淘汰 （トウタ） weeding out, elimination (e.g. of unneeded employees), culling, selection, selection (e.g. natural selection)

淘汰作用 （トウタサヨウ） sifting out, weeding out, selection, sorting

淘げる （よなげる） to separate and discard, to sieve and sort, to wash out (impurities, etc.)