Sexual selection

Abstract

Spolna selekcija je selekcija onih karakteristika koje su povezane s reproduktivnim uspjehom i borbom za spolnoga partnera. Takve karakteristike povećavaju šansu jedinke za uspješnim razmnožavanjem i prenošenjem svojih gena na potomstvo. Porijeklo spolne selekcije je u nastanku anizogamnih organizama, odnosno dva spola s različitim gametama i različitim reproduktivnim uspjehom. Spolna selekcija većinom djeluje na muški spol jer oni imaju veći reproduktivni uspjeh, mogu proizvesti više potomstva, a manje ulažu u potomstvo i stoga su manje „ograničavajući“ spol. Dva mehanizma preko kojih djeluje ovaj oblik selekcije su borba mužjaka i odabir ženke. Borbom mužjaka razvijaju se „oružja“, a odabirom ženke „atributi“. Ponekad djeluje i dodatni, treći mehanizam koji se naziva borba spolova ili spolni konflikt. Posljedica spolne selekcije je i različitost između spolova jedinki iste vrste, odnosno spolni dimorfizam. Osim na životinje, spolna selekcija ponekad djeluje i na biljke, prvenstveno, dvospolne biljke cvjetnjače. One spolnom selekcijom stvaraju cvjetove koji su ljepši, uočljiviji i primamljiviji oprašivačima, čime povećavaju svoj reproduktivni uspjeh.Sexual selection is a selection of characteristics that are associated with reproductive success and competition for the mate. Those characteristics increase chances of an individual for successful reproduction and chances of passing their genes to the next generation. The origin of sexual selection is associated with evolution of anisogamous organism, two sexes that produced different gametes and had different reproductive success. Sexual selection mostly operates on males because they have bigger reproductive success, create larger offspring but invest less in it and because of that, they are called less limited sex. This type of selection works thru two mechanism: male to male combat and female choice. Traits or characteristics selected by male to male combat are referred to as "weapons", and traits selected by female choice are called "ornaments". Sometimes, there is a third mechanism called sexual conflict. The consequences of sexual selection are difference between males and females of a species that are called sexual dimorphisms. Besides the animals, sexual selection sometimes operates on plants, primarly on hermaphroditic flowering plants. By sexual selection they create flowers that are more beautiful, noticeble and more attractive to pollinators, which increses their reproductive success