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Forums - General Discussion - How Evolution Defines Mass Effect's Aliens

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"Nothing in biology makes sense except in the light of evolution." 
-Theodosius Dobzhansky 

How are the races in Mass Effect related to creatures on Earth, like spiders, sharks, and camels? The answer is in their evolutionary development; how they have taken different routes based on the specifics of the environments they inhabit. 

The Mass Effect series weaves a beautiful tale of science fiction with its diverse species that gamers can easily relate to. The game offers a wealth of information about the fictional universe of ME, and even gamers who would not normally be interested in learning about animal ethology and planetary sciences eagerly read every word written in the codex. By making the ME universe a plausible one, Bioware succeeded in appealing to the curious gamer and paves the way for critical thought. It is only a matter of time before other developers follow suit, and science fiction becomes more than just fiction. 

In Bioware's Mass Effect (ME), each alien species takes a different path to becoming sapient species capable of language, culture, and space travel from their native planets. Naturally, this path is highly affected by the environment that the species inhabits. Evolutionary biology plays an important role in achieving immersion in the 'believable' ME galaxy. With an appreciation of these details, we explore the ways by which each race in ME borrows evolutionary strategies from earth-bound species to create their wildlife, planets, and intelligent aliens. 


Turians, as described in ME, are largely inspired by our own birds of prey (falcons, eagles, etc.). Unlike birds, their reflective metallic skin also forms the basis of an adaptation to their planet's close proximity to their sun and thus the exposure to intense solar radiation. Similar to all apex predators on earth (sharks, eagles, lions, etc.), Turians evolved forward-facing eyes that allow them to track down prey, undifferentiated teeth (similar to that of a crocodile), and talons for pinning and tearing apart prey. 

Although it's difficult to rationalize metallic skin occurring on earth (mineralization of tissues such as skin/feathers restricts their inherent plastic nature), the strategy to reflect intense sunlight is not a novel one. Desert dwelling plants evolved specialized cells (trichomes) and waxes that are capable of creating silvery reflective surfaces (analogous to Turian skin) capable of reflecting infrared radiation. This strategy would make sense considering how the Turian home planet of Palaven also has diverse flora and fauna all able to fashion 'metallic' skins capable of reflecting intense solar radiation. 


In contrast to Turians, Krogans find themselves at the bottom of the food chain on their native planet of Tuchanka. Typical of prey species evolution (toads, fish, deer, etc.), their eyes are side-facing giving them a wider range of view of encroaching predators. Their fast reproductive rates justify their survival in an ecology filled with hungry predators (consider reproductive rates of animals such as rabbits or rodents). Likely due to few and far between meals Krogans likely rely on, their hump (which would be analogous in function to that of a camel or fat storing tails in 'related' reptiles such as geckoes, salamanders, Komodo dragons, etc.) could have evolved to store fat in times of abundance and used up in times of deprivation. 

Similar to invasive species on earth, Krogans took quickly to adapting to novel environments without predation. It should be noted that rapid evolutionary changes often occur in invading species, in part due to rapid reproduction allowing for population-wide adaptive evolution. So, not only would they not succumb to selective pressures of reproductive constraints, but while reproducing, they are getting more opportunities to adapt to new environments (in scales of at least ~20 generations). Examples of these phenomena are found all over our world from purple loosestrife, zebra mussel to the cane toad. 


Drell evolution seems to have paralleled that of reptiles on earth coping with arid environments. Similar to the reptiles, horned scales evolved as a strategy to minimize desiccation (water loss) in their native deserts. Similarly, Drell are given two sets of eyelids, a strategy adapted by several reptiles adapting to a terrestrial environments. Blinking with two eyelids allows eyes to remain wet and clean from debris such as sand and dust. 

From a behavioral point of view, the hyoid bone present in Drell is described as giving them the ability to create sub-vocal sounds outside the human auditory range. In most birds and some reptiles, the hyoid bone serves as the structural foundation for tongue formation and would seem critical to the evolution of communication and speech in a would-be sapient species. Drell are also given an eidetic memory (also known as 'photographic memory') as a strategy for navigating their difficult environment. Although this strategy is seen in elephants and sea lions, eidetic memory (to the degree in which is it described in ME) is rare, if at all existent, in our own evolutionary history. 


The Rachni in ME1 show to be heavily influenced by eusocial (truly social) insects (i.e.: wasps, bees and ants) capable of forming castes within a colony. Unlike other animals, this strategy often forfeits reproductive fitness in individuals in favor of task-specific jobs that benefit the colony as a whole. Depending on the complexity of behavior within a species, you see complexity in the different types of castes (queens, workers, nursing workers, soldiers, super soldiers, etc.). The organization of a eusocial insect colony has allowed for tremendous evolutionary success of such species (having been able to thrive in every terrestrial environment), and could explain the threat Rachni pose in the ME universe. 

Castes seen in Mass Effect equip workers with the ability to suicide-bomb, soldiers with the power to spit out acid, and queens that act as a central hub to the collective consciousness of Rachni individuals. Interestingly, these abilities are seen across several species of ants and bees. Bomber ant workers bear acid-filled glands that explode when faced with adversity, several ant species are known for spraying or injecting formic acid in offense/defense, and practically all queens in social insects heavily control caste ratios and colonization strategies through pheromone cues. 


One of the most striking features of Quarians is their highly-compromised immune system. Members of this species are perpetually confined to the sterile environment of their enviro-suits, since it's considered very risky to venture out of it without good reason. It is easy to imagine that such a vulnerable species would not be able to survive for long. However, we cannot evaluate the success of any species without taking into account its environment. And the Quarian home planet is very different from the many others that they visit or inhabit. Furthermore, it is different from the environment of their migrant fleets. Left to natural selection, Quarians would have either died off or evolved enough to adapt to different environments. However, Quarians are advanced species that can go beyond the dictates of natural selection. Ironically, this is also their downfall. The fact that they are overprotected makes sure that they don't develop a natural immunity against new pathogens, and therefore are more immune-deficient, and more in need of their protective suits. This is one reason why humans develop certain allergies and why attempts at being overtly enthusiastic about hygiene may be misguided. 

In vertebrates, adaptive immunity (which creates pathogen-specific immune cells) evolved through an interaction with both beneficial and harmful microbes that forced a balance between exploiting the good and defending against the bad. Quarians in Mass Effect likely evolved this relationship in a way that relied heavily on benefitting from their surrounding microbiota as opposed to defending against them. This one-way relationship would naturally make them vulnerable outside of their environment. 


Salarians are an amphibious species characterized by high metabolism and a short lifespan. Although the link between metabolism and longevity isn't strongly established, there is evidence that, at least in some birds and reptiles, short-lived species are characterized by higher metabolic rates (ie: garter snakes and hummingbirds). In Mass Effect, Salarian fast metabolism is also accompanied by an increase in mental acuity and an excellent memory. There is no scientific evidence to support this piece of science fiction, although it is known that metabolic disruptions could result in impoverished cognitive ability.

Another interesting feature of Salarians is psychological imprinting, which is a mechanism by which Salarian young defer to the wishes of matriarchs of the families of both parents. This supposedly ensures unity among the members of the group. Psychological imprinting can happen in the young of many species. Parents, grandparents, and various caregivers can do this. However, unlike imprinting in Salarians, it is not an instant act, but rather a long process. Physiological maternal imprinting does happen inside the uterus, but again, is a process and not a single and isolated action.


Since Asari is arguably one of the most sexualized races in the ME universe, we will focus on the science behind their reproduction. 

According to Bioware, Asari are non-gendered species that have the ability to mate with any species of any gender. A more accurate description would be that these species do not have separate sexes, since they clearly exhibit female gender characteristics. 

An Asari mates by "melding", a process by which she attunes her nervous system to that of her partner. Although the offspring is always Asari, the mating partner contributes to the process by providing a "map" to randomize genetic information, thus making the Asari highly biodiverse. The ability to mate with a member of a different species, and to produce viable offspring is not very common, but is known to happen in certain plant and animal species, at least under experimental laboratory conditions. Furthermore, recent work has provided proof of neanderthal-homo sapien interbreeding. This ability would be of tremendous value since it makes Asari adaptive to new environments by impelling rapid evolutionary change. 

Furthermore, an Asari has access to her partner's emotions and memories, and can choose the traits to be passed on to the offspring. This last property is interesting for two main reasons. First, it ensures that change happens at a rate that is faster than genetic evolution, and one that takes into effect cultural and social evolution. Second, it gives the Asari the upper hand in reproduction, since they maintain control over what traits the partner can, in fact, "donate." So far, such freedom to choose certain traits during mating has not been shown in animals. However, "shopping" for desirable traits (especially in females) before mating is very common and advantageous. 


The Yahg are described as apex predators characterized by a strong and agile physique. This physical superiority is paired with a strong capacity to understand/interpret body language in any species. These characteristics have established the Yahg to be leaders of Parnack. Much like other pack-hunting species, the Yahg compete for the position of pack leader, but become loyal followers once a leader is established. Such dynamics are seen in many species (wolves, humans, dolphins, etc.) and usually evolve as a means to track hard to find/kill prey over large expanses of land. This type of behavior elucidates the environment of their native Parnack with large areas to cover and substantially large prey to hunt for. 

Additionally, one of the most striking features of a Yahg is its four sets of eyes that share similarities with those of the jumping spider (renowned for having some of the best vision among invertebrates). However, unlike the Yahg, these eyes are not an adaptation of apex predation but an adaptation to being both the hunter and the hunted. The forward facing eyes of the jumping spider allow for tracking prey, while additional eyes provide 360 vision that alerts them to other predators. 

A more interesting trait in this species is the ability to use their eyes to understand body language/intentions/emotions in other species. This would be a tremendous feat, considering how most intergalactic species evolved in a relatively independent manner of one another. Such ability would have been more plausible in a situation where species share common display of emotions. For instance, many non-human primates share certain facial expressions with humans, mainly because they also possess similar facial musculature. Another explanation would be that the Yahg can observe new species, and learn to interpret their intentions. This would be possible as long as the said species displays emotion. 

About The Authors 

Thwacke is a multidisciplinary think-tank of academics that aims to bridge the gap between video games and science in order to make their fiction creative, relevant, and immersing. As researchers at the forefront of new technology and science, we provide consultation that delivers fresh perspective that aim to make video games smarter. 

A surprisingly thoughtful and original article from IGN