User:Lacy.74/sandbox

Topic: Predator Prey Arms Race

Cruz, João Filipe, Helena Gaspar, and Gonçalo Calado. "Turning the Game Around: Toxicity in a Nudibranch-sponge Predator–prey Association." CHEMOECOLOGY 22.1 (2012): 47-53. Print.

This article is about escalation theory which proposes that the predator-prey relationship is not completely a coevolutionary arms race. This is based on the idea that in a situation with the predator and prey, the prey gets the short end of the stick with either injury or death while the predator has the inconvenience of having to find another meal. A specific case that helps answer the central question is dangerous prey, the evolution of chemical defenses in opisthobranches. This case was tested to find whether the arms race with dangerous prey made them chemically more protected than their prey that technically had the defensive properties first. The results found that the predator acquires its defenses directly from its prey, which allows the retention of the defensive compounds advantageous. This shows that the biological strategy of the prey to harm the predator at the same time permits the escalation of its own defenses and would be great to include as an example of dangerous prey and its effects.

Dietl, Gregory P. "Coevolution Of A Marine Gastropod Predator And Its Dangerous Bivalve Prey." Biological Journal of the Linnean Society 80.3 (2003): 409-36. Print.

This article describes the predator whelk and hard-shelled bivalve preys that were examined to test the question that coevolution was a major driving force in the species interaction. The fossil record of the predation was studied to address the central question as well as the frequency of the predation marks on the prey. The results showed that whelks use their shell to open the shell of their prey, often breaking their own shells as well as their preys. This type of predation lead to larger shelled prey being beneficial and then selected more frequently. At the same time, the predators are then selected for the more efficient at opening the larger shelled prey. This research shows that the predator adaptation was more proficient than the prey antipredatory adaptation. The increase in prey size supports an evolutionary change due to their predators. The increased prey capture efficiency of the predator was also most likely driven by the evolutionary increase in size. Therefore, based on this study dangerous preys do play a role in predator evolution.

Doebeli, Michael. "Genetic Variation and Persistence of Predator-prey Interactions in the Nicholson–Bailey Model." Journal of Theoretical Biology 188.1 (1997): 109-20. Print.

This article assumes predation efficiency depends on quantitative characters in the prey and predator. The study uses the Nicholson and Bailey model to compare to the monomorphic model. They are extending these models by the assumptions made and with a model with multiple diploid loci and additive effects to describe the genetics in both populations to test the presence of genetic variation. Predator-prey coexistence was found to be possible in a genetically variable system where the character adaptations of the prey and predator populations fluctuate. The coexistence is still possible with very high prey carrying capacities in a genetically variable system, which is a different idea than the monomorphic model. This difference shows that genetic variability promotes predator-prey coexistence.

Mougi, Akihiko, and Osamu Kishida. "Reciprocal Phenotypic Plasticity Can Lead to Stable Predator-prey Interaction." Journal of Animal Ecology 78.6 (2009): 1172-181. Print.

This article questions that phenotypic plasticity is a general portion of predator prey interactions. This study models a predator prey system while examining the type of reciprocal phenotypic plasticity that influences the system. This encompasses two scenarios, arms-race interaction or a matching-response interaction. The results showed that adaptive phenotypic plasticity is very apparent in predator prey interactions. The predator and prey interactions showed to be capable of stabilizing during an arms-race interaction. This scenario allows a two one predator, one prey systems where they are loosely coupled and one prey could have a defense. Therefore, this shows that in an arms-race interaction, the phenotypic plasticity can be stable.

Phillips, Ben, and Richard Shine. "When Dinner Is Dangerous: Toxic Frogs Elicit Species‐Specific Responses from a Generalist Snake Predator." The American Naturalist 170.6 (2007): 936-42. Print.

This article uses the idea that predators use asymmetrically strong selection on their prey, where selection is strong for the prey because its life is at stake, while selection is weak for the predator because only its meal is at stake. This system changes when the prey are dangerous toward the predators. The dangerous prey, specifically with toxicity, wouldn’t have any fitness after death, which could allow predators to overcome the toxic defense by waiting to consume the prey. This question was tested with highly venomous snakes that preyed on frogs. Some of the frogs were nontoxic while others were when captured by a predator. Both toxins would degrade within 20 minutes of death. The snakes showed different responses to the different prey types, waiting for the chemical defense to lose its toxicity before consuming. This shows that the prey capture has strong selection during coevolution with dangerous prey.

https://en.wikipedia.org/wiki/Evolutionary_arms_race

This asymmetric example could be more generally seen as the life-dinner principle. The life-dinner principle is the idea that in a situation with the predator and prey, the prey gets the short end of the stick with either injury or death while the predator just has the inconvenience of having to find another meal.

Asymmetrical Arms Race Example
More specific, scientifically researched situations of symmetrical and asymmetrical arms races would be helpful in furthering the credibility of this wiki page. For example, Phillips and Shine’s “When Dinner Is Dangerous: Toxic Frogs Elicit Species‐Specific Responses from a Generalist Snake Predator”. Also it could be beneficial to separate Symmetrical Arms Races and Asymmetrical Arms Races so readers could clearly see the difference between the two.

Rough-skinned Newt and the Common Garter Snake Example
In the example of the rough-skinned newt and the common garter snake, I think it would be helpful to readers to clarify what type of arms race this specific example is. For example, generally stating that the prey is dangerous and the predator’s with higher tolerance for the toxin have a higher fitness in that environment allowing those predators to have a higher survivability rate than predators with lower tolerance to the toxin, eventually leading the population to evolve.

More examples
More examples given in the wiki page are better when trying to explain to readers the credibility of the scientific research. Another example that could help support this topic would be the Marine Gastropod Predator and it’s dangerous Bivalve Prey. This example involves the co-evolution of both species, which led to larger shelled prey and more skillful predators.

More WIKI Edits

https://en.wikipedia.org/wiki/Evolutionary_arms_race

Predator Whelk and the Hard-Shelled Bivalve Prey
The whelk predators used their own shell to open the shell of their prey, often times breaking both shells of the predator and prey in the process. This led to the fitness of larger-shelled prey to be higher and then more selected for through generations, however, the predator’s population selected for those whom were more efficient at opening the larger-shelled prey (Dietl 2003). This example is an excellent example of asymmetrical arms race because while the prey is evolving a physical trait, the predators are adapting in a much different way.

Floodplain Death Adders and Separate Species of Frogs
Phillips and Shine did a study with the chemical defenses of toxic frogs in response to a snake predator, the floodplain death adders. These snakes eat three types of frogs, one nontoxic, one producing mucus when taken by the predator, and the highly toxic frogs, however, the snakes have also found if they wait to consume their toxic prey the potency decreases. In this specific case, the asymmetry enabled the snakes to overcome the chemical defenses of the toxic frogs after their death (Phillips and Shine 2007). The results of the study showed that the snake became accustomed to the differences in the frogs by their hold and release timing, always holding the nontoxic, while always releasing the highly toxic frogs, with the frogs that discharge mucus somewhere in between. The snakes would also spend generously more time gaped between the release of the highly toxic frogs than the short gaped time between the release of the frogs that discharge mucus. Therefore, the snakes have a much higher advantage of being able to cope with the different frogs defensive mechanisms, while the frogs could eventually increase the potency of their toxic knowing the snakes would adapt to that change as well, such as the snakes having venom themselves for the initial attack (Phillips and Shine 2007). This study showed that even with the dangerous prey, the coevolution is still highly asymmetrical because of the incredible advantage the predators have compared to the prey.

FINAL DRAFT STARTS HERE

Predator Prey Arms Races

Predator-prey coevolution can lead to an evolutionary arms race. While species evolve they accumulate adaptations and the individuals with preferred adaptations will exert a higher fitness and produce more viable offspring into their population. Through this, other species that are in close symbiotic relationships with each other must also evolve. This process is usually referred to as an arms race because the two coevolving species can either be in symmetrical arms race, a tie in the evolutionary race, or asymmetrical arms race, where one species will win the race.

Symmetrical arms race usually deals with two species changing in the same way. More often than not, symmetrical arms race is the consequence of competition over resources like food or habitat. Härdling (1998) modeled the symmetric evolution pattern of resource holding potential (RPH). RPH is a measure of the absolute fighting ability of an individual. The model showed that in conflicts, the winner is determined from the differing RPH and there can only be a symmetric race if the trait’s cost increases faster than a constant rate. An example of this would be plants in their habitat. If the original plant has longer roots, the other plants will not receive as much water and will have to elongate their roots to compete with the original. The plants are competing for the same resource, water, and are changing in the same way, extending their roots.

Asymmetrical arms races are much more common to scientific research because there are so many different kinds of relationships between species that fall under this category. Asymmetrical arms races do not evolve the same type of traits, however, if one evolves, it generates the need in the other species to also evolve in order to survive. This could deal with chemical traits, physical traits, or even personality traits. Predator and prey co evolve asymmetrically because the predator can evolve strategies to deal with the risks of their prey, while the prey is unable to exert selection post mortem (Cruz et al. 2012). Simplified, predator and prey tend to have an asymmetrical selection because while the predator is only risking its meal, the prey is risking its life.

Gregory P. Dietl was able to study the effects of coevolution through fossil records with the two species, predator whelk and the hard-shelled bivalve prey. He tested the question if coevolution was a driving force in the two species’ interactions with one another and was able to determine that it was. The whelk predators used their own shell to open the shell of their prey, often times breaking both shells in the process. This led to the fitness of larger-shelled prey to be higher and then more selected for through generations, however, the predator’s population selected for those whom were more efficient at opening the larger-shelled prey (Dietl 2003). This example is an interesting spin on the arms race and an excellent example of asymmetrical arms race because while the prey is evolving a physical trait, the predators are adapting in a much different way.

Another way of thinking about predator prey coevolution is how well the prey is able to escape the predator; as long as the prey escapes the predators the improved escape tactics will evolve, however, the predators will become more effective in attacking their prey. Mäkeläinen studied the escape reactions of two vole species, the bank vole and the field vole, from the predator weasel. The voles were allowed to either escape horizontally or vertically by climbing. The results showed that the weasel was less likely to follow the climbing voles, the bank voles, while the field voles were followed more frequently. This questions why the field vole would not adapt to the situation and climb the trees as well, though; the arms race is not a simple idea. The defensive mechanisms take generations to evolve and adapt to their environment. This specific case dealt with different habitat-dependent vulnerabilities (Mäkeläinen 2013), the field voles lived in a meadow environment and would instantly use the ground-level escape, while the bank voles lived in a forest and would use tree escape tactics instead. This study shows how many different factors can be involved in the arms race.

A commonly discussed predator prey arms race is the moth and the bat. These are interesting species because of the bat’s use of echolocation in finding their prey. Zeng et al. conducted a study specifically on the effect the moth’s wing scales have on the coevolution between the species. The study shows that moth wings, compared to butterfly wings, are more absorbent at the same frequencies emitted by most bats. While the moths coevolved in attempt to escape their predators, the adaptation barely reduces the detection distances of moths by bats (Zeng 2011). This shows how asymmetrical the predator prey arms race can be, while the prey can evolve and adapt over many generations, such a common symbiotic species of moths and bats, it only changes 5-6% of the prey’s outcome.

A highly researched and studied topic is the reaction of predators with dangerous prey. Predator prey relationships are usually heavily asymmetrical, though; when preys are dangerous it is a more even playing field. Phillips and Shine did a study with the chemical defenses of toxic frogs in response to a snake predator, the floodplain death adders. These snakes eat three types of frogs, one nontoxic, one producing mucus when taken by the predator, and the highly toxic frogs, however, the snakes have also found if they wait to consume their toxic prey the potency decreases. In this specific case, the asymmetry enabled the snakes to overcome the chemical defenses of the toxic frogs after their death (Phillips and Shine 2007). The results of the study showed that the snake became accustomed to the differences in the frogs by their hold and release timing, always holding the nontoxic, while always releasing the highly toxic frogs, with the frogs that discharge mucus somewhere in between. The snakes would also spend generously more time gaped between the release of the highly toxic frogs than the short gaped time between the release of the frogs that discharge mucus. Therefore, the snakes have a much higher advantage of being able to cope with the different frogs defensive mechanisms, while the frogs could eventually increase the potency of their toxic knowing the snakes would adapt to that change as well, such as the snakes having venom themselves for the initial attack (Phillips and Shine 2007). This study showed that even with the dangerous prey, the coevolution is still highly asymmetrical because of the incredible advantage the predators have compared to the prey.

Chemical defenses found within the prey to use against their predators are a popular mechanism but another way preys use chemical defenses are through cues in the predator’s diet that allows the prey to know more about their hunting habits. There are many different types of these cues, such as; predator odor and cues released by disturbed prey, alarm cues, and dietary cues (Surtrisno et al. 2013). The predators would then have to select for a trait to mask their cues through biochemical processes in their digestive tract so that their prey would not be able to detect them as easily.

A separate asymmetrical example is evolution of chemical defenses in opisthobranchs. They evolved from having a shell, an effective defensive organ, to developing chemical defenses, allowing them to lose the energetic cost of carrying around their shell. The idea of this study was the Escalation hypothesis, where it takes the concept of predator and prey, but uses it in a broader sense with an individual and all of its enemies when evolving. As a result, the opisthobranchs are not specifically evolving with one other species but all of their predators (Cruz et al. 2012). This hypothesis suggests that if an individual species has fewer adaptations that allow them to compete with multiple other species, rather than many adaptations to compete with one specific species, they are more likely to survive in a big event.

Alternatively to the escalation hypothesis, phenotypic plasticity was tested in relation to two separate interaction scenarios, an arms-race relationship where the defensive prey is more protective against both predator phenotypes and the offensive predator is a more efficient consumer against both prey phenotypes, or a matching response relationship where the offensive predator consumes more defensive prey and the normal predator consumes more normal prey. The study suggests that a typical arms race relationship has higher stability and more flexibility within the species and that is what leads to stable predator-prey interaction (Mougi 2009). To allow this stable predator-prey interaction, a study was conducted that proved that genetic variability promotes predator-prey coexistence (Doebeli 1997). This study was done to disprove the Nicholson and Bailey monomorphic model, which suggests that predator and prey are unable to coexist in a genetically variable system when the character adaptations fluctuate. Through extending their model and assuming predation efficiency depends on quantitative characters, Doebeli was able to support his final result. This is an important discovery because while predator-prey arms races are common, fluctuating genetic variability is an uncontrollable characteristic of many species and would be difficult to truly evaluate.

Predator-prey arms races are just beginning to be fully understood with major research studies first published within the last fifty years. There are so many different species and each species can relate and react in a distinctive practice. This allows scientists to be able to group these separate main sets and look even further into each relationship, finding similarities and differences within each. The arms race is a very important idea that the scientific world can use to it’s advantage, through using it when working with each specific species or even relating it to our own species and the overwhelmingly relatable human arms race with antibiotic resistance in bacteria, as just one example. This is a great reason predator prey arms races are relevant and imperative to be aware of because while evolution is a slow process, changes are always occurring and there is always more to learn and study.

References Cruz, J.F., H. Gaspar, and G. Calado. 2012. Turning the Game Around: Toxicity in a Nudibranch-sponge Predator–prey Association. CHEMOECOLOGY 22.1: 47-53.

Dietl, G. P. 2003. Coevolution Of A Marine Gastropod Predator And Its Dangerous Bivalve Prey. Biological Journal of the Linnean Society 80.3: 409-36.

Doebeli, M.. 1997. Genetic Variation and Persistence of Predator-prey Interactions in the Nicholson–Bailey Model. Journal of Theoretical Biology 188.1: 109-20.

Härdling, R.. 1999. Arms Races, Conflict Costs and Evolutionary Dynamics. Journal of Theoretical Biology 196.2: 163-67.

Mäkeläinen, S., L. Trebatická, J. Sundell, and H. Ylönen. 2013. Different Escape Tactics of Two Vole Species Affect the Success of the Hunting Predator, the Least Weasel. Behavioral Ecology and Sociobiology 68.1: 31-40.

Mougi, A. and O. Kishida. 2009. Reciprocal Phenotypic Plasticity Can Lead to Stable Predator-prey Interaction. Journal of Animal Ecology 78.6: 1172-181.

Phillips, B, and R. Shine. 2007. When Dinner Is Dangerous: Toxic Frogs Elicit Species‐Specific Responses from a Generalist Snake Predator. The American Naturalist 170.6: 936-42.

Sutrisno, R., P. M. Schotte, and B. D. Wisenden. 2014. Chemical Arms Race between Predator and Prey: A Test of Predator Digestive Countermeasures against Chemical Labeling by Dietary Cues of Prey. Journal of Freshwater Ecology 29.1: 17-23.

Zeng, J., N. Xiang, L. Jiang, G. Jones, Y. Zheng, B. Liu, and S. Zhang. 2011. Moth Wing Scales Slightly Increase the Absorbance of Bat Echolocation Calls. Ed. Wei-Chun Chin. PLoS ONE 6.11: E27190.