Evolutionary physiology is the study of the biological

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

physiological Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...

structures and processes; that is, the manner in which the functional characteristics of

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

s have responded to

natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generation ...

sexual selection Sexual selection is a mechanism of evolution in which members of one sex mate choice, choose mates of the other sex to mating, mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex ...

or changed by random

genetic drift Genetic drift, also known as random genetic drift, allelic drift or the Wright effect, is the change in the Allele frequency, frequency of an existing gene variant (allele) in a population due to random chance. Genetic drift may cause gene va ...

across multiple

generation A generation is all of the people born and living at about the same time, regarded collectively. It also is "the average period, generally considered to be about 20–⁠30 years, during which children are born and grow up, become adults, and b ...

s during the history of a population or species. It is a sub-discipline of both

physiology Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...

and

evolutionary biology Evolutionary biology is the subfield of biology that studies the evolutionary processes such as natural selection, common descent, and speciation that produced the diversity of life on Earth. In the 1930s, the discipline of evolutionary biolo ...

. Practitioners in the field come from a variety of backgrounds, including physiology, evolutionary biology,

ecology Ecology () is the natural science of the relationships among living organisms and their Natural environment, environment. Ecology considers organisms at the individual, population, community (ecology), community, ecosystem, and biosphere lev ...

, and

genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian ...

. Accordingly, the range of

phenotype In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological propert ...

s studied by evolutionary physiologists is broad, including life history traits, behavior, whole-organism performance,

functional morphology Functional may refer to: * Movements in architecture: ** Functionalism (architecture) ** Form follows function * Functional group, combination of atoms within molecules * Medical conditions without currently visible organic basis: ** Functional ...

biomechanics Biomechanics is the study of the structure, function and motion of the mechanical aspects of biological systems, at any level from whole organisms to Organ (anatomy), organs, Cell (biology), cells and cell organelles, using the methods of mechani ...

anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

, classical physiology,

endocrinology Endocrinology (from ''endocrine system, endocrine'' + ''wikt:-logy#Suffix, -ology'') is a branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions known as hormones. It is also concerned with the ...

biochemistry Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, a ...

, and

molecular evolution Molecular evolution describes how Heredity, inherited DNA and/or RNA change over evolutionary time, and the consequences of this for proteins and other components of Cell (biology), cells and organisms. Molecular evolution is the basis of phylogen ...

. The field is closely related to

comparative physiology Comparative physiology is a subdiscipline of physiology that studies and exploits the diversity of functional characteristics of various kinds of organisms. It is closely related to evolutionary physiology and environmental physiology. Many ...

ecophysiology Ecophysiology (from Greek , ''oikos'', "house(hold)"; , ''physis'', "nature, origin"; and , '' -logia''), environmental physiology or physiological ecology is a biological discipline that studies the response of an organism's physiology to envir ...

, and environmental physiology, and its findings are a major concern of

evolutionary medicine Evolutionary medicine or Darwinian medicine is the application of modern evolutionary theory to understanding health and disease. Modern biomedical research and practice have focused on the molecular and physiological mechanisms underlying hea ...

. One definition that has been offered is "the study of the physiological basis of fitness, namely, correlated evolution (including constraints and trade-offs) of physiological form and function associated with the environment, diet,

homeostasis In biology, homeostasis (British English, British also homoeostasis; ) is the state of steady internal physics, physical and chemistry, chemical conditions maintained by organism, living systems. This is the condition of optimal functioning fo ...

, energy management,

longevity Longevity may refer to especially long-lived members of a population, whereas ''life expectancy'' is defined Statistics, statistically as the average number of years remaining at a given age. For example, a population's life expectancy at birth ...

, and mortality and life history characteristics".

History

As the name implies, evolutionary physiology is the product of a merger between two distinct scientific disciplines. According to Garland and Carter, evolutionary physiology arose in the late 1970s, following debates concerning the metabolic and thermoregulatory status of

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

s (see physiology of dinosaurs) and mammal-like reptiles. This period was followed by attempts in the early 1980s to integrate quantitative genetics into

, which had spillover effects on other fields, such as

behavioral ecology Behavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for ethology, animal behavior due to ecology, ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined Tinbergen's f ...

and

. In the mid- to late 1980s, phylogenetic comparative methods started to become popular in many fields, including

physiological ecology Ecophysiology (from Greek , ''oikos'', "house(hold)"; , ''physis'', "nature, origin"; and , '' -logia''), environmental physiology or physiological ecology is a biological discipline that studies the response of an organism's physiology to envir ...

and

. A 1987 volume titled ''New Directions in Ecological Physiology'' had little ecology but a considerable emphasis on evolutionary topics. It generated vigorous debate, and within a few years the

National Science Foundation The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su ...

had developed a panel title
Ecological and Evolutionary Physiology
Shortly thereafter, selection experiments and experimental evolution became increasingly common in evolutionary physiology. Macrophysiology has emerged as a sub-discipline, in which practitioners attempt to identify large-scale patterns in physiological traits (e.g. patterns of co-variation with

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

) and their ecological implications. More recently, the importance of evolutionary physiology has been argued from the perspective of functional analyses,

epigenetics In biology, epigenetics is the study of changes in gene expression that happen without changes to the DNA sequence. The Greek prefix ''epi-'' (ἐπι- "over, outside of, around") in ''epigenetics'' implies features that are "on top of" or "in ...

, and an extended evolutionary synthesis. The growth of evolutionary physiology is also reflected in the emergence of sub-disciplines, such as evolutionary biomechanics and evolutionary

, which addresses such hybrid questions as "What are the most common endocrine mechanisms that respond to selection on behavior or life-history traits?"

Emergent properties

As a hybrid scientific discipline, evolutionary physiology provides some unique perspectives. For example, an understanding of physiological mechanisms can help in determining whether a particular pattern of phenotypic variation or co-variation (such as an

allometric Allometry (Ancient Greek "other", "measurement") is the study of the relationship of body size to shape, anatomy, physiology and behaviour, first outlined by Otto Snell in 1892, by D'Arcy Thompson in 1917 in ''On Growth and Form'' and by Juli ...

relationship) represents what could possibly exist or just what selection has allowed. Similarly, a thorough knowledge of physiological mechanisms can greatly enhance understanding of possible reasons for evolutionary correlations and constraints than is possible for many of the traits typically studied by evolutionary biologists (such as morphology).

Areas of research

Important areas of current research include: * Organismal performance as a central

(e.g., measures of speed or stamina in

animal locomotion In ethology, animal locomotion is any of a variety of methods that animals use to move from one place to another. Some modes of locomotion are (initially) self-propelled, e.g., running, swimming, jumping, flight, flying, hopping, soaring and gli ...

) * Role of

behavior Behavior (American English) or behaviour (British English) is the range of actions of Individual, individuals, organisms, systems or Artificial intelligence, artificial entities in some environment. These systems can include other systems or or ...

in physiological evolution * Physiological and endocrinological basis of variation in life history traits (e.g., clutch size) * Functional significance of

* Genomic basis of adaptation * Extent to which species differences are adaptive * Physiological underpinnings of limits to geographic ranges *

Geographic variation Unwarranted variation (or geographic variation) in health care service delivery refers to medical practice pattern variation that cannot be explained by illness, medical need, or the dictates of evidence-based medicine. It is one of the causes of lo ...

* Role of

in shaping physiological evolution * Magnitude of "phylogenetic signal" in physiological traits * Role of

pathogen In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of d ...

s and

parasites Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The en ...

in physiological evolution and immunity * Application of optimality modeling to elucidate the degree of adaptation * Role of phenotypic plasticity in accounting for individual, population, and species differences * Mechanistic basis of trade-offs and constraints on evolution (e.g., putative Carrier's constraint on running and breathing) * Limits on sustained metabolic rate * Origin of

scaling relations or

laws (and the so-called metabolic theory of ecology) * Individual variation (see also Individual differences psychology) * Functional significance of biochemical polymorphisms * Analysis of physiological variation via quantitative genetics * Paleophysiology and the evolution of endothermy *

Human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

adaptational

* Darwinian medicine * Evolution of dietary antioxidants

Techniques

Artificial selection Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant ...

and experimental evolutionmouse wheel running video
* Genetic analyses and manipulations * Measurement of selection in the wild * Phenotypic plasticity and manipulation * Phylogenetically based comparisons * Doubly labeled water measurements of free-living energy demands of animals

Funding and societies

In the United States, research in evolutionary physiology is funded mainly by the

. A number of scientific societies feature sections that encompass evolutionary physiology, including:
American Physiological Society "integrating the life sciences from molecule to organism"

Society for Integrative and Comparative Biology
*

Society for Experimental Biology The Society for Experimental Biology is a learned society for animal, cell and plant biologists. It was founded in 1923 at Birkbeck College to "promote the art and science of experimental biology in all its branches". It aims to demonstrate the im ...

Journals that frequently publish articles about evolutionary physiology

* '' American Naturalist''
''Comparative Biochemistry and Physiology''

''Comprehensive Physiology''

''Evolution''

''Functional Ecology''
* '' Integrative and Comparative Biology''
''Journal of Comparative Physiology''

''Journal of Evolutionary Biochemistry and Physiology''
* '' Journal of Evolutionary Biology''
''Journal of Experimental Biology''
* '' Ecological and Evolutionary Physiology'' (formerly Physiological and Biochemical Zoology)

References

External links

People, Labs, and Programs in Evolutionary Physiology

''Physiological and Biochemical Zoology'' Focused Collection: Trade-Offs in Ecological and Evolutionary Physiology
{{DEFAULTSORT:Evolutionary Physiology Physiology Evolutionary biology