* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Sex & Death: Introduction to the Philosophy of Biology
Long non-coding RNA wikipedia , lookup
Heritability of IQ wikipedia , lookup
Point mutation wikipedia , lookup
Copy-number variation wikipedia , lookup
Transposable element wikipedia , lookup
Epigenetics in learning and memory wikipedia , lookup
X-inactivation wikipedia , lookup
Oncogenomics wikipedia , lookup
Epigenetics of diabetes Type 2 wikipedia , lookup
Gene therapy wikipedia , lookup
Genetic engineering wikipedia , lookup
Epigenetics of neurodegenerative diseases wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Public health genomics wikipedia , lookup
Pathogenomics wikipedia , lookup
Polycomb Group Proteins and Cancer wikipedia , lookup
Gene nomenclature wikipedia , lookup
Essential gene wikipedia , lookup
Gene desert wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
Quantitative trait locus wikipedia , lookup
Nutriepigenomics wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
History of genetic engineering wikipedia , lookup
Genomic imprinting wikipedia , lookup
Gene expression programming wikipedia , lookup
Genome evolution wikipedia , lookup
Ridge (biology) wikipedia , lookup
Minimal genome wikipedia , lookup
Epigenetics of human development wikipedia , lookup
The Selfish Gene wikipedia , lookup
Biology and consumer behaviour wikipedia , lookup
Genome (book) wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Gene expression profiling wikipedia , lookup
Sex & Death: Introduction to the Philosophy of Biology Chapter 4: The Organism Strikes Back Overview The Organism Strikes Back 4.1 What is a gene? “Evolutionary Gene” fails Invisibility Argument 4.2 Genes are active germ line replicators First attempt to redefine “gene” 4.3 Genes are difference makers Second attempt to redefine “gene” 4.1 What Is a Gene? • Argument against gene selectionism: • Sober (1984b) distinguishes between selection for and selection of. • In gene selectionism only interested in selection for Debate on visibility of genes to selection: Area 1: • Explores which DNA sequences count as genes Area 2: • Explores the complexity of the relationship between the genes and the phenotypes that they help to build Area 1:What is a gene? • First Definition: a gene is a “reading sequence” • Second Definition: Dawkins and Williams, ‘evolutionary gene concept’ • Critics object to this second definition since it does not have a systematic phenotypic relationship. What is Phenotypic power? Two Responses: 1: Molecular genes: genes are functional biochemical units 2: Genes are “difference makers” 4.2 Genes are active Germ Line Replicators Dawkins (1982, 83) and active replicator is: “any replicator whose nature has some influence over its probability of being copied” 3 Criteria needed for the invisibility argument: 1) A constant phenotypic effect 2) Excludes impostors like individual nucleotides 3) The phenotypic effect of genes makes them more likely to be replicated 4.2 Genes are active Germ Line Replicators Problem: There is not always a constant phenotypic effect and hence condition one is not met. But: There are a few cases where there is a constant phenotypic effect 4.3 Genes Are Difference Makers • There are no genes for traits but for trait differences • Despite this being the more commonly used way of defining genes, it is ambiguous 4.3 Genes Are Difference Makers • Disadvantage of viewing genes as ‘difference makers’ is that it becomes unclear whether they have an independent reality as a gene • If this functional definition is not tied to anything molecular, it cannot be used in favour of gene selectionism as it speaks against cumulative selection: this is an empirical problem Summary: • Gene Selectionists have tried to formulate their conception of evolution in a manner which minimizes its vulnerability to empirical refutation • First Attempt: evolutionary concept of genes • Second Attempt: Genes as sequences of DNA that code for specific proteins Summary: • Third Attempt: Genes as ‘difference makers’: I.e. Make a difference in the phenotypic effect. • Hence, to prove the gene selectionist view the empirical and conceptual problems need to be overcome.