Kin selekcija, altruizam i teorija igara

undergraduate thesis

• Title (english): Kin selection, altruism and game theory
• Author: Lucija Mijanović
• Mentor: Damjan Franjević (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2015, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

U evolucijskoj biologiji, za organizam se kaže da se ponaša altruistično kada svojim ponašanjem omogućuje recipijentu dobrobit u vidu povećanja fitnesa na štetu vlastitog. Nakon što je primjećeno, takvo ponašanje je uzrokovalo velik interes biologa jer je naizgled u suprotnosti sa glavnim postavkama Darwinove teorije evolucije. Zašto bi se organizam ponašao na način da smanjuje vlastiti fitnes, te kako je moguće da prirodnom selekcijom takvo ponašanje nije nestalo? Prve teorije su išle u smjeru grupne selekcije, koja je glasila da se jedinka žrtvuje za dobrobit skupine, no vrlo brzo su primjećeni njeni nedostatci. Prvi veliki korak naprijed je napravio W. D. Hamilton, koji je postavio teoriju kin selekcije 1964. Pomaganjem srodniku organizam će povećati šanse za širenje gena koje oboje dijele, čime altruist povećava svoj inkluzivni fitnes. Objasnio je to matematičkim modelom koji uzima u obzir cijenu i dobrobit koju imaju altruist i srodnik od tog ponašanja, te njihovu povezanost (r x B > C). No primjećeni su i slučajevi altruizma koje kin selekcija ne objašnjava, jer donor i recipijent nisu srodnici. Taj dio zagonetke je riješio Robert Trivers 1971., predloživši teoriju recipročnog altruizma. Organizam će pomoći drugome ukoliko postoji vjerojatnost da će mu se pomoć uzvratiti. Ukoliko se uspije uspostaviti suradnja, obje jedinke profitiraju i suradnja se nastavlja. Njegovu teoriju su poduprli dokazi iz evolucijske teorije igara, te se danas uz kin selekciju smatra glavnim objašnjenjem za altruizam i suradnju u prirodi.

Abstract (english)

In evolutionary biology, an organism is said to behave altruistically when its behaviour causes fitness benefit to the recipient, at a cost to its own. Biologists became very interested in that kind of behaviour because it seemed contradictory to Darwin's theory of evolution. Why would an organism behave in a way that reduces its fitness and why has it not been eliminated by natural selection? First theories favored group selection, whose idea was that an organism sacrifices itself for the benefit of the group, but the shortcomings of the idea soon became obvious. First important progress was made by W. D. Hamilton in 1964., who proposed kin selection theory. By helping a relative, an organism increases chances in propagation of mutually shared genes, which in turn increases its inclusive fitness. He proposed a model which takes into account cost and benefit for altruist and recipient, and their relatedness (r x B > C). But altruism was noticed between non-kin too, so kin selection couldn't grasp the whole picture. That part of the puzzle was solved by Robert Trivers in 1971., who proposed reciprocal altruism theory. An organism will help another if he can expect help in return. If two organisms manage to establish cooperation, both of them benefit so cooperation will be maintaned. His theory was supported with evidence from evolutionary game theory, and today it's considered a main explanation for altruism and cooperation, next to kin selection.

• Keywords: kin selekcija; altruizam; teorija igara
• Keywords (english): kin selection; altruism; game theory
• Language: croatian
• URN:NBN: urn:nbn:hr:217:497711
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-12-15 11:27:54