Conversely, numerous instances have been documented whereby insects show kin preference, based on a whole range of processes which include preferred mating protocols, acoustic and visuals clues and pheromone detection.
Females that prevented aggression towards offspring and preferred mating with less aggressive males were most successful.
Evolutionary biologists have theorized that perhaps bird penises vanished because female birds preferred mates with smaller penises.
These findings have been attributed to direct family provisioning (i.e. kin selection, [3]), and to hunters being preferred mating partners due to their high social status, through which they might be signaling their good genes (i.e. costly signaling theory, [4], [5]).
To assess participants' preferred mating strategy (sociosexual orientation), questions forming the 'attitude' and 'desire' subscales of the SOI-R were used [ 3, 13].
Often larger individuals will represent higher quality mates; as described in the previous section, large males in Nasonia vitripennis had larger sperm reserves and were preferred mates based on their pheromone profiles (Ruther et al., 2007, 2009; Steiner & Ruther, 2009).
Key issues included low quality of the radiation-sterilised mass-reared flies, economical production of sufficient numbers of sterilised flies, and assortative mating of released and wild populations because of different preferred mating times [ 5- 7].
In 1860, he wrote Asa Gray: "the sight of a feather in a peacock's tail … makes me sick!" Darwin eventually proposed elaborate peacock trains could evolve if peahens preferred mating with peacocks that had elaborate trains.
It is not yet clear to what extent a male will prefer mate guarding over extra-pair fertilizations.
The Verhulst death probabilities depend on the phenotype, and so does the mating preference: females prefer mating partners with the largest (smallest) phenotype, if their own phenotype is larger smaller) than average.
