10 votes

What are the odds of being an albino human and have Down syndrome?

It is correct if (and only if) albinism and Down syndrome are independent events, that is, if albino people is not more nor less likely to have Down syndrome than non albino people (and vice-versa). ...
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  • 586
10 votes
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Saturated Mutagenesis Screening

This sort of method is indeed quite useful and frequently used in synthetic biology: I've used a similar approach before to generate 5' insulators for promoters. Calculating the exact theoretical ...
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  • 6,937
8 votes

How many (taxonomic) families are there?

The NCBI Taxonomy statistics page displays the following information: There are currently 73540 genera, 331418 species, and 23127 taxa of higher order. Since the number of taxa decreases with the ...
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  • 9,314
8 votes
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Long-term efficacy and absence of side effects of anti-covid vaccines

You are correct that we have been creating and approving vaccines for a very long time, so the procedures for looking at efficacy and side effects of vaccines in general long-term are quite well ...
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  • 14.8k
7 votes

Statistics: How are protein species distributed over cell types?

From my searches, there is no single resource that includes an atlas of all human proteins produced across all human cell types. However, there are several recent mass spectrometry studies that look ...
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  • 7,729
7 votes
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Which statistical test should be used for GC-content comparison?

You could try a permutation test. These are a kind of non-parametric statistical test which involve creating your own null distribution from your data. Your hypothesis $H_{1}$ in this case, is that ...
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  • 2,053
6 votes

How many (taxonomic) families are there?

The Plant List has 642 families listed: http://www.theplantlist.org/1.1/about/#changes. For a quick comparison, Wikipedia lists 522 fish families: en.wikipedia.org/wiki/List_of_fish_families 136 ...
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6 votes
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On evolution statistics

Remi.b's answer is great, but here's something less technical if that's what you're looking for: Genetic mutations happen ALL THE TIME. Every time a cell divides, there is an error rate of about one ...
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6 votes

On evolution statistics

In your 5 points you basically cover several concepts of evolutionary biology. 1) The number of mutations depend on mutation rate. The mutation rate varies along genome sequences, species and ...
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6 votes
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How many (taxonomic) families are there?

The 2011 paper How Many Species Are There on Earth and in the Ocean? indirectly answers this question as well as any other source you'll find I imagine. It estimates how many species there are total ...
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  • 3,180
6 votes

What is the name of this graph/plot?

I think it is Chord Diagram. you can see this for more information. "A chord diagram is a graphical method of displaying the inter-relationships between data in a matrix. The data are arranged ...
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  • 192
6 votes
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What is the best method to check for differential gene expression in large dataset? I want to identify aging differentially expressed genes

A standard pipeline for DGE would be Salmon for (pseudo)mapping + DESeq2 for statistical analysis. Salmon is one of a set of modern, fast and accurate mapping software. Requires a transcriptome to be ...
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  • 224
5 votes
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Biostatistics: Pollen dispersal directionality

(This isn't an answer, but hopefully it will help get it past the experimental design into just solving the equation.) Where did you get that α0 was not determined from their data? On p. 10 (256), ...
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  • 161
5 votes
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What are the odds of being an albino human and have Down syndrome?

Probability of independent events Assuming the albinism and Down syndrome are independent traits, then the probability of having both traits is the product of the probability of having each trait. ...
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5 votes
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Does one need to perform two Chi-square tests?

You should just have 1 chi-square test to test the hypothesis. Note that the problem is asking about F2 generation, not F1. H0 in a chi-square test is your prediction based on a model; H1 is that ...
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5 votes
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Book about ordination in ecology

I took a class in ordination methods a few months ago and found the following books helpful in better understanding the various techniques: Multivariate Statistical Methods: A Primer by Brian Manley ...
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4 votes
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Why does drinking milk lead to increased fractures?

The authors suggest a reason in their abstract: Given the observational study designs with the inherent possibility of residual confounding and reverse causation phenomena, a cautious ...
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  • 12.1k
4 votes
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Are sizes of potatoes normally distributed?

According to Evaluation of the Effect of Density on Potato Yield and Tuber Size Distribution potato tuber size was estimated using a normal distribution but they are not normally distributed They ...
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  • 943
4 votes

Long-term efficacy and absence of side effects of anti-covid vaccines

I will try here to sketch an answer starting from where @MattDMo left off. Question: How do we evaluate possible long-term side effects of a vaccine? (With specific application to the recently ...
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  • 3,772
4 votes

Beta-diversity for data with zeros

I would recommend using a Bray-Curtis dissimilarity matrix since it accounts for abundances and can handle the so called double zero problem. I'm on my commute now and so must return to this for a ...
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4 votes
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How much does dry moose scat weigh and vary in dry weight?

MacCracken and Van Ballenberge, 1987 report that pellet size varies a bit by sex and age; male pellet dry weight (all measurements are dry) averaged 1.9 grams (range 0.9-2.9), female 1.3 g (range 0.6-...
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  • 36.5k
3 votes
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Do experiences shape actions of insects? Animals?

"Simple" insects like fruit flies can learn to associate odors with food, e.g. see here for a pretty classic example. Drosophila even show some kind of depression which is acquired. Their sexual ...
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  • 695
3 votes

How to assess if biological measurements follow a normal or a log-normal distribution

Preprocessing will and should always depend upon the biology that you try to answer or discover (e.g.: There might be an experimental rationale to believe that some genes behave differently in ...
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  • 1,587
3 votes
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How to assess if biological measurements follow a normal or a log-normal distribution

From personal experience, nearly all count data whether from microarray or reads from RNAseq of some kind, requires a log transformation of the counts. Usually a small fraction is added to all values ...
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  • 1,309
3 votes
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What does the Gini index mean in a biochemical context?

The paper by Graczyk (2007) is probably relevant for you. It says that the Gini index is a measure of reactive selectivity of kinases, with values close to zero indicating no selectivity and values ...
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3 votes

Bootstrap question

If the values on the branches indeed represent bootstrap supports, they indicate the percentage of times a clade has been obtained in a set of trees computed from resamplings of a starting data matrix....
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  • 2,185
3 votes

Book about ordination in ecology

You might also want to consider: Tree diversity analysis by Kindt and Coe 2005. Freely and legally available here. Not very deep but nice and crisp introductions + its free. Numerical Ecology with R ...
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  • 31
3 votes
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How can the recurrence risk ratio be calculated?

If we look at web resources, what we will notice is that this ratio is not deployed at the family level but at the population level. In other words, when we look at a population, we can ask: What ...
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3 votes
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How many cells are there in C. elegans in each hour of its life?

The lineages provided at WormAtlas include references to the original publications. Concerning the embryonic lineage at the top of the page, the corresponding paper was published in 1983.1 Looking at ...
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  • 7,729
3 votes
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Is there a published calibration between footprint measurements to body length in moose?

Yes - I found a paper published in 1978 by Franzen et al "Alaskan moose measurements and weights and measurement-weight relationships" 1 In this paper they looked at a number of parameters ...
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  • 7,773

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