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But reproduction is a fundamental aspect of evolution, and (most?) cells in the body don't reproduce on their own, but rather they are manufactured. T cells for

by tines 5y ago

But reproduction is a fundamental aspect of evolution, and (most?) cells in the body don't reproduce on their own, but rather they are manufactured. T cells for example are manufactured by bone marrow and the thymus multiplies them if I'm understanding correctly. So I'm not sure how that fits in with the view you explained in your post. In other words the T cell doesn't get feedback on its own fitness. The fitness feedback is at the level of the reproductive success of a human being (healthy humans can have more kids than sick ones), not the reproductive success of a T cell (because it has no reproductive capabilities and therefore cannot be subject to selection pressures). Correct me if I'm wrong.

UnFleshedOne 5y ago
To support your point: there are cells that get direct fitness feedback. They call them cancer.
mensetmanusman 5y ago
Humans who make incorrect T cells die, then those T cells are gone from the evolution chain.
westurner 5y ago
Most cells or matter in the body? From https://www.nature.com/articles/nature.2016.19136 https://www.nature.com/articles/nature.2016.19136 : > A 'reference man' (one who is 70 kilograms, 20–30 years old and 1.7 metres tall) contains on average about 30 trillion human cells and 39 trillion bacteria, […] Those numbers are approximate — another person might have half as many or twice as many bacteria, for example — but far from the 10:1 ratio commonly assumed. Symbiosis https://en.wikipedia.org/wiki/Symbiosis https://en.wikipedia.org/wiki/Symbiosis : > Symbiosis […] is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasitic. […] > Symbiosis can be obligatory, which means that one or more of the symbionts depend on each other for survival, or facultative (optional), when they can generally live independently. […] > Symbiosis is also classified by physical attachment. When symbionts form a single body it is called conjunctive symbiosis, while all other arrangements are called disjunctive symbiosis.[3] When one organism lives on the surface of another, such as head lice on humans, it is called ectosymbiosis; when one partner lives inside the tissues of another, such as Symbiodinium within coral, it is termed endosymbiosis. Endosymbiont: https://en.wikipedia.org/wiki/Endosymbiont https://en.wikipedia.org/wiki/Endosymbiont : > Two major types of organelle in eukaryotic cells, mitochondria and plastids such as chloroplasts, are considered to be bacterial endosymbionts.[6] This process is commonly referred to as symbiogenesis. Symbiogenesis: https://en.wikipedia.org/wiki/Symbiogenesis https://en.wikipedia.org/wiki/Symbiogenesis #Secondary_endosymbiosis ... Viral eukaryogenesis: https://en.wikipedia.org/wiki/Viral_eukaryogenesis https://en.wikipedia.org/wiki/Viral_eukaryogenesis : > A number of precepts in the theory are possible. For instance, a helical virus with a bilipid envelope bears a distinct resemblance to a highly simplified cellular nucleus (i.e., a DNA chromosome encapsulated within a lipid membrane). In theory, a large DNA virus could take control of a bacterial or archaeal cell. Instead of replicating and destroying the host cell, it would remain within the cell, thus overcoming the tradeoff dilemma typically faced by viruses. With the virus in control of the host cell's molecular machinery, it would effectively become a functional nucleus. Through the processes of mitosis and cytokinesis, the virus would thus recruit the entire cell as a symbiont—a new way to survive and proliferate. T-Cell # Activation: https://en.wikipedia.org/wiki/T_cell#Activation https://en.wikipedia.org/wiki/T_cell#Activation > Both are required for production of an effective immune response; in the absence of co-stimulation, T cell receptor signalling alone results in anergy. […] > Once a T cell has been appropriately activated (i.e. has received signal one and signal two) it alters its cell surface expression of a variety of proteins. T-cell receptor § Signaling pathway: https://en.wikipedia.org/wiki/T-cell_receptor#Signaling_pathway https://en.wikipedia.org/wiki/T-cell_receptor#Signaling_path... Co-stimulation : https://en.wikipedia.org/wiki/Co-stimulation https://en.wikipedia.org/wiki/Co-stimulation : > Co-stimulation is a secondary signal which immune cells rely on to activate an immune response in the presence of an antigen-presenting cell.[1] In the case of T cells, two stimuli are required to fully activate their immune response. During the activation of lymphocytes, co-stimulation is often crucial to the development of an effective immune response. Co-stimulation is required in addition to the antigen-specific signal from their antigen receptors. Anergy: https://en.wikipedia.org/wiki/Clonal_anergy https://en.wikipedia.org/wiki/Clonal_anergy : > [Clonal] Anergy is a term in immunobiology that describes a lack of reaction by the body's defense mechanisms to foreign substances, and consists of a direct induction of peripheral lymphocyte tolerance. An individual in a state of anergy often indicates that the immune system is unable to mount a normal immune response against a specific antigen, usually a self-antigen. Lymphocytes are said to be anergic when they fail to respond to their specific antigen. Anergy is one of three processes that induce tolerance, modifying the immune system to prevent self-destruction (the others being clonal deletion and immunoregulation ).[1] Clonal deletion: https://en.wikipedia.org/wiki/Clonal_deletion https://en.wikipedia.org/wiki/Clonal_deletion : > There are millions of B and T cells inside the body, both created within the bone marrow and the latter matures in the thymus, hence the T. Each of these lymphocytes express specificity to a particular epitope, or the part of an antigen to which B cell and T cell receptors recognize and bind. There is a large diversity of epitopes recognized and, as a result, it is possible for some B and T lymphocytes to develop with the ability to recognize self.[4] B and T cells are presented with self antigen after developing receptors while they are still in the primary lymphoid organs.[3][4] Those cells that demonstrate a high affinity for this self antigen are often subsequently deleted so they cannot create progeny, which helps protect the host against autoimmunity.[2][3] Thus, the host develops a tolerance for this antigen, or a self tolerance.[3] "DNA threads released by activated CD4+ T lymphocytes provide autocrine costimulation" (2019) https://www.pnas.org/content/116/18/8985 https://www.pnas.org/content/116/18/8985 > A growing body of literature has shown that, aside from carrying genetic information, both nuclear and mitochondrial DNA can be released by innate immune cells and promote inflammatory responses. Here we show that when CD4+ T lymphocytes, key orchestrators of adaptive immunity, are activated, they form a complex extracellular architecture composed of oxidized threads of DNA that provide autocrine costimulatory signals to T cells. We named these DNA extrusions “T helper-released extracellular DNA” (THREDs). FWIU, there's also a gut-brain pathway? Or is that also this "signaling method" for feedback in symbiotic complex dynamic systems? From https://en.wikipedia.org/wiki/Complex_system https://en.wikipedia.org/wiki/Complex_system : > Complex systems are systems whose behavior is intrinsically difficult to model due to the dependencies, competitions, relationships, or other types of interactions between their parts or between a given system and its environment. Systems that are "complex" have distinct properties that arise from these relationships, such as nonlinearity, emergence, spontaneous order, adaptation, and feedback loops, among others. Because such systems appear in a wide variety of fields, the commonalities among them have become the topic of their independent area of research. In many cases, it is useful to represent such a system as a network where the nodes represent the components and links to their interactions. Graph, Hypergraph, Property graph, Linked Data, AtomSpace, RDF* + SPARQL*, ONNX, {...} > The term complex systems often refers to the study of complex systems, which is an approach to science that investigates how relationships between a system's parts give rise to its collective behaviors and how the system interacts and forms relationships with its environment.[1] The study of complex systems regards collective, or system-wide, behaviors as the fundamental object of study; for this reason, complex systems can be understood as an alternative paradigm to reductionism, which attempts to explain systems in terms of their constituent parts and the individual interactions between them. A multi-digraph of probably nonlinear relations may not be the best way to describe the fields of even just a few electroweak magnets? > As an interdisciplinary domain, complex systems draws contributions from many different fields, such as the study of self-organization and critical phenomena from physics, that of spontaneous order from the social sciences, chaos from mathematics, adaptation from biology, and many others. Complex systems is therefore often used as a broad term encompassing a research approach to problems in many diverse disciplines, including statistical physics, information theory, nonlinear dynamics, anthropology, computer science, meteorology, sociology, economics, psychology, and biology. ... Glossary of Systems Theory: https://en.wikipedia.org/wiki/Glossary_of_systems_theory https://en.wikipedia.org/wiki/Glossary_of_systems_theory

by tines 5y ago

UnFleshedOne 5y ago

To support your point: there are cells that get direct fitness feedback. They call them cancer.

mensetmanusman 5y ago

Humans who make incorrect T cells die, then those T cells are gone from the evolution chain.

westurner 5y ago

Most cells or matter in the body? From https://www.nature.com/articles/nature.2016.19136 https://www.nature.com/articles/nature.2016.19136 : > A 'reference man' (one who is 70 kilograms, 20–30 years old and 1.7 metres tall) contains on average about 30 trillion human cells and 39 trillion bacteria, […] Those numbers are approximate — another person might have half as many or twice as many bacteria, for example — but far from the 10:1 ratio commonly assumed. Symbiosis https://en.wikipedia.org/wiki/Symbiosis https://en.wikipedia.org/wiki/Symbiosis : > Symbiosis […] is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasitic. […] > Symbiosis can be obligatory, which means that one or more of the symbionts depend on each other for survival, or facultative (optional), when they can generally live independently. […] > Symbiosis is also classified by physical attachment. When symbionts form a single body it is called conjunctive symbiosis, while all other arrangements are called disjunctive symbiosis.[3] When one organism lives on the surface of another, such as head lice on humans, it is called ectosymbiosis; when one partner lives inside the tissues of another, such as Symbiodinium within coral, it is termed endosymbiosis. Endosymbiont: https://en.wikipedia.org/wiki/Endosymbiont https://en.wikipedia.org/wiki/Endosymbiont : > Two major types of organelle in eukaryotic cells, mitochondria and plastids such as chloroplasts, are considered to be bacterial endosymbionts.[6] This process is commonly referred to as symbiogenesis. Symbiogenesis: https://en.wikipedia.org/wiki/Symbiogenesis https://en.wikipedia.org/wiki/Symbiogenesis #Secondary_endosymbiosis ... Viral eukaryogenesis: https://en.wikipedia.org/wiki/Viral_eukaryogenesis https://en.wikipedia.org/wiki/Viral_eukaryogenesis : > A number of precepts in the theory are possible. For instance, a helical virus with a bilipid envelope bears a distinct resemblance to a highly simplified cellular nucleus (i.e., a DNA chromosome encapsulated within a lipid membrane). In theory, a large DNA virus could take control of a bacterial or archaeal cell. Instead of replicating and destroying the host cell, it would remain within the cell, thus overcoming the tradeoff dilemma typically faced by viruses. With the virus in control of the host cell's molecular machinery, it would effectively become a functional nucleus. Through the processes of mitosis and cytokinesis, the virus would thus recruit the entire cell as a symbiont—a new way to survive and proliferate. T-Cell # Activation: https://en.wikipedia.org/wiki/T_cell#Activation https://en.wikipedia.org/wiki/T_cell#Activation > Both are required for production of an effective immune response; in the absence of co-stimulation, T cell receptor signalling alone results in anergy. […] > Once a T cell has been appropriately activated (i.e. has received signal one and signal two) it alters its cell surface expression of a variety of proteins. T-cell receptor § Signaling pathway: https://en.wikipedia.org/wiki/T-cell_receptor#Signaling_pathway https://en.wikipedia.org/wiki/T-cell_receptor#Signaling_path... Co-stimulation : https://en.wikipedia.org/wiki/Co-stimulation https://en.wikipedia.org/wiki/Co-stimulation : > Co-stimulation is a secondary signal which immune cells rely on to activate an immune response in the presence of an antigen-presenting cell.[1] In the case of T cells, two stimuli are required to fully activate their immune response. During the activation of lymphocytes, co-stimulation is often crucial to the development of an effective immune response. Co-stimulation is required in addition to the antigen-specific signal from their antigen receptors. Anergy: https://en.wikipedia.org/wiki/Clonal_anergy https://en.wikipedia.org/wiki/Clonal_anergy : > [Clonal] Anergy is a term in immunobiology that describes a lack of reaction by the body's defense mechanisms to foreign substances, and consists of a direct induction of peripheral lymphocyte tolerance. An individual in a state of anergy often indicates that the immune system is unable to mount a normal immune response against a specific antigen, usually a self-antigen. Lymphocytes are said to be anergic when they fail to respond to their specific antigen. Anergy is one of three processes that induce tolerance, modifying the immune system to prevent self-destruction (the others being clonal deletion and immunoregulation ).[1] Clonal deletion: https://en.wikipedia.org/wiki/Clonal_deletion https://en.wikipedia.org/wiki/Clonal_deletion : > There are millions of B and T cells inside the body, both created within the bone marrow and the latter matures in the thymus, hence the T. Each of these lymphocytes express specificity to a particular epitope, or the part of an antigen to which B cell and T cell receptors recognize and bind. There is a large diversity of epitopes recognized and, as a result, it is possible for some B and T lymphocytes to develop with the ability to recognize self.[4] B and T cells are presented with self antigen after developing receptors while they are still in the primary lymphoid organs.[3][4] Those cells that demonstrate a high affinity for this self antigen are often subsequently deleted so they cannot create progeny, which helps protect the host against autoimmunity.[2][3] Thus, the host develops a tolerance for this antigen, or a self tolerance.[3] "DNA threads released by activated CD4+ T lymphocytes provide autocrine costimulation" (2019) https://www.pnas.org/content/116/18/8985 https://www.pnas.org/content/116/18/8985 > A growing body of literature has shown that, aside from carrying genetic information, both nuclear and mitochondrial DNA can be released by innate immune cells and promote inflammatory responses. Here we show that when CD4+ T lymphocytes, key orchestrators of adaptive immunity, are activated, they form a complex extracellular architecture composed of oxidized threads of DNA that provide autocrine costimulatory signals to T cells. We named these DNA extrusions “T helper-released extracellular DNA” (THREDs). FWIU, there's also a gut-brain pathway? Or is that also this "signaling method" for feedback in symbiotic complex dynamic systems? From https://en.wikipedia.org/wiki/Complex_system https://en.wikipedia.org/wiki/Complex_system : > Complex systems are systems whose behavior is intrinsically difficult to model due to the dependencies, competitions, relationships, or other types of interactions between their parts or between a given system and its environment. Systems that are "complex" have distinct properties that arise from these relationships, such as nonlinearity, emergence, spontaneous order, adaptation, and feedback loops, among others. Because such systems appear in a wide variety of fields, the commonalities among them have become the topic of their independent area of research. In many cases, it is useful to represent such a system as a network where the nodes represent the components and links to their interactions. Graph, Hypergraph, Property graph, Linked Data, AtomSpace, RDF* + SPARQL*, ONNX, {...} > The term complex systems often refers to the study of complex systems, which is an approach to science that investigates how relationships between a system's parts give rise to its collective behaviors and how the system interacts and forms relationships with its environment.[1] The study of complex systems regards collective, or system-wide, behaviors as the fundamental object of study; for this reason, complex systems can be understood as an alternative paradigm to reductionism, which attempts to explain systems in terms of their constituent parts and the individual interactions between them. A multi-digraph of probably nonlinear relations may not be the best way to describe the fields of even just a few electroweak magnets? > As an interdisciplinary domain, complex systems draws contributions from many different fields, such as the study of self-organization and critical phenomena from physics, that of spontaneous order from the social sciences, chaos from mathematics, adaptation from biology, and many others. Complex systems is therefore often used as a broad term encompassing a research approach to problems in many diverse disciplines, including statistical physics, information theory, nonlinear dynamics, anthropology, computer science, meteorology, sociology, economics, psychology, and biology. ... Glossary of Systems Theory: https://en.wikipedia.org/wiki/Glossary_of_systems_theory https://en.wikipedia.org/wiki/Glossary_of_systems_theory