Evolution of mating essay
Charles Darwin formalized the evolution of mating many years ago. According to Darwin, mating involves numerous selection processes to reproduce viable offspring. Animals assess their mates as they look for ‘good genes’ to transfer to the next generation. Different scholars have supported Darwin’s notion of sexual selection. For instance, Adam Jones a Texas biologist beliefs female selection of potential mating partners depends on the genetic fitness of a male to increase chances of offspring survival. This explains why peahen submits to specific colored peacocks than others (Castagnone-Sereno,& Danchin, 2014, p. 1325).
The podcast has provided me with an impressive opportunity to learn about the evolution of mating. I was particularly amused when I realized that the sharks invented copulation. I can now appreciate how natural selection has played a significant role in influencing specific traits in the animal. I was also surprised to see how a male shark bites the female pectoral fin (the fin located behind the gill) and arches in a way that allows the male claspers to come into contact with the female genital. Basically, after communicating its intention to a receptive female, the male shark flexes one of the claspers and inserts it into the female cloaca allowing him to deposit sperms (Harrison et al., 2014).
Sexual reproduction has proven to be the best strategy that permits the combination of varied genes that allows the offspring to be more flexible and adaptable to changes in the environment. Before the evolution of sex, reproduction was asexual. Asexual offspring are genetically identical to the parent. Becks & Agrawal (2012) highlighted that asexual reproduction is efficient in transferring identical genes to the offspring without the need for a male. I was particularly amused by the fact that a single female has the potential to establish a new population that has identical genes in a very short duration. Although asexual reproduction is effective in transferring identical genes, species in this category cannot be flexible to changes in the environment (Park, Jokela, & Michalakis, 2010, p.1016). Asexual offsprings have similar genetic makeup which means they share the same genetic weak point. A population sharing the same genetic weak point can be eliminated by the same disease. For instance, if a virus attacks a population sharing similar genetic weak points, the entire population can be eliminated in a very short period ( Miller, 2001).
We have learned different concepts in class which was reflected in the podcast. For instance, Darwin’s theory of sexual selection was reflected in the selection of mating partners in sharks. According to Mostowy & Engelstädter (2012), Darwin maintains that they are specific ‘good traits’ individuals have over others(p. 2037). Males exhibit certain ornate features that attract female mates. These features were reflected by the brightly colored peacock.
In summary, this podcast has provided me with an impressive learning opportunity about the origin of copulation. Sexual reproduction allows offspring to bear varied genetic makeup thus increasing chances of adaptability to changes in the environment.
Discussion board post
The large size of the liger is due to the unequal genetic expression of the cross-breed genes. Typically, the genetic makeup of a liger affects the growth size and longevity of this animal. Since the genetic makeup is unequally shared, genes meant to control growth rate fail to determine when growth should stop. As a result, the liger experiences vigorous growth than normal cats. The big size of the liger is not adaptive but only makes the animal demand more food. The size could be adaptive if the species is facing significant predators since it would scare away any potential enemy. Nature allows this genetic to occur to transfer genetic traits to the next generation. The wholphin is the most interesting animal since it bears both characteristics of a whale shark and a dolphin.
First response
The liger is a cross-breed between a lion and a tiger. The cat has an unequal genetic expression that cannot control the growth rate. This explains why the liger experiences rapid growth within the first few months after birth. I agree the size of the cat is not adaptive since it requires more food to feed. The size can only be adaptive in the wild when the animal is facing predators. Naturally, hybrid animals are sterile. Nature allows such genetic make to exist to pass over ‘good gene’ to the next generation. Since the animal cannot reproduce, the genes come to a dead-end. I think the coywolf is the most interesting animal since it depicts the beautiful characteristic of a Coyote and a Wolf.
Second response
The hybrid liger is a cross-breed between a male lion and a female tiger. These crossbreeds result in the unequal distribution of genetic expression. Genetic confusion of DNA fails to control the growth rate resulting in the rapid development of the cat. I agree that big size is not an adaptive characteristic in the wild. The big size requires more food twice that of a normal lion or a tiger. The size of the animal can be considered adaptive in the wild if the animal is facing predation. Liger is sterile; however, nature allows such genetic traits to exist to transfer good traits to the next generation. I think the Cama is the most interesting animal since it is fertile, unlike other hybrid animals.
References
Becks, L., & Agrawal, A. F. (2012). The Evolution of Sex Is Favoured During Adaptation to New Environments. Journal Of Evolutionary Biology, 10(5), 1-11.
Castagnone-Sereno, P., & Danchin, E. J. (2014). Parasitic success without sex – the nematode experience. Journal Of Evolutionary Biology, 27(7), 1323-1333.
Harrison, E., MacLean, R. C., Koufopanou, V., & Burt, A. (2014). Sex drives intracellular conflict in yeast. Journal Of Evolutionary Biology, 27(8), 1757-1763.
Miller, G. (2001). The mating mind : how sexual choice shaped the evolution of human nature. New York: Anchor Books.
Mostowy, R., & Engelstädter, J. (2012). Host-parasite coevolution induces selection for condition-dependent sex. Journal Of Evolutionary Biology, 25(10), 2033-2046.
Park, A. W., Jokela, J., & Michalakis, Y. (2010). Parasites and deleterious mutations: interactions influencing the evolutionary maintenance of sex. Journal Of Evolutionary Biology, 23(5), 1013-1023.