Questions tagged [phylogenetics]

A sub-discipline of evolutionary biology which involves the study of evolutionary relatedness between different organisms based on their molecular and morphological features.

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255 views

What are some useful (starter) metrics to use on phylogenetic trees?

I'm doing a computational biology project in which I simulate evolution under different inheritance rulesets and I am generating phylogenetic trees (beautifully visualised in Python with ete3). My ...
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148 views

Is there a name for this phenomenon described in “Phylogenies and the Comparative Method”?

The figures below are from Felsenstein's paper "Phylogenies and the Comparative Method". I was wondering if there was a specific name for this effect where there is an apparant correlation that is ...
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121 views

relative-rate of evolution

I am supposed to calculate the relative rate of evolution of two sequences (human and sheep) with a chicken serving as the outgroup. The sequences are pretty long, so I will just create a short ...
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184 views

Common Ancestry of ETCs and ATP Synthase complexes

Rickettsiales are widely regarded as the ancestor of eukaryotic mitochondria through endosymbiosis. Cyanobacteria are widely regarded as the ancestor of eukaryotic chloroplasts through endosymbiosis. ...
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126 views

Parsimony (cladistics)

I don't understand how to sum the changes in a phylogenetic tree. Here for example: http://www.med.nyu.edu/rcr/rcr/course/phylo-cladistic.html How do you end up with 8 for the first and 9 for the ...
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DNA barcoding, querry regarding tree based (cluster) methods for species identification

I am working on success rate of DNA barcoding in identification of species using distance and tree based methods. Regarding distance based method, I have used Adhoc and species identifier and ...
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846 views

When did birds and mammals diverge?

Which was the most recent common ancestor between mammals and birds? Form a rapid google research I could not find good answers. This site seems to imply it was at least 250 milions of years ago. ...
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236 views

What proves that speciation is a pairwise process? [duplicate]

I have been asked this questions by many biology students and even non-biologist without a pretty straightforward answer to give. We are quite accustomed to phylogenetic trees where a common ancestor ...
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517 views

Construct Phylogeny form Edgelist

I am working on large scale biodiversity simulations and have collected a lot of data on simulated phylogenies. I have a list of child-parent edgelist species in the form: ...
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Could homoplasy occur within a clade?

Consider the below phylogeny. taxon1 and 2 are sister taxa but: - share a brown color coat - differ from their closest common ancestor (light color coat) Is this a case of homoplasy (Analogous trait)?...
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243 views

Why is traditional rank based taxomomy considered by some as logically inconsistent with phylogenetic knowledge?

Following is from wikpedia: Under the traditional nomenclature codes, such as the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and ...
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How do I generate a phylometric tree given species names?

I have a list of species. I want to put those names into a tool and get back a visualized tree that includes names of shared order, suborder, family and genus. Is there an existing tool that does this ...
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113 views

What is the difference between phylogenetic tree “construction” and “reconstruction”?

When I look through papers, there are two terms Phylogenetic tree construction Phylogenetic tree "Re"construction What is the difference between phylogenetic tree "construction" and "reconstruction" ...
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77 views

Is there a term to quantify how spread a character is on a phylogenetic tree?

Is there a term which can quantify how 'spread out' a particular character is on a tree? I want to distinguish between a character which is only restricted to a particular clade vs. a character that ...
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87 views

The phylogenetic definition of the clade Dinosauria

Up until two years ago the clade of Dinosauria was defined as all the descendants of the most recent common ancestor of Triceratops and birds. From Wikipedia: Under phylogenetic nomenclature, ...
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71 views

How can I tell if a certain marker is useful to date a phylogeny?

If I have a phylogenetic tree for a genus, how can I tell if a certain protein would be a good phylogenetic marker to use if one wanted to use a molecular clock to date the age of some speciation ...
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342 views

How to get taxonomic specific ids for kingdom, phylum, class, order, family, genus and species from taxid?

I have a list of taxids that looks like this: 1204725 2162 1300163 420247 I am looking to get a file with taxonomic ids in order from the taxids above: ...
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133 views

phylogenetic Independent contrasts with unresolved tree

I have a dataset containing morphological and performance measures of species from various groups, including insects, lizards, frogs, spiders etc, and want to analyse the relationship between these ...
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Speciation and Phylogeny of Lactobacillus

The lactobacillus, also called Döderlein's bacillus is a genus of facultative aerobic bacteria. There are several species such as Lactobacillus acidophillus and Lactobacillus reuteri. I have several ...
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175 views

Why outgroups are supposed to be ancestral?

I was reading about phylogenies and found many literatures said that outgroups contain the ancestrial trait, but why is that? Aren't they also experiencing the same amount of evolutionary time and (...
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107 views

What is the most recent well-attested common ancestor of chimpanzees and humans?

Humans and chimpanzees are related and thus have a most recent common ancestor. Of course pinning down this precise point is essentially impossible, so I'm interested in close ancestors of this most ...
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Were there any terrestrial species in the ancestry of all crustaceans?

To the exception of woodlice, Crustaceans live in aquatic (marine or freshwater) environments. Crustaceans are arthropods which is an immensely diverse taxon. Many arthropods live in terrestrial ...
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How to choose the most appropriate measure of genetic distance

I am conducting a phylogeography study of a fish species and am trying to construct a phylogenetic tree to describe population structure and ancestry. I have constructed trees using various measures ...
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phylogenetics and substitution ratios for positive selection [closed]

So very new to phylogenetics!. I've been scrambling and reading so much to get this done!!. I would like to see if one or more of the sequences I have (from a gene family) are under positive ...
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Describing trait evolution across a very small phylogenetic tree [closed]

I am very new to phylogenetic comparative methods but I want to explore the evolutionary patterns of a number of quantitative traits I have across a small sample (5) of closely related species (...
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2answers
323 views

What contributes to the variation of protein sequence across different species? [closed]

What contribute to the variation of protein sequence across different species (e.g. phenotype, environment, evolutionary pressure) and how do those factors contribute to the variation? I have tried ...
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How to quantify the Abundance of a particular gene in Bacteria and Archaea?

For 16s rDNA metagenomic analysis, do I need to do the following steps? DNA extraction-> Purification-> PCR amplification-> Clone -> Pick every single colony-> PCR amplify -> Sequence -> ...
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Plant's phylogeny tree to identify which of them are closer (genetically) with another plant

I'am trying to create a phylogeny tree from some plants, as the post's title says, to help me conclude which of those plants are closer genetically with another one plant. So let's say that this is ...
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Draw simplified phylogenetic tree for kids

I need to draw simple, phylogenetic tree for kids lecture. I am looking for an online tool where I can enter organisms (e.g., human, wasp, fungus) and get figure of a phylogenetic tree. Tree should ...
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Evolutionary distance between Canidae, Felidae, and Rodentia

Comparing the families Canidae and Felidae, which have the shorter evolutionary distance to the order Rodentia? Less sophisticatedly put, are cats or dogs more related to rodents?
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Cats, Dogs and Bears - how are they related?

What is the ancestral relationship between cats, dogs and bears? I presume they are more closely related to one another than other paraphyletic clades of mammal. Which came first? What did their ...
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138 views

How to build S16 rRNAs phylogenetic trees?

Here is what I know so far: Multiple copies are present in prokaryotes, but according to a paper by Lukjancenko el al.[1] it is enough to select the most similar ones. There are stem regions in the ...
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250 views

What is the formal terminology for two species that are “close” to each other in a phylogenetic tree?

Take for example the human and the chimpanzee, they are "closely related" species since they are "close" to each other in a phylogenetic tree. However, this terminology seems pretty informal, what ...
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How to get the file of a published phylogeny of a taxon

If an article has a published phylogeny, is it common to get the newick file with branch lengths from the authors? In order to do further research with the tree.
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Creating a Phylogenetic tree using DNA sequences [closed]

I was wondering given DNA samples, how can we create a phylogenetic tree? I mean I don't even want to have actual DNA sequence. Can I generate small samples, like reads of a length 100 or 1000 of ...
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705 views

Why are vertebrae, specifically, so important in classification?

A fundamental level of animal classification is the distinction between vertebrates and invertebrates. The vertebrata are, arguably, often classified as higher life forms than the invertebrata. But ...
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2k views

Did modern alligators and caimans come from prehistoric crocodiles?

I know that crocodilians have been here since the time of the dinosaurs. I also know that crocodiles came first. But alligators have been here for a good 37 million years. Did alligators come from ...
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229 views

Usage of the taxonomic classification “Pinnipedia”

According to ITIS the classification Pinnipedia is invalid, and it is proposed to rather use Caniformia. The later group however includes a range of terrestrial animals as opposed to the pinnipeds (...
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232 views

What are the statistical tools for distinguishing molecular analogy from homology?

Scientists have developed statistical tools that distinguish "distant" homologies from coincidental molecular homoplasy in extremely divergent sequences. What are these tools?How are they used ? I ...
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294 views

The protostome/deuterostome distinction and why it is important

As I unerstand it, at some point an embryo develops a hole; this hole continues to punch through, and eventually makes an opening at the other side of the embryo. If the original hole becomes the ...
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“50% of the variance in antisocial phenotypes is the result of genetic factors” means what?

How can i understand the following sentence: Overall, the conclusions reached by these studies have been highly consistent in showing that approximately 50% of the variance in antisocial phenotypes ...
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903 views

Is the fixation rate always equal to the mutation rate for neutral alleles?

Background A classical result of population genetic is that the rate of fixation of netreual alleles is the mutation rate $\mu$. The reason is that each generation $PN_e\mu$ mutations enter the ...
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674 views

Distance matrix with different length sequences

In a project we're doing (in python), we want to create a distance matrix for a phylogenetic tree with multiple, different length sequences. However, what we've seen so far (AlignIO in biopython, etc.)...
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204 views

How closely related are two parasites Giardia intestinalis and Trichomonas vaginalis?

How closely related (from the evolutional point of view) are parasites Giardia intestinalis and Trichomonas vaginalis? Giardia genome is about 12 Mb and its major cellular proceses are rather simple. ...
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How evolutionarily conserved are UTRs?

Coding sequences of genes have a certain degree of evolutionary conservation, so that comparisons based on sequences (BLAST, HMMER etc) can be informative. Generally speaking, the more two species are ...
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466 views

Forming a cladogram from a table of information

Can someone please give me some tips or help me build a cladogram from the following table of information? The outgroup is Lancelets and the first derived character is vertebrae, followed by Lampreys ...
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1answer
5k views

How to read cladograms/phylograms?

I understand the difference between cladograms and phylograms; the latter can show the evolutionary linkage over time. However, I am having trouble finding out which two organisms are most closely ...
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Where can I find datasets containing large phylogenetic networks?

There are many datasets out there for phylogenetic trees, one can example can be found here. However, I couldn't find something for phylogenetic networks. According to Wikipedia: A phylogenetic ...
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What is the closest relative to odd-toed ungulate?

I have seen about 3 variation of phylogenetic tree about odd-toed ungulate and I don't know which one is really updated or outdated or which one have more backed up theory First is odd-toed ungulate ...
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Estimating population divergence time with a single mitochondrial marker

Is it possible to estimate population divergence time with a single mitochondrial marker? Here is additional information for my specific case: Mitochondrial marker: Cytochrome Oxidase Subunit 1 (...