Editing Pangenesis (section)

=== After pangenesis ===

Darwin's pangenesis theory was widely criticised, in part for its [[Lamarckism|Lamarckian]] premise that parents could [[inheritance of acquired characters|pass on traits acquired]] in their lifetime.<ref>{{Cite journal |last1=Liu |first1=Yongsheng |last2=Li |first2=Xiuju |date=2014-09-23 |title=Has Darwin's Pangenesis Been Rediscovered? |journal=BioScience |language=en |volume=64 |issue=11 |pages=1037–1041 |doi=10.1093/biosci/biu151 |issn=0006-3568 |doi-access=free}}</ref> Conversely, the neo-Lamarckians of the time seized upon pangenesis as evidence to support their case.<ref name=":6"/> Italian Botanist Federico Delpino's objection that gemmules' ability to self-divide is contrary to their supposedly innate nature gained considerable traction; however, Darwin was dismissive of this criticism, remarking that the particulate agents of smallpox and scarlet fever seem to have such characteristics.<ref name=":5"/> Lamarckism fell from favour after [[August Weismann]]'s research in the 1880s indicated that changes from use (such as lifting weights to increase muscle mass) and disuse (such as being lazy and becoming weak) were not heritable.<ref name="ImaginaryLamarck">{{Cite book |url=http://www.textbookleague.org/ |archive-url=https://web.archive.org/web/20000115220615/http://www.textbookleague.org/ |url-status=usurped |archive-date=January 15, 2000 |title=The Textbook Letter |last=Ghiselin |first=Michael T. |publisher=The Textbook League |date=September–October 1994 |contribution=Nonsense in schoolbooks: 'The Imaginary Lamarck' |author-link=Michael Ghiselin |access-date=2008-01-23 |contribution-url=http://www.textbookleague.org/54marck.htm}}</ref><ref>{{cite book |url=https://books.google.com/books?id=YKJ6gVYbrGwC |title=A History of the Life Sciences |last=Magner |first=Lois N. |publisher=[[Marcel Dekker]], [[CRC Press]] |year=2002 |isbn=978-0-203-91100-6 |edition=Third}}</ref> However, some scientists continued to voice their support in spite of Galton's and Weismann's results: notably, in 1900 Karl Pearson wrote that pangenesis "is no more disproved by the statement that 'gemmules have not been found in the blood,' than the atomic theory is disproved by the fact that no atoms have been found in the air."<ref>{{Cite book |url=https://books.google.com/books?id=PSwRAwAAQBAJ&q=The+Grammar+of+Science&pg=PA1 |title=The Grammar of Science |last=Pearson |first=Karl |publisher=Adam and Charles Black |year=1900 |isbn=9785877362529 |location=London |pages=335 |language=en}}</ref> Finally, the rediscovery of Mendel's Laws of Inheritance in 1900 led to pangenesis being fully set aside.<ref>{{cite book |last1=de Beer |first1=Gavin |title=Charles Darwin: A Scientific Biography |date=1965 |publisher=Doubleday & Company |location=Garden City, NY |page=206}}</ref> Julian Huxley has observed that the later discovery of [[chromosome]]s and the research of [[T. H. Morgan]] also made pangenesis untenable.<ref>{{Cite book |title=Heredity East and West: Lysenko and World Science |last=Huxley |first=Julian |publisher=Henry Schuman |year=1949 |location=New York |pages=11, 141}}</ref>

Some of Darwin's pangenesis principles do relate to heritable aspects of [[phenotypic plasticity]], although the status of gemmules as a distinct class of organic particles has been firmly rejected. However, starting in the 1950s, many research groups in revisiting Galton's experiments found that heritable characteristics could indeed arise in rabbits and chickens following DNA injection or blood transfusion.<ref name=":3">{{Cite journal |last=Liu |first=Yongsheng |date=2008 |title=A new perspective on Darwin's Pangenesis |journal=Biological Reviews |volume=83 |issue=2 |pages=141–149 |doi=10.1111/j.1469-185x.2008.00036.x |pmid=18429766 |s2cid=39953275}}</ref> This type of research originated in the Soviet Union in the late 1940s in the work of Sopikov and others, and was later corroborated by researchers in Switzerland as it was being further developed by the Soviet scientists.<ref name=":8">{{Cite journal |last=Kosin, I. L. and Masaru Kato |date=1963 |title=A failure to induce heritable changes in four generations of the White Leghorn chicken by inter- and intra-specific blood transfusion |url=http://lysvav.narod.ru/VH/Kosin_Kato.pdf |journal=Genetics Research Cambridge |volume=4 |issue=2 |pages=221–239 |doi=10.1017/S0016672300003578 |doi-access=free}}</ref><ref name=":4"/> Notably, this work was supported in the USSR in part due to its conformation with the ideas of [[Trofim Lysenko]], who espoused a version of neo-Lamarckism as part of [[Lysenkoism]].<ref name=":8"/> Further research of this heritability of acquired characteristics developed into, in part, the modern field of [[epigenetics]]. Darwin himself had noted that "the existence of free gemmules is a gratuitous assumption"; by some accounts in modern interpretation, gemmules may be considered a prescient mix of DNA, RNA, proteins, prions, and other mobile elements that are heritable in a non-Mendelian manner at the molecular level.<ref name="Geison69"/><ref name="West=Eberhard08">{{cite journal |last1=West-Eberhard |first1=M. J. |year=2008 |title=Toward a modern revival of Darwin's theory of evolutionary novelty |jstor=10.1086/594533 |journal=Philosophy of Science |volume=75 |issue=5 |pages=899–908 |doi=10.1086/594533 |citeseerx=10.1.1.456.9407 |s2cid=3850453 }}</ref><ref name="Liu09">{{cite journal |last1=Liu |first1=Y. S. |last2=Zhou |first2=X. M. |last3=Zhi |first3=M. X. |last4=Li |first4=X. J. |last5=Wan |first5=Q. L. |year=2009 |title=Darwin's contributions to genetics |url=http://jay.up.poznan.pl/JAG/pdfy/2009_Volume_50/2009_Volume_50_3-177-184.pdf |url-status=dead |journal=J Appl Genetics |volume=50 |issue=3 |pages=177–184 |doi=10.1007/BF03195671 |pmid=19638672 |s2cid=19919317 |archive-url=https://web.archive.org/web/20120330163705/http://jay.up.poznan.pl/JAG/pdfy/2009_Volume_50/2009_Volume_50_3-177-184.pdf |archive-date=2012-03-30}}</ref> Liu points out that Darwin's ideas about gemmules replicating outside of the body are predictive of ''in vitro'' gene replication used, for instance, in [[Polymerase chain reaction|PCR]].<ref name=":4"/>