The effect of inbreeding on natural selection in a seed-feeding beetle Article

The effect of inbreeding on natural selection in a seed-feeding beetle - Article Example The objective of the study is to understand whether offspring survival related to egg size is affected by inbreeding or not. To conduct the experiment beetle population was collected from Acacia gregii and bred in the laboratory for almost 12 generation before experimentation. Seed pods from both A. greggii and P.florida trees were used to fulfill the seeds requirement in the experiment and the seeds of the individual trees were thoroughly mixed to control seed coat variation among the seeds. Following the experimental design outbred females were mated with one sibling or non-sibling outbred male beetle after which the female laid their eggs on P.florida to record survival of all the offspring while A.greggii was used for rearing owing to the high rate of larval survival. These first generation adults when emerged from the seeds were used to create a second generation of both inbred and outbred offspring. The beetle pair was put in Petri dishes containing 20 seeds of P.florida and only one larva per seed was allowed to develop inside a chamber controlled at a temperature of 29-30 degrees. In the experimen t, 2-3 eggs were measured per Petri dish using a dissecting scope and finally 460 eggs from females mated to sibling males and 512 eggs from females mated to non-sibling males were collected. To illustrate the relation between the offspring survival and the size of the egg GAM model and linear probability models were used. The conclusive results showed that egg size did not differ much between females that were inbred and out bred; however, inbreeding vastly affected the survival rate. Eggs resulting from outbreeding survived more than those that were inbred. The values for egg to adult survival 0.66 in case of outbred offspring but a reduction of about 29.5% was seen in case of inbred ones. Linear probability model revealed that larva from larger eggs survived more than those emerging from smaller ones. It was evident from the logistic regression