Questions pertaining to populations of organisms.

learn more… | top users | synonyms

3
votes
1answer
36 views

What type of Interspecific relationship does this graph depict?

The other day in class, our AP Biology teacher presented us with the following graph and asked us to determine which of the following interspecific relationships it represents: (A) ...
3
votes
1answer
38 views
3
votes
0answers
25 views

Effect of sex-ratio on the effective population size

As stated on this wikipedia article, the effective population size $N_e$ when the sex ratio differs from $\frac{1}{2}$ is $$N_e = \frac{4N_mN_f}{N_m+N_f}$$ I understand the biased sex-ratio ...
3
votes
1answer
67 views

How could one calculate the gene flow between two populations?

Imagine there are two populations X and Y, and for each population you have the genotypes of each individual in that population (e.g. Aa, AA, aa, etc.), but for multiple loci (e.g. AABb). How could ...
1
vote
0answers
60 views

How many fish are there? [closed]

I am trying to research the estimated population of certain fish throughout time. The fish I cannot seem to find out what I want to know are: Tilapia; Trout; Salmon; Tuna; and Anchovies. Sources that ...
3
votes
1answer
236 views

Software to calculate Fst from sequence data

I'm looking for a software to calculate Fst from 3 loci DNA data of individuals from a metapopulation. I don't have any prior on the population structure (have no idea of the number of subpopulations ...
7
votes
1answer
2k views
18
votes
2answers
286 views

Was the recent “conservation hunt” of a black rhino supported by science?

CNN recently covered a sanctioned black rhino hunt in Namibia by Texan Corey Knowlton, who bid US$350,000 for the license. In the story, he claims that the hunt was actually supporting conservation of ...
5
votes
0answers
54 views

Variance in Fst in the infinite island model

The most famous result in the study of structured populations come from Sewall Wright. He showed that in an island model, where each subpopulation is of size $N$ and the migration rate is $m$, then ...
2
votes
1answer
33 views

Parametric Bootstrap Capture Recapture

I am using the (one sample) capture recapture for estimating hidden human population. One sample method uses purely frequencies of capture to estimate population. One of my colleague suggested ...
1
vote
2answers
193 views

Examples of prey predator interactions where density of predator is very low and prey form groups when the predator attacks the prey for food

Examples of prey predator interactions where density of predator is very low (has a threat of extinction) and prey form groups when the predator attacks the prey for food. I have searched this ...
1
vote
0answers
56 views

Population growth curve for rabbit without predation [closed]

What should a growth curve look like when a rabbit population is introduced on an uninhabited island without predation or disease or natural calamity and plenty of food? The answer seems to be given ...
1
vote
1answer
37 views

What do “reduced antipredator defense” and “reduced antipredator vigilance” mean?

I encountered the terms "reduced antipredator defense" and "reduced antipredator vigilance" in this book Can you help me to make sense of these terms?
11
votes
2answers
536 views

Is global life expectancy normally distributed?

I am trying to find out what the world distribution of life expectancy looks like.
0
votes
1answer
32 views

How to determine the relationship of competition or cooperation?

I am currently studying the interaction of Twitter memes (two or many), such as competition and cooperation. Is there any model or method in biology that can identify the types of the relationship, ...
0
votes
1answer
15 views

Where can I find a global life expectancy table?

I've found good information on specific countries and demographics, but I can't seem to find global numbers. I know that the world life expectancy is around 71.0, but I'm trying to get a percentile ...
2
votes
1answer
191 views

What is the global average BMI?

I have been looking for hours trying to find this number, and can't seem to get a straight answer. I've seen some studies that calculate the change in BMI, but for some reason they don't give you the ...
4
votes
2answers
72 views

Is it possible for two people to repopulate earth? [closed]

Today I was wondering this question whether it is possible for two people to repopulate Earth. What if everyone else disappeared, except for two people (man & woman)? Can they repopulate? In ...
1
vote
1answer
55 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 ...
2
votes
1answer
44 views

Who was the first to coin the terms of soft and hard selection?

Soft and hard selection are sometimes used with different definitions. I have been told that at first place hard and soft selection has been defined in the following way: soft selection: Each deme ...
5
votes
2answers
196 views

Difference between biological control and introducing species for conservation?

I have a biology assignment and we have to explain various methods and strategies for conservation, two of which are: Biological control Introduced Species What is the difference between ...
1
vote
0answers
44 views

Variance in reproductive success and effective population size

Background The effective population size $Ne$ is the size of the Wright-Fisher population that experience the same amount of drift than the population under consideration. The higher the variance in ...
2
votes
1answer
47 views

How do we call a region of low carrying capacity?

I am looking for a convenient word to define a region of the landscape where the local carrying capacity (population size) for a given species is low but different from zero. The species is still ...
3
votes
1answer
471 views

Why do genetic drift generates negative linkage disequilibrium?

The very first sentence of the abstract of this article is: "In finite populations subject to selection, genetic drift generates negative linkage disequilibrium, on average, even if selection acts ...
3
votes
1answer
63 views

History: Do evolutionary and ecological processes occur at the same timescales?

Classically, it was thought that evolutionary processes occurred at a much slower pace than demographic/ecological processes. Nobody, ever thought about incorporating both processes into the same ...
6
votes
2answers
124 views

Within and Between Allelic Class Diversity

I am reading Charlesworth et al. 1997. They talk about diversity within and between allelic classes. Nucleotide diversities ($π$) at each neutral site were estimated from the mean of $2 \sum z_t ...
2
votes
1answer
133 views

Why does the number of mutations per individuals follow a Poisson distribution?

I was reading this review. On page 11, left column, first paragraph, one can read: [..] there is a Poisson distribution of the equilibrium number of mutations per individual, if fitness effects ...
4
votes
0answers
64 views

Understanding F-statistics in population genetics

I am reading a classical Weir and Cockerham 1984 paper about Fst estimation. At the beginning (first page, right column), they define 3 statistics. $F$ is the correlation of genes within individuals ...
3
votes
0answers
38 views

Expected reproduction rate of a dandelion and/or fern

I am working a basic mathematical/computer simulation of an ecosystem, and I need to know the birth rate of each organism in my simulation. However, I could not find any data for how often a small, ...
7
votes
1answer
83 views

Basic Modelling in Quantitative Genetics

I am pretty bad in thinking quantitative genetics models. I am trying to get some basic understanding of modelling the evolution of a quantitative trait. I am therefore asking for help to analyze a ...
1
vote
0answers
29 views

Analytical Methods for Estimating Probability of Fixation

The probability of fixation $P$ of an allele is an very important measure and there exists several solutions to estimate this probability. Each method has its own assumptions and it is often hard to ...
2
votes
1answer
180 views

How do you convert mtDNA sequences in FASTA to FSTAT format?

I've got control region sequence data from a population of shark and I'm looking to convert this from FASTA to FSTAT in order to calculated the effective population size of females. The software I ...
2
votes
1answer
111 views

Recessive alleles at Hardy-Weinberg equilibrium

I've run into a question that I disagree with others on but I would like to receive the input of others. The question is: If a population is at Hardy-Weinberg equilibrium, which of the following can ...
0
votes
1answer
33 views

Literature that demonstrates organisms have a competitive advantage in numbers

I'm studying two bird populations that are competing against each other for a resource: Population A and Population B. Population A is present in much higher numbers than Population B, and as a ...
5
votes
1answer
3k views

How many honeybees are there, and how has the number changed across time?

How would you begin to estimate the world population of the European Honeybee (Apis mellifera)? Would recent colony collapse disorder show up as a blip? How about the spread of A. mellifera from ...
8
votes
1answer
207 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 ...
4
votes
1answer
97 views

Fixation rate at neutral loci

It is a classical result that the expected time for a neutral mutation to occur and to get fixed is $2 N \mu \frac{1}{2N} = \mu$, where $N$ is the population size and $\mu$ is the neutral mutation ...
4
votes
2answers
213 views

What is called the “area size that an animal usually lives in”?

What is called the "area size that an animal usually lives in" or "needs for a normal life"? Is there any specific term?
1
vote
0answers
35 views

Why does death exist? [duplicate]

The biological purpose of an organism is to reproduce and as soon as reproductive age is passed, aging kicks in and eventually leads to death. (This is what I learned from a gerontologist.) But then, ...
8
votes
0answers
93 views

How to define “Quasifixation” in continuous approximation of finite population?

Background Many models including the famous very first models derived by Sir Ronald Fisher in his early career, assume infinite population size. In an infinite population, an allele can rise in ...
3
votes
1answer
83 views

Mutation Rate in Multicellular Eukaryotes

I always hear people saying that the mutation rate is around $10^{-6}$ or $10^{-7}$. I don't even know if this number is the mutation rate of genes or of a single nucleotides and I actually (almost) ...
4
votes
0answers
358 views

Mutation-Selection-Drift Equilibrium

mutation-selection-drift equilibrium is one of the most important concept of population genetics. I could easily find the calculations for mutation-secltion equilibrium and for mutation-drift ...
4
votes
1answer
157 views

How to calculate the effective population size ($N_e$) with overlapping generations?

From this Source: If generations are overlapping, then the effective population size $N_e$ does not equal the population size $N$. I know mathematical formulations in order to find the effective ...
2
votes
0answers
71 views

How does the population fitness changes after a change in mutation rate

The mean population fitness as given by mutation load theory depends only on the genome-wide mutation rate ($U$). My question is: how many generations is needed to reach a new mutation load ...
7
votes
1answer
184 views

How many eukaryotes are there on Earth?

I have been reading: William B. Whitman, David C. Coleman, and William J. Wiebe, "Prokaryotes: The unseen majority", Proc. Natl. Acad. Sci. USA 95, pp. 6578–6583, June 1998. [Full Text] [PDF] ...
0
votes
0answers
68 views

How important is the womb's environment?

- Background - Talking about one phenotypic trait, the total phenotypic variance $V_p$ is decomposed into genetic and environmental variance for this trait, represented by the symbols $V_G$ and $V_E$ ...
8
votes
3answers
268 views

Evolution: One big population vs. many small populations

Let's say I want to evolve a bacterium that is resistant to an antibiotic. I want to do this by growing initially clonal populations of bacteria in presence of this antibiotic for a long time. I have ...
6
votes
1answer
242 views

What percentage of the (additive or not) genetic variance is explained by the 'n'- most important loci?

Standard models in population genetics look up at the evolution of few loci which impact fitness. The variance in fitness is determined by the genetic variance and the environmental variance (and the ...
3
votes
1answer
112 views

Inbreeding depression and dominance

From this article, second paragraph of the second page A classic theoretical result is that the mean of a character controlled by a single locus i with two alleles Ai1 and Ai2 is only affected by ...
4
votes
1answer
83 views

To what extent is immature eggs in insects (beetles) a good approximation for maximum fecundity?

To what extent is the number of immature eggs from dissected, newly emerged individuals a reasonable approximation for maximum/potential fecundity in insects (more specifically beetles)? I know that ...