# Tag Info

5

$r$ is the individual mortality rate per time step. Survivorship curves (plotted on a log scale) show the proportion of individuals surviving with time, and with a Type II curve a constant proportion is dying at each time step (constant mortality with age, $r$). When the model is expressed as $y$ you are looking at the number of individuals surviving to a ...

4

To obtain a full survival curve (basically a full life table) you would need to make quite a number of assumptions, since the data for paleolithic societies is scattered and probably biased. This is however not a field I know well, but I can point you to one recent paper (White, 2014) that explores how the ratio of young and old individuals in a population ...

4

this depends on what you mean by group. If you mean population then it is mostly environmental factors, although part of the environment can be other member of your species, some groups have a minimum functional size, such as passenger pigeons and breeding in groups behavior, or have density controls(if you are too spread out you might never run into ...

3

NCERT shows per capita value is divided by 1000, not hundred (%). So the data you see is 22.50 per thousand! So, the per capita rate is 22.50/1000 = 0.02250 that is almost equal to 0.0205 given in book! To make you understand better, remember that GDP and per capita GDP is different, the same way birth rate or death rate is calculated per 1000 but when we ...

3

For Discrete Time There are two quantities you should be careful not to mix up. One is the number of individuals who will die during a given interval: $d_x = N_x - N_{x+1}$. One is the fraction, out of those alive at the beginning of a given interval, who will die during the interval: $q_x = \frac{d_x}{N_x}$ ($N_x$ being the number of survivors at age $x$...

2

Its actually much simpler than you are making it out to be, carrying capacity is not an issue, humans long since surpassed the planets carrying capacity without advanced technology. The real factor is infant mortality. consider both K and r strategies Say you have two sets of parents each starting with the same amount of resources. In r strategy the approach ...

2

The issue in your reasoning is to associate a $r$ or $K$ as being a property intrinsic of the species which, while not entirely wrong, is rather misleading. The classical and simplistic model of population growth is the model of logistic growth $$n(t+1) = n(t) + rn(t)\left(1-\frac{n(t)}{K}\right)$$ , where $n(t)$ is the population size (number of ...

2

Here is a partial answer that also expands upon a previous comment: Between 1900 and 2013, 20,000 English surnames had gone extinct according to the Daily Mail's summary of research on surnames. This is a partial answer because it only tells us how many names are gone and is from the wrong time period. To completely answer your question, I suspect you ...

2

It the most basic form, the intrinsic rate of increase, $r$, is defined as: $\frac{dN}{dt} = rN = (a-b)N$ where $a$ is the birth rate per unit time and $b$ is the death rate per unit time. So $r$ is the birth rate minus the death rate. The modell can naturally also be extended to e.g. include carrying capacity or to make $r$ (or underlying parameters) ...

2

From the UN database (this info is also reported on wikipedia), the growth rate in India in 2016 was $r=1.019$. It is computed as $r = \frac{N_{2017}}{N_{2016}}$, where $N_{y}$ is the population size at year $y$. This estimate is based on the total number of residents (regardless of their legal status). More explanations $r$ is simply defined as \$r = \...

2

Infant mortality was high during the paleolithic, so the fecundity of females had to be quite a bit higher than 2 to sustain viable populations. A recent paper by White (2014) that explores how the ratio of young and old individuals in a population relates to demographic rates compiles data on hunter-gatherer societies from previous studies that you will ...

1

Given that you're dealing with fairly smart mammals with a short lifespan and limited distance migration, it seems likely that you're dealing with strong local selection effects that are going to be reflected in all three layers: Learned behaviors from observing other squirrels and their own interactions with humans. Epigenetic effects tied to things like ...

1

The transition to stationary populations is between stage 4 to stage 5 in all exemples of the DT model that I've seen. Not between stage 3 and 4. This is also what is being implied in the figure that you've included. In your link they also write: Countries like India in the third phase of demographic transition have fertility rates that have declined ...

1

National censuses are collected, published and disseminated primarily by each country's census or national statistical office (NSO) or its equivalent. Census data are published in each country's vernacular, and as appropriate, many offer English as well as other language versions. Statistical offices of international agencies (e.g. United Nations, ...

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I found a PLOS one article that might help. In this they used similar numbers you're planning to use (if i get your question and the article's data right). The influence of the sampling scheme was investigated by drawing 40 samples in three different ways: 1) all 40 samples from a single deme, 2) 4 samples from each of 10 demes and 3) one sample from ...

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I would definatley look at data from Swedish National Forest Inventory (Riksskogstaxeringen). They have time series data of multiple variables (DBH, size classes, species, dead wood etc) from plots all over the country. Extrapolations based on these data should produce reasonable estimates of total tree count, and probably the most accurate one that can be ...

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