Evolutionary theory of sex

The Evolutionary Theory of Sex is a biological hypothesis based on a systemics theory dealing with the evolution of sex. It was proposed by Vigen A. Geodakian and states that the "two sexes supplement each other and specialize in some functions are two opposite aspects of evolution — preservation and change." Reproduction is easier without a species having sex added as a complication, so if reproduction is not the point of sex then what is? What evolutionary advantage explains the widespread including of this complication to the reproductive process? This hypothesis suggests that the answer lies in chromosome based sex-determination systems that allow a degree of independent evolution of the sexes. For example, human females lack a Y chromosome so evolution of the Y chromosome can test variations without polluting the human genome.

This hypothesis hopes to explain many sex-related phenomena such as sexual dimorphism, sex chromosomes, asymmetry of brain and hands, reciprocal effects, and congenital heart defects.

The hypothesis includes the concepts of the Principle of Conjugated Subsystems and Asynchronous Evolution. The fitness landscape of a species is thought to be evaluated at nearby points by one sex resulting in greater and greater perfection at traits known to be advantageous; while the other sex specializes in evaluating (by reproducing or not) less nearby points in the fitness landscape through more untested genetic variations. (See Nelder-Mead method for a computer algorithm that illustrates searching a fitness landscape; some variations of which first search far points (male-like evolution) then decrease the distance of the search (females-like evolution).) The terminology of the algorithmic theory identifies the two sexes' evolutionary strategies or algorithms as "subsystems" and refers to the male sex's evolutionary algorithm as the "Operative Subsystem" and the female sex's evolutionary algorithm as the "Conservative Subsystem". The operative subsystem starts the change, verifies and selects the useful traits and then passes them to conservative subsystem to refine them thus creating a division of labour.

New information from the environment is first incorporated into male only genes, and then after many generations gets transferred to females (e.g. Transposon), so the evolution of males precedes the evolution of females; while the perfection of traits remains a female domain. This time shift (two phases of a trait’s evolution) creates two forms of a trait (male and female)—sexual dimorphism for the population.

The hypothesis was included in two psychology textbooks, a college study program, and was covered in Russian newspaper and magazine articles, two articles in a monthly Russian-language local newspaper published by a US travel agency, and Russian TV programs. However, not all of these ideas are widely-known or accepted, and remain almost unknown outside of Russia.

Systems modeling
The "International Society for the Systems Sciences"'s Bela Banathy states:

:"By OBSERVING various types of systems and studying their behavior, we can recognize characteristics that are common to all systems. Once we have identified and described a set of concepts that are common to the systems, and observed and discovered among some of them certain relationships, we can construct from them general systems PRINCIPLES. Thus, a systems principles emerges from an interaction/integration of related concepts. Next we are in the position to look for interrelations among principles and organize related principles in to certain conceptual schemes we call SYSTEMS MODELS. This process of starting from OBSERVATION and arriving at the CONSTRUCTION of systems models constitutes the first stage of developing a systems view."

V. Geodakian's "Principle of Conjugated Subsystems" is an example of this.

Principle of Conjugated Subsystems
The Principle of Conjugated Subsystems introduced by V. Geodakian states that:

:Any system adapting to a variable environment divides into two conjugated subsystems, specialized according to conservative and operative trends of evolution, which increases the system stability as a whole.

The idea of evolution implies two main and to some extent alternative aspects: conservation and variation. For better realization of the first aspect - conservation, the system ought to be steady, stable, and unchangeable (inert), i.e. to be if possible "farther" (in the informational terms) from destructive factors of the environment. But these factors simultaneously carry on useful information about changes in environment. And if the system has to get adapted to the latter, to be changed in accordance with the environmental alterations (the second aspect of evolution) it must be sensitive, labile and variable, i.e. to be as far as possible, "closer" (again in information terms) to harmful factors of the environment. Consequently the same idea of evolution raises conflicting requirements for the system: to be simultaneously "farther" from and "closer" to the environment.

The first possible solution: the system should be at some optimal "distance" from the environment. The second one: the system should differentiate into two conjugated subsystems, one of them to be removed “farther” from the environment for preserving the accumulated information, and another one to be drawn “nearer” to the environment for receiving new information. The second solution overcomes the conflict to some extent and increases the stability of the system as a whole.

Asynchronous Evolution
V. Geodakian claims that:

:"All biological theories especially classical genetics and Darwinism silently assume the idea of synchronous evolution. This approach is suitable for the description of evolution of unitary systems. However, these theories can not explain behavior of binary systems same as you can not solve three-dimensional problem within a plane. Binary systems have two subsystems (or forms) of relatively homogeneous elements. In the case of population they are male and female sexes. The subsystems change at a different speed. perative subsystem starts the change, verifies and selects the useful traits and then passes them to conservative subsystem. This delay creates a difference between the two subsystems both in morphological (dimorphism) and time (dichronism) aspects."

It seems that particular nature of the environmental factor which causes the discomfort of the organism has no significance for starting up these mechanisms. The cause of the discomfort (frost, dry periods, famine or enemies) makes no difference. The generalized ecological information has one dimension only (good or bad) and its cause is unimportant.

Wider reaction norm of females
Wider reaction norm of females was theoretically predicted in 1973. It means that in males the share of "hereditary component" must be larger and of the "environmental one" smaller than in females. Therefore in males the phenotypical distribution in population better reflects the genetic distribution. In females the environmental influence in ontogenesis is stronger, therefore any ontogenetic shift, any "education" or "training" is more efficient.

If the hypothesis is valid, the differences between monozygous female twins must be greater than between the male ones. At the same time in dizigous twins like in common siblings, everything must be vice versa. Two studies conducted on 44 monozygous pairs and 53 monozygous and 38 dizigous pairs of twins confirmed the predictions.

Much direct and indirect evidence can be presented in favor of the hypothesis. For example, greater conformism of females well known to psychologists has not been adequately interpreted up till now.

Ontogenetic plasticity
The wide reaction norm makes females more flexible in ontogenesis (adaptive). It enables the females to leave elimination and discomfort zones and to be gathered in the comfort zone around the population norm. It narrows the phenotypical dispersion of females and decreases their mortality.

Contrary, the narrow reaction norm of males makes them less flexible in ontogenesis, does not permit the phenotypical dispersion to be narrowed, i.e. to leave the elimination and discomfort zones. Greater phenotypic variation of male sex makes it more sensitive to the environment and increases its damageability and mortality. Slightly exaggerating, it is possible to tell, that informational relationship of a population with the environment is based upon the elimination of males and the education (ontogenetic shift) of females.

Higher mortality of males
In a course of ontogenesis the sex ratio for many species of plants, animals and humans goes down. It is related to the raised death rate and damageability of male’s systems in comparison with female ones at almost all ontogenesis stages and at all levels of organization. Whether we study various species (the humans, animals or plants), different levels of the organization (an individual, organ, tissue or a cell) or stability to different harmful factors of environment (low and high temperature, starvation, poisons, parasites, diseases, etc.)—anywhere the same picture is observed: the raised death rate or damageability of male’s systems in comparison with corresponding female’s.

Hamilton (1948) reviewed differential gender death rate for 70 species, including such various forms of a life, as nematodes, mollusks, crustaceans, insects, arachnoidea, birds, reptiles, fishes and mammals. According to these data, for 62 species (89%) average life of males is shorter, than females; for the majority of the remaining 11% there is no difference, and only on occasion males live longer, than females.

Higher mortality of males is one of the puzzles of sexuality, a general biological phenomenon, which no theory could explain satisfactorily. In new theory it is interpreted as a payment for new ecological information, as a useful form for population to get new information from the environment. For example males have higher susceptibility to all new diseases of our century (infarction, arteriosclerosis, cancer, schizophrenia and others).

Reversibility of males
Under extreme conditions, as a rule, more males are extinct and simultaneously more males are required for selection. Both males’ mortality and males’ birth-rate increase imply reversibility of males increase. In 1965 it was proposed that besides the direct relation, there exists a negative feedback between secondary and tertiary sex ratio

The feedback is represented in cross pollinating plants by the amount of pollen caught on the female flower and in animals by the intensity of sexual activity expressed via unequal aging of X- and Y-sperms and different affinity of the fresh and aged eggs to these latter. The small amount of pollen, intensive sexual activity of males, fresh sperm and aged eggs are factors leading to increase in the number of males.

Information transfer
Father and mother transfer each to descendant approximately identical amount of the genetic information, but the quantity of progeny that males can produce is much more compared to female. One male basically can transfer the information to the entire generation of a population. The females can not do that.

In a strictly monogamous population the number mothers and fathers is equal. Contrary, in a panmictic or polygamous population the number of mothers is always greater than the number of fathers. It means that the old hereditary information concerning the distribution of genotypes in panmictic population is better, more completely and representatively transmitted by the females.

Whereas a wide communication channel between males and their progeny makes possible better transmission of new information to the offspring. By leaving more offspring rare male organisms can multiply their ecologically valuable genotypes. So, in changing environment, different reaction norm and channel to the progeny create genotypic sexual dimorphism in the first generation

Is this "new" information gets leveled at fertilization or gets preserved? The existence of the reciprocal effects suggest that genetic mechanisms exist that prevent complete mixing of all genetic information. This is accomplished via Y chromosome which is transferred from father to son.

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