What does it mean that retroviruses are orthologous?

[T_aquaticus]

It is important to remember that evolution is a tree, not a ladder:

Both the human and mouse lineage have evolved since they split off from their common ancestor. Those genomes changed throughout their history. We can still find chunks of each genome that have the same genes in the same order (i.e. synteny), but chunks have also been shuffled around. There’s been a lot of shuffling and sequence changes over time when we try to compare the human and mouse genomes. Chromosome numbers and organization are different between mice and humans, so it doesn’t make sense to compare them one to one. For that matter, chromosome numbers can be different between different mouse species, and even within the same mouse species. Chromosome numbers can even be different between humans:

The 44 Chromosome Man | Understanding Genetics

This is why “locus” is used instead of “same base”. The same locus means the spot as it would have existed in our common ancestor, as best as we can determine given the evolutionary histories of both species. Orthologous DNA is DNA that has been directly inherited from a common ancestor, not necessarily the “same base”.

[beaglelady]

How would you like to take a wonderful online course on Genetics and Evolution?
See this: Introduction to Genetics and Evolution
It’s offered by Duke University and taught by Mohamad Noor. (I think “Noor” is Arabic for “light”). He’s an engaging teacher and very personable. It’s taught in English but subtitles in Arabic are supposedly available. There is no charge, and the class starts today. I loved it and think that you will love it also. You don’t even have to buy a book, although they do suggest several titles. Help is available if you have questions. People from all over the world take this course.

Let me know what you think.

[islam_emam]

@beaglelady

How would you like to take a wonderful online course on Genetics and Evolution?
See this: Introduction to Genetics and Evolution
It’s offered by Duke University and taught by Mohamad Noor. (I think “Noor” is Arabic for “light”). He’s an engaging teacher and very personable. It’s taught in English but subtitles in Arabic are supposedly available. There is no charge, and the class starts today. I loved it and think that you will love it also. You don’t even have to buy a book, although they do suggest several titles. Help is available if you have questions. People from all over the world take this course.

Let me know what you think.

Yes, the word Noor means “light” in Arabic. I know this course, I watched only the introduction from it, unfortunately and I was too lazy to complete it, but I really want to watch this interesting course. This course has the advantage that about 40% of it is translated into Arabic, but there is a translation file that I can use With artificial intelligence in its translation, or even Google Translator for Arabic, it is very good, but I am really determined to watch it

[islam_emam]

@T_aquaticus

This is why “locus” is used instead of “same base”. The same locus means the spot as it would have existed in our common ancestor, as best as we can determine given the evolutionary histories of both species. Orthologous DNA is DNA that has been directly inherited from a common ancestor, not necessarily the “same base”.

Yes I understand, thank you very much

[islam_emam]

@glipsnort

The latter. For closely related species, like humans and chimpanzees, the two are similar, but for mouse and humans, large chunks of sequence have moved between chromosomes and the concept of the same coordinate and same chromosome don’t really mean anything. Even between human and chimpanzee, the ‘same coordinate’ really means lying in the same sequence context, since the actual lengths of sequence from the beginning of the chromosome are different. For that matter, the same is true if you’re comparing two human genomes.

Thank you very much for your effort in simplifying such informations

[beaglelady]

@islam_emam

With artificial intelligence in its translation, or even Google Translator for Arabic, it is very good, but I am really determined to watch it

Did you sign up? You can drop it at any time if you need to. If you stay with it you will learn the course material and lots of English also.

[islam_emam]

@beaglelady

Did you sign up? You can drop it at any time if you need to. If you stay with it you will learn the course material and lots of English also

Yes, I have signed up and I will complete the course because it will not only provide me with a lot of information, but also with many new terms and words.

[beaglelady]

That’s great. Isn’t Professor Noor a wonderful teacher? I don’t know if you are familiar with the Star Trek franchise, but Professor Noor is a science consultant for Star Trek Discovery.

[islam_emam]

It really looks great teacher, and you motivated me to follow the course as quickly as possible