Unit 3 Padlet: Populations by SAKURA LANA CAITLYN DE GUZMAN https://padlet.com/1090185/umyu5pw7ajgcg1lz en-us 2021-05-24 04:23:18 UTC 2021-05-24 04:44:00 UTC hello@padlet.com Human Population Dynamics 1090185 https://padlet.com/1090185/umyu5pw7ajgcg1lz/wish/1552567876 Humans experience population growth or decline through infant mortality rates, birth rates, immigration, emigration and the development of a country. Factors that go into a population declining or increasing are access to family planning, nutrition, education and jobs. A way to predict the doubling time of a population size is by the rule of 70. This rule states that dividing the number of 70 by the percentage population growth rate approximates the population doubling time. A density independent factor is a limit on population growth regardless of population density (size). Some examples of density independent factors are weather, climate, storms, fire, heatwaves, or droughts. However a density dependent factor is affected by the size of a population. Some density dependent factors are access to clean water, air, food availability, disease, and territory size. ]]> 2021-05-24 04:24:19 UTC https://padlet.com/1090185/umyu5pw7ajgcg1lz/wish/1552567876 Age Structure Diagrams 1090185 https://padlet.com/1090185/umyu5pw7ajgcg1lz/wish/1552568241 An age structure diagram is a model that predicts the population growth rate by a shape. It shows a comparative ratio of males to females and the bars show various age groups from infants - adolescents - reproduce - post reproductive. 

]]> 2021-05-24 04:24:31 UTC https://padlet.com/1090185/umyu5pw7ajgcg1lz/wish/1552568241 Population Growth and Resource Availability 1090185 https://padlet.com/1090185/umyu5pw7ajgcg1lz/wish/1552568557 Population Growth refers to the rate a population can grow however it is limited by the availability of resources in a habitat, space and competition between species. An exponential growth is when populations grow at their intrinsic rate of increase (r) and are limited by resource increase by a fixed rate each year.  This type of exponential growth is described using a J Curve because of the shape of the accelerated growth rate. A logistic population growth model shows a population exponentially growing until environmental resistance such as limited factors make it reach its carrying capacity. The population growth makes an S shaped curve.]]> 2021-05-24 04:24:40 UTC https://padlet.com/1090185/umyu5pw7ajgcg1lz/wish/1552568557 Survivorship Curves 1090185 https://padlet.com/1090185/umyu5pw7ajgcg1lz/wish/1552569509 Survivorship curves are used to compare the pattern of mortality between species. The curves show the number of members of a population that reaches various age groups. There are three types of survivorship curves which detail a different pattern for each one. Type 1 shows a curve in which most of the population dies off toward their old age. This curve shows the reproductive pattern of K-selected species because energy and time goes into parental care which is why their species dies off at old age. 
Type 2 curve shows a constant loss population that is not affected by age. Age doesn't determine survivalism or mortality. This curve shows that the survivability reality is constant regardless of age 
Type 3 curve shows a species that has an early loss population and few live to old age. This pattern can be seen in r-selected species because the huge number of offspring and no or few parental care results in the majority of offspring to die young.
]]> 2021-05-24 04:25:03 UTC https://padlet.com/1090185/umyu5pw7ajgcg1lz/wish/1552569509 Generalist and Specialist Species 1090185 https://padlet.com/1090185/umyu5pw7ajgcg1lz/wish/1552569874 A generalist is a species that has a broad niche and is able to adapt to many environmental conditions. They do not have a limited diet and are able to survive by using a variety of resources. Generalist species can be found in a larger range of locations around the world as they are adaptable. Additionally, they have a higher tolerance to environmental change. 
A key feature of generalist species is that they have a higher advantage of surviving in  habitat that is changing. They are able to survive because they have a large range of resources which allows them to  adapt to a wide range of environmental conditions and diet as well. A specialist species, on the other hand, has a narrow niche and is not adaptable to change in their environment. They have a limited diet and can not survive without their necessary diet. Specialist species are found in specific habitats because they need the appropriate amount of food, water, sunlight and shelter. Their range of tolerance is low which means that they are not suitable to change in their environment. Everything needs to be balanced or else a specialist population will decline. 
A key feature of a specialist species is that they are not able to survive as well in a changing habitat as generalist species are.
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