Questions tagged [demography]

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12 views

Strict molecular clock rate and time axis on Bayesian skyline plot

I have an alignment of roughly 1 million bp ddRAD data and I'm planning to run a BSP analysis on three species of dolphins to detect past changes in effective population sizes for each of them. Since ...
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1answer
43 views

Why squirrel behaviour varies greatly throughout India?

Common squirrels seen in India, probably Indian palm squirrels; seem to have drastic different behaviour. And all squirrels of a definite locality, behave in a very consistently same whay. That seems ...
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1answer
93 views

What factors affect the number of individuals in an animal group?

Social animals can live in groups whose numbers vary greatly according to species (for instance wolves vs deer herds vs buffalo stampedes vs lemmings). Is this number regulated only by environmental ...
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4answers
10k views

Value of r (intrinsic rate of natural increase)

What is the current value of 'r' (instrinsic rate of natural increase) in India? How do we calculate it? My book says that In 1981, the r value for human population in India was 0.0205. But this ...
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1answer
640 views

Do death rate and birth rate become equal at replacement fertility rate?

A population transitions from stage 3 to stage 4 when the fertility rate reaches the population replacement level of 2.1. My question is that if the population replacement level reached, shouldn't ...
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0answers
239 views

World population pyramid since 1800 [closed]

I am interested in understanding how the global population pyramid has changed in the last couple of centuries. I have two questions: 1) Has this been calculated? Are there estimates of population ...
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0answers
211 views

What is the biology behind human population dynamics?

A paradox: Human population growth looks a lot like a simple logistic growth pattern. But the simplest interpretation of logistic growth doesn't seem to fit. Is this peculiar to humans, or does it ...
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1answer
164 views

How can a species switch from r to K - reproductive strategy in a single generation?

I ask because it seems as though humanity is in the midst of doing exactly this. Only a few decades ago, human population was growing exponentially, and it seemed destined to keep growing until ...
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92 views

Hybridization of an Indo-Aryan ethnic group and a Tibeto-Burmese ethnic group

The state in which I reside houses these two distinct ethnic groups. Physical Traits of the Indo-Aryan group Height:Medium Eyes:does not posses epicanthic fold Nasal bones:is not flat and broad ...
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1answer
344 views

What is the percentage of people living in England in 1500 AD whose lineage is still alive?

This sounds a bit random, but it stems from a lecture in statistical genetics which I attended a while ago. We were shown a population lineage graph from which it was clear that most lineages ...
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1answer
108 views

Human population growth - where can I find the data?

Out of curiosity, I'd like play around with data of human global demography. Where can I find data that describe the "per region (per continent for example) population size" versus time since the "...
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1answer
540 views

What sample sizes are ideal for carrying out Bayesian Skyline Plots?

I am interested in creating Bayesian Skyline Plots to look at demographic changes in certain population groups. However, these populations have very little within population variation. Around 5 ...
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1answer
629 views

Fecundity per woman in early humans

The average fecundity per woman varies a lot from country to country. I call average fecundity per woman the average number of born children per woman. In Homo sapiens, what was the average fecundity ...
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1answer
233 views

Survival curve in early humans

The survival curve/function describes the probability of a given individual to survive to age $x$. In humans, today's survival function is very much influenced by medicine. This leads me to wonder ...
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3answers
2k views

Survivorship Curves: Type II curve mortality rate is not constant?

In graphs of survivorship curves, I'm seeing that the Type II curves are straight lines, and the supplementary text says that the mortality rate is constant (i.e. the slope of the line is constant). ...
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2answers
96 views

Tree census data for Sweden/Scandinavia?

Is anyone aware of any attempts to count or approximate the number of trees there are in Sweden or Scandinavia? I have a small popular science side project for which this would be useful