Pests, Plagues & Politics Lecture 4. How Insects Got Where They Are!!. Or Insect Evolution. Key Points Insect Evolution. Evolution by Natural Selection Survival of the Fittest The 5 Principles How is Paleoentomology important? Evolutionary Timeframes Important events in insect evolution.
“I have called this principle,
by which each slight variation,
if useful, is preserved, by the term
by the English philosopher Herbert Spencer
Forces (usually environmental change) that select
for (in favor of) those organisms that are best suited
to survive the change.
Selective pressure also selects against those organisms
that are not able to “cope” with change.
oldest salvaged DNA is from an amber termite ca. 100 mya.
CT Scan of an amber
A 100 mya wasp.
A North American Honey Bee
Coleoptera – Aquatic beetle
The Pterygotes: 350 mya
Primitively winged insects known as PALEOPTEROUS
Simple wing articulation
Seen today in the orders:
Odonata = the dragonflies
Ephemeroptera = the mayflies
Mayfly - Ephemeroptera
Neoptera (new or “modern” wing)
Today this covers 97% of all extant species
Ca. 290 mya
(note: soon after the wing flexion mechanism)
utilize favorable aspects of different habitats
for different life stages.
“Humans are not the end result of predictable evolutionary progress, but rather a fortuitous cosmic afterthought, a tinytwig on the enormouslyarborescent bushof life.”--S.J. Gould, 1995