Parsimony

Biol 181 Lecture on how to use parsimony to evaluate phylogenetic trees.

[@Anthony-dy2cv]

GOD BLESS YOUR SOUL. I was searching everywhere for a video that could explain this but they were either too hard to understand or too high level for me to comprehend. But this was incredibly straightforward and motivating. Ma'am you are an amazing teacher.

[@mafnoor]

Perfect-- just the supplement I needed for my class-- thank you!

[@jessicalv6442]

Amazingly clear!!!!! Thanks a LOT! Campbell biology didn't do the explanation better than you :) You're amazing!

[@joshgialis2844]

Very informative video! Thank you for the upload Dr. Claire.

[@tatianaayala-delamatta5124]

I usually don't have issues with biology, but this stumped me in my lab. You have single-handedly saved me! Thank you!

[@soakable4500]

hi im an ap bio student, and you actually made sense of this.

[@Cinderthebeaver]

Thank you ! 10 minutes before my test and I understood the tree but not the dna sequence matchin it ! ❤

[@nupatowoch3063]

Now here is an insight one.. Appreciate your hard work

[@anwesasaha8321]

This is so beautifully explained, thank you ma'am.

[@tilakdhoble2245]

You are a Great Teacher...!! Thank you so much for this...!

[@user-hi4wh4ye5x]

Amazing job, Thanks

[@Jessica-zs7be]

Now I can explain better to students, thank you

[@hassannaser7112]

than you ,, from Syria

[@mattashley1385]

Incredible video, you made it so clear! Thank you!

[@ameerrifai4408]

thank you Dr. Claire

[@8nansky528]

I ADORE READING

[@JVishGenX]

Best explanation. Thank you so much :D :D :D

[@nobinrm]

This is so beautiful. thank u for such a great video.

[@chandamitagoswami7745]

Thankyou for the simplest explanation.

[@aruntheeban1]

Very well explained!!!

[@gautamkannan1909]

Excellent explanation !!

[@MJ-ye7dd]

This is the best👌

[@BalthazarUhsus]

great video!

[@sarahmartinez1021]

you're a great teacher!

[@aoifecartwright9915]

hi, if there was gaps in the sequence, could a site still be considered informative?

[@tallulahbelle788]

hey! This might seem like a silly question but when you are talking about the ancestral state, how can you tell what that is without having a prior understanding as to which of the species have evolved most recently? thank you!

[@dr.clairesays5104]

It's actually not a silly question at all. We often assume that the outgroup shows the ancestral trait, however, this is not a very good assumption, because of course the outgroup has also continued to evolve since it separated from the ingroup. Sometimes you can use the fossil record to determine the ancestral trait for bony features. I've simplified the building of phylogenetic trees here considerably for an introductory class, but it actually quite complicated. In reality, it usually involves large data sets, complex statistical models, and very fast computers.

[@svenakin777]

Great explanation, thank you!

[@zeynepkurt2801]

Superb !!!

[@siddhirao8328]

Wow I easily understood it thank you so much !

[@kenmagee8690]

Thank you so much !! Great explanation !!

[@archasvityagi9997]

DR. u have explained well. What about character weight when we have large no of species with their maximum available characters. I am trying with thirty morphological characters of 45 species using PAUP.

[@dr.clairesays5104]

Hi Archasvi! Sorry I didn't get back to you sooner. I'm actually not a taxonomist and I don't run analyses like the one you are describing in my research, so I am afraid I can't help you. I hope you were able to find someone to help you!

[@simbiotic24]

thank you so much for this.

[@aarons.1349]

Can I choose only 1 informative site to make the tree, even tho there are multiple informative sites I can choose from??

[@dr.clairesays5104]

In the real world you would use many, possibly hundreds of informative sites. The more sites agree with your proposed tree, the more confident you become in the tree. A single site does not provide a lot of support for a particular tree. Remember, all trees represent hypothesized relationships between taxa and we use all available data to provide support for the various hypotheses.

[@francosantin1636]

Very clear explanation :)

[@mohitbhardwaj5430]

Hello Miss! Please explain the Neighborhood joining method or maximum likelihood method

[@abdulkader7104]

min 2:30 orangutangs are the out group se we assume that they have the ancestral trait, and then we can look for shared derived traits within the in group

[@anirbanbanerjee9482]

helpful for basic idea

[@nadlinjustin8850]

Thanks for explanation, but would like anther lecture on how to Generate a parsimony network in TCS software.

[@ayaqz3144]

thank you so much

[@tarahclue6737]

Thank you

[@nancycamacho274]

So if the sequences was GGAT would that be considered Parsimony Informative?

[@dr.clairesays5104]

It depends on what the ancestral trait is. If the ancestral trait is A or T, then that data would indicate that the two species with G are more closely related. If the ancestral trait is G, then that would be non informative.

[@mousumikhatun2002]

Thank you... From India 🇮🇳

[@mayurbiotech1657]

Thnks mam, the sequence just next to the parsim informative sequence consisting of CCTT is also informative right?

[@dr.clairesays5104]

Yes, that would also be an informative site. In a real world situation, you combine data from multiple informative sites to choose the most parsimonious tree.

[@Tchotch_ke]

In the third (G T G T) why is it not 3 but 2?

[@dr.clairesays5104]

The scenario I proposed was that there was a change from T to G in the ancestor of all the apes and then a switch back to T in the Gorilla lineage. Which is 2 evolutionary changes. You could also propose that there was a change from T to G in the human lineage and another in the chimpanzee lineage. Again, that's 2 evolutionary changes. I hope that helps!

[@akr5863]

Thank You....From India

[@mianaman2842]

thanks

[@wherearetgepoank1117]

You furgot to put Jesus in the tree. That going to be the raght one, tha one with Jesus in it. Yeah I’m totally kidding, that was an amazing video. You really took a complicated subject and explained it in a very parsimonious way. Kind a meta-and very brilliant. I wish you were my genetics teacher in college.

[@niamcd6604]

EVOLUTION THEORY NEEDS URGENT UPDATES!!! YET, anyone in the academia is too scared to openly say that because of the eugenist people behind its crazy blind support for it.

[@xuanlai6446]

Is that how u r supposed to read orangutan??

[@onikarutherford7021]

I keep confusing this word with "persimmon" in my bio class 🤦‍♀️

[@arifsalmani351]

ARIF