BIOL2022 L22 nMDS and hypothesis testing

Label the steps appropriately (please).

Species diversity indexes: Different diversity indices emphasise different things. Two examples are the following. Which emphasises what?

In either the Simpson’s index or the Shannon-Weiner index, despite their differences, they both have high index values if:

In a(n) [blank_start]____________[blank_end], a [blank_start]________[blank_end] stress value means the model is good.

In a Bray-Curtis dissimilarity matrix, a low number means:

ANOSIM is ANalysis Of SIMilarities. Retains philosophy underpinning [blank_start]________[blank_end], driven by [blank_start]________[blank_end]. Hands [blank_start]________[blank_end] designs best. [blank_start]____________[blank_end] permutation test combined with randomisation approach to generate significance levels (Monte Carlo tests) Null – no difference in assemblage composition [blank_start]________[blank_end] sites.

Steps for ANOSIM: 1. Test statistic – reflects difference among sites to differences within sites. Based on rank similarities in the underlying triangular matrix, generates [blank_start]____________[blank_end]. 2. Recompute [above] under permutations of sample labels. If null is true there should be little change to [above] if labels arbitrarily assigned. 3. Significance value – refer the observed value of [above] to permutation distribution. If it is unlikely (<5%) to fall in this distribution, reject null H

Which statistical test works with any distance measure that is appropriate to the data, and uses permutations to make it distribution free?

Which statistical test calculates % contribution of each species to the dissimilarities between all pairs of sampling units in different groups and % contribution to similarities between all pairs within groups?

Which one is capable of working with more complex designs?