Current research in evolutionary biology
Encyclopedia
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 phenomena include speciation
, the evolution of sexual reproduction, the evolution of cooperation
, the evolution of ageing
, and evolvability
.
Second, biologists ask the most straightforward evolutionary question: "what happened and when?". This includes fields such as paleobiology
, 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, 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
needs to be updated to take into account modern molecular knowledge. This requires a great deal of mathematical development, in order 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
, sexual selection
, genetic drift
, genetic draft
, developmental constraints, mutation bias and biogeography
.
An evolutionary approach is also key to much current research in biology that does not set out to study evolution per se, especially in organismal biology and ecology
. For example, evolutionary thinking is key to life history theory
. Annotation of genes and their function relies heavily on comparative, i.e. evolutionary, approaches. The field of evo-devo
investigates how developmental processes work by using the comparative method to determine how they evolved.
Molecular genetics
Molecular genetics is the field of biology and genetics that studies the structure and function of genes at a molecular level. The field studies how the genes are transferred from generation to generation. Molecular genetics employs the methods of genetics and molecular biology...
and even computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
.
First, some fields of evolutionary research try to explain phenomena that were poorly accounted for by the work of the modern evolutionary synthesis
Modern evolutionary synthesis
The modern evolutionary synthesis is a union of ideas from several biological specialties which provides a widely accepted account of evolution...
. These phenomena include speciation
Speciation
Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...
, the evolution of sexual reproduction, the evolution of cooperation
Co-operation (evolution)
Co-operation or co-operative behaviours are terms used to describe behaviours by organisms which are beneficial to other organisms, and are selected for on that basis. Under this definition, altruism is a form of co-operation in which there is no direct benefit to the actor...
, the evolution of ageing
Evolution of ageing
Enquiry into the evolution of ageing aims to explain why almost all living things weaken and die with age. There is not yet agreement in the scientific community on a single answer...
, and evolvability
Evolvability
Evolvability is defined as the capacity of a system for adaptive evolution. Evolvability is the ability of a population of organisms to not merely generate genetic diversity, but to generate adaptive genetic diversity, and thereby evolve through natural selection.In order for a biological organism...
.
Second, biologists ask the most straightforward evolutionary question: "what happened and when?". This includes fields such as paleobiology
Paleobiology
Paleobiology is a growing and comparatively new discipline which combines the methods and findings of the natural science biology with the methods and findings of the earth science paleontology...
, as well as systematics
Systematics
Biological systematics is the study of the diversification of terrestrial life, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees...
and phylogenetics
Phylogenetics
In biology, phylogenetics is the study of evolutionary relatedness among groups of organisms , which is discovered through molecular sequencing data and morphological data matrices...
.
Third, the modern evolutionary synthesis
Modern evolutionary synthesis
The modern evolutionary synthesis is a union of ideas from several biological specialties which provides a widely accepted account of evolution...
was devised at a time when nobody understood the molecular basis of genes. Today, evolutionary biologists try to determine the genetic architecture
Genetic architecture
Genetic architecture refers to the underlying genetic basis of a phenotypic trait. A synonymous term is the 'genotype-phenotype map', the way that genotypes map to the phenotypes....
of interesting evolutionary phenomena such as adaptation
Adaptation
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....
and speciation
Speciation
Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...
. 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
Gene duplication
Gene duplication is any duplication of a region of DNA that contains a gene; it may occur as an error in homologous recombination, a retrotransposition event, or duplication of an entire chromosome.The second copy of the gene is often free from selective pressure — that is, mutations of it have no...
or even genome duplication
Polyploidy
Polyploid is a term used to describe cells and organisms containing more than two paired sets of chromosomes. Most eukaryotic species are diploid, meaning they have two sets of chromosomes — one set inherited from each parent. However polyploidy is found in some organisms and is especially common...
). Evolutionary biologists try to reconcile the high heritability
Heritability
The Heritability of a population is the proportion of observable differences between individuals that is due to genetic differences. Factors including genetics, environment and random chance can all contribute to the variation between individuals in their observable characteristics...
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
Population genetics
Population genetics is the study of allele frequency distribution and change under the influence of the four main evolutionary processes: natural selection, genetic drift, mutation and gene flow. It also takes into account the factors of recombination, population subdivision and population...
that catalyzed the modern evolutionary synthesis
Modern evolutionary synthesis
The modern evolutionary synthesis is a union of ideas from several biological specialties which provides a widely accepted account of evolution...
needs to be updated to take into account modern molecular knowledge. This requires a great deal of mathematical development, in order to relate DNA sequence data to evolutionary theory as part of a theory of molecular evolution
Molecular evolution
Molecular evolution is in part a process of evolution at the scale of DNA, RNA, and proteins. Molecular evolution emerged as a scientific field in the 1960s as researchers from molecular biology, evolutionary biology and population genetics sought to understand recent discoveries on the structure...
. For example, biologists try to infer which genes have been under strong selection by detecting selective sweeps.
Fourth, the modern evolutionary synthesis
Modern evolutionary synthesis
The modern evolutionary synthesis is a union of ideas from several biological specialties which provides a widely accepted account of evolution...
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
Natural selection
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....
, sexual selection
Sexual selection
Sexual selection, a concept introduced by Charles Darwin in his 1859 book On the Origin of Species, is a significant element of his theory of natural selection...
, genetic drift
Genetic drift
Genetic drift or allelic drift is the change in the frequency of a gene variant in a population due to random sampling.The alleles in the offspring are a sample of those in the parents, and chance has a role in determining whether a given individual survives and reproduces...
, genetic draft
Genetic hitchhiking
Genetic hitchhiking is the process by which an allele may increase in frequency by virtue of being linked to a gene that is positively selected. Proximity on a chromosome may allow genes to be dragged along with a selective sweep experienced by an advantageous gene nearby...
, developmental constraints, mutation bias and biogeography
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
.
An evolutionary approach is also key to much current research in biology that does not set out to study evolution per se, especially in organismal biology and ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
. For example, evolutionary thinking is key to life history theory
Life history theory
Life history theory posits that the schedule and duration of key events in an organism's lifetime are shaped by natural selection to produce the largest possible number of surviving offspring...
. Annotation of genes and their function relies heavily on comparative, i.e. evolutionary, approaches. The field of evo-devo
Evolutionary developmental biology
Evolutionary developmental biology is a field of biology that compares the developmental processes of different organisms to determine the ancestral relationship between them, and to discover how developmental processes evolved...
investigates how developmental processes work by using the comparative method to determine how they evolved.