Under natural conditions, which of the following may cause allele frequencies to change? a. limited resources, which could cause one allele to have an advantage b. a random assortment of alleles during sexual reproduction c. no emigration from the population d. no immigration into the population

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.