Login

Join for Free!
116898 members


what is pseudoreplicates ??

Debate and discussion of any biological questions not pertaining to a particular topic.

Moderator: BioTeam

what is pseudoreplicates ??

Postby Vision » Tue Feb 01, 2005 9:30 pm

Im having trouble understanding what pseudoreplicates is.

I have searched the net and couldnt find anything. Can someone point me to the right direction please.

And how would you define 'population units' I am having trouble finding definiton for these.


Thanks in Advance
Vision
Garter
Garter
 
Posts: 18
Joined: Sat Jan 29, 2005 4:20 pm

Postby thank.darwin » Tue Feb 01, 2005 9:33 pm

You've got me there - Does anyone know this - I would like to know to
No amount of experimentation can ever prove me right; a single experiment can prove me wrong.
-Albert Einstein
User avatar
thank.darwin
Inland Taipan
Inland Taipan
 
Posts: 347
Joined: Thu Jan 27, 2005 7:39 pm
Location: Vancouver, Canada

Postby Thenewguy » Fri Feb 04, 2005 4:32 pm

pseudoreplicates

I can only take a guess - pseudo is the Latin referring to false and replicates I guess would be self-explanatory, my question is in what context was this word? I remember learning about pseudopodia of single celled organisms like Euplotes of the hypotricha family. In my own studies I've found that the word pseudo is often attached to names of cellular components that at first seem to be something they are not.

Of course this isn’t an answer but perhaps a step in the right direction. You’ve certainly peaked my interest.
User avatar
Thenewguy
Garter
Garter
 
Posts: 7
Joined: Thu Jan 06, 2005 4:15 am
Location: Ottawa, Ontario


Postby DevGrp » Fri Feb 04, 2005 4:48 pm

Its a statisical trick frequently used in phylogenetic analysis.

http://www.icp.ucl.ac.be/~opperd/private/bootstrap.html

Bootstrapping is a way of testing the reliability of the dataset. It is the creation of pseudoreplicate datasets by resampling. Bootstrapping allows you to assess whether the distribution of characters has been influenced by stochastic effects. In phylogenetic analyses nonparametric bootstrapping is the most commonly used method. The pseudoreplicate datasets are generated by randomly sampling the original character matrix to create new matrices of the same size as the original. The frequency with which a given branch is found is recorded as the bootstrap proportion. These proportions can be used as a measure of the reliability (within limitations) of individual branches in the optimal tree.

Thus bootstrap analysis:
is a statistical method for obtaining an estimate of error
is used to evaluate the reliability of a tree
is used to examine how often a particular cluster in a tree appears when nucleotides or aminoacids are resampled


So it appears to be a way of creating new replicates from a large data set and reanalysing them to check your original result?

Not that I really understand statistics.

Would a real Statistician please step forward!
DevGrp
Death Adder
Death Adder
 
Posts: 82
Joined: Wed Jan 26, 2005 12:32 pm
Location: UK

Postby Vision » Tue Feb 08, 2005 10:56 pm

Thenewguy wrote:pseudoreplicates

I can only take a guess - pseudo is the Latin referring to false and replicates I guess would be self-explanatory, my question is in what context was this word? I remember learning about pseudopodia of single celled organisms like Euplotes of the hypotricha family. In my own studies I've found that the word pseudo is often attached to names of cellular components that at first seem to be something they are not.

Of course this isn’t an answer but perhaps a step in the right direction. You’ve certainly peaked my interest.


I too have come across the word in serveral papers and the word was mainly used in a experiment, evolution, taxonomy context. Why it caught my intrest too.

From the quote by DevGrp pseudoreplicate is basically resampling your data many times to find if it is reliable which Im sure is right.

Thanks everyone for there help!
Vision
Garter
Garter
 
Posts: 18
Joined: Sat Jan 29, 2005 4:20 pm


Return to General Discussion

Who is online

Users browsing this forum: No registered users and 6 guests

cron