Demographic Scenarios Research Articles

Combined next-generation sequencing and morphology reveal fine-scale speciation in Crocodile Skinks (Squamata: Scincidae: Tribolonotus).

Next-generation sequencing has vast potential to revolutionize the fields of phylogenetics and population genetics through its ability to collect genomic scale data sets of thousands of orthologous loci. Despite this potential, other types of data (e.g. morphology, ecology) remain important, particularly for studies endeavouring to delimit species. Here, we integrate next-generation sequencing with morphology to examine divergence between populations of Tribolonotus pseudoponceleti on the islands of Buka and Bougainville in the Solomon Archipelago. We used the Ion Torrent PGM to collect over 648Mbp of sequence data for 12 samples, representing 1526 loci recovered from all samples, and 3342 were recovered from at least six samples. Genetic structure analyses strongly support the distinctiveness of these two populations, and Bayes factor delimitations decisively select speciation between Buka and Bougainville. Principal components and discriminant function analyses reveal concordant morphological divergence. Finally, demographic analyses via diffusion approximation and approximate Bayesian computation prefer a complex model of mid-Pleistocene divergence with migration, and a later decrease or cessation of migration and population size shift, suggesting a scenario in which migration was enabled by Pleistocene merging of these two islands, and limited when isolated by higher sea levels. Further analysis of four Sanger sequenced loci in IMa2 had limited power to distinguish among models including and excluding migration, but resulted in similar population size and divergence time estimates, although with much broader confidence intervals. This study represents a framework for how next-generation sequencing and morphological data can be combined and leveraged towards validating putative species and testing demographic scenarios for speciation.

Ultimate Population Size: Some Investigations under Stable Population Theory

Some models have been proposed for the projection of future size of population for short and long terms under the stability conditions with changed regime of fertility schedule. The main aim of this paper is to see the size of population if fertility is curtailed up to the level of replacement, especially in developing countries. Models have been illustrated taking a set of real and hypothetical data consistent with the current demographic scenario of India. It was found that the proposed models are the extended forms of the models developed by the previous researchers and the projected population are more or less consistent with them.

Modeling the Effects of Commercial Harvest on Population Growth of River Turtles

Abstract Commercial turtle harvest is considered one of the major contributing factors to declines in turtle populations. Few long-term studies have evaluated turtle population response to harvest and little is known about demographic rates for many turtle species. We gathered demographic rates from the literature for snapping turtles (Chelydra serpentina), smooth softshells (Apalone mutica), and spiny softshells (Apalone spinifera), which are harvested in Missouri, and developed deterministic, density-independent, stage-based matrix models to assess turtle population response to plausible harvest rates we estimated from field sampling. Further, we used population modeling to determine annual harvest rates that would result in λ = 1 for each demographic scenario. We developed one model for snapping turtles and another for both softshell species combined due to the lack of available species-specific demographic data for either softshell species. Using mean demographic rates for survival and fecundity, sn...

Towards More Comprehensive Projections of Urban Temperature-Related Mortality

Towards More Comprehensive Projections of Urban Temperature-Related MortalityAbstract Number:2461 Patrick Kinney*, Elisaveta Petkova, Jan Vink, Joe Francis, Radley Horton, and Daniel Bader Patrick Kinney* Columbia University, United States, E-mail Address: [email protected] Search for more papers by this author , Elisaveta Petkova Columbia Climate and Health Program, United States, E-mail Address: [email protected] Search for more papers by this author , Jan Vink Cornell Program on Applied Demographics, United States, E-mail Address: [email protected] Search for more papers by this author , Joe Francis Cornell Program on Applied Demographics, United States, E-mail Address: [email protected] Search for more papers by this author , Radley Horton Columbia University Center for Climate Systems Research, United States, E-mail Address: [email protected] Search for more papers by this author , and Daniel Bader Columbia University Center for Climate Systems Research, United States, E-mail Address: [email protected] Search for more papers by this author AbstractHigh temperatures have long been recognized to have substantial impacts on mortality and, with growing concerns about climate change, numerous studies have developed projections of future heat-related deaths around the world. Projections of temperature-related mortality are often limited by insufficient information necessary to formulate hypotheses about future demographics as well as population sensitivity to high temperatures. In this paper, we explore the potential future impacts of high temperatures on mortality in New York City while incorporating novel projections of heat adaptation and demographic change. We start by developing heat adaptation models that project the population response to heat until 2100 based on daily temperature and mortality data from 1900 to present. We continue with developing demographic scenarios that characterize the possible changes in the NYC population during the study period. Finally, we calculate future heat-related deaths in the city by combining the derived temperature-mortality relationships and population scenarios with the downscaled temperature projections from the 33 global climate models and two Representative Concentration Pathways (RCPs), RCP4.5 and RCP8.5, developed in support of the Intergovernmental Panel on Climate Change (IPCC)’s Fifth Assessment Report (AR5). Projected heat-related mortality was lowest for the demographic scenario of constant population and highest for the scenario of increased domestic in-migration. For instance, by the 2080s and assuming moderate adaptation, the median annual number of projected deaths under RCP4.5 and across the 33 GCMs was 603 for the constant population and 1277 for the increased domestic in-migration scenario, compared to 638 annual deaths during the 2000s baseline period. The number of deaths projected under RCP8.5 was over twice as high. These findings can be of value to future work aimed at developing more comprehensive projections of temperature-related mortality.

Static and moving frontiers: the genetic landscape of Southern African Bantu-speaking populations.

A consensus on Bantu-speaking populations being genetically similar has emerged in the last few years, but the demographic scenarios associated with their dispersal are still a matter of debate. The frontier model proposed by archeologists postulates different degrees of interaction among incoming agropastoralist and resident foraging groups in the presence of "static" and "moving" frontiers. By combining mitochondrial DNA and Y chromosome data collected from several southern African populations, we show that Bantu-speaking populations from regions characterized by a moving frontier developing after a long-term static frontier have larger hunter-gatherer contributions than groups from areas where a static frontier was not followed by further spatial expansion. Differences in the female and male components suggest that the process of assimilation of the long-term resident groups into agropastoralist societies was gender biased. Our results show that the diffusion of Bantu languages and culture in Southern Africa was a process more complex than previously described and suggest that the admixture dynamics between farmers and foragers played an important role in shaping the current patterns of genetic diversity.

Changes in the distribution of cloud forests during the last glacial predict the patterns of genetic diversity and demographic history of the tree fern Alsophila firma (Cyatheaceae)

AbstractAimWe investigated changes in distribution of cloud forests during the last 130 kyr, and tested whether these changes explain the spatial patterns of genetic diversity of the tree fern Alsophila firma (Cyatheaceae), a species restricted to this habitat.LocationMexican cloud forests.MethodsWe sampled 204 individuals from 16 localities. Genetic data consisted of DNA sequences for five chloroplast microsatellites and one nuclear gene. We used distribution modelling to predict the historical distribution of cloud forests during the last glacial period, using two palaeoclimate models: the Model for Interdisciplinary Research on Climate (MIROC) and the Community Climate System Model (CCSM). We tested the correlation between temporal cloud forest stability and genetic diversity and used an approximate Bayesian computation (ABC) framework to test two plausible demographic scenarios.ResultsThe range fluctuations observed for cloud forests during the last 130 kyr are key factors affecting the distribution of genetic variation in A. firma. Increased genetic diversity in areas with high temporal environmental suitability is probably the result of increased population sizes and higher interpopulation connectivity. In accordance with the expansion of cloud forests predicted by CCSM, the genetic data supported the scenario of a population expansion occurring c. 110 ka, followed by population divergence c. 20 ka. However, population dynamics involving expansion of suitable microclimates could reconcile the stability of cloud forests predicted by MIROC and the observed genetic patterns.Main conclusionsThe predicted changes in the distribution of cloud forests were congruent with the population genetics of A. firma. However, the choice of palaeoclimate model has a substantial impact on the inferences drawn from the observed genetic and demographic patterns. The use of alternative palaeoclimate hypotheses and biome modelling can provide a common analytical framework for evaluating the historical cohesiveness of forest communities.

Drosophila suzukii: the genetic footprint of a recent, worldwide invasion.

Native to Asia, the soft-skinned fruit pest Drosophila suzukii has recently invaded the United States and Europe. The eastern United States represents the most recent expansion of their range, and presents an opportunity to test alternative models of colonization history. Here, we investigate the genetic population structure of this invasive fruit fly, with a focus on the eastern United States. We sequenced six X-linked gene fragments from 246 individuals collected from a total of 12 populations. We examine patterns of genetic diversity within and between populations and explore alternative colonization scenarios using approximate Bayesian computation. Our results indicate high levels of nucleotide diversity in this species and suggest that the recent invasions of Europe and the continental United States are independent demographic events. More broadly speaking, our results highlight the importance of integrating population structure into demographic models, particularly when attempting to reconstruct invasion histories. Finally, our simulation results illustrate the general challenge in reconstructing invasion histories using genetic data and suggest that genome-level data are often required to distinguish among alternative demographic scenarios.

Cosi2: an efficient simulator of exact and approximate coalescent with selection.

Efficient simulation of population genetic samples under a given demographic model is a prerequisite for many analyses. Coalescent theory provides an efficient framework for such simulations, but simulating longer regions and higher recombination rates remains challenging. Simulators based on a Markovian approximation to the coalescent scale well, but do not support simulation of selection. Gene conversion is not supported by any published coalescent simulators that support selection. We describe cosi2, an efficient simulator that supports both exact and approximate coalescent simulation with positive selection. cosi2 improves on the speed of existing exact simulators, and permits further speedup in approximate mode while retaining support for selection. cosi2 supports a wide range of demographic scenarios, including recombination hot spots, gene conversion, population size changes, population structure and migration. cosi2 implements coalescent machinery efficiently by tracking only a small subset of the Ancestral Recombination Graph, sampling only relevant recombination events, and using augmented skip lists to represent tracked genetic segments. To preserve support for selection in approximate mode, the Markov approximation is implemented not by moving along the chromosome but by performing a standard backwards-in-time coalescent simulation while restricting coalescence to node pairs with overlapping or near-overlapping genetic material. We describe the algorithms used by cosi2 and present comparisons with existing selection simulators. A free C++ implementation of cosi2 is available at http://broadinstitute.org/mpg/cosi2.

Natural selection for the Duffy-null allele in the recently admixed people of Madagascar.

While gene flow between distantly related populations is increasingly recognized as a potentially important source of adaptive genetic variation for humans, fully characterized examples are rare. In addition, the role that natural selection for resistance to vivax malaria may have played in the extreme distribution of the protective Duffy-null allele, which is nearly completely fixed in mainland sub-Saharan Africa and absent elsewhere, is controversial. We address both these issues by investigating the evolution of the Duffy-null allele in the Malagasy, a recently admixed population with major ancestry components from both East Asia and mainland sub-Saharan Africa. We used genome-wide genetic data and extensive computer simulations to show that the high frequency of the Duffy-null allele in Madagascar can only be explained in the absence of positive natural selection under extreme demographic scenarios involving high genetic drift. However, the observed genomic single nucleotide polymorphism diversity in the Malagasy is incompatible with such extreme demographic scenarios, indicating that positive selection for the Duffy-null allele best explains the high frequency of the allele in Madagascar. We estimate the selection coefficient to be 0.066. Because vivax malaria is endemic to Madagascar, this result supports the hypothesis that malaria resistance drove fixation of the Duffy-null allele in mainland sub-Saharan Africa.

The robustness of the weak selection approximation for the evolution of altruism against strong selection.

The weak selection approximation of population genetics has made possible the analysis of social evolution under a considerable variety of biological scenarios. Despite its extensive usage, the accuracy of weak selection in predicting the emergence of altruism under limited dispersal when selection intensity increases remains unclear. Here, we derive the condition for the spread of an altruistic mutant in the infinite island model of dispersal under a Moran reproductive process and arbitrary strength of selection. The simplicity of the model allows us to compare weak and strong selection regimes analytically. Our results demonstrate that the weak selection approximation is robust to moderate increases in selection intensity and therefore provides a good approximation to understand the invasion of altruism in spatially structured population. In particular, we find that the weak selection approximation is excellent even if selection is very strong, when either migration is much stronger than selection or when patches are large. Importantly, we emphasize that the weak selection approximation provides the ideal condition for the invasion of altruism, and increasing selection intensity will impede the emergence of altruism. We discuss that this should also hold for more complicated life cycles and for culturally transmitted altruism. Using the weak selection approximation is therefore unlikely to miss out on any demographic scenario that lead to the evolution of altruism under limited dispersal.

Active Ageing: Intergenerational Relationships and Social Generativity.

This contribution is a reflection on the concept of active ageing from the perspective of relational sociology. At the same time, it offers practical implications and outlines possible future courses of action, in the face of demographic and relational scenarios rapidly changing, and the challenges that each day people of all generations are called to cope with. Active ageing is quite a recent concept and indicates an attitude towards ageing that enhances the quality of life as people become older. The goal of active ageing is to enable people to realise their potential for physical, social and mental well-being and to participate in social life also in the last stage of the life cycle. In this phase, the presence of a network of support, security and care adequate to the possible onset of problems and criticalities is crucial. Relational sociology frames the phenomenon of an ageing population in a dense network of social relations, primarily at the level of family and community. For this reason, as supported by the most recent sociological literature and evidence from studies conducted in Italy and abroad (cf. SHARE), it is extremely important to investigate the link between active ageing, intergenerational orientation (solidarity and exchanges) and practices of prosociality (i.e. engagement in third-sector activities and volunteering in later life).

A review of the effects of artemether-lumefantrine on gametocyte carriage and disease transmission.

While significant advances have been made in the prevention and treatment of malaria in recent years, these successes continue to fall short of the World Health Organization (WHO) goals for malaria control and elimination. For elimination strategies to be effective, limited disease transmission, achieved through rapid reduction in the infectious parasite reservoir and decreased gametocyte carriage, will be critical. Artemisinin-based combination therapy (ACT) forms the cornerstone of WHO-recommended treatment for uncomplicated Plasmodium falciparum malaria, and in combination with other effective interventions will undoubtedly play a vital role in elimination programmes. The gametocytocidal properties of artemisinins are a bonus attribute; there is epidemiological evidence of reductions in malaria incidence and transmission in African regions since the introduction of these agents. Many studies and analyses have specifically investigated the effects of the ACT, artemether-lumefantrine (AL) on gametocyte carriage. In this systematic review of 62 articles published between 1998 and January 2014, the effects of AL on gametocyte carriage and malaria transmission are compared with other artemisinin-based anti-malarials and non-ACT. The impact of AL treatment of asymptomatic carriers on population gametocyte carriage, and the potential future role of AL in malaria elimination initiatives are also considered. Despite the inherent difficulties in comparing data from a range of different studies that also utilized different diagnostic approaches to assess baseline gametocyte counts, the gametocytocidal effect of AL was proportionately consistent across the studies reviewed, suggesting that AL will continue to play a vital role in the treatment of malaria and contribute to clearing the path towards malaria elimination. However, the specific place of AL is the subject of much ongoing research and will undoubtedly be dependent on different demographic and geographical scenarios. Utilizing ACT, such as AL, within malaria elimination strategies is also associated with a number of other challenges, such as balancing potential increased use of ACT (e g, treatment of asymptomatic carriers and home-based treatment) with rational use and avoidance of drug resistance development.

Soft selective sweeps in complex demographic scenarios.

Adaptation from de novo mutation can produce so-called soft selective sweeps, where adaptive alleles of independent mutational origin sweep through the population at the same time. Population genetic theory predicts that such soft sweeps should be likely if the product of the population size and the mutation rate toward the adaptive allele is sufficiently large, such that multiple adaptive mutations can establish before one has reached fixation; however, it remains unclear how demographic processes affect the probability of observing soft sweeps. Here we extend the theory of soft selective sweeps to realistic demographic scenarios that allow for changes in population size over time. We first show that population bottlenecks can lead to the removal of all but one adaptive lineage from an initially soft selective sweep. The parameter regime under which such “hardening” of soft selective sweeps is likely is determined by a simple heuristic condition. We further develop a generalized analytical framework, based on an extension of the coalescent process, for calculating the probability of soft sweeps under arbitrary demographic scenarios. Two important limits emerge within this analytical framework: In the limit where population-size fluctuations are fast compared to the duration of the sweep, the likelihood of soft sweeps is determined by the harmonic mean of the variance effective population size estimated over the duration of the sweep; in the opposing slow fluctuation limit, the likelihood of soft sweeps is determined by the instantaneous variance effective population size at the onset of the sweep. We show that as a consequence of this finding the probability of observing soft sweeps becomes a function of the strength of selection. Specifically, in species with sharply fluctuating population size, strong selection is more likely to produce soft sweeps than weak selection. Our results highlight the importance of accurate demographic estimates over short evolutionary timescales for understanding the population genetics of adaptation from de novo mutation.

Genome-wide patterns of differentiation among house mouse subspecies.

One approach to understanding the genetic basis of speciation is to scan the genomes of recently diverged taxa to identify highly differentiated regions. The house mouse, Mus musculus, provides a useful system for the study of speciation. Three subspecies (M. m. castaneus, M. m. domesticus, and M. m. musculus) diverged ∼350 KYA, are distributed parapatrically, show varying degrees of reproductive isolation in laboratory crosses, and hybridize in nature. We sequenced the testes transcriptomes of multiple wild-derived inbred lines from each subspecies to identify highly differentiated regions of the genome, to identify genes showing high expression divergence, and to compare patterns of differentiation among subspecies that have different demographic histories and exhibit different levels of reproductive isolation. Using a sliding-window approach, we found many genomic regions with high levels of sequence differentiation in each of the pairwise comparisons among subspecies. In all comparisons, the X chromosome was more highly differentiated than the autosomes. Sequence differentiation and expression divergence were greater in the M. m. domesticus-M. m. musculus comparison than in either pairwise comparison with M. m. castaneus, which is consistent with laboratory crosses that show the greatest reproductive isolation between M. m. domesticus and M. m. musculus. Coalescent simulations suggest that differences in estimates of effective population size can account for many of the observed patterns. However, there was an excess of highly differentiated regions relative to simulated distributions under a wide range of demographic scenarios. Overlap of some highly differentiated regions with previous results from QTL mapping and hybrid zone studies points to promising candidate regions for reproductive isolation.

Testing for multiple invasion routes and source populations for the invasive brown treesnake (Boiga irregularis) on Guam: implications for pest management

The brown treesnake (Boiga irregularis) population on the Pacific island of Guam has reached iconic status as one of the most destructive invasive species of modern times, yet no published works have used genetic data to identify a source population. We used DNA sequence data from multiple genetic markers and coalescent-based phylogenetic methods to place the Guam population within the broader phylogeographic context of B. irregularis across its native range and tested whether patterns of genetic variation on the island are consistent with one or multiple introductions from different source populations. We also modeled a series of demographic scenarios that differed in the effective size and duration of a population bottleneck immediately following the invasion on Guam, and measured the fit of these simulations to the observed data using approximate Bayesian computation. Our results exclude the possibility of serial introductions from different source populations, and instead verify a single origin from the Admiralty Archipelago off the north coast of Papua New Guinea. This finding is consistent with the hypothesis that B. irregularis was accidentally transported to Guam during military relocation efforts at the end of World War II. Demographic model comparisons suggest that multiple snakes were transported to Guam from the source locality, but that fewer than 10 individuals could be responsible for establishing the population. Our results also provide evidence that low genetic diversity stemming from the founder event has not been a hindrance to the ecological success of B. irregularis on Guam, and at the same time offers a unique ‘genetic opening’ to manage snake density using classical biological approaches.

Climate change underlies global demographic, genetic, and cultural transitions in pre-Columbian southern Peru.

Several archaeological studies in the Central Andes have pointed at the temporal coincidence of climatic fluctuations (both long- and short-term) and episodes of cultural transition and changes of socioeconomic structures throughout the pre-Columbian period. Although most scholars explain the connection between environmental and cultural changes by the impact of climatic alterations on the capacities of the ecosystems inhabited by pre-Columbian cultures, direct evidence for assumed demographic consequences is missing so far. In this study, we address directly the impact of climatic changes on the spatial population dynamics of the Central Andes. We use a large dataset of pre-Columbian mitochondrial DNA sequences from the northern Rio Grande de Nasca drainage (RGND) in southern Peru, dating from ∼840 BC to 1450 AD. Alternative demographic scenarios are tested using Bayesian serial coalescent simulations in an approximate Bayesian computational framework. Our results indicate migrations from the lower coastal valleys of southern Peru into the Andean highlands coincident with increasing climate variability at the end of the Nasca culture at ∼640 AD. We also find support for a back-migration from the highlands to the coast coincident with droughts in the southeastern Andean highlands and improvement of climatic conditions on the coast after the decline of the Wari and Tiwanaku empires (∼1200 AD), leading to a genetic homogenization in the RGND and probably southern Peru as a whole.

SMARTPOP: inferring the impact of social dynamics on genetic diversity through high speed simulations.

BackgroundSocial behavior has long been known to influence patterns of genetic diversity, but the effect of social processes on population genetics remains poorly quantified – partly due to limited community-level genetic sampling (which is increasingly being remedied), and partly to a lack of fast simulation software to jointly model genetic evolution and complex social behavior, such as marriage rules.ResultsTo fill this gap, we have developed SMARTPOP – a fast, forward-in-time genetic simulator – to facilitate large-scale statistical inference on interactions between social factors, such as mating systems, and population genetic diversity. By simultaneously modeling genetic inheritance and dynamic social processes at the level of the individual, SMARTPOP can simulate a wide range of genetic systems (autosomal, X-linked, Y chromosomal and mitochondrial DNA) under a range of mating systems and demographic models. Specifically designed to enable resource-intensive statistical inference tasks, such as Approximate Bayesian Computation, SMARTPOP has been coded in C++ and is heavily optimized for speed and reduced memory usage.ConclusionSMARTPOP rapidly simulates population genetic data under a wide range of demographic scenarios and social behaviors, thus allowing quantitative analyses to address complex socio-ecological questions.

Molecular diversity, phylogeography and genetic relationships of the Silene paradoxa group of section Siphonomorpha (Caryophyllaceae)

We investigate the genetic diversity and demographic patterns of the Silene paradoxa group from section Siphonomorpha, which includes the three species S. paradoxa, S. fruticosa and S. aristidis. Eight additional taxa, belonging to the same section, were also included in this study for comparative purposes: S. nutans, S. viridiflora and six species of the italica complex. The nuclear internal transcribed spacer (ITS) and the two chloroplast spacers trnH–psbA and trnS–trnG show that the paradoxa group constitutes a separate genetic lineage within section Siphonomorpha and includes three well-differentiated species, characterized by different levels of genetic diversity and demographic histories. All three species showed specific haplotypes and ITS variants, intraspecific variation and contrasting demographic histories. S. paradoxa probably followed a demographic expansion scenario, whereas S. fruticosa and S. aristidis most likely went through spatial expansions in the past. Chasmophyte species and species from open rocky habitats are found in both the paradoxa group and the italica complex, suggesting that the switch between the chasmophytic and open habitats occurred at least twice in the Siphonomorpha section.

Patterns of nucleotide diversity at photoperiod related genes in Norway spruce [Picea abies (L.) Karst

The ability of plants to track seasonal changes is largely dependent on genes assigned to the photoperiod pathway, and variation in those genes is thereby important for adaptation to local day length conditions. Extensive physiological data in several temperate conifer species suggest that populations are adapted to local light conditions, but data on the genes underlying this adaptation are more limited. Here we present nucleotide diversity data from 19 genes putatively involved in photoperiodic response in Norway spruce (Picea abies). Based on similarity to model plants the genes were grouped into three categories according to their presumed position in the photoperiod pathway: photoreceptors, circadian clock genes, and downstream targets. An HKA (Hudson, Kreitman and Aquade) test showed a significant excess of diversity at photoreceptor genes, but no departure from neutrality at circadian genes and downstream targets. Departures from neutrality were also tested with Tajima's D and Fay and Wu's H statistics under three demographic scenarios: the standard neutral model, a population expansion model, and a more complex population split model. Only one gene, the circadian clock gene PaPRR3 with a highly positive Tajima's D value, deviates significantly from all tested demographic scenarios. As the PaPRR3 gene harbours multiple non-synonymous variants it appears as an excellent candidate gene for control of photoperiod response in Norway spruce.

Theoretical Modeling of Influence of Children on Family Purchase Decision Making

Children traditionally were not considered important consumer segment. However, with changing economic, social and demographic scenario, the situation has undergone a change. Substantial research has found that children have influence in family purchase decisions. McNeal (1987) categorized children as three markets in one: they are current market that spends money on their desires, they are a future market for most goods and services and they are markets of influential that cause billions of dollars of purchase among their parents. A study by Nickelodeon (2013) states that power of kids influence over purchasing decisions has increased significantly over the years and decision making among families is collaborative. McNeal (1998) reported that children's indirect purchase through influencing parents decisions soared from USD 5 billion in 1960s to USD 188 billion in 1997. Today children are not passive users but influential buyers and are socialized in this role from an early age. The topic gains special relevance from Indian context due to various reasons. The influence of children in decision making is still an unexplored topic in India. The study specially gains relevance as India has witnessed huge cultural, social and economic changes in the past decade. With compounded annual growth rate of 5.36% predicted for average household disposable income between 2005-2025 (McKinsey Global Institute, 2007) the financial position of families is much stronger. As per Census 2010 of India, demographically India is a young nation with 30% of the population below the age group of 15 years. According to consumer socialization theory family, peers, media are important socialization agents. Also according to research, child's influence is effected by product category, age of child, family communication pattern (Ahuja and Stinson, 1993, Caruana and Vassallo, 2003, Haynes et al., 1993; Ozgen, 2003). The model integrates these two different areas of research to develop a conceptual model to explore the relation of influence of children with respect to different factors. The model introduces the concept of “parent's re-socialization”.