|WMG||This article contains wild mass guessing, or original research about the settings, characters, or events in a work of fiction.|
The evolutionary changes between present-day humans and the Eloi involve a combination of neoteny, progenesis, and insular dwarfism. Neoteny would be selected for first, while humans still have [reasonably] advanced [medical and sanitation?] technology. Progenesis would be selected for later, by dietary limitations (see below) and the need for a higher reproductive rate to compensate for deaths caused by the Morlocks.
TODO: Explain r/K selection theory and the transition from K-selection in present-day humans to r-selection in the Eloi. r-selection is consistent with the small body size of the Eloi.
This section requires expansion
Evidence for neoteny
TODO: Mention this BBC News article
Evidence for progenesis
Metabolism and diet
Chapter 4 states that the Eloi are fruitarian:
- Fruit, by the by, was all their diet. These people of the remote future were strict vegetarians
Such a diet would be poor in vitamin D. This may explain why the Eloi are light-skinned despite living in sunny areas. (However, their skin must not be so light as to create a significant risk of sunburn.)
The low caloric content of the Eloi diet suggests that the Eloi have slower metabolisms than similarly sized present-day humans. This may be achieved by decreased thyroid activity, which is consistent with neoteny and/or[clarify] progenesis. The iodine content of the Eloi diet is not precisely known. The Eloi diet appears to lack oceanic sources of iodine, but the iodine content of typical soils is unknown. Nor is it practical to speculate on the genes controlling iodine metabolism in the Eloi thyroid. TODO: In present-day humans, iodine deficiency can cause mental retardation. To what extent would brain function be altered as human descendants evolve to tolerate reduced iodine intake? What about the lack of visible goiter?
TODO: Look at sources relevant to "The short stature of pygmies may be in part an adaptation to conserve vitamin D in the low-UV rainforest environment." (I am aware that the environment observed by the Traveller did not have a lot of tree cover to block the UV rays.)
TODO: Also see what we can pull from answers to CrazySlayaNinjaBear's question about physiology of herbivore-adapted humans.
TODO: How is obligate nasal breathing relevant? It depends on the details of the developmental cycle.
In chapter 4, the Time Traveller compares his own voice volume and modal pitch to those of the Eloi:
- It came into my head, oddly enough, that my voice was too harsh and deep for them.
Compared to adult present-day humans, the Eloi have less-developed vocal ligaments, softer laryngeal cartilages, and smaller overall dimensions of the respiratory tract. This relates to the developmental differences mentioned above.
TODO: More quotes
The Eloi have poor cardiovascular fitness due to their lack of regular physical exercise. The Time Traveller observes this (Ch. 4):
- I never met people more indolent or more easily fatigued.
TODO: More quotes
The acute stress reaction in the Eloi is poorly controlled and carries a significant risk of vasovagal syncope or more serious heart rhythm disruptions. This may explain Weena's collapse in chapter 9.
TODO: Quotes for the above
Nervous system and behavior
In chapter 4, the Traveller makes several observations about Eloi behavior. For instance, the Eloi appear to be limited in overall intelligence: (TODO: Clarify how the interpretation of this quote is necessarily subjective)
- Then one of them suddenly asked me a question that showed him to be on the intellectual level of one of our five-year-old children
Also, the Eloi exhibit symptoms of attention deficit disorder (a.k.a. ADHD predominantly inattentive):
- A queer thing I soon discovered about my little hosts, and that was their lack of interest. They would come to me with eager cries of astonishment, like children, but like children they would soon stop examining me and wander away after some other toy.
Eloi society is based substantially on the fission-fusion pattern. TODO: Continue explaining/clean up
Fission: Ch. 7: "we went down into the wood ... We soon met others of the dainty ones, laughing and dancing in the sunlight as though there was no such thing in nature as the night."
Fusion: Ch. 5: "...these little people gathered into the great houses after dark, and slept in droves."
- A Wikipedian has redirected the progenesis article to the neoteny article. The factual accuracy of this is disputed. This is the last good revision of the progenesis article. See also mathematical description of the heterochrony classes.
- The more general term is phyletic dwarfism; insular dwarfism per se is not necessarily correct here.
- In many present-day urbanized areas, endocrine disruptors and obesity tend to favor acceleration instead (Kluger, Jeffrey. "Little Women." Time 31 October 2011, pp. 46-56). TODO: Explain how this might matter in the long term — perhaps the ancestors of the Eloi manage to fix these problems, while the ancestors of the Morlocks do not?
- Michelle Roberts. Fair-skinned people may need extra vitamin D. BBC News. 3 October 2011. Accessed 3 October 2011.