Editing Founder effect (section)

==In island ecology==
Founder populations are essential to the study of [[island biogeography]] and [[island ecology]]. A natural "blank slate" is not easily found, but a classic series of studies on founder population effects was done following the catastrophic [[1883 eruption of Krakatoa]], which erased all life on the island.<ref>{{Cite journal |last=Treub |first=Melchior |date=1888 |title=Notice sur la nouvelle flore de Krakatau |url=https://www.biodiversitylibrary.org/item/24955#page/229/mode/1up |journal=Annales du Jardin botanique de Buitenzorg |volume=7 |pages=213–223 |via=Biodiversity Heritage Library}}</ref><ref>{{Cite journal |last=Bordage |first=Edmond |date=1916 |title=Le repeuplement végétal et animal des îles Krakatoa depuis l'éruption de 1883 |url=https://www.persee.fr/doc/geo_0003-4010_1916_num_25_133_8848 |journal=Annales de géographie |volume=25 |issue=133 |pages=1–22 |doi=10.3406/geo.1916.8848}}</ref> Another continuing study has been following the biocolonization of [[Surtsey]], [[Iceland]], a new volcanic island that erupted offshore between 1963 and 1967. An earlier event, the [[Toba catastrophe theory|Toba eruption]] in Sumatra about 73,000 years ago, covered some parts of India with {{convert|3|-|6|m|0|abbr=on}} of ash, and must have coated the [[Nicobar Islands]] and [[Andaman Islands]], much nearer in the ash fallout cone, with life-smothering layers, forcing the restart of their [[biodiversity]].<ref>{{Cite journal|last1=O’Connell|first1=Kyle A.|last2=Oaks|first2=Jamie R.|last3=Hamidy|first3=Amir|last4=Shaney|first4=Kyle J.|last5=Kurniawan|first5=Nia|last6=Smith|first6=Eric N.|last7=Fujita|first7=Matthew K.|date=August 2020|title=Impacts of the Toba eruption and montane forest expansion on diversification in Sumatran parachuting frogs ( Rhacophorus )|url=https://onlinelibrary.wiley.com/doi/10.1111/mec.15541|journal=Molecular Ecology|language=en|volume=29|issue=16|pages=2994–3009|doi=10.1111/mec.15541|pmid=32633832 |bibcode=2020MolEc..29.2994O |s2cid=220384153 |issn=0962-1083}}</ref>

However, not all founder effect studies are initiated after a natural disaster; some scientists study the reinstatement of a species that became locally extinct or hadn't existed there before. A study has been in place since 1958 studying the wolf/moose interaction on [[Wolves and moose on Isle Royale|Isle Royale]] in Lake Superior after those animals naturally migrated there, perhaps on winter ice. Hajji and others, and Hundertmark & Van Daele, studied the current population statuses of past founder effects in [[Corsican red deer]] and Alaskan elk, respectively. Corsican red deer are still listed as an [[endangered species]], decades after a severe bottleneck. They inhabit the Tyrrhenian islands and surrounding mainlands currently, and before the bottleneck, but Hajji and others wanted to know how the deer originally got to the islands, and from what parent population or species they were derived. Through molecular analysis, they were able to determine a possible lineage, with red deer from the islands of [[Corsica]] and [[Sardinia]] being the most related to one another. These results are promising, as the island of Corsica was repopulated with red deer from the Sardinian island after the original Corsican red deer population became extinct, and the deer now inhabiting the island of Corsica are diverging from those inhabiting Sardinia.<ref>{{cite journal |doi=10.1007/s10531-007-9297-9 |title=Phylogeography and founder effect of the endangered Corsican red deer (Cervus elaphus corsicanus) |journal=Biodiversity and Conservation |volume=17 |issue=3 |pages=659–73 |year=2007 |last1=Hajji |first1=Ghaiet M. |last2=Charfi-Cheikrouha |first2=F. |last3=Lorenzini |first3=Rita |last4=Vigne |first4=Jean-Denis |last5=Hartl |first5=Günther B. |last6=Zachos |first6=Frank E. |s2cid=26357327 }}</ref><ref>{{cite journal |doi=10.1007/s10592-009-0013-z |title=Founder effect and bottleneck signatures in an introduced, insular population of elk |journal=Conservation Genetics |volume=11 |pages=139–47 |year=2009 |last1=Hundertmark |first1=Kris J. |last2=Van Daele |first2=Larry J. |s2cid=24280253 }}</ref>

Kolbe and others set up a pair of genetically sequenced and morphologically examined [[lizard]]s on seven small islands to watch each new population's growth and adaptation to its new environment. Specifically, they were looking at the effects on limb length and perch width, both widely varying phenotypic ranges in the parent population. Unfortunately, immigration did occur, but the founder effect and adaptive differentiation, which could eventually lead to peripatric speciation, were statistically and biologically significant between the island populations after a few years. The authors also point out that although adaptive differentiation is significant, the differences between island populations best reflect the differences between founders and their genetic diversity that has been passed down through the generations.<ref>{{cite journal |doi=10.1126/science.1209566 |pmid=22300849 |title=Founder Effects Persist Despite Adaptive Differentiation: A Field Experiment with Lizards |journal=Science |volume=335 |issue=6072 |pages=1086–9 |year=2012 |last1=Kolbe |first1=J. J. |last2=Leal |first2=M. |last3=Schoener |first3=T. W. |last4=Spiller |first4=D. A. |last5=Losos |first5=J. B. |bibcode=2012Sci...335.1086K |citeseerx=10.1.1.363.77 |s2cid=12374679 }}</ref>

Founder effects can affect complex traits, such as song diversity. In the [[Common myna|Common Myna]] (''Acridotheres tristis''), the percentage of unique songs within a repertoire and within‐song complexity were significantly lower in birds from founder populations.<ref>{{Cite journal|last1=Hill|first1=Samuel D.|last2=Pawley|first2=Matthew D. M.|date=2019|title=Reduced song complexity in founder populations of a widely distributed songbird|journal=Ibis|language=en|volume=161|issue=2|pages=435–440|doi=10.1111/ibi.12692|s2cid=92000651|issn=1474-919X}}</ref>

It was found by Tarr et al. (1998) that the loss of heterozygosity of the [[Laysan finch]] (''Telespiza cantans'') after founding events on small islands in the Pacific Ocean closely matched theoretical calculations upon examination of [[microsatellite]] loci.<ref>{{Cite journal |last1=Tarr |first1=C. L. |last2=Conant |first2=S. |last3=Fleischer |first3=R. C. |date=1998 |title=Founder events and variation at microsatellite loci in an insular passerine bird, the Laysan finch ( Telespiza cantans ) |journal=Molecular Ecology |language=en |volume=7 |issue=6 |pages=719–731 |doi=10.1046/j.1365-294x.1998.00385.x|doi-access=free |bibcode=1998MolEc...7..719T }}</ref>