Supplement - Chromosome 2 in the Great Apes

This video is a supplement to an earlier video, found here:
http://www.youtube.com/watch?v=3sKScsbhOd4

After a comparison with the white-cheeked gibbon chromosome, I have been able to determine when an inversion mutation occured that led to a difference between the orangutan and the other great apes on chromosome 2a.

Music: Ludwig von Beehoven, Symphony No. 6 in F major ("Pastoral"), Op. 68; V. Allegretto (excerpt - coda)

Category:

Education

Tags:

• great
• ape
• chromosome
• inversion
• mutation
• orangutan
• gibbon
• evolution

[honey2heaven]

Are you saying the whole gibbon chromosome 20 matches with the human chromosome 2 (excluding the inversion), or only um...well what percentage are we taking about here? And if it's not the full chromosome how do you propose it jumped chromosomes without a fusion?

[phoenixshade3]

No, the entire chromosome 20 is not homologous to human chromosome 2. There have been many chromosomal rearrangements in the ~20 My since gibbons and great apes diverged. Among those rearrangements are a specific type called a translocation. In a translocation, a segment of one chromosome becomes attached (usually exchanged) with a segment of another.

(more)

[phoenixshade3]

(con'd)

There are several mechanisms that can result in a translocation, but the simplest is related to the way genes on a single chromatid can recombine with genes from a homologous chromatid - a process known as crossing over.

In relatively rare cases, crossing over can occur between non-homologous chromatids. The result is a new chromosome that contains part of both original chromatids. A paper on this subject is freely available:

ww w.genetics. org/cgi/reprint/146/1/69

[phoenixshade3]

(con'd)

Thanks for the very good question... I am inspired to do a future video on the subject. (In fact, I have been planning to do an entire series of videos on genetics, so this would fit into that series quite nicely.)

[CrashCrazE13]

BRILLIANT! Are you a researcher? Or just doing this for interest?

[phoenixshade3]

Mostly out of personal interest and to stem the rising tide of ignorance. I do plan to return to school and persue a graduate degree in the near future, probably in some field related to molecular biology or genetics.

But right now, it's just for fun.

[CrashCrazE13]

Well I think it's amazing how deep someone can study into things like this. Hope you continue.

[Sinmaker1315]

I'd like to add a supplement to your comment CrashCrazE13, not only brilliant but the direct implications of chromosomal mutations and explaining away ID and creationist challenges all in a neat 3:30 min pair of videos. You even cite your source.

[honey2heaven]

And again, kind thanks for an informative response.

[ooglebydoogleby]

i wish i understood the details of that better i understand the gist but am unable to asses the quallity of the argument in any but a cursory way.