Clark, and Willie J.
Rapid evolution of reproductive proteins in abalone and Drosophila. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences — A review of abalone sperm-egg and Drosophila male accessory gland proteins evolution. The authors favor sexual conflict as a likely explanation for rapid evolution although for most examples the evidence adaptive evolution is limited and can fit other forms of sexual selection without the need to invoke male-female conflict. Singh, Rama S.
Kulathinal, eds. Rapidly evolving genes and genetic systems. Oxford: Oxford Univ. Provides a collection of chapters divided into five sections discussing different aspects of rapid evolutionary change with examples of rapidly evolving genes and genetic systems including, but not limited to, those related to reproduction.
Swanson, Willie J. The rapid evolution of reproductive proteins. Nature Reviews Genetics — A widely cited review article that provides examples from a wide variety of taxa on rapid evolution of reproductive proteins and the potential role of sexual selection. Turner, Leslie M. Causes and consequences of the evolution of reproductive proteins. International Journal of Developmental Biology — Discusses a common pattern of rapid evolution of reproductive proteins.
The authors make a case for evolutionary biologists to incorporate gene manipulation techniques in order to determine the functional consequences of inferred selective changes during the evolutionary history of reproductive proteins. Users without a subscription are not able to see the full content on this page.
Please subscribe or login. Chapter 14 Rates of sea urchin bindin evolution H. Lessios and Kirk S. Chapter 16 Evolutionary genomics of the sperm proteome Timothy L. Karr and Steve Dorus. Chapter 17 Fast evolution of reproductive genes: when is selection sexual? Alberto Civetta. Chapter 18 Rapid morphological, behavioral, and ecological evolution in Drosophila: comparisons between the endemic Hawaiian Drosophila and the cactophilic repleta species group Patrick M. Chapter 19 Ancient yet fast: rapid evolution of mating genes and mating systems in fungi Timothy Y. Part IV Pathogens and their Hosts.
Chapter 20 Rapid evolution of innate immune response genes Brian P.
Lazzaro and Andrew G. Chapter 23 The rapid evolution of gene expression Carlo G. Chapter 24 Rate variation in the evolution of development: a phylogenetic perspective Artyom Kopp.
Rapidly Evolving Genes and Genetic Syste
Chapter 25 Natural hybridization as a catalyst of rapid evolutionary change Michael L. Arnold, Jennafer A. Hamlin, Amanda N. Brothers, and Evangeline S. Chapter 26 Rapid evolution of pollinator-mediated plant reproductive isolation Annika M. Moe, Wendy L. Clement, and George D. Chapter 27 Sexual system genomics and speciation Rob J. Kulathinal and Rama S. End Matter Index.
All rights reserved. Rapidly evolving genes have extremely high rates of amino acid change. As genome sequencing has become more affordable, this general trend is seen in a wide variety of other sequenced species, such as primates, rodents, fruit flies and butterflies.
Our lab also found an important protein involved in forming the egg coat in primates to be rapidly evolving, and other studies have found a variety of other rapidly evolving sperm—egg proteins in different species. Figure 4. Abalone historically have had overlapping ranges along the coast of California.
Because they are external fertilizers, their sperm and eggs mix together in ocean water. Their sperm—egg protein interactions must be specific to each species to prevent hybridization. Rapid evolution has been detected in abalone reproductive genes, even within these closely related species, which has led to diversification. In particular, researchers in the Vacquier and Swanson labs are using the abalone system to study species specificity of sperm and egg binding. Historically, abalone species lived in overlapping boundaries across the coast of the western United States. They provide an ideal system for studying reproduction and species specificity, because even though species of abalone have overlapping ranges and spawning times, there is very little hybridization between species.
This fact indicates that there must be some type of species specificity happening at the sperm—egg level. Researchers can use a conservative test for rapid evolution to study changes in sperm and egg genes Figure 3. Indeed, we see that rapid changes have led to the extreme diversification of reproductive genes, even within closely related species of abalone Figure 4. Why are reproductive genes so diverse, in some cases evolving much faster than immunity and defense genes that are under constant pressure because of microbial attacks? Every sexually reproducing organism has its own unique strategy for attracting mates of the opposite sex.
Mating strategies may involve alluring chemicals emitted by one sex, extravagant coloration, extreme size, sexy vocalizations and many other oddities. The male bowerbird works hard to build a colorful nest of rocks, flowers and sticks to entice females. And just like its namesake, the male peacock spider of Australia raises his elaborately colored flaps and dances to attract female onlookers.
The female porcupine, however, prefers a shower of urine from male porcupine suitors before choosing a mate. These bizarre strategies have evolved over time in a complex balance that includes surviving to adulthood time to mate! A trait beneficial for male attractiveness may not necessarily be beneficial for male survival.
For example, the male peacock has a colorful display of feathers irresistible to female peacocks, but which may attract undue attention from predators. The unwieldy tail might cause its demise. To boot, males and females may not have the same interests. This could create a situation in which there is conflict between male and female reproductive genes.
Sexual conflict happens when males and females are in an evolutionary arms race for optimal reproductive potential. Because two parties are involved, what is good for one may not be good for the other. For example, males may be evolving sperm that are better and faster at fusing with the egg than all the other sperm, whereas females may be counteracting these more efficient sperm by evolving eggs that resist quick fertilization to prevent polyspermy.
Darcy or Elizabeth Bennet? In promiscuous species, females mate with many partners during their estrous, or fertile, period. In monogamous species, females mate with one partner during their estrous period—so serial monogamists are included. Depending on a variety of factors, such as availability of resources, promiscuity or monogamy could be adaptive for a species.
In highly promiscuous systems, males are free to sow their wild oats with many different females, giving them high reproductive potential. Figure 5. Primates have diverse mating systems, and closely related species have very different mating habits. This diversity provides an excellent platform for studying its effects on the evolution of reproductive traits and proteins.
Rapidly Evolving Genes and Genetic Systems - Oxford Scholarship
Because of their diverse mating systems, primates provide an excellent system to study how mating system differences have affected reproductive trait and protein evolution See Figure 5. Even between closely related species, such as humans and bonobos, mating systems differ dramatically. Humans are mostly monogamous, and bonobos are some of the most promiscuous primates—a female bonobo may mate up to 50 times with different males during a single estrous period. Many studies have shown that in more promiscuous mating systems, size differences between the sexes, testes size in males, complex genital morphology and other morphological, behavioral and molecular traits areexaggerated.
Thus, promiscuity and competition between males influence the evolution of complex sexual structures. Figure 6. Image from P. Brennan, et al. Proceedings of the Royal Society B Why is there so much diversity in reproductive traits and genes? Sexual selection favors genes that give a reproductive advantage, and these genes can increase over time in a given population. In our peacock example, natural selection would not favor the male peacock tail, because it decreases survival by increasing predation, but sexual selection through female preference favors an otherwise unfavorable trait.
Although Darwin briefly discussed sexual selection in On the Origin of Species , modern interpretations of sexual selection group it into two parts: precopulatory sexual selection before sex or mating occurs and postcopulatory sexual selection after sex occurs.