Evolution of insects

Evolution has produced astonishing variety of appendages in insects, such as these antennae.

The most recent understanding of the evolution of insects is based on studies of the following branches of science: molecular biology, insect morphology, paleontology, insect taxonomy, evolution, embryology, bioinformatics and scientific computing. It is estimated that the class of insects originated on Earth about 480 million years ago, in the Ordovician, at about the same time terrestrial plants appeared.[1] Insects are thought to have evolved from a group of crustaceans.[2] The first insects were landbound, but about 400 million years ago in the Devonian period one lineage of insects evolved flight, the first animals to do so.[1] The oldest insect fossil has been proposed to be Rhyniognatha hirsti, estimated to be 400 million years old, but the insect identity of the fossil has been contested.[3] Global climate conditions changed several times during the history of Earth, and along with it the diversity of insects. The Pterygotes (winged insects) underwent a major radiation in the Carboniferous (358 to 299 million years ago) while the Endopterygota (insects that go through different life stages with metamorphosis) underwent another major radiation in the Permian (299 to 252 million years ago).

Most extant orders of insects developed during the Permian period. Many of the early groups became extinct during the mass extinction at the Permo-Triassic boundary, the largest extinction event in the history of the Earth, around 252 million years ago.[4] The survivors of this event evolved in the Triassic (252 to 201 million years ago) to what are essentially the modern insect orders that persist to this day. Most modern insect families appeared in the Jurassic (201 to 145 million years ago).

In an important example of co-evolution, a number of highly successful insect groups — especially the Hymenoptera (wasps, bees and ants) and Lepidoptera (butterflies) as well as many types of Diptera (flies) and Coleoptera (beetles) — evolved in conjunction with flowering plants during the Cretaceous (145 to 66 million years ago).[5][6]

Many modern insect genera developed during the Cenozoic that began about 66 million years ago; insects from this period onwards frequently became preserved in amber, often in perfect condition. Such specimens are easily compared with modern species, and most of them are members of extant genera.

  1. ^ a b "Landmark study on the evolution of insects". Sciencedaily.com. November 6, 2014.
  2. ^ "Linking Insects with Crustacea: Physiology of the Pancrustacea: An Introduction to the Symposium". Oxford Academic. August 5, 2015. Retrieved May 25, 2015.
  3. ^ Haug, Carolin (2017). "The presumed oldest flying insect: More likely a myriapod?". PeerJ. 5: e3402. doi:10.7717/peerj.3402. PMC 5452959. PMID 28584727.
  4. ^ Rasnitsyn, A.P.; Quicke, D.L.J. (2002). History of Insects. Kluwer Academic Publishers. ISBN 978-1-4020-0026-3.[page needed]
  5. ^ J. Stein Carter (2005-03-29). "Coevolution and Pollination". University of Cincinnati. Archived from the original on 2009-04-30. Retrieved 2009-05-09.
  6. ^ Renne, Paul R.; Deino, Alan L.; Hilgen, Frederik J.; Kuiper, Klaudia F.; Mark, Darren F.; Mitchell, William S.; Morgan, Leah E.; Mundil, Roland; Smit, Jan (7 February 2013). "Time Scales of Critical Events Around the Cretaceous-Paleogene Boundary" (PDF). Science. 339 (6120): 684–687. Bibcode:2013Sci...339..684R. doi:10.1126/science.1230492. PMID 23393261. S2CID 6112274.