Talk:Effective population size

English?
This page is nice, but if readers can't follow the math, they're completely lost as to what the concept of effective population size actually means. Can an expert in the field help explain the concept in words? —Preceding unsigned comment added by 128.148.5.26 (talk) 02:34, 17 April 2008 (UTC)


 * The quote from Wright's paper seems to be an attempt in that direction, but it looks as if some important part of the context got dropped, rendering the quote incomprehensible. It says "the same".  Obvious question: the same as WHAT??  It doesn't say!  A similar problem afflicts the subsection called Variance effective size.  Someone's not very good at writing words. Michael Hardy (talk) 05:11, 17 April 2008 (UTC)


 * Agreed with both. I came here because I wanted to learn about the topic but now I'm totally lost. 97.104.210.67 (talk) 22:13, 15 October 2009 (UTC)

Basic Point Overlooked
It would greatly help the average reader if the page said first and foremost that effective population is roughly the number of breeding adults, children are not counted, since not including juveniles is probably the main difference between the total population and the effective population LikesStars (talk) 15:49, 29 October 2014 (UTC)

Reference 2
The second Reference has a wrong DOI, which points to page 425 instead of 430 of Science vol 87. — Preceding unsigned comment added by 212.235.211.98 (talk) 08:48, 2 September 2013 (UTC)

Question to Bgwhite on section headers
Hi Bgwhite. I am trying to insert an introductory paragraph to explain the 4 types of effective population size, but you keep saying my edit causes a problem with the section headers. I have looked at the WP link you provided, but do still not understand what the problem is. Please explain. — Preceding unsigned comment added by 86.154.101.88 (talk) 07:39, 9 April 2016 (UTC)

Error in introduction: time versus population size
In the Introduction, the second paragraph contains the statement "the coalescence time is equal to the census population size". That cannot be right. Time and population size are two different physical properties. — Preceding unsigned comment added by 86.154.102.86 (talk) 08:43, 9 June 2016 (UTC)
 * I added more detail, and the wikilinks point to substantially more. With the exception of constants (which depend on assumptions of diploidy) the formula is correct. They are of course not the same thing, being different physical properties, but a major finding of coalescence theory is that they are numerically equal. It is correct. Joannamasel (talk) 14:31, 9 June 2016 (UTC)


 * Thanks. Two points. First, "effective population is measured" - I think you omitted "size"? Second, can you illustrate your claim with a simple numerical example using time units (seconds, years, whatever). For example, "the population size is 12 drosophila flies, and their time to coalescence is x days" (How can these two different properties ever be comparable, much less equal as you say? If they are numerically equal by chance, all I have to do is change the time unit from days to years and they will certainly not be numerically equal.) 86.154.102.86 (talk) 14:47, 9 June 2016 (UTC)


 * Thanks, I added "size" in, and added the correct time units (generations), which hopefully makes clearer how they can be equal: numbers of individuals and numbers of generations are in the end both numbers, mathematically.Joannamasel (talk) 03:45, 11 June 2016 (UTC)

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Missing variable definitions
I do not have enough knowledge on this topic to do so, but could someone go through and define the variables for the relevant sections? For example, P is usually 'population' but here population seems to be N, so what is P? Given that both are used in the 'inbreeding effective size', it's important to have them distinguished.

Additionally, Ne is described as 'effective population' but is not well defined as to what the actual difference from N is. Given that the ratio is so variable and that it is the point of the article, I'd expect it to be well defined up front as to why it would be different. Zephalis (talk) 21:27, 30 December 2018 (UTC)

Technical tag
The article is too technical for a general audience and uses too many wikilinks instead of clear explanations (see the English? section of the talk page for a similar discussion from 2009). The second paragraph is a good example (but is not the sole example). For instance, "The effective population size is most commonly measured with respect to the coalescence time" should include a brief description of what “coalescence time” is rather than a link. Similarly, "In an idealised diploid population with no selection at any locus, the expectation of the coalescence time in generations is equal to twice the census population size" is indistinguishable (to me) from TV technobabble and contains multiple technical terms that need to be dropped or explained: “diploid”, “selection” (possibly a well-known term), “locus” (has a general definition but is probably being used as a technical term), “expectation”, “coalescence time”, and “generations” (possibly a well-known term).

The second paragraph also does not seem to justify its thesis, but this apparent non-sequitur might just be a result of editors assuming that readers will know the links between some concepts: If the first sentence said that “the effective population size is most commonly measured as the coalescence time”, that would be much more clear (but I do not know if it is correct) and would link the concepts in all of these sentences together. It is possible that these ambiguities are distinct from the technical language, but I do not understand the technical language, so I cannot tell if they are distinct problems. If someone more knowledgeable sees them as distinct, please separate this section into two sections. Rscragun (talk) 20:42, 28 November 2020 (UTC)
 * First sentence: effective sample size is measured “with respect to” (which is vague) coalescence time
 * Second sentence: relationship between coalescence time and census population size (no mention of effective population size)
 * Third sentence: relationship between effective population size, genetic diversity, and mutation rate (no mention of coalescence time)
 * Fourth sentence: introduces new term (“coalescent effective population size”) suggesting to a casual reader that maybe coalescence time a measure of effective sample size