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Evolutionary Biology
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Evolutionary biology is a subfield of biology concerned with the study of the
evolutionary processes that produced the diversity of life on Earth. Someone
who studies evolutionary biology is known as an evolutionary biologist.
Evolutionary biologists study the descent of species, and the origin of new
species.
Subfields
The study of evolution is the unifying concept in evolutionary biology.
Evolutionary biology is a conceptual subfield of biology that intersects with
other subfields that are delimited by biological organisation level (e.g., cell
biology, population biology), taxonomic level (e.g., zoology, ornithology,
herpetology) or angle of approach (e.g., field biology, theoretical biology,
experimental evolution, palaeontology). Usually, these intersections are
combined into specific fields such as evolutionary ecology and evolutionary
developmental biology.
History
Evolutionary biology, as an academic discipline in its own right, emerged
during the period of the modern evolutionary synthesis in the 1930s and 1940s.
It was not until the 1970s and 1980s, however, that a significant number of
universities had departments that specifically included the term evolutionary
biology in their titles, often in conjunction with ecology and behaviour. In the
United States, as a result of the rapid growth of molecular and cell biology,
many universities have split (or aggregated) their biology departments into
molecular and cell biology-style departments and ecology and evolutionary
biology-style departments (which often have subsumed older departments in
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botany, zoology and the like). The subdiscipline of palaeontology is often found
in Earth science/geology/geoscience departments.
Microbiology has recently developed into an evolutionary discipline. It was
originally ignored due to the paucity of morphological traits and the lack of a
species concept in microbiology. Now, evolutionary researchers are taking
advantage of a more extensive understanding of microbial physiology, the ease
of microbial genomics, and the quick generation time of some microbes to
answer evolutionary questions. Similar features have led to progress in viral
evolution, particularly for bacteriophages.
Important evolutionary biologists
Many biologists have contributed to our current understanding of evolution.
Although the term had been used sporadically starting at the turn of the century,
evolutionary biology in a disciplinary sense gained currency during the period
of "the evolutionary synthesis." Theodosius Dobzhansky and E. B. Ford were
important in the establishment of an empirical research programme for
evolutionary biology as were theorists R. A. Fisher, Sewall Wright and J. B. S.
Haldane. Ernst Mayr, George Gaylord Simpson and G. Ledyard Stebbins were
also important discipline-builders during the modern synthesis, in the fields of
systematics, palaeontology and botany, respectively. Through training many
future evolutionary biologists, James Crow, Richard Lewontin, Dan Hartl,
Marcus Feldman, and Brian Charlesworth have also made large contributions to
building the discipline of evolutionary biology.
Journals
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Some scientific journals specialise exclusively in evolutionary biology as a
whole, including the journals Evolution, Journal of Evolutionary Biology, and
BMC Evolutionary Biology. Some journals cover sub-specialties within
evolutionary biology, such as the journals Systematic Biology, Molecular
Biology and Evolution and its sister journal Genome Biology and Evolution,
and Cladistics.
Other journals combine aspects of evolutionary biology with other related
fields. For example, Molecular Ecology, Proceedings of the Royal Society of
London Series B, The American Naturalist and Theoretical Population Biology
have overlap with ecology and other aspects of organismal biology. Overlap
with ecology is also prominent in the review journals Trends in Ecology and
Evolution and Annual Review of Ecology, Evolution, and Systematics. The
journals Genetics and PLoS Genetics overlap with molecular genetics questions
that are not obviously evolutionary in nature.
Current research topics
Current research in evolutionary biology covers diverse topics, as should be
expected given the centrality of evolution to understanding biology. Modern
evolutionary biology incorporates ideas from diverse areas of science, such as
molecular genetics and even computer science.
First, some fields of evolutionary research try to explain phenomena that were
poorly accounted for by the work of the modern evolutionary synthesis. These
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phenomena include speciation, the evolution of sexual reproduction, the
evolution of cooperation, the evolution of ageing, and evolvability.
Third, the modern evolutionary synthesis was devised at a time when nobody
understood the molecular basis of genes. Today, evolutionary biologists try to
determine the genetic architecture of interesting evolutionary phenomena such
as adaptation and speciation. They seek answers to questions such as how many
genes are involved, how large are the effects of each gene, to what extent are the
effects of different genes interdependent, what sort of function do the genes
involved tend to have, and what sort of changes tend to happen to them (e.g.,
point mutations vs. gene duplication or even genome duplication). Evolutionary
biologists try to reconcile the high heritability seen in twin studies with the
difficulty in finding which genes are responsible for this heritability using
genome-wide association studies.
One challenge in studying genetic architecture is that the classical population
genetics that catalyzed the modern evolutionary synthesis must be updated to
take into account modern molecular knowledge. This requires a great deal of
mathematical development to relate DNA sequence data to evolutionary theory
as part of a theory of molecular evolution. For example, biologists try to infer
which genes have been under strong selection by detecting selective sweeps.
Fourth, the modern evolutionary synthesis involved agreement about which
forces contribute to evolution, but not about their relative importance. Current
research seeks to determine this. Evolutionary forces include natural selection,
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sexual selection, genetic drift, genetic draft, developmental constraints,
mutation bias and biogeography.
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