different calls. This is a specific example of a _____ barrier, called _______ .
prezygotic barrier ... behavioral isolation
Two species of water lilies in the same pond do not interbreed because one blooms at night and the other during the day. The reproductive barrier between them is an example of _____.
temporal isolation
Give an example of a postzygotic reproductive barrier
Two fruit flies of different species produce sterile offspring.
Individuals of different species living in the same area may be prevented from interbreeding by responding to different mating dances. This is called _____.
behavioral isolation
There are two groups of pine trees that appear to be very similar phenotypically and genotypically. However, one releases pollen in January, when the female structures of that group are receptive, and one in March. What kind of reproductive barrier is this?
temporal isolation
At which point in the adaptation of a population is it clear that speciation has occurred?
gene pool changes establish reproductive barriers between two populations
According to the fossil record, what is the average length of time that successful species survive?
5 million years
Lake Malawi, in the African Rift Valley, is home to more than a hundred species of cichlid fishes, each with slightly different diets and habits. All these fishes probably evolved from one ancestor, making them an example of _____.
adaptive radiation
Biologists have found more than 500 species of fruit flies on the various Hawaiian Islands, all apparently descended from a single ancestor species. This example illustrates _____.
adaptive radiation
What is the punctuated model of evolution?
the tempo of evolution comprises abrupt episodes of speciation among long periods of equilibrium
The existence in North America of numerous "species pairs" of similar but distinct species with distinct geographic ranges is taken to be indirect evidence of _____.
numerous allopatric speciation events
Who discovered Sympatric speciation by polyploidy in the 1900s?
Hugo de Vries
True or False:
mutation of cell cycle genes is not a probable event in the evolution of a polyploid species
Give an example of a crop that is not polyploid
the pea
If a new species of plant is to be produced by means of allopolyploidy from two parental species that are 2n = 4 and 2n = 8, how many chromosomes would you expect in the somatic cells of the new species?
Can a new species arise in a single generation? if so, how?
if a change in chromosome number creates a reproductive barrier
Comparison of fossils with living humans seems to show that there have been no significant physical changes in Homo sapiens in 30,000 to 50,000 years. What might an advocate of punctuated equilibrium say about this?
Lack of change is consistent with the punctuated equilibrium model.
What is the major problem that biologists see in the gradualist model of evolution?
Most fossil species appear suddenly in the fossil record without transitional forms.
habitat isolation
a prezygotic barrier; when populations live in different habitats and do not mate
behavioral isolation
a prezygotic barrier; little or no sexual attraction between males and females of different species
temporal isolation
a prezygotic barrier; mating or flowering occurs during different seasons or times of day
mechanical isolation
a prezygotic barrier; structural differences in genitilia or flowers prevent copulation or pollen transfer
gametic isolation
a prezygotic barrier; male and female gametes fail to attract each other or are inviable
reduced hybrid variability
a postzygotic barrier; hybrid zygotes fail to develop or fail to reach sexual maturity
reduced hybrid fertility
a postzygotic barrier; hybrids fail to produce functional gametes
hybrid breakdown
a postzygotic barrier; offspring of hybrids have reduced viability or fertility
ecological species concept
species are defined in terms of ecological niche, the resources it uses
pluralisitic species concept
there is no universal explanation for the cohesion of individuals in a species
morphological species concept
species are characterized by a set of unique structural features
genealogical species concept
species have a unique genealogical history
Allopatric speciation
geographic barriers can lead to the origin of species
give an example of a ring species
Ensotina eschscholtzii: north american salamander- populations are separated along eastern and western California. Hence the salamander evolved into 2 different species
adaptive radiation
evolution of diversely adapted species from a common ancestor
sympatric speciation
a new species can originate in the geographical midst of the parent species
what is polyploidy?
accident during (plant) cell division that result in extra sets of chromosomes
what is an autopolyploid?
an individual that has more than 2 sets of chromosomes, all derived from a single species
what is an allopolyploid?
an individual whose genes are derive from 2 different species
what are exaptations?
structurs that evolve in one context but become co-opted for another fuction
allometric growth
proportioning that helps a body part give its specific form
evolutionary change in the rate or timing of developmental events
the retention in an adult organism of the juvenille features of its early ancestors
homeotic genes
genes that determine structural position and placement of body parts
HOX genes
class of homeotic genes that provide positional information in an animal embryo