Socioecology
Encyclopedia
Socioecology is the scientific study of how social structure and organization are influenced by organisms' environment. Socioecology is related to sociology
, the study of society
, and ecology
, the study of the interaction between organism
s and their environment
.
Socioecology tends to focus on non-human primate
s.
One of its major goals is to explain the evolution
of diversity among social systems. Socioecologists are also interested in mating systems.
In 2001, paleontologist Scott D. Sampson
published a study speculating on the socioecology of ceratopsid dinosaurs in the light of correlations between anatomy and behavior in extant wildlife observed by earlier researchers. The evolution of ceratopsid dinosaur shares characteristics with the evolution of some mammal groups, both were "geologically brief" events precipitating the simultaneous evolution of large body size, derived feeding structures, and "varied hornlike organs." Ceratopsid social behavior had been controversial with some authors envisioning large "socially complex" herds represented by bone beds in the fossil record and some like Lehman arguing that such aggregations of individuals amounted to regional infestations as sometimes occurs with modern tortoises and crocodiles.
Sampson argues in favor of complex herding using the socioecology of modern ecological and anatomical ceratopsian analogues. A biologist named Jarman observed among modern ungulates correlations between "ecological variables including feeding style, body size, group size, home range, antipredator behavior, growth pattern, and social organization." He speculated that a taxon's social organization was effected by the distribution of resources through the effect that distribution had on the dispersion of females of the taxon throughout the environment. Herding is normal in environments where resources are less predictable, while territoriality tends to evolve in environments with a more consistent distribution of resources. Ceratopsids feature both prominent mating signals (horns and frills) and at least periodic gregarious behaviors. Ceratopsids were adapted to processing high-fiber
plant material, having highly derived dental batteries and large body sizes with a probable attending "low mass-specific metabolic rat[e]." They may have utilized fermentation
to break down plant material with a gut microflora. Ceratopsians may have been only social during the dry season and scattered when the rainy season started. Many African herding animals do this today. Ceratopsid bone beds tend to come from more inland environments than other ceratopsian remains. Other workers had concluded that for part of the year ceratopsids lived in small groups near the coasts and when the dry season came they formed large herds and moved inland. This migration away from the coasts may have represented a move to nesting grounds.
If ceratopsids were to have sexual dimorphism
modern ecological analogues suggest it would be in their mating signals like horns and frills. No convincing evidence for sexual dimorphism in body size or mating signals is known in ceratopsids, although was present in Protoceratops andrewsi whose sexes were distinguishable based on frill and nasal prominence size. This is consistent with other known tetrapod
groups where midsized animals tended to exhibit markedly more sexual dimorphism than larger ones. However, if there were sexually dimorphic traits they may have been soft tissue variations like colorations or dewlaps that would not have been preserved as fossils. Sampson found in previous work that at least centrosaurines did not achieve adult morphology with its accompanying mating signals until nearly fully grown. Relative age of the animals was determined based on the size, degree of coossification, secondary ossification, and growth related changes in bone texture. Sampson finds commonality between the retarded growth of mating signals in centrosaurines and the extended adolescence
of animals whose social structures are ranked hierarchies founded on age-related differences. In these sorts of groups young males are typically sexually mature for several years before actually beginning to breed, when their mating signals are most fully developed. Females, by contrast due not have such an extended adolescence.
Lehman had previously argued that the higher diversities of species and population densities supported the notions that ceratopsid bone beds were left by temporary infestations lacking in social structure like in crocodiles and tortoises. However, Sampson observes that crocodiles themselves actually show complex behavioral hierarchies. He also notes that some modern herding mammals, at least occasionally, form groups denser than those hinted at by ceratopsid bone beds. Herds would also have afforded some level of protection from the chief predators of ceratopsids, tyrannosaurids.
Sociology
Sociology is the study of society. It is a social science—a term with which it is sometimes synonymous—which uses various methods of empirical investigation and critical analysis to develop a body of knowledge about human social activity...
, the study of society
Society
A society, or a human society, is a group of people related to each other through persistent relations, or a large social grouping sharing the same geographical or virtual territory, subject to the same political authority and dominant cultural expectations...
, 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...
, the study of the interaction between organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
s and their environment
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
.
Socioecology tends to focus on non-human primate
Primate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s.
One of its major goals is to explain the evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
of diversity among social systems. Socioecologists are also interested in mating systems.
Ceratopsian dinosaurs
Scott D. Sampson
Scott D. Sampson is a paleontologist and chief curator of the Utah Museum of Natural History. Sampson is notable for his work on the carnivorous theropod dinosaurs Majungasaurus and Masiakasaurus and his extensive research into the Late Cretaceous Period, particularly in...
published a study speculating on the socioecology of ceratopsid dinosaurs in the light of correlations between anatomy and behavior in extant wildlife observed by earlier researchers. The evolution of ceratopsid dinosaur shares characteristics with the evolution of some mammal groups, both were "geologically brief" events precipitating the simultaneous evolution of large body size, derived feeding structures, and "varied hornlike organs." Ceratopsid social behavior had been controversial with some authors envisioning large "socially complex" herds represented by bone beds in the fossil record and some like Lehman arguing that such aggregations of individuals amounted to regional infestations as sometimes occurs with modern tortoises and crocodiles.
Sampson argues in favor of complex herding using the socioecology of modern ecological and anatomical ceratopsian analogues. A biologist named Jarman observed among modern ungulates correlations between "ecological variables including feeding style, body size, group size, home range, antipredator behavior, growth pattern, and social organization." He speculated that a taxon's social organization was effected by the distribution of resources through the effect that distribution had on the dispersion of females of the taxon throughout the environment. Herding is normal in environments where resources are less predictable, while territoriality tends to evolve in environments with a more consistent distribution of resources. Ceratopsids feature both prominent mating signals (horns and frills) and at least periodic gregarious behaviors. Ceratopsids were adapted to processing high-fiber
Fiber
Fiber is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread.They are very important in the biology of both plants and animals, for holding tissues together....
plant material, having highly derived dental batteries and large body sizes with a probable attending "low mass-specific metabolic rat[e]." They may have utilized fermentation
Fermentation (biochemistry)
Fermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. In contrast, respiration is where electrons are donated to an exogenous electron acceptor, such as oxygen,...
to break down plant material with a gut microflora. Ceratopsians may have been only social during the dry season and scattered when the rainy season started. Many African herding animals do this today. Ceratopsid bone beds tend to come from more inland environments than other ceratopsian remains. Other workers had concluded that for part of the year ceratopsids lived in small groups near the coasts and when the dry season came they formed large herds and moved inland. This migration away from the coasts may have represented a move to nesting grounds.
If ceratopsids were to have sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
modern ecological analogues suggest it would be in their mating signals like horns and frills. No convincing evidence for sexual dimorphism in body size or mating signals is known in ceratopsids, although was present in Protoceratops andrewsi whose sexes were distinguishable based on frill and nasal prominence size. This is consistent with other known tetrapod
Tetrapod
Tetrapods are vertebrate animals having four limbs. Amphibians, reptiles, birds and mammals are all tetrapods; even snakes and other limbless reptiles and amphibians are tetrapods by descent. The earliest tetrapods evolved from the lobe-finned fishes in the Devonian...
groups where midsized animals tended to exhibit markedly more sexual dimorphism than larger ones. However, if there were sexually dimorphic traits they may have been soft tissue variations like colorations or dewlaps that would not have been preserved as fossils. Sampson found in previous work that at least centrosaurines did not achieve adult morphology with its accompanying mating signals until nearly fully grown. Relative age of the animals was determined based on the size, degree of coossification, secondary ossification, and growth related changes in bone texture. Sampson finds commonality between the retarded growth of mating signals in centrosaurines and the extended adolescence
Adolescence
Adolescence is a transitional stage of physical and mental human development generally occurring between puberty and legal adulthood , but largely characterized as beginning and ending with the teenage stage...
of animals whose social structures are ranked hierarchies founded on age-related differences. In these sorts of groups young males are typically sexually mature for several years before actually beginning to breed, when their mating signals are most fully developed. Females, by contrast due not have such an extended adolescence.
Lehman had previously argued that the higher diversities of species and population densities supported the notions that ceratopsid bone beds were left by temporary infestations lacking in social structure like in crocodiles and tortoises. However, Sampson observes that crocodiles themselves actually show complex behavioral hierarchies. He also notes that some modern herding mammals, at least occasionally, form groups denser than those hinted at by ceratopsid bone beds. Herds would also have afforded some level of protection from the chief predators of ceratopsids, tyrannosaurids.