Philosophical Study On Biological Individuality

The study of biological individuality is of great significance in the theory of biological philosophy and the practice of biological science.Biological philosophy is actually a philosophy based on biological individuality.The definition of biological individual and its individuality is the premise of individuality research.In view of the complexity and diversity of life,hierarchy definition is a reasonable choice.After reviewing various definitions in scholars’ theory,the defining conditions of biological individuals can be mainly divided into necessary conditions and sufficient conditions.Genes,individual organisms,groups and species,belonging to entities of different levels,can be called biological individuals in a certain biological sense.The definition of biological individuality is divided into multiple subjects,multiple classifications and multiple attributes,which can be answered from different angles and aspects.Then,According to several important aspects of biological individuality such as survival,development and reproduction,biological individuals(individual organism level)can be divided into six categories: bottleneck individual,staged individual,connective individual,meristematic individual,collective individual and symbiotic individual.The thought of“species as individuals” has experienced three stages: logical entity,historical entity and causal entity.As individuals,species also have unique individuality,which mainly include reticular pedigree relationship,fuzzy boundary and internal integration,allometric reproduction,struggle,dependence and symbiosis,and species as a unit of selection.The research results of biological individuality formed by western scholars based on the evolutionary paradigm mainly include synchronic analysis,genetic analysis and diachronic analysis.Synchronic analysis is a classic approach to biological individuality,which focuses on the hierarchical selection characteristics of biological individuals.The most important part of abstract selection theory is the representation of three principles,including the principle of variation,the principle of heredity and the principle of differential fitness.The second content is the heritable variance in fitness.A unit of selection is any entity for which there is heritable context-independent variance in fitness among entities.Multi-level selection model refers to dividing biological objects into different levels,and different levels can be regarded as selection units,namely individual selection,group selection and species selection.Gene analysis is aimed at the replicator approach,which observes biological individuality from the perspective of genes.Biological individuals are divided into“replicator-carrier/interactor”in dichotomy mode.From the perspective of gene,gene is the unit of replicator,which is eternal,while organism is the carrier/ interactor,an entity unit that interacts with the environment and is temporary.The unit selected from the perspective of gene is no longer an entity above the biological level,but a gene or organism.Diachronic analysis is about the evolutionary transition route of biological individuals,and analyzes the emergence nature of biological individuality.After the concept of transition was introduced into the evolutionary context,the theory of “major transition” was put forward,and the individual evolutionary history of organisms was divided into 9 major transition events.These events involved the formation of replication macromolecules,the formation of genes,the increase of complexity,the realization of division of labor and selection,the formation of cooperative groups,etc.,and the evolution unit developed from low-level to high-level.The individuality of microorganisms is also an important aspect of biological individuality.As a simple breeder,microorganisms have primitive,dynamic,adaptive and evolutionary properties.The individuality of viruses lies in gene rearrangement,combination and variation.The latest case is the evolution of variability of COVID-19 virus.After combing and summarizing the literature,it is found that these theoretical views are aimed at the reproduction,heredity,variation,adaptation,functional cooperation and other attributes of biological individuals,but do not pay attention to the spatiotemporal attributes of biological individuals,such as morphology,size,weight and so on.Therefore,this paper divides them into deep attributes and shallow attributes respectively.Deep attributes are important attributes of organisms and are the focus of biologists’ research.At the same time,these discussions of biological individuality are generally about the innate attributes of organisms.Therefore,this paper divides them into congenital attributes and acquired attributes again,lists them,and briefly explains the various categories of biological individuality in the table.This paper holds that among the various attributes of biological individuality,the organism with the two attributes of survival and reproduction is a complete unit.Unit integrity is the most standard requirement for organisms.