Question

how would evolution affect this table
5. Feral pigeons (Columba livia domestica) have long been considered the most frustrating pest bird. Flocks of these pigeons pose a threat to crops, livestock, and human health as their large numbers can decimate crops and act as disease vectors for pathogens that affect both livestock and humans. However, in places like New York's Washington Square Park, pigeons are well-loved and well-fed members of the community. Controlling these pigeon populations has been a challenge as the mass killings, starving, or poisoning of flocks have been met with public outrage. Researchers set out to find a more humane way of controlling feral pigeon populations, and settled on using nicarbazin bait. Nicarbazin is an avian contraceptive that decreases egg viability by binding to the ZP-3 sperm receptor and decreasing the chances of fertilization. ZP-3 is the receptor that binds the sperm to the surface of the egg at the beginning of fertilization. Nicarbazin has been used successfully to control feral pigeon populations for years. A Nicarbazin-baited population in Washington Square Park displayed a rise in flock numbers, leading researchers to explore the levels of egg viability in the treated populations. They discovered that some birds are affected by the nicarbazin as expected, they produce few viable eggs. However, other birds are producing nearly all viable eggs. Upon further investigation, reproductive researchers have found a mutant allele that alters the shape of ZP-3 receptor and influences the effects of nicarbazin. The mutant allele, Z, at this locus is dominant over the P allele and female pigeons homozygous for Z have the highest egg viability. Pigeons that are heterozygous for this gene have medium egg viability. As part of your summer internship with these researchers, you categorize the 100 female birds in the study population. You count 20 females with high egg viability and 60 females with low egg viability, the rest are in between.

Answer 1

1). The researchers had found that nicarbazin decline production of eggs and the hatchability by conciliation the internal structure of egg and the receptors of the sperm. When it is consumed by a female, the rates of hatchability decreased to around zero with no other side effects.

2). The Z allele is the sex-linked alleles. the male pigeon consists of two Z sex chromosomes and they can be heterozygous for the alleles at that locus whereas the females are hemizygous always, they consists of only single Z allele at that locus. And due to natural selection the sex-linked allele is favoured over the P allele and also Z allele is dominant over the P allele.

3). For the determination if a trait is heritable or not, individuals from both the extremes of the population are mated with their own kind, and the offspring produced by them are raised in the control environment. If there is an average difference between the groups of the offsprings then the given trait is heritable.

4). Selection factor for the resistance to nicarbazin, monensin , and combination of both are done through experimental procedures. From these selection factors it was estimated that the selection in the presence of monensin result into very slight increase in the ability of reproduction.

5). The traces or remains of the species from the past geologic age called as fossils are the evidence that population evolves. These fossils are embedded into the rocks by the natural processes.