# Tag Info

Accepted

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

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 ...
• 14.7k

### Value of r (intrinsic rate of natural increase)

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 ...
Accepted

### Value of r (intrinsic rate of natural increase)

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 ...
• 68.1k

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

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, ...
• 504
Accepted

### Why squirrel behaviour varies greatly throughout India?

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 ...
• 6,987

### Value of r (intrinsic rate of natural increase)

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 ...
• 16.7k

### What is the biology behind human population dynamics?

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 ...
• 14.7k
Accepted

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

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 ...
• 68.1k

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

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 ...
1 vote

### Ancestral inference from demographic data

As mentioned in the OP, one can perform an estimate using birth-and-death process. Let us consider an population from a particular year with the initial size $N_0$ - then the probability that the ...
• 3,852
1 vote
Accepted

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

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 ...
• 16.7k

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