Evolutionary biology

From Wikipedia, the free encyclopedia
  (Redirected from Evolutionary biologist)
Jump to: navigation, search
For the textbook, see Evolutionary Biology (textbook).

Evolutionary biology is the subfield of biology that studies the evolutionary processes that produced the diversity of life on Earth starting from a single origin of life. These processes include natural selection, the descent of species, and the origin of new species.

The discipline emerged through what Julian Huxley called the modern evolutionary synthesis (of the 1930s) of understanding from several previously unrelated fields of biological research, including genetics, ecology, systematics and palaeontology.

Current research has widened to cover the genetic architecture of adaptation, molecular evolution, and the different forces that contribute to evolution including sexual selection, genetic drift and biogeography. The newer field of evolutionary developmental biology ("evo-devo") investigates how embryonic development is controlled, thus creating a wider synthesis that integrates developmental biology with the fields covered by the earlier evolutionary synthesis.

Subfields[edit]

The study of evolution is the central unifying concept in biology. Biology can be divided in various ways. One way is by the level of biological organisation, from molecular to cell, organism to population. Another way is by taxonomic group, with fields such as zoology (all animals), ornithology (birds), and herpetology (reptiles and amphibians). A third way is by approach, such as field biology, theoretical biology, experimental evolution, and palaeontology. These alternative ways of dividing up the subject can be combined with evolutionary biology to create subfields like evolutionary ecology and evolutionary developmental biology.

History[edit]

Evolutionary biology, as an academic discipline in its own right, emerged during the period of the modern evolutionary synthesis in the 1930s and 1940s (Smocovitis, 1996). It was not until the 1980s that many universities had departments of evolutionary biology. In the United States, many universities have created departments of molecular and cell biology or ecology and evolutionary biology, in place of the older departments of botany and zoology. Palaeontology is often grouped with earth science.

J. B. S. Haldane (1892 – 1964) helped to create the field of population genetics.

Microbiology too is becoming an evolutionary discipline, now that microbial physiology and genomics are better understood. The quick generation time of bacteria and viruses such as bacteriophages makes it possible to explore evolutionary questions.

Many biologists have contributed to our current understanding of evolution. Theodosius Dobzhansky and E. B. Ford established an empirical research programme. Ronald Fisher, Sewall Wright and J. S. Haldane created a sound theoretical framework. Ernst Mayr in systematics, George Gaylord Simpson in palaeontology and G. Ledyard Stebbins in botany helped to form the modern synthesis. James Crow,[1] Richard Lewontin,[2] Dan Hartl,[3] Marcus Feldman,[4][5] and Brian Charlesworth[6] trained a generation of evolutionary biologists.

Current research topics[edit]

Current research in evolutionary biology covers diverse topics and incorporates ideas from diverse areas, such as molecular genetics and computer science.

First, some fields of evolutionary research try to explain phenomena that were poorly accounted for in the modern evolutionary synthesis. These include speciation,[7] the evolution of sexual reproduction,[8] the evolution of cooperation, the evolution of ageing, and evolvability.[9]

Second, biologists ask the most straightforward evolutionary question: "what happened and when?". This includes fields such as palaeobiology, as well as systematics and phylogenetics.

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, how interdependent are the effects of different genes, what do the genes do, and what changes happen to them (e.g., point mutations vs. gene duplication or even genome duplication). They 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.[10]

One challenge in studying genetic architecture is that the classical population genetics that catalysed 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.[11]

Fourth, the modern evolutionary synthesis involved agreement about which forces contribute to evolution, but not about their relative importance.[12] Current research seeks to determine this. Evolutionary forces include natural selection, sexual selection, genetic drift, genetic draft, developmental constraints, mutation bias and biogeography.

An evolutionary approach is key to much current research in organismal biology and ecology, such as in life history theory. Annotation of genes and their function relies heavily on comparative, i.e., evolutionary, approaches. The field of evolutionary developmental biology ("evo-devo") investigates how developmental processes work, and compares them in different organisms determine how they evolved.

Journals[edit]

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.

See also[edit]

References[edit]

  1. ^ "The Academic Genealogy of Evolutionary Biology: James F. Crow". 
  2. ^ "The Academic Genealogy of Evolutionary Biology:Richard Lewontin". 
  3. ^ "The Academic Genealogy of Evolutionary Biology: Daniel Hartl". 
  4. ^ "Feldman lab alumni & collaborators". 
  5. ^ "The Academic Genealogy of Evolutionary Biology: Marcus Feldman". 
  6. ^ "The Academic Genealogy of Evolutionary Biology: Brian Charlesworth". 
  7. ^ Wiens JJ (2004). "What is speciation and how should we study it?". American Naturalist. 163 (6): 914–923. doi:10.1086/386552. JSTOR 10.1086/386552. PMID 15266388. 
  8. ^ Otto SP (2009). "The evolutionary enigma of sex". American Naturalist. 174 (s1): S1–S14. doi:10.1086/599084. PMID 19441962. 
  9. ^ Jesse Love Hendrikse; Trish Elizabeth Parsons; Benedikt Hallgrímsson (2007). "Evolvability as the proper focus of evolutionary developmental biology". Evolution & Development. 9 (4): 393–401. doi:10.1111/j.1525-142X.2007.00176.x. 
  10. ^ Manolio TA; Collins FS; Cox NJ; Goldstein DB; Hindorff LA; Hunter DJ; McCarthy MI; Ramos EM; Cardon LR; Chakravarti A; Cho JH; Guttmacher AE; Kong A; Kruglyak L; Mardis E; Rotimi CN; Slatkin M; Valle D; Whittemore AS; Boehnke M; Clark AG; Eichler EE; Gibson G; Haines JL; Mackay TFC; McCarroll SA; Visscher PM (2009). "Finding the missing heritability of complex diseases". Nature. 461 (7265): 747–753. Bibcode:2009Natur.461..747M. doi:10.1038/nature08494. PMC 2831613Freely accessible. PMID 19812666. 
  11. ^ Sabeti PC; Reich DE; Higgins JM; Levine HZP; Richter DJ; Schaffner SF; Gabriel SB; Platko JV; Patterson NJ; McDonald GJ; Ackerman HC; Campbell SJ; Altshuler D; Cooper R; Kwiatkowski D; Ward R; Lander ES (2002). "Detecting recent positive selection in the human genome from haplotype structure". Nature. 419 (6909): 832–837. Bibcode:2002Natur.419..832S. doi:10.1038/nature01140. PMID 12397357. 
  12. ^ Provine WB (1988). "Progress in evolution and meaning in life". Evolutionary progress. University of Chicago Press. pp. 49–79.