main points - jakegoheen.com
TRANSCRIPT
Main Points
1) Defining “mammal”
-- taxonomic perspective
-- evolutionary perspective
-- distinguishing features among classes within
Subphylum Vertebrata
2) Discussion of Ceballos and Ehrlich 2009
3) Characteristics of mammals
-- internal soft anatomy
-- external anatomy
-- will discuss skull in lab
Terms: cladogram, clade, amnion, homeothermy, derived
character, ancestral/primitive character, convergence,
homology, pelage, vibrissae, adaptive coloration (disruptive,
aposematic, cryptic)1
Kingdom Animalia (~1,200,000 species)
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Some taxonomic perspective
Kingdom Animalia (~1,200,000 species)
Phylum Chordata (~63,000 species)
-- dorsal hollow nerve cord (at least in embryos)
-- notochord
-- gill slits
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Some taxonomic perspective
Kingdom Animalia (~1,200,000 species)
Phylum Chordata (~63,000 species)
-- dorsal hollow nerve cord (at least in embryos)
-- notochord
-- gill slits
Subphylum Vertebrata (~60,000 species)
-- backbone (vertebral column)
-- braincase
-- internal skeleton
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Some taxonomic perspective
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How do vertebrates differ from each other?
• presence of amnion = fluid to protect egg or embryo
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How do vertebrates differ from each other?
• two, three, or four-chambered heart
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How do vertebrates differ from each other?
• homeothermy = near-constant body temperature
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Convergence versus homology
fossorial
marsupial
(marsupial mole)
fossorial
rodent
(western pocket
gopher)
fossorial
afrosoricid
(golden mole)
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Convergence versus homology
nectarivore (Anoura)
frugivore (Chiroderma)
sanguinivore (Desmodus)
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Sauropsida
(split occurred
~200-250 MYA)12
Kingdom Animalia (~1,200,000 species)
Phylum Chordata (~63,000 species)
-- dorsal hollow nerve cord
-- notochord
-- gill slits
Subphylum Vertebrata (~60,000 species)
-- backbone
-- braincase
-- internal skeleton
Class Mammalia (~5,400 species)
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Some taxonomic perspective
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Roughly three years ago…
olinguito (Bassaricyon neblina)
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Roughly two years ago…
little black tapir (Tapirus kabomani)
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Roughly 8 months ago…
skywalker hoolock gibbon (Hoolock tianxing)
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The global distribution of newly discovered mammals
(Ceballos and Ehrlich 2009)
• roughly 1/10th of the world’s mammals discovered
since 1993
• many of these “morphologically distinct”
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Discussion Q: look at this figure. Can you put it into words?
1) glandular skin: sweat glands
Some internal characteristics of mammals
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1) glandular skin: sweat glands
mammary glands (modified sweat glands)
Some internal characteristics of mammals
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1) glandular skin: sweat glands
mammary glands (modified sweat glands)
scent and musk glands
Some internal characteristics of mammals
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1) glandular skin: sweat glands
mammary glands (modified sweat glands)
scent and musk glands
venom glands (not diagnostic)
Some internal characteristics of mammals
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2) young develop in female’s uterus (excepting Prototherians)
Some internal characteristics of mammals
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2) young develop in female’s uterus (excepting Prototherians)
3) large brain, relative to other vertebrates
Some internal characteristics of mammals
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2) young develop in female’s uterus (excepting Prototherians)
3) large brain, relative to other vertebrates
4) well-developed facial muscles
Some internal characteristics of mammals
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1) hair: vibrissa (plural: vibrissae)
guard hairs
under hairs
Some external characteristics of mammals
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Adaptive coloration
• Disruptive coloration
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Adaptive coloration
• Aposematic coloration
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Adaptive coloration
• Cryptic coloration
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