Modern evolutionary synthesis
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The modern evolutionary synthesis is a 20th-century synthesis of ideas from several fields of biology that provides a widely accepted account of evolution. It is also referred to as the new synthesis, the modern synthesis, the evolutionary synthesis, millennium synthesis or the neo-Darwinian synthesis.
The synthesis, produced between 1936 and 1947, reflects the consensus about how evolution proceeds.1 The previous development of nineteenth century evolutionary ideas by Charles Darwin, Gregor Mendel and others and the population genetics, between 1918 and 1932, was a stimulus, as it showed that Mendelian genetics was consistent with natural selection and gradual evolution. The synthesis is still, to a large extent, the current paradigm in evolutionary biology.2
The modern synthesis solved difficulties and confusions caused by the specialisation and poor communication between biologists in the early years of the 20th century. At its heart was the question of whether Mendelian genetics could be reconciled with gradual evolution by means of natural selection. A second issue was whether the broad-scale changes (macroevolution) seen by palaeontologists could be explained by changes seen in local populations (microevolution).
The synthesis included evidence from biologists, trained in genetics, who studied populations in the field and in the laboratory. These studies were crucial to evolutionary theory. The synthesis drew together ideas from several branches of biology which had become separated, particularly genetics, cytology, systematics, botany, morphology, ecology and paleontology.
Julian Huxley invented the term, when he produced his book, Evolution: The Modern Synthesis (1942). Other major figures in the modern synthesis include R. A. Fisher, Theodosius Dobzhansky, J. B. S. Haldane, Sewall Wright, E. B. Ford, Ernst Mayr, Bernhard Rensch, Sergei Chetverikov, George Gaylord Simpson, and G. Ledyard Stebbins.
- 1 Summary of the modern synthesis
- 2 Developments leading up to the synthesis
- 3 The modern synthesis
- 4 Further advances
- 5 After the synthesis
- 6 See also
- 7 References
- 8 Bibliography
- 9 Further reading
- 10 External links
- All evolutionary phenomena can be explained in a way consistent with known genetic mechanisms and the observational evidence of naturalists.
- Evolution is gradual: small genetic changes regulated by natural selection accumulate over long periods. Discontinuities amongst species (or other taxa) are explained as originating gradually through geographical separation and extinction. This theory contrasts with the saltation theory of William Bateson (1894).6
- Natural selection is by far the main mechanism of change; even slight advantages are important when continued. The object of selection is the phenotype in its surrounding environment.
- The role of genetic drift is equivocal. Though strongly supported initially by Dobzhansky, it was downgraded later as results from ecological genetics were obtained.
- Thinking in terms of populations, rather than individuals, is primary: the genetic diversity existing in natural populations is a key factor in evolution. The strength of natural selection in the wild is greater than previously expected; the effect of ecological factors such as niche occupation and the significance of barriers to gene flow are all important.
- In palaeontology, the ability to explain historical observations by extrapolation from microevolution to macroevolution is proposed. Historical contingency means explanations at different levels may exist. Gradualism does not mean constant rate of change.
The idea that speciation occurs after populations are reproductively isolated has been much debated. In plants, polyploidy must be included in any view of speciation. Formulations such as 'evolution consists primarily of changes in the frequencies of alleles between one generation and another' were proposed rather later. The traditional view is that evolutionary developmental biology (evo-devo) played little part in the synthesis,7 but an account of Gavin de Beer's work by Stephen J. Gould suggests he may be an exception.8
Charles Darwin's On the Origin of Species (1859) was successful in convincing most biologists that evolution had occurred, but was less successful in convincing them that natural selection was its primary mechanism. In the 19th and early 20th centuries, variations of Lamarckism, orthogenesis ('progressive' evolution), and saltationism (evolution by jumps) were discussed as alternatives.9 Also, Darwin did not offer a precise explanation of how new species arise. As part of the disagreement about whether natural selection alone was sufficient to explain speciation, George Romanes coined the term neo-Darwinism to refer to the version of evolution advocated by Alfred Russel Wallace and August Weismann with its heavy dependence on natural selection.10 Weismann and Wallace rejected the Lamarckian idea of inheritance of acquired characteristics, something that Darwin had not ruled out.11
Weismann's idea was that the relationship between the hereditary material, which he called the germ plasm (German, Keimplasma), and the rest of the body (the soma) was a one-way relationship: the germ-plasm formed the body, but the body did not influence the germ-plasm, except indirectly in its participation in a population subject to natural selection. Weismann was translated into English, and though he was influential, it took many years for the full significance of his work to be appreciated.12 Later, after the completion of the modern synthesis, the term neo-Darwinism came to be associated with its core concept: evolution, driven by natural selection acting on variation produced by genetic mutation, and genetic recombination (chromosomal crossovers).10
Gregor Mendel's work was re-discovered by Hugo de Vries and Carl Correns in 1900. News of this reached William Bateson in England, who reported on the paper during a presentation to the Royal Horticultural Society in May 1900.13 It showed that the contributions of each parent retained their integrity rather than blending with the contribution of the other parent. This reinforced a division of thought, which was already present in the 1890s.14 The two schools were:
- Saltationism (large mutations or jumps), favored by early Mendelians who viewed hard inheritance as incompatible with natural selection15
- Biometric school: led by Karl Pearson and Walter Weldon, argued vigorously against it, saying that empirical evidence indicated that variation was continuous in most organisms, not discrete as Mendelism predicted.
The relevance of Mendelism to evolution was unclear and hotly debated, especially by Bateson, who opposed the biometric ideas of his former teacher Weldon. Many scientists believed the two theories substantially contradicted each other.16 This debate between the biometricians and the Mendelians continued for some 20 years and was only solved by the development of population genetics.
Thomas Hunt Morgan began his career in genetics as a saltationist, and started out trying to demonstrate that mutations could produce new species in fruit flies. However, the experimental work at his lab with the common fruit fly, Drosophila melanogaster, which helped establish the link between Mendelian genetics and the chromosomal theory of inheritance, demonstrated that rather than creating new species in a single step, mutations increased the genetic variation in the population.17
The first step towards the synthesis was the development of population genetics. R. A. Fisher, J. B. S. Haldane, and Sewall Wright provided critical contributions. In 1918, Fisher produced the paper "The Correlation Between Relatives on the Supposition of Mendelian Inheritance,"18 which showed how the continuous variation measured by the biometricians could be the result of the action of many discrete genetic loci. In this and subsequent papers culminating in his 1930 book The Genetical Theory of Natural Selection,19 Fisher was able to show how Mendelian genetics was, contrary to the thinking of many early geneticists, completely consistent with the idea of evolution driven by natural selection.20 During the 1920s, a series of papers by Haldane applied mathematical analysis to real world examples of natural selection such as the evolution of industrial melanism in peppered moths.20 Haldane established that natural selection could work in the real world at a faster rate than even Fisher had assumed.21
Sewall Wright focused on combinations of genes that interacted as complexes, and the effects of inbreeding on small relatively isolated populations, which could exhibit genetic drift. In a 1932 paper, he introduced the concept of an adaptive landscape in which phenomena such as cross breeding and genetic drift in small populations could push them away from adaptive peaks, which would in turn allow natural selection to push them towards new adaptive peaks.2022 Wright's model would appeal to field naturalists such as Theodosius Dobzhansky and Ernst Mayr who were becoming aware of the importance of geographical isolation in real world populations.21 The work of Fisher, Haldane and Wright founded the discipline of population genetics. This is the precursor of the modern synthesis, which is an even broader coalition of ideas.202123 One limitation of the modern synthesis version of population genetics is that it treats one gene locus at a time, neglecting genetic linkage and resulting linkage disequilibrium between loci.
Theodosius Dobzhansky, a Ukrainian emigrant, who had been a postdoctoral worker in Morgan's fruit fly lab, was one of the first to apply genetics to natural populations. He worked mostly with Drosophila pseudoobscura. He says pointedly: "Russia has a variety of climates from the Arctic to sub-tropical... Exclusively laboratory workers who neither possess nor wish to have any knowledge of living beings in nature were and are in a minority."24 Not surprisingly, there were other Russian geneticists with similar ideas, though for some time their work was known to only a few in the West. His 1937 work Genetics and the Origin of Species25 was a key step in bridging the gap between population geneticists and field naturalists. It presented the conclusions reached by Fisher, Haldane, and especially Wright in their highly mathematical papers in a form that was easily accessible to others. It also emphasized that real world populations had far more genetic variability than the early population geneticists had assumed in their models, and that genetically distinct sub-populations were important. Dobzhansky argued that natural selection worked to maintain genetic diversity as well as driving change. Dobzhansky had been influenced by his exposure in the 1920s to the work of a Russian geneticist Sergei Chetverikov who had looked at the role of recessive genes in maintaining a reservoir of genetic variability in a population before his work was shut down by the rise of Lysenkoism in the Soviet Union.2021
E. B. Ford's work complemented that of Dobzhansky. It was as a result of Ford's work, as well as his own, that Dobzhansky changed the emphasis in the third edition of his famous text from drift to selection.26 Ford was an experimental naturalist who wanted to test natural selection in nature. He virtually invented the field of research known as ecological genetics. His work on natural selection in wild populations of butterflies and moths was the first to show that predictions made by R. A. Fisher were correct. He was the first to describe and define genetic polymorphism, and to predict that human blood group polymorphisms might be maintained in the population by providing some protection against disease.27
Ernst Mayr's key contribution to the synthesis was Systematics and the Origin of Species, published in 1942.28 Mayr emphasized the importance of allopatric speciation, where geographically isolated sub-populations diverge so far that reproductive isolation occurs. He was skeptical of the reality of sympatric speciation believing that geographical isolation was a prerequisite for building up intrinsic (reproductive) isolating mechanisms. Mayr also introduced the biological species concept that defined a species as a group of interbreeding or potentially interbreeding populations that were reproductively isolated from all other populations.202129 Before he left Germany for the United States in 1930, Mayr had been influenced by the work of German biologist Bernhard Rensch. In the 1920s Rensch, who like Mayr did field work in Indonesia, analyzed the geographic distribution of polytypic species and complexes of closely related species paying particular attention to how variations between different populations correlated with local environmental factors such as differences in climate. In 1947, Rensch published Neuere Probleme der Abstammungslehre. Die transspezifische Evolution (1959 English translation of 2nd edition: Evolution Above the Species Level).30 This looked at how the same evolutionary mechanisms involved in speciation might be extended to explain the origins of the differences between the higher level taxa. His writings contributed to the rapid acceptance of the synthesis in Germany.3132
George Gaylord Simpson was responsible for showing that the modern synthesis was compatible with paleontology in his book Tempo and Mode in Evolution published in 1944. Simpson's work was crucial because so many paleontologists had disagreed, in some cases vigorously, with the idea that natural selection was the main mechanism of evolution. It showed that the trends of linear progression (in for example the evolution of the horse) that earlier paleontologists had used as support for neo-Lamarckism and orthogenesis did not hold up under careful examination. Instead the fossil record was consistent with the irregular, branching, and non-directional pattern predicted by the modern synthesis.2021
The botanist G. Ledyard Stebbins was another major contributor to the synthesis. His major work, Variation and Evolution in Plants, was published in 1950. It extended the synthesis to encompass botany including the important effects of hybridization and polyploidy in some kinds of plants.20
The modern evolutionary synthesis continued to be developed and refined after the initial establishment in the 1930s and 1940s. The work of W. D. Hamilton, George C. Williams, John Maynard Smith and others led to the development of a gene-centered view of evolution in the 1960s. The synthesis as it exists now has extended the scope of the Darwinian idea of natural selection to include subsequent scientific discoveries and concepts unknown to Darwin, such as DNA and genetics, which allow rigorous, in many cases mathematical, analyses of phenomena such as kin selection, altruism, and speciation.
In The Selfish Gene (1976), author Richard Dawkins asserts the gene is the only true unit of selection.33 (Dawkins also attempts to apply evolutionary theory to non-biological entities, such as cultural memes, imagined to be subject to selective forces analogous to those affecting biological entities.)
Others, such as Stephen Jay Gould, reject the notion that genetic entities are subject to anything other than genetic or chemical forces, (as well as the idea evolution acts on "populations" per se), reasserting the centrality of the individual organism as the true unit of selection, whose specific phenotype is directly subject to evolutionary pressures.
In 1972, the notion of gradualism in evolution was challenged by a theory of punctuated equilibrium put forward by Gould and Niles Eldredge, proposing evolutionary changes could occur in relatively rapid spurts, when selective pressures were heightened, punctuating long periods of morphological stability, as well-adapted organisms coped successfully in their respective environments.
Discovery in the 1980s of Hox genes and regulators conserved across multiple phyletic divisions began the process of addressing basic theoretical problems relating to gradualism, incremental change, and sources of novelty in evolution. Suddenly, evolutionary theorists could answer the charge that spontaneous random mutations should result overwhelmingly in deleterious changes to a fragile, monolithic genome: Mutations in homeobox regulation could safely—yet dramatically—alter morphology at a high level, without damaging coding for specific organs or tissues.
As these discoveries suggest, the synthesis continues to undergo regular review, drawing on insights offered by both new biotechnologies and new paleontological discoveries.34
There are a number of discoveries in earth sciences and biology which have arisen since the synthesis. Listed here are some of those topics which are relevant to the evolutionary synthesis, and which seem soundly based.
The Earth is the stage on which the evolutionary play is performed. Darwin studied evolution in the context of Charles Lyell's geology, but our present understanding of Earth history includes some critical advances made during the last half-century.
- The age of the Earth has been revised upwards. It is now estimated to be approximately 4.54 billion years old, nearly one-third of the age of the universe. The Phanerozoic (current eon) only occupies the last one-ninth of this period of time.35
- The triumph of Alfred Wegener's idea of continental drift came around 1960. The key principle of plate tectonics is that the lithosphere exists as separate and distinct tectonic plates, which ride on the fluid-like (visco-elastic solid) asthenosphere. This discovery provides a unifying theory for geology, linking phenomena such as volcanoes, earthquakes, orogeny, and providing data for many paleogeographical questions.36 One major question is still unclear: when did plate tectonics begin?37
- Our understanding of the evolution of the atmosphere of Earth has progressed. The substitution of oxygen for carbon dioxide (CO2) in the atmosphere, which occurred in the Proterozoic, caused probably by cyanobacteria in the form of stromatolites, caused changes leading to the evolution of aerobic organisms.3839
- The identification of the first generally accepted fossils of microbial life was made by geologists. These rocks have been dated as about 3.465 billion years ago.40 Charles Doolittle Walcott was the first geologist to identify Precambrian fossil bacteria from microscopic examination of thin rock slices. He also thought stromatolites were organic in origin. His ideas were not accepted at the time, but may now be appreciated as great discoveries.41
- Information about paleoclimates is increasingly available, and being used in paleontology. One example: the discovery of massive ice ages in the Proterozoic, following the great reduction of CO2 in the atmosphere. These ice ages were immensely long, and led to a crash in microflora.42 (See also Cryogenian period and Snowball Earth.)
- Catastrophism and extinction events. A partial reintegration of catastrophism has occurred,43 and the importance of mass extinctions in large-scale evolution is now apparent. Extinction events disturb relationships between many forms of life and may remove dominant forms and release a flow of adaptive radiation amongst groups that remain. Causes include meteorite strikes (Cretaceous–Paleogene extinction event; Late Devonian extinction); flood basalt provinces (Deccan Traps at Cretaceous–Paleogene boundary; Siberian Traps at P–Tr; and other less dramatic processes.4445
Conclusion: Our present knowledge of earth history strongly suggests that large-scale geophysical events influenced macroevolution and megaevolution. These terms refer to evolution above the species level, including such events as mass extinctions, adaptive radiation, and the major transitions in evolution.4647
Once symbiosis was discovered in lichen and in plant roots (rhizobia in root nodules) in the 19th century, the idea arose that the process might have occurred more widely, and might be important in evolution. Heinrich Anton de Bary invented the concept of symbiosis;48 several Russian biologists promoted the idea;49 Edmund Beecher Wilson mentioned it in his book The Cell in Development and Heredity (1925);50 as did Ivan Wallin in his Symbionticism and the Origin of Species (1927);51 and there was a brief mention by Julian Huxley in 1930;52 all in vain because sufficient evidence was lacking. Symbiosis as a major evolutionary force was not discussed at all in the evolutionary synthesis.53
The role of symbiosis in cell evolution was revived partly by Joshua Lederberg,54 and finally brought to light by Lynn Margulis in a series of papers and books.5556 Some organelles are recognized as being of microbial origin: mitochondria and chloroplasts definitely, cilia, flagella and centrioles possibly, and perhaps the nuclear membrane and much of the chromosome structure as well. What is now clear is that the evolution of eukaryote cells is either caused by, or at least profoundly influenced by, symbiosis with bacterial and archaean cells in the Proterozoic.
The origin of the eukaryote cell by symbiosis in several stages was not part of the evolutionary synthesis. It is, at least on first sight, an example of megaevolution by big jumps. However, what symbiosis provided was a copious supply of heritable variation from microorganisms, which was fine-tuned over a long period to produce the cell structure we see today. This part of the process is consistent with evolution by natural selection.57
The ability to analyse sequence in macromolecules (protein, DNA, RNA) provides evidence of descent, and permits us to work out genealogical trees covering the whole of life, since now there are data on every major group of living organisms. This project, begun in a tentative way in the 1960s, has become a search for the universal tree or the universal ancestor, a phrase of Carl Woese.5859 The tree that results has some unusual features, especially in its roots. There are two domains of prokaryotes: bacteria and archaea, both of which contributed genetic material to the eukaryotes, mainly by means of symbiosis. Also, since bacteria can pass genetic material to other bacteria, their relationships look more like a web than a tree. Once eukaryotes were established, their sexual reproduction produced the traditional branching tree-like pattern, the only diagram Darwin published in On the Origin of Species. The last universal ancestor (LUA) would be a prokaryotic cell before the split between the bacteria and archaea. LUA is defined as most recent organism from which all organisms now living on Earth descend (some 3.5 to 3.8 billion years ago, in the Archean eon).60
This technique may be used to clarify relationships within any group of related organisms. It is now a standard procedure, and examples are published regularly. April 2008 sees the publication of a tree covering all the animal phyla, derived from sequences from 150 genes in 77 taxa.61
Early attempts to identify relationships between major groups were made in the 19th century by Ernst Haeckel, and by comparative anatomists such as Thomas Henry Huxley and E. Ray Lankester. Enthusiasm waned: it was often difficult to find evidence to adjudicate between different opinions. Perhaps for that reason, the evolutionary synthesis paid surprisingly little attention to this activity. It is certainly a lively field of research today.
What once was called embryology played a modest role in the evolutionary synthesis,62 mostly about evolution by changes in developmental timing (allometry and heterochrony).63 Man himself was, according to Louis Bolk, a typical case of evolution by retention of juvenile characteristics (neoteny). He listed many characters where "Man, in his bodily development, is a primate foetus that has become sexually mature."64 Unfortunately, his interpretation of these ideas was non-Darwinian, but his list of characters is both interesting and convincing.65
Evolutionary developmental biology springs from clear proof that development is closely controlled by special genetic systems, and the hope that comparison of these systems will tell us much about the evolutionary history of different groups.6667 In a series of experiments with the fruit fly Drosophila, Edward B. Lewis was able to identify a complex of genes whose proteins bind to the cis-regulatory regions of target genes. The latter then activate or repress systems of cellular processes that accomplish the final development of the organism.6869 Furthermore, the sequence of these control genes show co-linearity: the order of the loci in the chromosome parallels the order in which the loci are expressed along the anterior-posterior axis of the body. Not only that, but this cluster of master control genes programs the development of all higher organisms.7071 Each of the genes contains a homeobox, a remarkably conserved DNA sequence. This suggests the complex itself arose by gene duplication.727374 In his 1995 Nobel lecture, Lewis said "Ultimately, comparisons of the HOM-C throughout the animal kingdom should provide a picture of how the organisms, as well as the genes of the HOM-C, have evolved."75
The term deep homology was coined to describe the common origin of genetic regulatory apparatus used to build morphologically and phylogenetically disparate animal features.76 It applies when a complex genetic regulatory system is inherited from a common ancestor, as it is in the evolution of vertebrate and invertebrate eyes. The phenomenon is implicated in many cases of parallel evolution.77
A great deal of evolution may take place by changes in the control of development. This may be relevant to punctuated equilibrium theory, for in development a few changes to the control system could make a significant difference to the adult organism. An example is the giant panda, whose place in the Carnivora was long uncertain.78 Apparently, the giant panda's evolution required the change of only a few genetic messages (5 or 6 perhaps), yet the phenotypic and lifestyle change from a standard bear is considerable.7980 The transition could therefore be effected relatively swiftly.
Since the late 20th century, there have been excavations in parts of the world which had scarcely been investigated before. Also, there is fresh appreciation of fossils discovered in the 19th century, but then denied or deprecated: the classic example is the Ediacaran biota from the immediate Precambrian, after the Cryogenian period. These soft-bodied fossils are the first record of multicellular life. The interpretation of this fauna is still in flux.
Many outstanding discoveries have been made, and some of these have implications for evolutionary theory. The discovery of feathered dinosaurs and early birds from the Early Cretaceous of Liaoning Province in notheast China have convinced most paleontologists that birds did evolve from coelurosaurian theropod dinosaurs. Less well known, but perhaps of equal evolutionary significance, are the studies on early insect flight, on stem tetrapods from the Late Devonian,8182 and the early stages of whale evolution.83
Recent work has shed light on the evolution of flatfish (order Pleuronectiformes), such as plaice, sole, turbot and halibut. Flatfish are interesting because they are one of the few vertebrate groups with external asymmetry. Their young are perfectly symmetrical, but the head is remodelled during a metamorphosis, which entails the migration of one eye to the other side, close to the other eye. Some species have both eyes on the left (turbot), some on the right (halibut, sole); all living and fossil flatfish to date show an 'eyed' side and a 'blind' side.84 The lack of an intermediate condition in living and fossil flatfish species had led to debate about the origin of such a striking adaptation. The case was considered by Jean-Baptiste Lamarck,85 who thought flatfish precursors would have lived in shallow water for a long period, and by Charles Darwin, who predicted a gradual migration of the eye, mirroring the metamorphosis of the living forms. Darwin's long-time critic St. George Mivart thought that the intermediate stages could have no selective value,86 and in the 6th edition of On the Origin of Species, Darwin made a concession to the possibility of acquired traits.87 Many years later the geneticist Richard Goldschmidt put the case forward as an example of evolution by saltation, bypassing intermediate forms.8889
A recent examination of two fossil species from the Eocene has provided the first clear picture of flatfish evolution. The discovery of stem flatfish with incomplete orbital migration refutes Goldschmidt's ideas, and demonstrates that "the assembly of the flatfish bodyplan occurred in a gradual, stepwise fashion."90 There are no grounds for thinking that incomplete orbital migration was maladaptive, because stem forms with this condition ranged over two geological stages, and are found in localities which also yield flatfish with the full cranial asymmetry. The evolution of flatfish falls squarely within the evolutionary synthesis.84
Horizontal gene transfer (HGT) (or lateral gene transfer) is any process in which an organism gets genetic material from another organism without being the offspring of that organism.
Most thinking in genetics has focused on vertical transfer, but there is a growing awareness that horizontal gene transfer is a significant phenomenon. Amongst single-celled organisms it may be the dominant form of genetic transfer. Artificial horizontal gene transfer is a form of genetic engineering.
Aaron O. Richardson and Jeffrey D. Palmer state: "Horizontal gene transfer (HGT) has played a major role in bacterial evolution and is fairly common in certain unicellular eukaryotes. However, the prevalence and importance of HGT in the evolution of multicellular eukaryotes remain unclear."91
The bacterial means of HGT are:
- Transformation, the genetic alteration of a cell resulting from the introduction, uptake and expression of foreign genetic material (DNA or RNA).
- Transduction, the process in which bacterial DNA is moved from one bacterium to another by a bacterial virus (a bacteriophage, or 'phage').
- Bacterial conjugation, a process in which a bacterial cell transfers genetic material to another cell by cell-to-cell contact.
- Gene transfer agent (GTA) is a virus-like element which contains random pieces of the host chromosome. They are found in most members of the Alphaproteobacteria order Rhodobacterales.92 They are encoded by the host genome. GTAs transfer DNA so frequently that they may have an important role in evolution.93
A 2010 report found that genes for antibiotic resistance could be transferred by engineering GTAs in the laboratory.92
Some examples of HGT in Metazoa are now known. Genes in bdelloid rotifers have been found which appear to have originated in bacteria, fungi, and plants. This suggests they arrived by horizontal gene transfer. The capture and use of exogenous (~foreign) genes may represent an important force in bdelloid evolution.9495 The team led by Matthew S. Meselson at Harvard University has also shown that, despite the lack of sexual reproduction, bdelloid rotifers do engage in genetic (DNA) transfer within a species or clade. The method used is not known at present.
- Developmental systems theory
- Gene-centered view of evolution
- History of evolutionary thought
- Objections to evolution
- Particulate inheritance
- Polymorphism (biology)
- National Academy of Sciences 1999, p. 28: "The scientific consensus around evolution is overwhelming."
- Mayr 2002, p. 270
- Huxley 2010
- Mayr & Provine 1998
- Mayr 1982, p. 567 et seq.
- Bateson 1894
- Smocovitis 1996, p. 192
- Gould 1977, p. 221–222
- Bowler 2003, pp. 236–256
- Gould 2002, p. 216
- Kutschera, Ulrich (December 2003). "A comparative analysis of the Darwin-Wallace papers and the development of the concept of natural selection". Theory in Biosciences (Jena; Berlin & Heidelberg: Urban & Fischer; Springer-Verlag) 122 (4): 343–359. doi:10.1007/s12064-003-0063-6. ISSN 1431-7613.
- Bowler 2003, pp. 253–256
- Ambrose, Mike. "Mendel's Peas". Norwich, UK: Germplasm Resources Unit, John Innes Centre. Retrieved 2015-05-22.
- Bateson 1894: The division of thought was between gradualists of the Darwinian school, and saltationists such as Bateson. Mutations (as 'sports') and polymorphisms were well known long before the Mendelian recovery.
- Larson 2004, pp. 157–166
- Grafen & Ridley 2006, p. 69
- Bowler 2003, pp. 271–272
- Fisher, Ronald A. (January 1919). "XV.—The Correlation between Relatives on the Supposition of Mendelian Inheritance". Transactions of the Royal Society of Edinburgh (London: Robert Grant & Son; Williams & Norgate) 52 (2): 399–433. doi:10.1017/S0080456800012163. ISSN 0080-4568. OCLC 4981124. "Paper read by J. Arthur Thomson on July 8, 1918 to the Royal Society of Edinburgh."
- Fisher 1999
- Larson 2004, pp. 221–243
- Bowler 2003, pp. 325–339
- Wright 1932, pp. 356–366
- Gould 2002, pp. 503–518
- Mayr & Provine 1998, p. 231
- Dobzhansky 1937
- Dobzhansky 1951
- Ford 1964; Ford 1975
- Mayr 1999
- Mayr & Provine 1998, pp. 33–34
- Rensch 1947; Rensch 1959
- Smith, Charles H.. "Rensch, Bernhard (Carl Emmanuel) (Germany 1900-1990)". Some Biogeographers, Evolutionists and Ecologists: Chrono-Biographical Sketches. Bowling Green, KY: Western Kentucky University. Retrieved 2015-05-22.
- Mayr & Provine 1998, pp. 298–299, 416
- Bowler 2003, p. 361
- Pigliucci, Massimo (December 2007). "Do we need an extended evolutionary synthesis?". Evolution (Hoboken, NJ: John Wiley & Sons for the Society for the Study of Evolution) 61 (12): 2743–2749. doi:10.1111/j.1558-5646.2007.00246.x. ISSN 0014-3820. PMID 17924956.
- Dalrymple 2001, pp. 205–221
- van Andel 1994
- Witze, Alexandra (July 13, 2006). "Geology: The start of the world as we know it". Nature (London: Nature Publishing Group) 442 (7099): 128–131. doi:10.1038/442128a. ISSN 0028-0836. PMID 16837994.
- Schopf & Klein 1992
- Lane 2002
- Schopf 1999
- Yochelson 1998
- Knoll & Holland 1995
- Huggett 1997
- Hallam & Wignall 1997
- Elewa 2008
- The terms (or their equivalents) were used as part of the synthesis by Simpson 1984 and Rensch 1947. They were also used by some non-Darwinian evolutionists such as Yuri Filipchenko and Richard Goldschmidt. Here we use the terms as part of the evolutionary synthesis: they do not imply any change in mechanism.
- Maynard Smith & Szathmáry 1997
- de Bary 1879
- Khakhina 1992
- Wilson 1925
- Wallin 1927
- Huxley 1929–1930, p. 505
- Sapp 1994
- Lederberg, Joshua (October 1952). "Cell Genetics and Hereditary Symbiosis" (PDF). Physiological Reviews (Bethesda, MD: American Physiological Society) 32 (4): 403–430. ISSN 0031-9333. PMID 13003535.
- Margulis & Fester 1991
- Margulis 1993
- Maynard Smith & Szathmáry 1997: The origin of the eukaryote cell is one of the seven major transitions, according to these authors.
- Woese, Carl (June 9, 1998). "The universal ancestor". Proc. Natl. Acad. Sci. U.S.A. (Washington, D.C.: National Academy of Sciences) 95 (12): 6854–6859. doi:10.1073/pnas.95.12.6854. ISSN 0027-8424. PMC 22660. PMID 9618502.
- Doolittle, W. Ford (June 25, 1999). "Phylogenetic Classification and the Universal Tree". Science (Washington, D.C.: American Association for the Advancement of Science) 284 (5423): 2124–2128. doi:10.1126/science.284.5423.2124. ISSN 0036-8075. PMID 10381871.
- Doolittle, W. Ford (February 2000). "Uprooting the Tree of Life" (PDF). Scientific American (Stuttgart: Georg von Holtzbrinck Publishing Group) 282 (2): 90–95. doi:10.1038/scientificamerican0200-90. ISSN 0036-8733. PMID 10710791. Archived from the original (PDF) on 2006-09-07. Retrieved 2015-05-24.
- Dunn, Casey W.; Hejnol, Andreas; Matus, David Q. et al. (April 10, 2008). "Broad phylogenetic sampling improves resolution of the animal tree of life". Nature (London: Nature Publishing Group) 452 (7188): 745–749. doi:10.1038/nature06614. ISSN 0028-0836. PMID 18322464.
- Laubichler & Maienschein 2007
- de Beer 1930
- Bolk 1926
- Gould 1977, p. 357: Short-list of 25 characters.
- Raff & Kaufman 1983
- Carroll 2005
- Lewis 1997, pp. 247–272
- Lawrence 1992
- Duncan, Ian (December 1987). "The Bithorax Complex". Annual Review of Genetics (Palo Alto, CA: Annual Reviews) 21: 285–319. doi:10.1146/annurev.ge.21.120187.001441. ISSN 0066-4197.
- Lewis, Edward B. (March 18, 1992). "Clusters of Master Control Genes Regulate the Development of Higher Organisms". JAMA: The Journal of the American Medical Association (Chicago, IL: American Medical Association) 267 (11): 1524–1531. doi:10.1001/jama.1992.03480110100042. ISSN 0098-7484. PMID 1347087.
- McGinnis, William; Levine, Michael S.; Hafen, Ernst; Kuroiwa, Atsushi (March 29, 1984). "A conserved DNA sequence in homoeotic genes of the Drosophila Antennapedia and bithorax complexes". Nature (London: Nature Publishing Group) 308 (5958): 428–433. doi:10.1038/308428a0. ISSN 0028-0836. PMID 6323992.
- Scott, Matthew P.; Weiner, Amy J. (July 1, 1984). "Structural relationships among genes that control development: sequence homology between the Antennapedia, Ultrabithorax, and fushi tarazu loci of Drosophila". Proc. Natl. Acad. Sci. U.S.A. (Washington, D.C.: National Academy of Sciences) 81 (13): 4115–4119. doi:10.1073/pnas.81.13.4115. ISSN 0027-8424. PMC 345379. PMID 6330741.
- Gehring 1998
- Lewis 1997, p. 266
- Shubin, Neil; Tabin, Cliff; Carroll, Sean B. (August 14, 1997). "Fossils, genes and the evolution of animal limbs". Nature (London: Nature Publishing Group) 388 (6643): 639–648. doi:10.1038/41710. ISSN 0028-0836. PMID 9262397.
- Shubin, Neil; Tabin, Cliff; Carroll, Sean B. (February 12, 2009). "Deep homology and the origins of evolutionary novelty". Nature (London: Nature Publishing Group) 457 (7231): 818–823. doi:10.1038/nature07891. ISSN 0028-0836. PMID 19212399.
- Sarich, Vincent M. (September 28, 1973). "The Giant Panda is a Bear". Nature (London: Nature Publishing Group) 245 (5422): 218–220. doi:10.1038/245218a0. ISSN 0028-0836.
- Davis 1964
- Stanley 1979, p. 157
- Clack 2002
- "Jenny Clack's Home Page".
- Both whale evolution and early insect flight are discussed in Raff 1996. These discussions provide a welcome synthesis of evo-devo and paleontology.
- Janvier, Philippe (July 10, 2008). "Palaeontology: Squint of the fossil flatfish". Nature (London: Nature Publishing Group) 454 (7201): 169–170. doi:10.1038/454169a. ISSN 0028-0836. PMID 18615071.
- Lamarck 1809
- Mivart 1871
- Darwin 1872, pp. 186–188
- Goldschmidt, Richard (December 15, 1933). "Some Aspects of Evolution". Science (Washington, D.C.: American Association for the Advancement of Science) 78 (2033): 539–547. doi:10.1126/science.78.2033.539. ISSN 0036-8075.
- Goldschmidt 1940
- Friedman, Matt (July 10, 2008). "The evolutionary origin of flatfish asymmetry". Nature (London: Nature Publishing Group) 454 (7201): 209–212. doi:10.1038/nature07108. ISSN 0028-0836. PMID 18615083.
- Richardson, Aaron O.; Palmer, Jeffrey D. (January 2007). "Horizontal gene transfer in plants". Journal of Experimental Botany (Oxford, UK: Oxford University Press) 58 (1): 1–9. doi:10.1093/jxb/erl148. ISSN 0022-0957. PMID 17030541.
- McDaniel, Lauren D.; Young, Elizabeth; Delaney, Jennifer et al. (October 1, 2010). "High Frequency of Horizontal Gene Transfer in the Oceans". Science (Washington, D.C.: American Association for the Advancement of Science) 330 (6000): 50. doi:10.1126/science.1192243. ISSN 0036-8075. PMID 20929803.
- Maxmen, Amy (September 30, 2010). "Virus-like particles speed bacterial evolution". Nature News (London: Nature Publishing Group). doi:10.1038/news.2010.507.
- Gladyshev, Eugene A.; Meselson, Matthew; Arkhipova, Irina R. (May 30, 2008). "Massive Horizontal Gene Transfer in Bdelloid Rotifers". Science (Washington, D.C.: American Association for the Advancement of Science) 320 (5880): 1210–1213. doi:10.1126/science.1156407. ISSN 0036-8075. PMID 18511688.
- Arkhipova, Irina R.; Meselson, Matthew (August 16, 2005). "Diverse DNA transposons in rotifers of the class Bdelloidea". Proc. Natl. Acad. Sci. U.S.A. (Washington, D.C.: National Academy of Sciences) 102 (33): 11781–11786. doi:10.1073/pnas.0505333102. ISSN 0027-8424. PMC 1188004. PMID 16081532.
- Bateson, William (1894). Materials for the Study of Variation Treated with Especial Regard to Discontinuity in the Origin of Species. London; New York: Macmillan & Co. LCCN 07001821. OCLC 1944285. Retrieved 2015-05-22.
- Bolk, Louis (1926). Der Problem der Menschwerdung The Problem of the Incarnation (in German). Jena: Gustav Fischer Verlag. OCLC 493856594.
- Bowler, Peter J. (2003). Evolution: The History of an Idea (3rd completely rev. and expanded ed.). Berkeley, CA: University of California Press. ISBN 0-520-23693-9. LCCN 2002007569. OCLC 49824702.
- Carroll, Sean B. (2005). Endless Forms Most Beautiful: The New Science of Evo Devo and the Making of the Animal Kingdom. Illustrations by Jamie W. Carroll, Josh P. Klaiss, Leanne M. Olds (1st ed.). New York: W. W. Norton & Company. ISBN 0-393-06016-0. LCCN 2004029388. OCLC 57316841.
- Clack, Jennifer A. (2002). Gaining Ground: The Origin and Evolution of Tetrapods. Life of the Past. Bloomington, IN: Indiana University Press. ISBN 0-253-34054-3. LCCN 2001004783. OCLC 47767251.
- Dalrymple, G. Brent (2001). "The age of the Earth in the twentieth century: a problem (mostly) solved". In Lewis, C. L. E.; Knell, S. J. The Age of the Earth: from 4004 BC to AD 2002. Geological Society Special Publication 190. London: Geological Society of London. doi:10.1144/gsl.sp.2001.190.01.14. ISBN 1-86239-093-2. ISSN 0305-8719. LCCN 2003464816. OCLC 48570033.
- Darwin, Charles (1872). The Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life (6th ed.). London: John Murray. The book is available from The Complete Work of Charles Darwin Online. Retrieved 2015-05-25. The Chapter VII in this edition is taken up with answering critics of natural selection.
- Davis, D. Dwight (1964). The Giant Panda: A Morphological Study of Evolutionary Mechanisms. Fieldiana: Zoology Memoirs 3. Chicago, IL: Chicago Natural History Museum. doi:10.5962/bhl.title.5133. LCCN 64008995. OCLC 1895716.
- Dawkins, Richard (1976). The Selfish Gene. Oxford, UK: Oxford University Press. ISBN 0-19-857519-X. LCCN 77350605. OCLC 2681149.
- de Bary, Heinrich Anton (1879). Die Erscheinung der Symbiose (in German). Strassburg: Verlag von Karl J. Trübner. OCLC 65143305.
- de Beer, Gavin (1930). Embryology and Evolution. Oxford, UK: The Clarendon Press. LCCN 30015530. OCLC 733362. 2nd (1940) and 3rd (1958) editions under the title Embryos and Ancestors.
- Dobzhansky, Theodosius (1937). Genetics and the Origin of Species. Columbia University Biological Series. New York: Columbia University Press. LCCN 37033383. OCLC 766405.
- Elewa, Ashraf M. T., ed. (2008). Mass Extintion. Berlin; Heidelberg: Springer-Verlag. ISBN 978-3-540-75915-7. LCCN 2007938882. OCLC 182664250.
- Fisher, R. A. (1999) [Originally published 1930; Oxford, UK: The Clarendon Press]. The Genetical Theory of Natural Selection. Edited with a foreword and notes by J. H. Bennett (A complete variorum ed.). Oxford, UK: Oxford University Press. ISBN 0-19-850440-3. LCCN 00702764. OCLC 45308589.
- Ford, E. B. (1964). Ecological Genetics. London; New York: Methuen Publishing; John Wiley & Sons. LCCN 64009038. OCLC 875507052.
- Gehring, Walter J. (1998). Master Control Genes in Development and Evolution: The Homeobox Story. The Terry Lectures. Foreword by Frank Ruddie. New Haven, CT: Yale University Press. ISBN 0-300-07409-3. LCCN 98019922. OCLC 38936739.
- Goldschmidt, Richard (1940). The Material Basis of Evolution. New Haven, CT; London: Yale University Press; Oxford University Press. LCCN 40012233. OCLC 849551. "This book presents an elaboration of the material which was used, in less technical and less detailed form, for presentation in eight Silliman Lectures delivered in December, 1939"
- Gould, Stephen Jay (1977). Ontogeny and Phylogeny. Cambridge, MA: Belknap Press of Harvard University Press. ISBN 0-674-63940-5. LCCN 76045765. OCLC 2508336.
- Gould, Stephen Jay (2002). The Structure of Evolutionary Theory. Cambridge, MA: Belknap Press of Harvard University Press. ISBN 0-674-00613-5. LCCN 2001043556. OCLC 47869352.
- Grafen, Alan; Ridley, Mark, eds. (2006). Richard Dawkins: How a Scientist Changed the Way We Think. Oxford, UK; New York: Oxford University Press. ISBN 978-0-19-929116-8. LCCN 2005033395. OCLC 851822245.
- Hallam, A.; Wignall, P. B. (1997). Mass Extinctions and their Aftermath. Oxford, UK; New York: Oxford University Press. ISBN 0-19-854916-4. LCCN 97022349. OCLC 37141126.
- Huggett, Richard J. (1997). Catastrophism: Asteroids, Comets, and other Dynamic Events in Earth History. London; New York: Verso. ISBN 1-85984-129-5. LCCN 97048852. OCLC 38073337.
- Huxley, Julian (1929–1930). "The A B C of Genetics". The Science of Life 2. London: The Amalgamated Press, Inc. LCCN unk82109388. OCLC 3171056.
- Huxley, Julian (2010) [Originally published 1942]. Evolution: The Modern Synthesis. With a new foreword by Massimo Pigliucci and Gerd B. Müller (Definitive ed.). Cambridge, MA: MIT Press. ISBN 978-0-262-51366-1. LCCN 2009014111. OCLC 317824678.
- Khakhina, Liya Nikolaevna (1992). Margulis, Lynn; McMenamin, Mark, eds. Concepts of Symbiogenesis: A Historical and Critical Study of the Research of Russian Botanists. Bio-Origins Series. Foreword by Alexander Vucinich; translated by Stephanie Merkel and Robert Coalson. New Haven, CT: Yale University Press. ISBN 0-300-04816-5. LCCN 92014466. OCLC 25711687.
- Knoll, Andrew H.; Holland, Heinrich D. (1995). "Oxygen and Proterozoic Evolution: An Update". Effects of Past Global Change on Life. Washington, D.C.: National Academy Press. ISBN 0-309-05127-4. LCCN 94038695. OCLC 42854432.
- Lamarck, Jean-Baptiste (1809). Philosophie Zoologique. Paris: Dentu et L'Auteur. OCLC 2210044. Philosophie zoologique (1809) on Internet Archive. Retrieved 2015-05-25.
- Lane, Nick (2002). Oxygen: The Molecule that made the World. Oxford, UK; New York: Oxford University Press. ISBN 0-19-850803-4. LCCN 2002727103. OCLC 50017677.
- Larson, Edward J. (2004). Evolution: The Remarkable History of a Scientific Theory. Modern Library Chronicles 17. New York: Modern Library. ISBN 0-679-64288-9. LCCN 2003064888. OCLC 53483597.
- Laubichler, Manfred D.; Maienschein, Jane, eds. (2007). From Embryology to Evo-Devo: A History of Developmental Evolution. Dibner Institute Studies in the History of Science and Technology. Cambridge, MA: MIT Press. ISBN 978-0-262-12283-2. LCCN 2006047208. OCLC 71173875.
- Lawrence, Peter A. (1992). The Making of a Fly: The Genetics of Animal Design. Oxford, UK; Cambridge, MA: Blackwell Science. ISBN 0-632-03048-8. LCCN 91027871. OCLC 24211238.
- Lewis, Edward B. (1997). "The Bithorax Complex: The First Fifty Years" (PDF). In Ringertz, Nils. Nobel Lectures in Physiology or Medicine 1991 – 1995. Singapore; River Edge, NJ; London: World Scientific. ISBN 981-02-3062-1. OCLC 37912537. Retrieved 2015-05-24.
- Margulis, Lynn (1993). Symbiosis in Cell Evolution: Microbial Communities in the Archean and Proterozoic Eons (2nd ed.). New York: W. H. Freeman and Company. ISBN 0-7167-7029-6. LCCN 92014565. OCLC 25747601.
- Margulis, Lynn; Fester, René, eds. (1991). Symbiosis as a Source of Evolutionary Innovation: Speciation and Morphogenesis. Cambridge, MA: MIT Press. ISBN 0-262-13269-9. LCCN 90020439. OCLC 22597587. "Based on a conference held in Bellagio, Italy, June 25-30, 1989."
- Maynard Smith, John; Szathmáry, Eörs (1997) [Originally published 1995; Oxford, UK: W. H. Freeman/Spektrum]. The Major Transitions in Evolution. Oxford, UK; New York: Oxford University Press. ISBN 0-19-158600-5. OCLC 715217397.
- Mayr, Ernst (1982). The Growth of Biological Thought: Diversity, Evolution, and Inheritance. Cambridge, MA: Belknap Press of Harvard University Press. ISBN 0-674-36445-7. LCCN 81013204. OCLC 7875904.
- Mayr, Ernst (1999) [First published 1942; Cambridge, MA: Columbia University Press]. Systematics and the Origin of Species from the Viewpoint of a Zoologist (1st Harvard University Press pbk. ed.). Cambridge, MA: Harvard University Press. ISBN 0-674-86250-3. LCCN 99036391. OCLC 41565294.
- Mayr, Ernst (2002) [First published in the USA in 2001 by Basic Books. What Evolution Is. London: Phoenix. ISBN 0-7538-1368-8. OCLC 53155951.
- Mayr, Ernst; Provine, William B., eds. (1998) [Originally published 1980]. The Evolutionary Synthesis: Perspectives on the Unification of Biology. With a new preface by Ernst Mayr (1st Harvard University Press pbk. ed.). Cambridge, MA: Harvard University Press. ISBN 0-674-27226-9. LCCN 98157613. OCLC 851069127.
- Mivart, St. George Jackson (1871). On the Genesis of Species. London: Macmillan & Co. LCCN 06022514. OCLC 3401100.
- National Academy of Sciences (1999). Science and Creationism: A View from the National Academy of Sciences (2nd ed.). Washington, D.C.: National Academy Press. ISBN 0-309-06406-6. LCCN 99006259. OCLC 43803228. Retrieved 2015-05-21.
- Raff, Rudolf A. (1996). The Shape of Life: Genes, Development, and the Evolution of Animal Form. Chicago, IL: University of Chicago Press. ISBN 0-226-70266-9. LCCN 95049224. OCLC 33664782.
- Raff, Rudolf A.; Kaufman, Thomas C. (1983). Embryos, Genes, and Evolution: The Developmental-Genetic Basis of Evolutionary Change. Illustrated by Elizabeth C. Raff. New York: Macmillan. ISBN 0-02-397500-8. LCCN 82015160. OCLC 8283741.
- Rensch, Bernhard (1947). Neuere Probleme der Abstammungslehre. Die transspezifische Evolution Newer Problems of Evolutionary Theory: The trans-specific Evolution (in German). Stuttgart: Ferdinand Enke Verlag. OCLC 2271422.
- Sapp, Jan (1994). Evolution by Association: A History of Symbiosis. New York: Oxford University Press. ISBN 0-19-508821-2. LCCN 94006321. OCLC 243613674.
- Schopf, J. William (1999). Cradle of Life: The Discovery of Earth's Earliest Fossils. Princeton, NJ: Princeton University Press. ISBN 0-691-00230-4. LCCN 98042443. OCLC 39839128.
- Schopf, J. William; Klein, Cornelis, eds. (1992). The Proterozoic Biosphere: A Multidisciplinary Study. Cambridge, UK; New York: Cambridge University Press. ISBN 0-521-36615-1. LCCN 91015085. OCLC 26310475.
- Simpson, George Gaylord (1984) [Originally published 1944]. Tempo and Mode in Evolution. Columbia Classics in Evolution (Reprint ed.). New York: Columbia University Press. ISBN 0-231-05847-0. LCCN 83023132. OCLC 611959369.
- Smocovitis, Vassiliki Betty (1996). Unifying Biology: The Evolutionary Synthesis and Evolutionary Biology. Princeton, NJ: Princeton University Press. ISBN 0-691-03343-9. LCCN 96005605. OCLC 34411399.
- Stanley, Steven M. (1979). Macroevolution: Pattern and Process. San Francisco, CA: W. H. Freeman and Company. ISBN 0-7167-1092-7. LCCN 79015464. OCLC 5101557.
- van Andel, Tjeerd H. (1994). New Views on an Old Planet: A History of Global Change (2nd ed.). Cambridge, UK; New York: Cambridge University Press. ISBN 0-521-44755-0. LCCN 94007078. OCLC 29910095.
- Wallin, Ivan E. (1927). Symbionticism and the Origin of Species. Baltimore, MD: Williams & Wilkins Co. LCCN 27001327. OCLC 2280464.
- Wilson, Edmund B. (1925). The Cell in Development and Heredity (3rd revised and enlarged ed.). New York: Macmillan & Co. LCCN 25001800. OCLC 327856.
- Wright, Sewall (1932). "The Roles of Mutation, Inbreeding, Crossbreeding and Selection in Evolution". In Jones, Donald F. Proceedings of the Sixth International Congress of Genetics 1. Ithaca, NY: Genetics Society of America. OCLC 439596433.
- Yochelson, Ellis L. (1998). Charles Doolittle Walcott: Paleontologist. Kent, OH: The Kent State University Press. ISBN 0-87338-599-3. LCCN 97036490. OCLC 45730085.
- Allen, Garland E. (1978). Thomas Hunt Morgan: The Man and His Science. Princeton, NJ: Princeton University Press. ISBN 0-691-08200-6. LCCN 77085526. OCLC 3710729.
- Dawkins, Richard (1990). The Blind Watchmaker. Penguin Science. London: Penguin Books. ISBN 0-14-014481-1. OCLC 60143870.
- Futuyma, Douglas J. (1998). Evolutionary Biology (3rd ed.). Sunderland, MA: Sinauer Associates. ISBN 0-87893-189-9. LCCN 97037947. OCLC 37560100.
- Haldane, J. B. S. (1932). The Causes of Evolution. London; New York: Longmans, Green & Co. LCCN 32033284. OCLC 5006266. "This book is based on a series of lectures delivered in January 1931 at the Prifysgol Cymru, Aberystwyth, and entitled 'A re-examination of Darwinism'."
- Huxley, Julian, ed. (1976) [Originally published 1940; Oxford, UK: The Clarendon Press. The New Systematics (Reprint ed.). St. Clair Shores, MI: Scholarly Press. ISBN 0-403-01786-6. LCCN 40035139. OCLC 3103491.
- Margulis, Lynn; Sagan, Dorion (2002). Acquiring Genomes: A Theory of the Origins of Species (1st ed.). New York: Basic Books. ISBN 0-465-04391-7. LCCN 2002001521. OCLC 50033408.
- Wright, Sewall (March 1, 1931). "Evolution in Mendelian Populations". Genetics (Bethesda, MD: Genetics Society of America) 16 (2): 97–159. ISSN 0016-6731. PMID 17246615.
- Rose, Michael R.; Oakley, Todd H. (November 24, 2007). "The new biology: beyond the Modern Synthesis" (PDF). Biology Direct (BioMed Central) 2 (30). doi:10.1186/1745-6150-2-30. ISSN 1745-6150. PMC 2222615. PMID 18036242. A review of biology in light of recent innovations since the initiation of modern synthesis.