The evolution of human life course

2021 ◽  
Author(s):  
Francesco Suman
Keyword(s):  
Life History ◽  
Phenotypic Plasticity ◽  
Life History Traits ◽  
Homo Sapiens ◽  
Human Life ◽  
Life History Evolution ◽  
Extended Evolutionary Synthesis ◽  
Genetic Accommodation ◽  
Selective Pressures ◽  
Life History Pattern

Homo sapiens’ life history pattern possesses both fast and slow components, in a combination that is unique among the extant great apes. One of the issues debated in current evolutionary research is the role played by phenotypic plasticity as a non-genetic means of adaptation to evolutionary challenges. While life history parameters are shaped at a species level by genetic adaptations via natural selection, they remain very sensitive to changes in the environment. Relying on updated evidence and on key explanatory tools of the Extended Evolutionary Synthesis (phenotypic plasticity, niche construction, and inclusive inheritance), it is likely that environmentally induced plasticity led the way in human life history evolution, promoting subsequent genetic accommodation. To the extent that culturally transmitted behaviors altered the selective pressures that acted on life history traits across generations during human evolution, a culturally driven plasticity dynamic shaping human life history traits can be identified. Two case studies in particular are discussed: the human adaptations to the domestication of fire and the self-domestication hypothesis.

The evolution of childhood as a by-product?

2006 ◽  
Vol 29 (3) ◽  
pp. 288-289
Author(s):  
Peter Kappeler
Keyword(s):  
Life History ◽  
Life Histories ◽  
Nonhuman Primates ◽  
Homo Sapiens ◽  
Human Life ◽  
Life History Evolution ◽  
History Evolution ◽  
Linguistic Skills

The proposition that selective advantages of linguistic skills have contributed to shifts in ontogenetic landmarks of human life histories in early Homo sapiens is weakened by neglecting alternative mechanisms of life history evolution. Moreover, arguments about biological continuity through sweeping comparisons with nonhuman primates do not support various assumptions of this scenario.

scholarly journals What Drives Life-History Variation in the Livebearing Fish Poeciliopsis prolifica? An Assessment of Multiple Putative Selective Agents

2021 ◽  
Vol 8 ◽  
Author(s):  
Andrea J. Roth-Monzón ◽  
Mark C. Belk ◽  
J. Jaime Zúñiga-Vega ◽  
Jerald B. Johnson
Keyword(s):  
Life History ◽  
Population Density ◽  
Interspecific Competition ◽  
Resource Availability ◽  
Life History Traits ◽  
Life History Evolution ◽  
Embryo Size ◽  
Selective Pressures ◽  
Selective Agents ◽  
Livebearing Fish

Life-history traits are directly linked to fitness, and therefore, can be highly adaptive. Livebearers have been used as models for understanding the evolution of life histories due to their wide diversity in these traits. Several different selective pressures, including population density, predation, and resource levels, can shape life-history traits. However, these selective pressures are usually considered independently in livebearers and we lack a clear understanding of how they interact in shaping life-history evolution. Furthermore, selective pressures such as interspecific competition are rarely considered as drivers of life-history evolution in poeciliids. Here we test the simultaneous effects of several potential selective pressures on life-history traits in the livebearing fish Poeciliopsis prolifica. We employ a multi-model inference approach. We focus on four known agents of selection: resource availability, stream velocity, population density, and interspecific competition, and their effect on four life-history traits: reproductive allocation, superfetation, number of embryos, and individual embryo size. We found that models with population density and interspecific competition alone were strongly supported in our data and, hence, indicated that these two factors are the most important selective agents for most life-history traits, except for embryo size. When population density and interspecific competition increase there is an increase in each of the three life-history traits (reproductive allocation, superfetation, and number of embryos). For individual embryo size, we found that all single-agent models were equivalent and it was unclear which selective agent best explained variation. We also found that models that included population density and interspecific competition as direct effects were better supported than those that included them as indirect effects through their influence on resource availability. Our study underscores the importance of interspecific competitive interactions on shaping life-history traits and suggests that these interactions should be considered in future life-history studies.

Language and life history: A new perspective on the development and evolution of human language

2006 ◽  
Vol 29 (3) ◽  
pp. 259-280 ◽  
Author(s):  
John L. Locke ◽  
Barry Bogin
Keyword(s):  
Life History ◽  
Adult Development ◽  
Homo Sapiens ◽  
Human Life ◽  
Modern Human ◽  
Linguistic Knowledge ◽  
Human Language ◽  
Juvenile Period ◽  
Development Of Language ◽  
New Perspective

It has long been claimed that Homo sapiens is the only species that has language, but only recently has it been recognized that humans also have an unusual pattern of growth and development. Social mammals have two stages of pre-adult development: infancy and juvenility. Humans have two additional prolonged and pronounced life history stages: childhood, an interval of four years extending between infancy and the juvenile period that follows, and adolescence, a stage of about eight years that stretches from juvenility to adulthood. We begin by reviewing the primary biological and linguistic changes occurring in each of the four pre-adult ontogenetic stages in human life history. Then we attempt to trace the evolution of childhood and juvenility in our hominin ancestors. We propose that several different forms of selection applied in infancy and childhood; and that, in adolescence, elaborated vocal behaviors played a role in courtship and intrasexual competition, enhancing fitness and ultimately integrating performative and pragmatic skills with linguistic knowledge in a broad faculty of language. A theoretical consequence of our proposal is that fossil evidence of the uniquely human stages may be used, with other findings, to date the emergence of language. If important aspects of language cannot appear until sexual maturity, as we propose, then a second consequence is that the development of language requires the whole of modern human ontogeny. Our life history model thus offers new ways of investigating, and thinking about, the evolution, development, and ultimately the nature of human language.

scholarly journals Life history evolution, species differences, and phenotypic plasticity in hemiparasitic eyebrights ( Euphrasia )

2020 ◽  
Vol 107 (3) ◽  
pp. 456-465 ◽  
Author(s):  
Max R. Brown ◽  
Natacha Frachon ◽  
Edgar L. Y. Wong ◽  
Chris Metherell ◽  
Alex D. Twyford
Keyword(s):  
Life History ◽  
Phenotypic Plasticity ◽  
Species Differences ◽  
Life History Evolution ◽  
History Evolution

Endocrinology

2019 ◽  
pp. 612-672
Author(s):  
Richard G. Bribiescas
Keyword(s):  
Life History ◽  
Social Dynamics ◽  
Human Life ◽  
Life History Evolution ◽  
Sexually Dimorphic ◽  
Human Variation ◽  
Men And Women ◽  
Metabolic Hormones ◽  
Gene Environment ◽  
Key Aspects

This chapter on endocrinology aims to shed light on the biology of hormones within the context of human life history evolution. An evolutionary perspective contributes to not only our understanding of human evolution, but also to the contemporary and emerging health challenges across the spectrum of ecologies and environments. Evolutionary endocrinology extends our understanding of human biology and health through the engagement of gene–environment interactions, social dynamics, human variation, and how hormones regulate life history traits such as growth, immune function, metabolism, and ageing. This chapter describes key aspects of endocrinology that are specific to men and women, while also being mindful of the importance of human variation. For example, men and women exhibit reproductive states that deploy specific functions. In women, these are menstruation, gestation, and lactation. These processes are governed largely by the hypothalamic–pituitary–ovarian axis and how it responds to environmental challenges such as nutritional demands, activity, and social stresses. Men also exhibit reproductive states, although they are mostly in the form of investment in sexually dimorphic tissue and behavioural variation. These states are governed by hormones which allocate resources between tissues that are indicative of different forms of reproductive effort. These include sexually dimorphic muscle tissue and adiposity. Spermatogenesis is obviously key but has differential effects on fertility compared to gametogenesis in women. Additional aspects of human evolutionary endocrinology include stress homoeostasis and metabolism, which involve the hypothalamic–pituitary–adrenal axis as well as the thyroid and other metabolic hormones.

Sign in / Sign up

Export Citation Format

Share Document