∞ generated and posted on 2016.12.22 ∞

The study of heredity or, more generally, the flow of biologically encoded information through both space and time.

Genetics is the study of nucleic acids as hereditary material and information-containing molecules as well as how both that information and how that information is accessed can change over time.

Sub-disciplines of genetics include Mendelian genetics, molecular genetics, cytogenetics, microbial genetics, and population genetics. The study of heredity substantially preceded the formal study of genetics by millennia while the formal study of genetics predated any molecular appreciation of how heredity occurs by decades.

Figure legend: Variation on the study of genetics. Note the indication of a building up of sub-disciplines starting with the molecular and going towards the population wide. Cytogenetics is the study of eukaryotic chromosomes especially visually (i.e., such as one does when studying mitosis and meiosis). Mendelian genetics is the study of the genetics of diploid organisms especially in terms of offspring-parent phenotypic relationships. Molecular genetics is considered is the study of genetic information flow at the molecular level. Population genetics, in turn, is the study of genetic variation among organisms within populations.

A flawed appreciation of genetics hampered Darwin's efforts to understand evolution, and even with the rediscovery of Mendelian genetics in the early years of the Twentieth Century, its proper application to evolutionary theory lagged behind by years.

Today we are all but overwhelmed by genetic information, as gleaned from high-throughput DNA sequencing technologies, but there nonetheless remain substantial gaps in our understanding how an organism's genetics (genotype) translates into an organism's phenotype except in the broadest sense of transcription followed by translation which in turn is followed by complex considerations of biochemistry, developmental biology, physiology, and even ecology. This gap in our knowledge and indeed the current state of quite a bit of modern biology is ironic given that genetics began as a solely phenotype-based discipline from which genotype information could only be inferred.

Figure legend: Interrelationships between genotype, phenotype, environment, and various phenomena and disciplines including those making up genetics. Approximately by row, note the concepts of mutation, gene expression, physiological adaptation (versus evolutionary adaptation), sequencing, comparative genetics, genomics, Mendelian genetics, genetic mapping, genetic analysis, reverse genetics, ecology, population genetics, and epidemiology.

The following is a list of important concepts associated with the science of genetics:

Allele, Allele-neutral, Ames test, Auxotroph, Bacterial chromosome, Bacterial sex, Base pair, Base pairing, Base substitution, Catabolite repression, Chromosome, Clone, Codon, Competence (genetic), Conjugation, Conjugative plasmid, Constitutive expression, Corepressor, Diploid, Direct (positive) selection, DNA, DNA polymerase, Dominant, Donor cell, Endosymbiont, Epistasis, Frameshift mutation, Gene, Generalized transduction, Genetic code, Genetic recombination, Genetics, Genome, Genomics, Genotype, Haploid, Hereditary material, Heterozygote, Homozygote, Human autosomal dominant conditions, Human autosomal recessive conditions, Indirect (negative) selection, Inducer, Induction (bacteriophage), Induction (genetic), Isogenic, Lethal allele, Locus, Mendelian genetics, Messenger RNA (mRNA), Microbial genetics, Missense mutation, Molecular genetics, Mutagen, Mutation, Mutation rate, Nonsense codon, Nonsense mutation, Nucleoside analog, Operator, Operon, Phenotype, Plasmid, Plasmid, Polymorphism, Promoter, Recessive, Recipient cell, Recombinant DNA, Recombination, Replica plating, Replication, Replication fork, Repression, Repressor, Resistance plasmid, RNA, RNA polymerase, Sarcina (morphology), Sense codon, Sequence, Sex, Sex-linked recessive, Spontaneous mutation, Stop codon, Terminator, Tetrad, Transcription, Transcriptional regulation, Transduction, Transformation (genetic), Translation, Transposon, Vertical gene transfer

The following video is an introduction to what genetics is all about: