The Major Transitions in Evolution - AbsoluteAstronomy.com

The Major Transitions in Evolution is a book written by John Maynard Smith

John Maynard Smith

John Maynard Smith,His surname was Maynard Smith, not Smith, nor was it hyphenated. F.R.S. was a British theoretical evolutionary biologist and geneticist. Originally an aeronautical engineer during the Second World War, he took a second degree in genetics under the well-known biologist J.B.S....

and Eörs Szathmáry

Eörs Szathmáry

Eörs Szathmáry is a Hungarian theoretical evolutionary biologist at the late Collegium Budapest Eörs Szathmáry (born 1959) is a Hungarian theoretical evolutionary biologist at the late Collegium Budapest Eörs Szathmáry (born 1959) is a Hungarian theoretical evolutionary biologist at the late...

(Oxford University Press

Oxford University Press

Oxford University Press is the largest university press in the world. It is a department of the University of Oxford and is governed by a group of 15 academics appointed by the Vice-Chancellor known as the Delegates of the Press. They are headed by the Secretary to the Delegates, who serves as...

, 1995). This was a seminal publication that continues to contribute to ongoing issues in evolutionary biology.

Transitions described in the book
Transition from:	Transition to:	Notes
Replicating molecules	"Populations" of molecule Molecule A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge... s in compartments	Can't observe
Independent replicators (probably RNA RNA Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life.... )	Chromosomes	RNA world hypothesis RNA world hypothesis The RNA world hypothesis proposes that life based on ribonucleic acid pre-dates the current world of life based on deoxyribonucleic acid , RNA and proteins. RNA is able both to store genetic information, like DNA, and to catalyze chemical reactions, like an enzyme protein...
RNA as both gene Gene A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains... s and enzyme Enzyme Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates... s	DNA DNA Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in... as genes; protein Protein Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of... s as enzymes
Prokaryote Prokaryote The prokaryotes are a group of organisms that lack a cell nucleus , or any other membrane-bound organelles. The organisms that have a cell nucleus are called eukaryotes. Most prokaryotes are unicellular, but a few such as myxobacteria have multicellular stages in their life cycles... s	Eukaryote Eukaryote A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear... s	Can observe
Asexual Asexuality Asexuality , in its broadest sense, is the lack of sexual attraction and, in some cases, the lack of interest in sex. Sometimes, it is considered a lack of a sexual orientation... clones Cloning Cloning in biology is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually. Cloning in biotechnology refers to processes used to create copies of DNA fragments , cells , or...	Sex Sex In biology, sex is a process of combining and mixing genetic traits, often resulting in the specialization of organisms into a male or female variety . Sexual reproduction involves combining specialized cells to form offspring that inherit traits from both parents... ual population Population A population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals... s	Evolution of sex Evolution of sex The evolution of sexual reproduction is currently described by several competing scientific hypotheses. All sexually reproducing organisms derive from a common ancestor which was a single celled eukaryotic species. Many protists reproduce sexually, as do the multicellular plants, animals, and fungi...
Protist Protist Protists are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista, which includes mostly unicellular organisms that do not fit into the other kingdoms, but this group is contested in modern taxonomy... s	Multicellular organism Multicellular organism Multicellular organisms are organisms that consist of more than one cell, in contrast to single-celled organisms. Most life that can be seen with the the naked eye is multicellular, as are all animals and land plants.-Evolutionary history:Multicellularity has evolved independently dozens of times... s — animal Animal Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and... s, plant Plant Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or... s, fungi Fungus A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...	Evolution of multicellularity
Solitary individuals	Colonies Colony (biology) In biology, a colony reference to several individual organisms of the same species living closely together, usually for mutual benefit, such as stronger defense or the ability to attack bigger prey. Some insects live only in colonies... with non-reproductive caste Caste Caste is an elaborate and complex social system that combines elements of endogamy, occupation, culture, social class, tribal affiliation and political power. It should not be confused with race or social class, e.g. members of different castes in one society may belong to the same race, as in India... s	Evolution of eusociality Evolution of eusociality Eusociality is used to describe a high level of order within a group of individuals of a species. The highly structured colonies of ants, bees, and wasps are the most famous cases of eusociality, though other examples exist...
Primate Primate A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment... societies	Human Human Humans are the only living species in the Homo genus... societies with language Language Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication... , enabling meme Meme A meme is "an idea, behaviour or style that spreads from person to person within a culture."A meme acts as a unit for carrying cultural ideas, symbols or practices, which can be transmitted from one mind to another through writing, speech, gestures, rituals or other imitable phenomena... s	Sociocultural evolution Sociocultural evolution Sociocultural evolution is an umbrella term for theories of cultural evolution and social evolution, describing how cultures and societies have changed over time...

Maynard Smith and Szathmary identified several properties common to the transitions:

Smaller entities have often come about together to form larger entities. e.g. Chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...

s, eukaryote
Eukaryote
A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...

s, sex multicellular colonies.
Smaller entities often become differentiated as part of a larger entity. e.g. DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

& protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

, organelles, anisogamy, tissues, castes
The smaller entities are often unable to replicate in the absence of the larger entity. e.g. Organelles, tissues, castes
The smaller entities can sometimes disrupt the development of the larger entity, e.g. Meiotic drive (selfish non-Mendelian genes), parthenogenesis, cancers, coup d’état
New ways of transmitting information have arisen.e.g. DNA-protein, cell heredity, epigenesis, universal grammar
Universal grammar
Universal grammar is a theory in linguistics that suggests that there are properties that all possible natural human languages have.Usually credited to Noam Chomsky, the theory suggests that some rules of grammar are hard-wired into the brain, and manifest themselves without being taught...

.

As stated by the authors, this book was aimed at professional biologists and assumes considerable prior knowledge. They have also published a presentation of their ideas for a general readership under the title The Origins of Life - From the Birth of Life to the Origins of Language.

See also