Polymorphism, variation and evolutionary change in early vertebrates from the Gogo Formation, Western Australia

The imperfection of the fossil record was used by Charles Darwin to explain the lack of evidence for 'organs of extreme perfection and complication', which under his theory of natural selection must have evolved through a series of gradual transitions. In addition, a major premise in the t...

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Main Author: Trinajstic, Kate
Format: Journal Article
Published: Royal Society of Western Australia 2009
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/6197
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author Trinajstic, Kate
author_facet Trinajstic, Kate
author_sort Trinajstic, Kate
building Curtin Institutional Repository
collection Online Access
description The imperfection of the fossil record was used by Charles Darwin to explain the lack of evidence for 'organs of extreme perfection and complication', which under his theory of natural selection must have evolved through a series of gradual transitions. In addition, a major premise in the theory of natural selection is that variation between organisms is required so selection for particular traits can occur. The fossil record has subsequently revealed a small number of sites comprising fossils of exceptional preservation including the Gogo Formation of Western Australia. Here a unique Late Devonian (Frasnian) reef fauna, with exceptional three-dimensional preservation of macrofossils combined with unprecedented soft-tissue preservation has preserved examples of the transitional forms and morphological variation Darwin predicted. The most significant discoveries have contributed: insights into reproductive biology, including the oldest known vertebrate embryos and evidence of sexual dimorphism with internal fertilization; the anatomy and variation present in the earliest gnathostomes, the placoderms, provides evidence of directional selection; some of the earliest morphological changes required in the transition from an aquatic to land environment are seen in the primitive tetrapodomorph, Gogonasus.
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spelling curtin-20.500.11937-61972017-01-30T10:51:16Z Polymorphism, variation and evolutionary change in early vertebrates from the Gogo Formation, Western Australia Trinajstic, Kate heterochrony evolutionary trends placoderm Darwin reproduction evolution The imperfection of the fossil record was used by Charles Darwin to explain the lack of evidence for 'organs of extreme perfection and complication', which under his theory of natural selection must have evolved through a series of gradual transitions. In addition, a major premise in the theory of natural selection is that variation between organisms is required so selection for particular traits can occur. The fossil record has subsequently revealed a small number of sites comprising fossils of exceptional preservation including the Gogo Formation of Western Australia. Here a unique Late Devonian (Frasnian) reef fauna, with exceptional three-dimensional preservation of macrofossils combined with unprecedented soft-tissue preservation has preserved examples of the transitional forms and morphological variation Darwin predicted. The most significant discoveries have contributed: insights into reproductive biology, including the oldest known vertebrate embryos and evidence of sexual dimorphism with internal fertilization; the anatomy and variation present in the earliest gnathostomes, the placoderms, provides evidence of directional selection; some of the earliest morphological changes required in the transition from an aquatic to land environment are seen in the primitive tetrapodomorph, Gogonasus. 2009 Journal Article http://hdl.handle.net/20.500.11937/6197 Royal Society of Western Australia fulltext
spellingShingle heterochrony
evolutionary trends
placoderm
Darwin
reproduction
evolution
Trinajstic, Kate
Polymorphism, variation and evolutionary change in early vertebrates from the Gogo Formation, Western Australia
title Polymorphism, variation and evolutionary change in early vertebrates from the Gogo Formation, Western Australia
title_full Polymorphism, variation and evolutionary change in early vertebrates from the Gogo Formation, Western Australia
title_fullStr Polymorphism, variation and evolutionary change in early vertebrates from the Gogo Formation, Western Australia
title_full_unstemmed Polymorphism, variation and evolutionary change in early vertebrates from the Gogo Formation, Western Australia
title_short Polymorphism, variation and evolutionary change in early vertebrates from the Gogo Formation, Western Australia
title_sort polymorphism, variation and evolutionary change in early vertebrates from the gogo formation, western australia
topic heterochrony
evolutionary trends
placoderm
Darwin
reproduction
evolution
url http://hdl.handle.net/20.500.11937/6197