scholarly journals The Growth Rate Hypothesis as a predictive framework for microevolutionary adaptation to selection for high population growth: an experimental test under phosphorus rich and phosphorus poor conditions

2020 ◽  
Author(s):  
Kimberley D. Lemmen ◽  
Libin Zhou ◽  
Spiros Papakostas ◽  
Steven A.J. Declerck
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Somatic Growth ◽  
Positive Association ◽  
Common Garden ◽  
Growth Rate Hypothesis ◽  
High Population Growth ◽  
Microevolutionary Change ◽  
Selection For ◽  
Transplant Experiments

AbstractThe growth rate hypothesis, a central concept of Ecological Stoichiometry, explains the frequently observed positive association between somatic growth rate and somatic phosphorus content (Psom) in organisms across a broad range of taxa. Here, we explore its potential in predicting intraspecific microevolutionary adaptation. For this, we subjected zooplankton populations to selection for fast population growth (PGR) in either a P-rich (HP) or P-poor (LP) food environment. With common garden transplant experiments we demonstrate evolution in HP populations towards increased PGR concomitant with an increase in Psom. In contrast we show that LP populations evolved higher PGR independently of Psom. We conclude that the GRH hypothesis has considerable value for predicting microevolutionary change, but that its application may be contingent on stoichiometric context. Our results highlight the potential of cryptic evolution in determining the performance response of field populations to elemental limitation of their food resources.

Lessons from a century of conservation translocations

2021 ◽  
Author(s):  
Shane D Morris ◽  
Katherine E. Moseby ◽  
Barry W. Brook ◽  
Christopher N. Johnson
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Population Growth Rate ◽  
Historical Context ◽  
Extrinsic Factors ◽  
Global Database ◽  
Terrestrial Vertebrates ◽  
Failure Classification ◽  
High Population Growth ◽  
Number Of Individuals

Translocation—moving individuals for release in different locations—is among the most important conservation interventions for increasing or re-establishing populations of threatened species. However, translocations often fail. To improve their effectiveness, we need to understand the features that distinguish successful from failed translocations. Here, we assembled and analysed a global database of translocations of terrestrial vertebrates (n=514) to assess the effects of various design features and extrinsic factors on success. We analysed outcomes using standardized metrics i.e. a categorical success/failure classification, and population growth rate. Probability of categorical success and population growth rate increased with the total number of individuals released but with diminishing returns above about 20-50 individuals. There has been no increase in numbers released per translocation over time. Positive outcomes—reported success and high population growth—were less likely for translocation in Oceania, possibly because invasive species are a major threat in this region and are difficult to control at translocation sites. Increased rates of categorical reported success and population growth were found for Europe and North America, suggesting the key role of historical context in positive translocation outcomes. Categorical success has increased throughout the 20th century, but that increase may have plateaued at about 75% since about 1990. Our results suggest there is potential for further increase in the success of conservation translocations. This could be best achieved by greater investment in individual projects, as indicated by total number of animals released.

Using the Newspaper to Disseminate Vasectomy Information in Kenya

1993 ◽  
Vol 14 (2) ◽  
pp. 165-172 ◽  
Author(s):  
David John Wilkinson ◽  
Pamela Fenney Lyman ◽  
Katherine Mason ◽  
Grace E. Wambwa
Keyword(s):  
Growth Rate ◽  
Family Planning ◽  
Population Growth ◽  
Rural Areas ◽  
Communication Systems ◽  
Population Growth Rate ◽  
Socioeconomic Groups ◽  
Lower Socioeconomic ◽  
High Population Growth ◽  
Large Response

Recent research in Kenya shows that, although there is still a high population growth rate, there is increasing interest among men as well as women in family planning and in limiting family size. Vasectomy, however, is little known and practiced in Kenya. A major reason for this is a general lack of knowledge about the procedure and where it may be obtained. Little effort has been put into addressing the barriers to vasectomy acceptance in Kenya, partly because of the commonly held assumption that Kenyan men would not be interested in the method. Innovative Communication Systems, with the support of the Association for Voluntary Surgical Contraception, implemented a study using the print media to examine this perception. Advertisements providing information about the method were placed in newspapers and a magazine. An unexpectedly large response was received—over 800 written requests for information from all parts of the country. The majority of inquiries were from rural areas, and there was a high proportion of requests from the coastal district, a Muslim area generally considered to be extremely resistant to family planning. A large proportion of inquiries came through a Kiswahili newspaper appealing to lower socioeconomic groups.

Increased population growth rate in invasive polyploidCentaurea stoebein a common garden

2012 ◽  
Vol 15 (9) ◽  
pp. 947-954 ◽  
Author(s):  
Min A. Hahn ◽  
Yvonne M. Buckley ◽  
Heinz Müller-Schärer
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Population Growth Rate ◽  
Common Garden

scholarly journals Devil in the details: growth, productivity, and extinction risk of a data-sparse devil ray

2016 ◽  
Author(s):  
Sebastián A. Pardo ◽  
Holly K. Kindsvater ◽  
Elizabeth Cuevas-Zimbrón ◽  
Oscar Sosa-Nishizaki ◽  
Juan Carlos Pérez-Jiménez ◽  
...  
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Growth Rates ◽  
Population Growth Rate ◽  
Extinction Risk ◽  
Somatic Growth ◽  
Small Scale ◽  
Fishing Mortality ◽  
Population Growth Rates ◽  
Size At Age

Devil rays (Mobulaspp.) face rapidly intensifying fishing pressure to meet the ongoing international trade and demand for their gill plates. This has been exacerbated by trade regulation of manta ray gill plates following their 2014 CITES listing. Furthermore, the paucity of information on growth, mortality, and fishing effort for devil rays make quantifying population growth rates and extinction risk challenging. Here, we use a published size-at-age dataset for a large-bodied devil ray species, the Spinetail Devil Ray (Mobula japanica), to estimate somatic growth rates, age at maturity, maximum age and natural and fishing mortality. From these estimates, we go on to calculate a plausible distribution of the maximum intrinsic population growth rate (rmax) and place the productivity of this large devil ray in context by comparing it to 95 other chondrichthyan species. We find evidence that larger devil rays have low somatic growth rate, low annual reproductive output, and low maximum population growth rates, suggesting they have low productivity. Devil ray maximum intrinsic population growth ratermaxis very similar to that of manta rays, indicating devil rays can potentially be driven to local extinction at low levels of fishing mortality. We show that fishing rates of a small-scale artisanal Mexican fishery were up to three times greater than the natural mortality rate, and twice as high as our estimate ofrmax, and therefore unsustainable. Our approach can be applied to assess the limits of fishing and extinction risk of any species with indeterminate growth, even with sparse size-at-age data.

Growth and Maturation of Southwest Nova Scotia Atlantic Herring (Clupea harengus harengus)

1982 ◽  
Vol 39 (2) ◽  
pp. 288-295 ◽  
Author(s):  
M. Sinclair ◽  
A. Sinclair ◽  
T. D. Iles
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Population Growth Rate ◽  
Somatic Growth ◽  
Atlantic Herring ◽  
Population Abundance ◽  
Age Composition ◽  
Somatic Growth Rate ◽  
Adult Growth ◽  
Juvenile Population

Juvenile and adult growth rates, and the maturation schedule, for the southwest Nova Scotia herring stock (NAFO SA 4WX) were investigated over the period 1968–78. The variance in juvenile (age 2) summer growth is not well accounted for by initial weight, juvenile population abundance, and temperature unless a discontinuity in growth pattern starting in 1970 is accounted for. Length at maturity and at recruitment to the adult schools appears to be inversely related to the population abundance experienced during juvenile growth. However, at very low juvenile population size, maturation appears to be inhibited. Somatic growth rate and its year-to-year variability decreases close to an order of magnitude with the onset of maturation. Because of this decrease with age and the radical shifts in age, composition with time, population growth rate fluctuates markedly. Because high population abundance parallels downward shifts in age composition, there is a clear, positive relationship between population growth rate and population abundance. There is a dome-shaped relationship between cohort somatic growth rate and cohort size at intermediate ages, suggesting that over a broad range in population size, adult growth rate is not density-dependent. This growth response is interpreted in relation to planktivorous feeding in a patchy environment. Strong year-class strength variability coupled with a marked decline in somatic growth rate with age results in non-steady state population production. When the age composition is biased towards older ages, catch (defined by F0.1 guidelines) exceeds population production resulting in rapid stock declines. The growth characteristics of herring are discussed in relation to the literature and "analytical" yield models.Key words: Atlantic herring, growth, maturation, production

scholarly journals Population and Development vs Quality of Life: A Sociological Appraisal

2021 ◽  
Vol 7 (5) ◽  
pp. 45-51
Author(s):  
Mohammad Taghi Sheykhi
Keyword(s):  
Quality Of Life ◽  
Growth Rate ◽  
Population Growth ◽  
Population Growth Rate ◽  
Population Increase ◽  
High Population ◽  
Population Growth Rates ◽  
High Population Growth ◽  
Very High

The two variables of population and development affect each other in an indirect manner in which when population increase happens, development is reduced. The two effectively impact quality of life. It is strongly recommended to control population in order to achieve development. Sociologists are widely responsible to create the balance of population and development. As resources are limited in each country, an organized and planned population is needed towards any development. The phenomenon development being multi-lateral, needs an appropriate population size. It is worth mentioning that population naturally grows, but resources for development do not. Overall, Asia, Africa, and Latin America had very high population growth rate of 2.1% between 1955 and 1975. Fortunately, increase of literacy and education has caused population growth rates to decline in the past two decades in many parts of the developing countries. The only part of the developing world with high population growth rate is Africa in which the population will increase to over 4.2 billion by the year 2100; threatening other parts of the world. Such a situation will widely endanger quality of life.

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