Evolutionary Biology - Station 11
  • Darwin and Theory
  • Evidence
  • Hardy-Weinberg
  • Mechanism
  • Speciation
  • Origin Of Life
  • Credits
  • Video
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Some scientists believe that a man-made mass extinction may occur in the coming years. Just to let you know.
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Would this be considered allopatric or sympatric separation?
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An example of a small phylogenetic tree
Speciation
  • Speciation refers to the origin of new species
  • A species is defined as group of members who have the potential to breed & create viable offspring.
  • Reproductive isolation is the existence of barriers that prevent 2 species producing viable offspring.
  • Allopatric refers to geographic separation while sympatric is when species still live in same area
  • There are many types of isolation that organisms encounter: geographic, ecological, temporal, behavioral, mechanical and gametic ​
Phylogenetics
  • All of life is related through one common ancestor and phylogeny is the evolutionary history of these relationships
  • A phylogenetic tree is a diagram made to showcase this history.
  • To read a phylogenetic tree one must understand a few terms:
  • Lineage: An ancestor and its descendant populations. These are represented as a line drawn on a time axis
  • Node: Is when a single lineage divides into 2 separate lines. On a phylogenetic tree, these are depicted as a split.
  • Root: Is the common ancestor to all the organisms in the tree. It is always the oldest organism from the graph and the farthest from present day species.
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  • Darwin and Theory
  • Evidence
  • Hardy-Weinberg
  • Mechanism
  • Speciation
  • Origin Of Life
  • Credits
  • Video