slide deck summer 2020

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http://fav.me/dcg0d31
What is a
Species?

2. Learning Objectives
• Define a biological species.
• Describe the forces that lead to the evolution of new
species.
• Categorize the various reproductive isolating
mechanisms.
• Compare and contrast several forms of prezygotic and
postzygotic barriers to reproduction.
• Compare and contrast allopatric and sympatric
mechanisms of speciation.
• Identify the proper way to name a biological species.
• Describe different species concepts.
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4. https://www.youtube.com/watch?v=lv
AUgFb1cLY
https://www.youtube.com/watch?v
=vDpydv6VbtU
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What is a species?

5. Figure 24.4

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8. https://www.youtube.co
m/watch?v=-XVMfNIJ53I 8

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12. Biological Species Concept
•1.
•2.
•3.
Ernst Mayr
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14. Other Species Concepts
• Morphological S. C.
• Evolutionary Lineage Concept
• Ecological S. C.
• General Lineage Concept
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15. Reproductive Isolation
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16. Reproductive Isolating
Mechanisms
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17. Reproductive Barriers Cause Speciation
Section 14.2 Figure 14.4
Prezygotic reproductive barriers =
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18. Practice!
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19. Reproductive Barriers Cause Speciation
Section 14.2
Postzygotic reproductive barriers =
Figure 14.4
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20. Reproductive Barriers Cause Speciation
Section 14.2 Figure 14.24
Stilts: ©Tim Fitzharris/Minden Pictures; Sperm: ©Francis Leroy, Biocosmos/Science Source; Chick: ©S.
Alden/PhotoLink/Getty Images RF; Stilt: USDA Natural Resources Conservation Service
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21. Spatial Patterns of Speciation
Section 14.3 Figure 14.5
Reproductive barriers arise in three ways, depending
on spatial patterns:
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22. Spatial Patterns of Speciation -
Allopatric
Section 14.3 Figure 14.5
In allopatric speciation,
a barrier physically
separates a population
into two groups that
cannot interbreed.
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23. Spatial Patterns of Speciation
Section 14.3 Figure 14.7
For example, Galápagos tortoises diverged into several subspecies
on different islands.
Left & right tortoise: ©Tui De Roy/Minden Pictures
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24. Spatial Patterns of Speciation -
Sympatric
Section 14.3 Figure 14.5
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25. Spatial Patterns Define Three
Types of Speciation
Section 14.3 Figure 14.9
Cichlid fish have
diversified into several
species in a small
African lake.
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26. Spatial Patterns Define Three
Types of Speciation
Section 14.3 Figure 14.10
Sympatric speciation also occurs
when gametes unite to form
polyploid offspring with more
chromosomes than either parent.
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27. Figure 24.11

28. Figure 24.8

29. Apply the
Scientific
Method
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30. Naming species
Carl von Linné
AKA Carolus Linnaeus
1707-1778
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31. Binomial nomenclature
• 2-part name, Latinized
Genus + specific epithet
= Species name (scientific name)
• Typed in Italics
• Underlined when handwritten
• Examples:
Homo sapiens Homo neanderthalensis
Canis lupus Canis latrans
Crotalus atrox Crotalus horridus
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32. Taxonomic Hierarchy
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