Tuesday, 2 October 2018

Origin and Evolution

           When we study something, history and origin of it are major fields to be explored for they shed more light in understanding the future than anything else. So I thought of giving You guys a brief but a scientific history on butterflies and their evolution.
  • Origin is the beginning of life forms as we discuss in evolution theory
  • Origin and diversification of butterflies over the geologic time is the evolution of butterflies
           Many ancient species, their origins and evolution can be unveiled in fossils, dating back millions of years. However in the case of lepidopterans (butterflies and moths are collectively called as Lepidopterans) fossils are of not such good use. They are delicate creatures and that delicacy prevents them from forming good fossils for us to study. 
           There are only a few well preserved fossils of early lepidopterans (such as the 40 million years old Prodryas persophone of the Eocene).These creatures are remarkably not that different from present day forms. Archaeolepis mane is one of the earliest known lepidopteran fossils which is from lower Jurassic (190 million years ago). 
             There are fossil evidence which dates back 201.3 million years into the Triassic-Jurassic boundary but they are not complete fossils. These fossils suggest a Norian (212 million years ago) divergence of glossatan and non-glossatan lepidopterans in molecular estimates. (van Eldijk, Timo J. B.; Wappler, Torsten; Strother, Paul K.; van der Weijst, Carolien M. H.; Rajaei, Hossein; Visscher, Henk; van de Schootbrugge, Bas (10 January 2018). "A Triassic-Jurassic window into the evolution of Lepidoptera". Science Advances.)

             Many describe that butterflies developed in Cretaceous Period (65 million to 135 million years ago) diverging from a moth lineage. By 80 million years ago all the modern day butterfly families were well differentiated.

              As of many insects, evolution of butterflies are also closely linked with the evolution of flowering plants.

Fossil Papilionid Butterfly Lithopsyche antiqua from Early Oligocene. photo by-Chiswick Chap


           Present day butterflies are classified into two superfamilies,          

  1. Hedyloidea - moth butterflies
  2. Papilionoidea - true butterflies

             

           Superfamily Papilionoidea or true butterflies consists of six distinct families,
  1. Papilionidae - swallowtails, apollos and birdwings
  2. Pieridae - yellows and whites
  3. Nymphalidae - brush footed butterflies
  4. Lycaenidae - blues
  5. Riodinidae - metalmark butterflies
  6. Hespiriidae - skippers (Hespirids were treated as a separate superfamily until recent molecular phylogenetics proved otherwise) 
Phylogenetic relationships of butterfly families


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"Butterflies", Nature's Jewellery by Induru Hettiarachchi is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.