Editing Fossil (section)

=== Modern era ===
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|quote = The fossil record is life's evolutionary epic that unfolded over four&nbsp;billion years as environmental conditions and genetic potential interacted in accordance with natural selection.|source = The Virtual Fossil Museum<ref>{{cite web| url=http://www.fossilmuseum.net/| title=The Virtual Fossil Museum – Fossils Across Geological Time and Evolution| access-date=4 March 2007| archive-url=https://web.archive.org/web/20070308145410/http://www.fossilmuseum.net/| archive-date=8 March 2007| url-status=live}}</ref>|width = 40%|bgcolor =}}

Paleontology has joined with [[evolutionary biology]] to share the interdisciplinary task of outlining the tree of life, which inevitably leads backwards in time to Precambrian microscopic life when cell structure and functions evolved. Earth's deep time in the Proterozoic and deeper still in the Archean is only "recounted by microscopic fossils and subtle chemical signals."<ref>Knoll, A, (2003) Life on a Young Planet. (Princeton University Press, Princeton, NJ)</ref> Molecular biologists, using [[phylogenetics]], can compare protein [[amino acid]] or [[nucleotide]] sequence homology (i.e., similarity) to evaluate taxonomy and evolutionary distances among organisms, with limited statistical confidence. The study of fossils, on the other hand, can more specifically pinpoint when and in what organism a mutation first appeared. Phylogenetics and paleontology work together in the clarification of science's still dim view of the appearance of life and its evolution.<ref>{{cite book |editor=Donovan, S. K.|editor2=Paul, C. R. C.|date= 1998 |chapter=An Overview of the Completeness of the Fossil Record |title=The Adequacy of the Fossil Record |pages=111–131 |publisher=Wiley |location= New York |isbn=978-0-471-96988-4}}</ref>

[[File:Eldredgeops-rana-crassituberculata.jpg|thumb|[[Phacopid]] [[trilobite]] ''Eldredgeops rana crassituberculata''. The genus is named after [[Niles Eldredge]]]]

[[Niles Eldredge]]'s study of the ''[[Phacops]]'' [[trilobite]] genus supported the hypothesis that modifications to the arrangement of the trilobite's eye lenses proceeded by fits and starts over millions of years during the [[Devonian]].<ref>[[Fortey, Richard]], ''Trilobite!: Eyewitness to Evolution''. Alfred A. Knopf, New York, 2000.</ref> Eldredge's interpretation of the ''Phacops'' fossil record was that the aftermaths of the lens changes, but not the rapidly occurring evolutionary process, were fossilized. This and other data led [[Stephen Jay Gould]] and Niles Eldredge to publish their seminal paper on [[punctuated equilibrium]] in 1971.

[[Synchrotron]] [[X-ray]] [[Tomography|tomographic]] analysis of early Cambrian bilaterian [[embryo]]nic microfossils yielded new insights of [[Animal|metazoan]] evolution at its earliest stages. The tomography technique provides previously unattainable three-dimensional resolution at the limits of fossilization. Fossils of two enigmatic bilaterians, the worm-like ''[[Markuelia]]'' and a putative, primitive [[protostome]], ''[[Pseudooides]]'', provide a peek at [[germ layer]] embryonic development. These 543-million-year-old embryos support the emergence of some aspects of [[arthropod]] development earlier than previously thought in the late Proterozoic. The preserved embryos from [[China]] and [[Siberia]] underwent rapid [[Diagenesis|diagenetic]] phosphatization resulting in exquisite preservation, including cell structures.{{Technical inline|date=May 2021}} This research is a notable example of how knowledge encoded by the fossil record continues to contribute otherwise unattainable information on the emergence and development of life on Earth. For example, the research suggests ''Markuelia'' has closest affinity to priapulid worms, and is adjacent to the evolutionary branching of [[Priapulida]], [[Nematode|Nematoda]] and [[Arthropod]]a.<ref>{{cite journal | last1 = Donoghue | first1 = PCJ | last2 = Bengtson | first2 = S | last3 = Dong | first3 = X | last4 = Gostling | first4 = NJ | last5 = Huldtgren | first5 = T | last6 = Cunningham | first6 = JA | last7 = Yin | first7 = C | last8 = Yue | first8 = Z | last9 = Peng | first9 = F | year = 2006 | title = Synchrotron X-ray tomographic microscopy of fossil embryos | journal = Nature | volume = 442 | issue = 7103| pages = 680–683 | doi=10.1038/nature04890| pmid = 16900198 |display-authors= etal | bibcode = 2006Natur.442..680D | s2cid = 4411929 }}</ref>{{Technical inline|date=May 2021}}

Despite significant advances in uncovering and identifying paleontological specimens, it is generally accepted that the fossil record is vastly incomplete.<ref name="foote1999">{{cite journal | last1 = Foote | first1 = M. | last2 = Sepkoski | first2 = J.J. Jr | title = Absolute measures of the completeness of the fossil record | date = 1999 | journal = Nature | volume = 398 | issue = 6726 | pages = 415–417 | doi = 10.1038/18872| pmid = 11536900 | bibcode = 1999Natur.398..415F | s2cid = 4323702 }}</ref><ref name="benton2009">{{cite journal | last = Benton | first = M. | date = 2009 | title = The completeness of the fossil record | journal = Significance | volume = 6 | issue = 3 | pages = 117–121 | doi = 10.1111/j.1740-9713.2009.00374.x| s2cid = 84441170 | doi-access = free }}</ref> Approaches for measuring the completeness of the fossil record have been developed for numerous subsets of species, including those grouped taxonomically,<ref name="zliobaite2021">{{cite journal | last1 = Žliobaitė | first1 = I. | last2 = Fortelius | first2 = M. | date = 2021 | title = On calibrating the completometer for the mammalian fossil record | journal = Paleobiology | volume = 48 | pages = 1–11 | doi = 10.1017/pab.2021.22| s2cid = 238686414 | doi-access = free }}</ref><ref name="eiting2009">{{cite journal | last1 = Eiting | first1 = T.P. | last2 = Gunnell | first2 = G.G | title = Global Completeness of the Bat Fossil Record | journal = Journal of Mammalian Evolution | date = 2009 | volume = 16 | issue = 3 | pages = 151–173 | doi = 10.1007/s10914-009-9118-x| s2cid = 5923450 }}</ref> temporally,<ref name="brocklehurst2012">{{cite journal | title = The Completeness of the Fossil Record of Mesozoic Birds: Implications for Early Avian Evolution | last1 = Brocklehurst | first1 = N. | last2 = Upchurch | first2 = P. | last3 = Mannion | first3 = P.D. | last4 = O'Connor | first4 = J. | journal = PLOS ONE| date = 2012 | volume = 7 | issue = 6 | page = e39056 | doi = 10.1371/journal.pone.0039056| pmid = 22761723 | pmc = 3382576 | bibcode = 2012PLoSO...739056B | doi-access = free }}</ref> environmentally/geographically,<ref name="retallack1984">{{cite journal | title = Completeness of the rock and fossil record: some estimates using fossil soils | last = Retallack | first = G. | journal = Paleobiology | volume = 10 | issue = 1 | date = 1984 | pages = 59–78 | doi = 10.1017/S0094837300008022| bibcode = 1984Pbio...10...59R | s2cid = 140168970 }}</ref> or in sum.<ref name="benton1994">{{cite journal | last1 = Benton | first1 = M.J. | last2 = Storrs | first2 = G.Wm. | title = Testing the quality of the fossil record: Paleontological knowledge is improving | journal = Geology | date = 1994 | volume = 22 | number = 2 | pages = 111–114 | doi = 10.1130/0091-7613(1994)022<0111:TTQOTF>2.3.CO;2| bibcode = 1994Geo....22..111B }}</ref><ref name="holland1999">{{cite journal | last1 = Holland | first1 = S.M. | last2 = Patzkowsky | first2 = M.E. | date = 1999 | volume = 27 | number = 6 | pages = 491–494 | doi = 10.1130/0091-7613(1999)027<0491:MFSTFR>2.3.CO;2 | title = Models for simulating the fossil record| journal = Geology | bibcode = 1999Geo....27..491H }}</ref> This encompasses the subfield of [[taphonomy]] and the study of biases in the paleontological record.<ref name="koch1978">{{cite journal | last = Koch | first = C. | title = Bias in the published fossil record | journal = Paleobiology | volume = 4 | number = 3 | pages = 367–372 | doi = 10.1017/S0094837300006060 | date = 1978| bibcode = 1978Pbio....4..367K | s2cid = 87368101 }}</ref><ref name="signor1982">{{cite book | last1 = Signore | first1 = P.W. III | last2 = Lipps | first2 = J.H. | chapter = Sampling bias, gradual extinction patterns and catastrophes in the fossil record | title = Geological Implications of Impacts of Large Asteroids and Comets on the Earth | series = Geological Society of America Special Papers | year = 1982 | volume = 190 | editor-last1 = Silver | editor-first1 = L.T. | editor-last2 = Schultz | editor-first2 = P.H. | pages = 291–296 | doi = 10.1130/SPE190-p291| isbn = 0-8137-2190-3 }}</ref><ref name="vilhena2013">{{cite journal | last1 = Vilhena | first1 = D.A. | last2 = Smith | first2 = A.B. | title = Spatial Bias in the Marine Fossil Record | journal = PLOS ONE| volume = 8 | number = 10 | page = e74470 | doi = 10.1371/journal.pone.0074470 | date = 2013| pmid = 24204570 | pmc = 3813679 | bibcode = 2013PLoSO...874470V | doi-access = free }}</ref>