Insect Evolution

1
Insect Evolution
2
500 400
300 200 100
0
Silurian
Devonian
Carboniferous
Permian
Triassic
Jurassic
Cretaceous
Entognatha
Archaeognatha
Zygentoma
Hexapoda
Ephemeroptera
Odonata
Insecta
Plecoptera
Embiodea
Pterygota
Zoraptera
Dermaptera
Grylloblattodea
?
Mantophasmatodea
Orthoptera
Phasmatodea
Blattaria
Isoptera
Mantodea
Neoptera
Psocoptera
Phthiraptera
Thysanoptera
Hemiptera
Coleoptera
Rhaphidioptera
Megaloptera
Neuroptera
Hymenoptera
Mecoptera
Holometabola
Siphonaptera
Diptera
Apterygotes
Strepsiptera
Trichoptera
Paleoptera
Lepidoptera
Hemimetabolous
Holometabolous
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Relationships among Hexapoda
Collembola
Entognatha
Protura
Diplura
Hexapoda
Archaeognatha
Insecta
Thysanura
Pterygota
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Evolution of the Insects
(Carpenter - 1953) Four stages in insect evolution
4. Development of metamorphosis
3. Development of wing flexion mechanisms
2. Development of wings
1. Appearance of primitive wingless insects
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Stages of Insect Evolution (Carpenter, 1953)
1. Apterygotes
First insect fossils
First terrestrial arthropod fossils
First terrestrial arthropod trace fossils
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Trace Fossils
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Hexapoda Characteristics
1) Fusion of second maxillae
1st maxilla
2nd maxilla
2) Fixation of abdominal segments at 11
3) Loss of jointed abdominal appendages
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Stages of Insect Evolution (Carpenter, 1953)
1. Apterygotes on Land
Devonohexapodus - marine hexapod from the
Devonian
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Stages of Insect Evolution (Carpenter, 1953)
2. Development of wings
a. From what structural elements are wings
composed?
b. For what purpose were wing-like structures
first used?
2. Development of wings
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Stages of Insect Evolution (Carpenter, 1953)
2. Development of wings
1. Paranotal Theory
paranotal lobes
Paleodictyoptera
11
Stages of Insect Evolution (Carpenter, 1953)
2. Development of wings
1. Paranotal Theory
venation
lobes
12
Stages of Insect Evolution (Carpenter, 1953)
2. Development of wings
2. Gill Theory
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Stages of Insect Evolution (Carpenter, 1953)
2. Development of wings
2. Gill Theory
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Stages of Insect Evolution (Carpenter, 1953)
2. Development of wings
2. Gill Theory
Pros
genes in crustaceans for basal legs are
homologous with genes for wing development
Cons
skimming (Marsden) rare in primitive
pterygotes
- most insect ancestors are terrestrial
- aquatic insects appear 100 my after wings
- genetic evidence weak since wings are
polygenic
- Carboniferous insects big wings but no
fossilized aquatic nymphs
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500 400
300 200 100
0
Silurian
Devonian
Carboniferous
Permian
Triassic
Jurassic
Cretaceous
Entognatha
Archaeognatha
Zygentoma
Hexapoda
Ephemeroptera
Odonata
Insecta
Plecoptera
Embiodea
Pterygota
Zoraptera
Dermaptera
Grylloblattodea
?
Mantophasmatodea
Orthoptera
Phasmatodea
Blattaria
Isoptera
Mantodea
Neoptera
Psocoptera
Phthiraptera
Thysanoptera
Hemiptera
Coleoptera
Rhaphidioptera
Megaloptera
Neuroptera
Hymenoptera
Mecoptera
Holometabola
Siphonaptera
Diptera
Strepsiptera
Trichoptera
Lepidoptera
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Stages of Insect Evolution (Carpenter, 1953)
3. Wing Flexion
Ephemeroptera
3. Development of wing flexion mechanisms
Odonata
Ephemeroptera Odonata Paleoptera
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Stages of Insect Evolution (Carpenter, 1953)
3. Wing Flexion
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Stages of Insect Evolution (Carpenter, 1953)
3. Wing Flexion
Development of wing flexion mechanism
1. Neopterous condition
2. Allowed for better running locomotion, etc.
3. Became dominant and today represents 90 of
orders and 97 of species
4. Includes all other modern insects
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Stages of Insect Evolution (Carpenter, 1953)
4. Development of Metamorphosis
Hemimetabolous (Incomplete metamorphosis)
Holometabolous (Complete metamorphosis)
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Stages of Insect Evolution (Carpenter, 1953)
4. Development of Metamorphosis
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Stages of Insect Evolution (Carpenter, 1953)
4. Development of Metamorphosis
Hemimetabolous
Holometabolous
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Stages of Insect Evolution (Carpenter, 1953)
4. Development of Metamorphosis
Evidence for pronymph as holometabolous larva
- First instar cuticle in both secreted at same
time
- Lack wing buds
- Similar reduced nervous systems
- Both have high levels of JH
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500 400
300 200 100
0
Silurian
Devonian
Carboniferous
Permian
Triassic
Jurassic
Cretaceous
Entognatha
Archaeognatha
Zygentoma
Hexapoda
Ephemeroptera
Odonata
Insecta
Plecoptera
Embiodea
Pterygota
Zoraptera
Dermaptera
Grylloblattodea
?
Mantophasmatodea
Orthoptera
Phasmatodea
Blattaria
Isoptera
Mantodea
Neoptera
Psocoptera
Phthiraptera
Thysanoptera
Hemiptera
Coleoptera
Rhaphidioptera
Megaloptera
Neuroptera
Hymenoptera
Mecoptera
Holometabola
Siphonaptera
Diptera
Apterygotes
Strepsiptera
Trichoptera
Paleoptera
Lepidoptera
Hemimetabolous
Holometabolous