# biology

1. ### Chi Square test

Hi Guys, Hope you all are doing well. I am very new to statistics and I have a little doubt regarding what test to use to analyze my data. I have some bacterial population counts (4 bacterial species) for 4 different geographical sites. I wish to see the association between bacterial prevalence...
2. ### one way ANOVA or paired t test?

Apologies if this is a basic question, but my stats is very rusty these days! Background: I'm looking at a procedure that automates FISH analysis in a genetics diagnostics laboratory. I am currently running 7 patients that are negative controls (known normal patients) on the automated system to...
3. ### Significance between ratios?

I'm performing a survival analysis where I compare between 2 conditions in one cell type (cell type 1) vs two conditions in the other (cell type 2). The "Recovery factor" = Survival Condition1/Survival Condition2 Survival Condition1 and Survival Condition2 are each calculated from the mean of...
4. ### Combining data from different sources

Hi, I have data from two very different sources (bird counts from ships and bird counts from the shore) which aim to estimate the same population/outcome. Both data have different covariates/predictors and thus it is difficult to combine both data in the same regression model. Does...
5. ### Simspons Diversity Index

I have calculated the simpsons diveristy index for three different strata: Understorey (1-D= 0.55), Subcanopy (1-D=0.77), canopy (1-D=0.83) How can I test if there is a significant difference between these? Do I need to? Any help would be greatly appreciated. I have had a play around in...
6. ### Ploting continuous caracter on a phylogenetic tree

Hi, I study comparative biology and have been trying to estimate ancestral character states for continuous characters using the package phytools. The optimization of the characters is perfect but I have problems editing the outcome image. My main goal is that all the branches have the...
7. ### SPSS-Uneven Sample Size and choice of analysis for two fixed factors with 4 variables

Hi All, I have a dilemma that I have been trying to find the answers myself but cant seem to find anything to solve my problem. I have conducted an experiment on fish to determine the effects of temperature on gut transit rates at different times 10 temporal points (1,2,3 hours eg). I have...
8. ### Which statistical analysis to perform (Soil Science/Soil enzymology)

Hello everyone, I tried to find through the forum to get some help and it was helpful to get some information but still have some confusion so I am posting the question here. So my major is Soil science and I am looking at the effects of a product (fertilizer) on soil microorganisms and...
9. ### How do I select a method of regression analysis - Allometry - Animal Growth - Gnu

I am analysing the growth of the wildebeest or gnu. To do this I am comparing the changes in A: Body length (L), B: Girth (G) and C: Shoulder height (Sh) to Body mass (Mb). I have a sample of 42 animals, each measured once (after being culled). They range in body mass from foetuses of about...
10. ### Is biological disposition an Independent Variable? What do you think?

I've been asked to look at the relationship between child attachment in the first year of life and problem behavior at age 10. Also, whether gender of the child may predict problem behavior at age 10. So I need to design a study, (longitudinal study I would say) and get women from a local...
11. ### Possible stats tests to use?

Hi, After racking my brain not knowing what to do with my data I thought I'd give it a shot and post here, as I'm still unsure what I can do to test it. Movement count per 10 seconds and survival was measured in the same animals along entire lifespan at set time points, such that when...
12. ### Which test? - Significance of Sample Size

Hi all, (First-time poster) I'm working with tagging data for 35 tracked fish. Each fish was tracked of 3 seasons, with detections (3873 overall) corresponding to a fish entering the detection area of one of the many placed monitors within the study area. I would like to perform a stats...
13. ### Seems so simple: differences... and yet but not between groups... Which test to use?

Hi there :) This seems so simple I'm hoping someone can help me! :confused: I've got the mean values for no. effective alleles in 5 different populations of fish. So, 5 rivers, each with a mean value... and I'm trying to give a statistical value as to whether there are significant...
14. ### DNA comparison: Repeated-measures ANOVA.. but too many parameters to consider?

Dilemma about which test to correctly use... It's a tricky, confusing, one! I'm looking at DNA extraction methods, here's how I've got the data set up: Genotyped data from 80 fish, using 14 markers. So, for each fish, for 14 markers, theres two paired values per marker (2 alleles)...
15. ### I don't understand the results of my ANOVA

I have run general linear model (ANOVA) in SPSS to test whether habitat type (2 categories) and habitat disturbance (2 categories) have an effect on the size of deer groups. When I use the data for ALL groups (including mixed sex groups, all male groups and all female groups - they're all under...
16. ### What statistical test do i need to run?

Hi there folks, I'm having a little difficulty choosing what statistical test i need to run, I've conducted a series of behavioural experiments, that involves three different groups; yet all have the same individuals. The trials are based around recording behaviour both before and after the...
17. ### probability of finding 2 random DNA fragments matching between genomes

Hi all, I have a question about probabilty. There are 2 genomes (a long string, composed of 4 letters: A, T, G & C), each 150,000 bases (letters) long. Now, I generate 10,000 random fragments (sub-strings) from each genome, each exactly 20 bases long. What is the probability of finding...
18. ### ANOVA or Kruskal Walli

Hi! I have measured respiration in 3 treated and one untreated control cell line with N= 27, 25, 31 & 31. Can I use a one way anova or should I use a kruskal wallis test? Or are there any better options? Thanks J
19. ### [Multinomial Distribution] Help with applying Multinomial to a biological problem

Hello all, I need help with a stats question I'm trying to solve for a biological question. http://en.wikipedia.org/wiki/Multinomial_distribution. Say you have a town and each street on it will have a different number of bins. In each bin you will find a different number of baseballs, most...
20. ### Extract colour values pr pixel from a selected area of a photo - package suggestions?

I am a biology student currently working on my master thesis which deals with i. a. bird plumage variation. I have many photos taken in the field, and I need programming or a program to acquire the colour values per pixel of the area I am interested in. Unfortunately, I do not know that much...