Questions tagged [phylogeny]

Phylogeny is a statistical approach for reconstructing evolutionary relationships using trees

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31
votes
4answers
9k views

Why does the FASTA sequence for coronavirus look like DNA, not RNA?

I'm looking at a genome sequence for 2019-nCoV on NCBI. The FASTA sequence looks like this: ...
19
votes
1answer
2k views

Is it possible for coronavirus or SARS to be synthetic?

I have heard several conspiracy theories regarding the origin of the new coronavirus, 2019-nCov. For example that the virus and/or SARS were produced in a laboratory or were some variant of Middle ...
12
votes
3answers
153 views

What is the best way to account for GC-content shift while constructing nucleotide-based phylogenetic tree?

Let's say I want to construct a phylogenetic tree based on orthologous nucleotide sequences; I do not want to use protein sequences to have a better resolution. These species have different GC-content....
11
votes
1answer
1k views

What is the best method to estimate a phylogenetic tree from a large dataset of >1000 loci and >100 species

I have a large phylogenomic alignment of >1000 loci (each locus is ~1000bp), and >100 species. I have relatively little missing data (<10%). I want to estimate a maximum-likelihood ...
11
votes
1answer
358 views

State of the art mutation simulation software

There are many features affecting mutation probabilities, e.g. CpG mutations are 10-fold more likely than other types of mutations. Is there a model (preferably with software) which can take two ...
10
votes
4answers
3k views

How do I generate a color-coded tanglegram?

I want to compare two phylogenies and colour the association lines based on some metadata I have. I have been using ape cophyloplot but I have not had any success in getting the lines to colour ...
10
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3answers
2k views

A new paper suggests the Corona Virus has "Uncanny similarity of unique inserts in the 2019-nCoV spike protein to HIV-1" - What does this mean?

Quote: We found 4 insertions in the spike glycoprotein (S) which are unique to the 2019-nCoV and are not present in other coronaviruses. Importantly, amino acid residues in all the 4 inserts have ...
8
votes
2answers
1k views

What is 'k' in sequencing?

When a DNA sequence is sequenced, I've only ever dealt with A,T,C,G and N which indicates un-identifiable bases. However, I came across a 'k' recently and I had asked another researcher who gave me an ...
8
votes
3answers
140 views

How does one construct a cladogram of intraspecies relationships?

I have SNP data from several cultivars of rice which I have used to produce alignments, but I don't think that the usual models and algorithms used for generating phylogenetic trees are appropriate, ...
8
votes
3answers
1k views

A tool or webserver for building PSSM matrix

I have some protein sequences and I want to build a position-specific scoring matrix (PSSM) for them and then upload this PSSM to NCBI PSI-BLAST. I used CHAPS program for this pupose but uploading the ...
7
votes
2answers
454 views

How to isolate genes from whole genomes for phylogenetic tree analysis?

I have 446 whole Klebsiella Pneumoniae genomes I want to build a phylogenetic tree from. After reading about constructing phylogenetic trees it seems the only option for large numbers of genomes is to ...
7
votes
2answers
331 views

Truncating branch length values of Phylogenetic tree with biopython

I have been using biopython 1.72 to display my phylogenetic tree files. Using the function 'Phylo.draw(pars_tree, branch_labels=lambda c: c.branch_length)' to ...
6
votes
2answers
601 views

Are phylogenetic tree construction algorithms any different than general clustering algorithms?

Are phylogenetic tree construction algorithms any different from clustering algorhithms? I suspect the answer is no. Of course phylogenetic tree construction uses biological knowledge, e.g special ...
5
votes
4answers
4k views

How to create Phylogenetic Trees from fasta files in Python or R?

I have around a hundred Fasta files (and will collect several thousand) with DNA sequences and +50x coverage. What is a recommended method to construct a phylogenetic tree? Solutions in Python or R ...
5
votes
2answers
115 views

Perfect Phylogeny vs Maximum parsimony

I am searching various sources about phylogenetics. I saw some materials about perfect phylogeny and also phylogenies acquired from maximum parsimony constraint. They seem very similar to me. Are they ...
5
votes
2answers
132 views

Counting letters in phylip alignment columns with Biopython

I have been using python 3.6 and biopython 1.72 to work with protein data files. I am using a protein sequence file (phylip format), for example: ...
5
votes
1answer
847 views

Ancestry of the coronavirus 2019-nCov, WuHan city, China

In one of the answers to another question about the corona virus a link was given to this phylogenetic analysis of the virus. Can somebody assist a non-bio type here? It seems to show that the ...
5
votes
2answers
198 views

Calculate the percentage of each unique phylogenetic tree in a BEAST output

I have a nexus formatted BEAST output containing 20,000 phylogenetic trees of seven taxa. Is there any way to get the percentage of each unique phylogenetic tree contained in this output? I already ...
5
votes
4answers
233 views

tool to visualize a collection of phylogenetic trees

I have a collection of phylogenetic trees produced from clustering DNA sequences, mostly a few nodes in each cluster/tree, with several clusters of size 1. And I would like to visualize them all ...
5
votes
1answer
205 views

which NCBI tool is optimized to identify a species from a DNA fragment?

“The Iceman” was a man who lived 5300 years ago and whose body was recovered from an Alpine glacier in 1991. Some fungal material was recovered from his clothing and sequenced. Ice man : found as a ...
5
votes
1answer
410 views

MrBayes runs as single-core, but hangs when multi-core

I compiled MrBayes v3.2.7 from github, with the configuration options ./configure --without-beagle --enable-mpi. The program is called mb. I tried one of the ...
5
votes
2answers
192 views

How to plot character state changes from a presence-absence matrix on to a phylogeny

I wish to assign character state changes from a presence-absence matrix to a phylogeny. Thus I want to identify the most parsimonious hypothesis for which node and branch a given "mutation" or "change"...
5
votes
1answer
325 views

How to find which scales are available in SeqUtil of Biopython?

I am trying to analyse the hydrophobicity of a sequence using BioPython's "SeqUtil". ...
5
votes
0answers
72 views

Help with identifying disease modules [closed]

I've made an application that at this point ranks all combinations of drug pairs relevant to a biological network/graph in the order of how disruptive the outcome of deleting the targets of a given ...
4
votes
1answer
107 views

What origins for virus HIV1?

What origins for virus HIV1? This is the alignment of a small part of the POL protein of the HIV1 virus GenBank KU749412.1, with the POL protein of the Visna virus GenBank L06906.1 ...
4
votes
1answer
459 views

Interpretion of my coronavirus 2019-nCov, Wuhan, China BLAST tree?

This is the BLAST tree of the latest coronavirus out of China (from Wuhan Institute of Virology, China). It seems strange that there is so much divergence from all the other coronaviruses. Is this ...
4
votes
1answer
390 views

Help interpreting my phylogenetic tree construction of bacterial species in same genus

I constructed a phylogenetic tree using mole blast, and it created a neighbor joining tree, so I used the alignment of those sequences with mine (1-43) in mega with TN93+G+I model but I don't ...
4
votes
2answers
86 views

Do any computational phylogenetic methods enable the specification of ancestral states?

Various phylogenetic algorithms estimate ancestral states of a phylogenetic dataset. Is there a way in either maximum parsimony, distance-based methods, or Bayesian inference to indicate what the ...
4
votes
2answers
3k views

How to convert a phylogeny to a dendrogram in R

I want to convert my phylogeny into a dendrogram so I can use it with dendextend in R to produce a tanglegram. I have made some progress but I keep encountering errors, see below: ...
4
votes
1answer
162 views

Test to determine if two genes/exons share the same evolutionary histories?

In classic phylogenetic inference one is usually given various orthologue sequences of a given gene across various species. Those sequences are then multiple aligned and used to construct a ...
4
votes
1answer
543 views

In calculating the retention index, why do we use the character state with the lowest frequency?

To calculate the retention index for a phylogenetic tree, we use the following formula: $$\frac{\text{maximum number of steps on tree - number of steps on the tree}} {\text{maximum number of steps on ...
4
votes
1answer
190 views

Problems in creating desired phylogenetic tree with ggtree

I am working on haplotype data and want to make a tree out of haplogroups using ggtree. I have following data in newick format. ...
4
votes
1answer
134 views

Comparing phylogenetic models with different datasets

I'm a linguist interested in phylogenetic tree inference using language data. I'm posting here because I'm using Bayesian phylogenetic methods in my work (probably using BEAST and/or RevBayes). For ...
4
votes
1answer
178 views

Merging ssu-align alignments

ssu-align is an HMM-based MSA tool for ribosome's small subunit (SSU) sequences. It's bundled with three SSU models: archaeal, bacterial eukaryotic Approach Given a set of archaeal and ...
3
votes
2answers
378 views

PDB file downloading: pymol automation vs. manual

I automated a PDB download using a Pymol script (below) ...
3
votes
2answers
176 views

How to find/build the evolutionary history of a protein from its sequence?

I'd like to build the evolutionary history of a protein, given its sequence. Namely, given a FASTA entry how can I build an evolutionary tree? Here is the 5wxy protein as an example: ...
3
votes
1answer
548 views

Are the conclusions in "The proximal origin of SARS-CoV-2" legit?

I don't have any background in genetics and bioinformatics, so I ask you if you think that the arguments provided in the article The proximal origin of SARS-CoV-2 by Andersen et al. are convincing. In ...
3
votes
1answer
67 views

For phylogenetic tree construction from core-genome which one is preferable: amino-acid based MSA or nucleotide based MSA?

The genomes are from same species. Is it true that, in phylogenetic tree constructed from amino-acid based MSA (multiple sequence alignment) some information are lost, so for phylogenetic ...
3
votes
1answer
80 views

How to interpret UniProt allele patterns?

In creating a parser for the UniProt flat file uniprot_sprot.dat (directory) in the manual for the comments POLYMORPHISM there ...
3
votes
1answer
22 views

calculating phylogenetic tree from pairwise distances

I have a file with a 3-column list of pairwise distances: A B distance A C distance B C distance ... And I would like to calculate a phylogenetic tree for all the ...
3
votes
2answers
42 views

Consensus on how to select SNPs for creating a phylogeny when the full dataset is too large

I have got a quite large VCF file (about 20k samples with 160k SNPs after filtering for quality etc.) and I would like to get a phylogeny for it. However, the whole dataset's too large for my ...
3
votes
2answers
647 views

How to find common sequences among 6 multi-fasta files

I have 6 multi-fasta files, every of them contains ca 1500 sequences like that: ...
3
votes
2answers
746 views

How do I estimate branch length of a maximum parsimony phylogeny in R?

I am trying to estimate a phylogenetic tree in R with ape and phangorn. With pratchet() and optim.parsimony(), I can estimate a ...
3
votes
1answer
346 views

Issues installing Dendropy

I want to perform phylogenetic analysis using Dendropy. I have installed dendropy using command sudo pip install -U dendropy but when I import it in python3.5.1 it ...
3
votes
2answers
389 views

mrbayes, Sumt ; Error when setting parameter "Filename" (1)

question 1 I wanted to use sumt command after completion of mcmc run. Whenever I use, sumt Filename=infile.nex, it gives me the error: ...
3
votes
1answer
163 views

How to assess the quality of assembled .fasta genome files?

I have assembled 3 .fasta files from contigs infastq format of 3 different Homo sapiens. I would like to see if the assembled ...
3
votes
1answer
130 views

Combine multiple species trees

I have five species trees run using starBeast and Beauti. Here is a link to the paper discussing both, http://journals.plos.org/ploscompbiol/article/file?type=supplementary&id=info:doi/10.1371/...
3
votes
1answer
98 views

Coronavirus phylogeny and evolution

This new article presents the phylogeny of the coronaviruses and the placement of the new coronavirus in it. This made me wonder of what we know about the coronavirus evolution, particularly where it ...
3
votes
1answer
100 views

Is there an R package that computes homoplasy excess ratios (HER)?

I want to calculate the homoplasy excess ratio for a phylogenetic tree, for example homoplasy resulting from recombination. I am wondering if there are any R packages out there that will do this? I ...
3
votes
1answer
119 views

How many single copy gene are needed to construct the phylogenetic tree?

I ran the orthomcl program with genomes of the whole streptomyces genus(from ncbi) as input, but I only got 22 orthologous groups(streptomyces's genome size vary from 2M to 15M, which shows the great ...