Evolutionary Research
- Lafyva
- Aug 10
- 6 min read
Updated: Sep 15
Men's Visual Cortex Neurons
Research indicates that males have approximately 25% more neurons in the visual cortex compared to females, which is linked to higher concentrations of androgen receptors in this brain region during embryogenesis. This neural difference may contribute to observed variations in visual processing between the sexes. Men generally show greater sensitivity to fine detail and rapidly moving stimuli, while women tend to be better at discriminating between colors, particularly in the middle of the visual spectrum such as shades of blue and green.
The differences are thought to stem from the influence of androgens, like testosterone, on the development of the visual system. Some researchers suggest these traits could be adaptive, possibly reflecting evolutionary roles where males, as hunters, benefited from enhanced detection of movement and distant objects, while females, as gatherers and caregivers, developed superior color discrimination useful for identifying edible plants and monitoring offspring.
Regarding photoreceptor ratios, the provided context does not specifically mention a higher rod-to-cone ratio in men. However, it does note that men require slightly longer wavelengths of light to perceive the same hue as women and have a broader range in the central spectrum where color discrimination is reduced. Additionally, color blindness is significantly more prevalent in males (7%) than in females (0.4%), largely due to the genetic basis of color vision deficiencies being located on the X chromosome.
Darwin was never an atheist, indeed. He started as an Anglican and believer in almost perfect adaptation of species to their environment, went through a large - already... Darwinian - period in which he rather leaned to the idea of a necessary God as First Cause, and in his... later stage he became an (ontological) agnostic. Even then, he still distanced himself from atheism. I don't think that he'd applaude Maddox's attitude regarding Sheldrake's theory, for instance. (Or, maybe he was just a normal guy-of-his-time... -and-space. Perhaps he'd be a Dawkins nowadays, but, fortunately, somehow, he lived in the 19th century.)
While Darwin's theory enters in conflict with various positions derived more or less from Plato's theory of Forms - albeit not necessarily with purely mathematical "Platonism", for instance -, it can coexist with spooky elements like Sheldrake's morphic resonance. Quality of evidence would be what Darwin would ask - and perhaps Sheldrake's research has it, others trying to reproduce his experiments a la carte are expected. There is some open space for a kind of Akashic memory, provided that one doesn't use it to infirm the place of universal conditions+random mutations+natural selection in macroevolution as a sort of general rule. If there's a designer, he's one of the universe tout court, would Darwin say.
Blake Ross, clearly. There are many differences which we might deem key-differences. Some derive from others. I'll give some examples, but before that I'd mention that in some civilizations polytheism is more implicit, e.g., in China, or in Ancient Greece and Rome. Also, in some pockets of the monotheistic/Abrahamic religion, polytheism is rather residual, not barely vestigial. The variations inside this transcendentally unified (Abrahamic) religion transcend the cultic boundaries (between Islam, Christianity, and Judaism). Any time, a small branch of this tree can become the epitome of monotheism.
Now, having a plurality of Gods means having a fair amount of unbreakable Limits. That might be the reason that the Chinese, though they had capabilities, didn't reach the Americas in the 14th century, or that mutatis mutandis the Indians (the Kerala school of astronomy and mathemathics) did not developed a systematic theory of the infinitesimal calculus.
Where Ares reigns there is no place for mass destruction weapons, when Athena leaves the academy, all the sciences serve to achieve full spectrum dominance.
Another key-difference can be described in evolutionary terms: being monotheist, an organism aims for maximum adaptability, thus he became maladapted to the current environment and needs ALWAYS to quickly transform it in a quite radical manner. A polytheistic organism is excellently adapted to a number of features of the occupied environment. He doesn't barely survive, he really thrives, and has no need to polish his reality. We can affect/remove a feat or two - or even more, but not too much, or he will dissapear - now and he shall survive and thrive - if he doesn't thrives, he dies. I think thae opposite of that is what Nietzsche had in mind when he talked about Christianity as slave morality - being focused on survival.
Some could be tempted to equivalate monotheism and neoteny. Monotheism is not neoteny (per se) - and some of its key-features, e.g., neuroplasticity -, but obsessively aiming for maximum neoteny. (Here we have a difference, which, indeed, is not necessarily oppositive: it is between being child-like - which is not necessarily a very pronounced feature in Christians, but it's the only true aim for Christians - and being... childish.) That's why I say human - a very neotenical species - is not naturally Christian, but Christianity is by necessity transhumanist.
sometimes residual and vestigial are used as synonyms. also, sometimes I think it was residual that meant something totally inactive and vestigial that was somehow active. my discourse there is not so clear, as I lack the proper terms.
I used residual for something that persisted and it might act in parallel as a part of another (non-monotheistic) structure, and vestigial for elements which were fully devoided of such a force, although they might point to an astute "reader" towards their origins or some way they could have had meaning, i.e. function, in polytheistic forms of cult
The fight-or-flight response was a concept developed by Walter B. Cannon in the course of his studies on the secretion of epinephrine from the adrenal medulla of laboratory animals. This concept was an outgrowth of his studies of homeostatic mechanisms, particularly as they related to the sympathetic-adrenal medulla system. Cannon’s research on homeostasis and the fight-or-flight response led him to delve into mechanisms of “voodoo death” and to propose a new theory of emotions, known as the Cannon-Bard theory. Cannon thought that the sympathetic nervous system and the adrenal medulla operated as a functional unit, with epinephrine as the chemical messenger. He did not understand that the postganglionic sympathetic nerves utilized norepinephrine as a chemical transmitter. Cannon’s research legacy is a rich one and his work is still cited frequently by contemporary researchers in the field of stress.
AI Overview
While both concepts involve how an organism's phenotype is influenced by its environment, "gene-environment interaction" refers to the specific way different genotypes respond differently to environmental cues, leading to varying phenotypic outcomes, whereas "phenotypic plasticity" simply describes the ability of a single genotype to express different phenotypes depending on the environment it encounters; essentially, plasticity is the broader concept encompassing the potential for gene-environment interactions to occur.
Example of Gene-Environment Interaction:
Skin Cancer and Sun Exposure: Individuals with a genetic predisposition to skin cancer (e.g., fair skin) are at significantly higher risk of developing melanoma when exposed to high levels of sunlight compared to people with darker skin tones, demonstrating how the same environmental factor (sun exposure) can have a much stronger impact on certain genotypes.
Example of Phenotypic Plasticity:
Seasonal Polyphenism in Butterflies: Depending on the temperature during development, certain butterfly species can develop different wing patterns, with one pattern appearing in the summer and a different one in the winter, showcasing how a single genotype can produce different phenotypes based on environmental cues.
Key Differences:
Focus:Gene-environment interaction focuses on how different genotypes respond differently to environmental cues, while phenotypic plasticity focuses on the ability of a single genotype to adapt to different environments.
Level of Detail:Gene-environment interaction examines the specific genetic mechanisms behind how the environment influences a trait, whereas phenotypic plasticity is a more general description of the ability to change phenotype based on environmental conditions.
AI Overview
Yes, phenotypic plasticity is the ability of an organism's genotype to produce different phenotypes in response to environmental conditions, and it encompasses gene-environment interactions:
Explanation
Phenotypic plasticity is the study of how an organism's genes and environment interact to produce its anatomy, behavior, and morphology. It's a broad term that includes processes that can be reversible, irreversible, transgenerational, or within an organism's lifespan.
Gene-environment interactions
The variation in phenotypic plasticity between individuals of the same species is caused by gene-by-environment interactions (GxE).
Examples
Some examples of phenotypic plasticity include:
Crucian carp increasing their body depth in response to predatory pike
Galapagos marine iguanas reducing their body length in response to low food availability
Common shrews reducing the size of their skull and other parts of skeleton from summer to winter
Understanding GxE interactions is important in many fields, including agronomy and industrial microbiology.
Allele type
If the two alleles are the same, the individual is homozygous for that allele. If the alleles are different, the individual is heterozygous.
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