An Evolutionary Marvel

An Evolutionary Marvel

• Although birthday girl Kimberly Chapman will think of Hugh Jackman,  I must reluctantly clarify that the title refers to the Y chromosome. Yes, that stump of chromosomal appendage endowed with the SRY gene ( So why the change of heart?

Alpha Male: Because the Y chromosome carries much less variation than any other chromosome, it was theorized that only a few alpha males (one male for every four females) passed on their genes. This would mean that men have fewer ancestors than women. How does one test this theory?

Not so skewed: Scientists looked at genetic variations in eight African and eight European men. Then they ran computer simulations with various models of skewed ratios of reproducing males to females over hundreds of thousands of years of evolution. The best fit of data was four females to three males. So why the limited variation in Y chromosome DNA?

No junk in this trunk: The models showed that evolution weeded out the variation, reducing much of the Y chromosome to highly repetitive strings of letters. One possibility is that this is a clever way of making repairs and preventing the Y from becoming lost altogether. Time will tell.


#HappyBirthdayKim   #ScienceEveryday  

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70 Responses to An Evolutionary Marvel

  1. Rajini Rao says:

    Vivi Rr , what does that have to do with anything on this post?

  2. Rajini Rao says:

    This woman would never call men dogs, Roelf Renkema .

  3. Rajini Rao says:

    We have quite a few Hugh Jackman aficionados on G+; I think the truth will out 🙂

    Yes, lean mean machine indeed Gnotic Pasta .

  4. Rajini Rao re:”Don’t mean to insult dogs.”

    I’ve had you circled for a long time, and I’ve loved reading your posts (great science). But I have to point out that you went from reprimanding someone who said something about seeing Hugh Jackman in a gay role to joking about men being lower than dogs. I just wanted to point out the irony.

  5. Rajini Rao says:

    You interpreted the strikethrough to mean that, Christopher Butler . Perhaps, that’s the irony 🙂

    I like men and I like dogs. It was a joke.

  6. Kawthar A says:

    Sorry Rajini Rao i didn’t read anything!! O_o 

    He has the most beautiful  Y chromosome i have ever seen!!!!!!

  7. Rajini Rao says:

    Go back and read the post, Kawthar AL ABDALLA !! 😛


  8. Kawthar A says:

    😛 in a 10 mins maybe!! 😛

  9. Rajini Rao says:

    I understand, thanks for explaining Vivi Rr ! 🙂

    Off topic comments are welcome on my posts.

  10. I don’t mean to be a wet blanket, honestly. I’ve had you circled for a long time because I enjoy your posts so much. I realize you we’re joking. But one of the more unfortunate realities is that what would be considered passively aggressive sexism toward women is fine when directed at men. Which is why “feminism” is an acceptable point of view, but not, well, “masculinsm”. 😉

  11. Rajini Rao says:

    Thanks, Christopher Butler . Sorry to offend. I’ll edit that comment 🙂

  12. Rajini Rao says:

    Roelf Renkema , the Y chromosome is truly an evolutionary puzzle. Why does it have so much palindromic and repetitive DNA and why has it reduced so much in size, for example. Viewed in the light of evolution, it must make sense but we don’t know what that is!

  13. Kawthar A says:

    Seriously speaking, that’s an interesting share, thanks Rajini Rao 🙂

  14. Very interesting… and I didn’t even have to go to class 🙂

  15. Rajini Rao says:

    Roelf Renkema , external factors certainly factor into evolution and are a major force for change. Men leaving for war could explain skewed ratios. I’m not able to connect that to the Y chromosome losing genetic baggage, though. At a molecular level, I mean. I’ll keep thinking about it 🙂

  16. Rajini Rao says:

    Rashid Moore , “Madam, I’m Adam” would be fitting to this post, right? 

  17. Rajini Rao says:

    I may have‘ed it when I was on the ScienceSunday page and linked it to a curator-only page somehow. Replaced with a new short url, thanks.

  18. Kawthar A says:

    this post keeps popping up in my stream! 🙂

  19. Rajini Rao says:

    “The SRY gene evolved from the SOX gene” – can’t make this stuff up. Oh the endless puns. Please stop me, someone. For the record, I blame Hugh Jackman for making so many of us say things we don’t mean on this thread 😛

    Edit: darn, can’t even type straight on this thread.

  20. Rajini Rao says:

    SRY, Kawthar AL ABDALLA . It’s Feisal Kamil ‘s fault.

  21. Kawthar A says:

    I need to concentrate on something! 😛’s your fault now, i will not take your side anymore!! Feisal Kamil 

  22. Kawthar A says:

    i knew it that Tee hee was on the way :p

  23. Matt Kuenzel says:

    Fascinating. I was going to write a post on an interesting result showing non-DNA inheritance (is this still called ‘epigenetic’?) from the father. Here is the key paragraph, Consider the results of an experiment Nadeau and his colleague Vicki R. Nelson [at CWRU] published last August. They created an inbred strain of mice and then compared two sets of females that were genetically identical except for one small difference: one set had a father whose Y chromosome came from another strain of mouse and contained a different set of genetic variants. That shouldn’t have affected the daughter mice at all, because females don’t inherit the Y chromosome. But the presence of that uninherited DNA in the previous generation exerted a profound effect on many of the more than 100 traits tested in the two sets of female offspring, whose own DNA was exactly the same. These results, Nelson and Nadeau concluded, suggest that “transgenerational genetic effects rival conventional genetics in frequency and strength.”

    PS: I really, really want to read this article but can’t access it and the author has not responded to my request.


    Could you help? 

  24. Kawthar A says:

    LOL 😉 Gnotic Pasta 

  25. Is this the reason why some women are of the opinion that all men are the same ? 😉

  26. Mary T says:

    I need to stop swooning and read the article 😛

    Kawthar AL ABDALLA LOL!

  27. Mary T says:

    I am not awake.  Can;t get past Hugh Jackman.  Sorry, not a morning person 😛

  28. Kawthar A says:

    lol morning dear! ❤ Mara Rose you just need more 10 mins! :p

  29. Mary T says:

    Good Morning, Dear.  I need more caffeine and more sleep.  Up early, for me, to take Izzy (my German Sheperd) to the vet for her vaccines.

  30. Kawthar A says:

    Have a peaceful day then! 🙂

  31. Mary T says:

    Feisal Kamil yes, poor Izzy, she doesn’t like getting poked :(.

    Kawthar AL ABDALLA I will come back home and take a nap.  I love my sleep!  You know how late I stay up!  I’m bad.

  32. Mary T says:

    Thanks Feisal Kamil Nite, Nite ❤

  33. Kawthar A says:

    Yes i do know 😉 Mara Rose 

    Nite (2) Feisal Kamil 

  34. Rajini Rao says:

    Matt Kuenzel , I’ll email you the pdf of the PNAS paper in a bit.

  35. Rajini Rao says:

    Roelf Renkema , there is evidence that Y has lost material since it diverged from the X chromosome. The link in my post is a starting point, but here is a good article:

  36. Hehe nice… all I can think of is Feisal Kamil’s silly SRY comment 😛 

    That and the mtDNA evidence for mapping human migration… But this is an awesome post, thanks for bringing it to my attention Rajini Rao !

  37. Rajini Rao says:

    Cheap excuse to post some Hugh Jackman, but all for a good cause (Kimberly’s favorite as well as Y chromosome conundrums) 😛

  38. LOL, since my wife is a bio grad, she and I often have some ridiculous awesome punning on the Y chromosome 😛 

    But I do love the connection – Hugh Jackman and the Birthday post 🙂

  39. Rajini Rao says:

    You have to admit that is one area where guys fall short 😀

  40. LOL yes, well if you have to respond to “So that’s why all you guys ask why for everything” it degenerates and rapidly goes downhill from there 😛

  41. I finally found this deep in the hash search, Rajini Rao, so I’m glad you mentioned it elsewhere because with those exploding notifications I otherwise would’ve missed it!

    And I’m hesitant to comment because right now it’s sitting at 69 comments and I incredibly immature amused to see that number under Mr. Hot Stuff there. ;D

    But I screencapped it.  >:D

  42. Rajini Rao says:

    Haha, Kimberly Chapman gets an awesome awful demerit as a birthday gift ;D

  43. Mary W. says:

    Boy I have missed out on some Hugh Jackman fun! What a gorgeous photo!

  44. Mary W. says:

    Happy Belated Birthday Kimberly Chapman 🙂

  45. Kawthar A says:

    Hello Mary Owens how are you doing dear!?

  46. Mary W. says:

    I blame Gnotic Pasta for my bad cold (cough)! Seriously, though…still facing some challenges but “hangin’ in there “… Thanks for asking Kawthar AL ABDALLA.

  47. Kawthar A says:

    lol we usually blame Feisal Kamil for everything, but we can blame Gnotic Pasta this time 😉

    Hope you feel better now 🙂 Mary Owens 

  48. Kawthar A says:

    btw..thanks for commenting on this post, enjoying my coffee now 😛 Mary Owens 

  49. Rajini Rao says:

    Isn’t it great that every time someone comments here we get to see Hugh Jackman learn about the marvelous Y chromosome, again?

  50. Kawthar A says:

    😀 thanks Rajini Rao again! 😛

  51. Rajini Rao says:

    You’re the best, Dan! 😀

    (I’m really not going to get any work done at this rate).

  52. Kawthar A says:

    Thanks! 😛 it’s shopping time, and..uhm…thanks 😛

  53. Rajini Rao says:

    Depends on whether Hugh likes the ‘stache Rashid Moore 😉

  54. Ohhh sheesh I just realized he’s clean shaven here 😛

  55. Rajini Rao says:

    Can someone put shades on the guy? Those big brown eyes are distracting me.

  56. Rajini Rao says:

    Great, send some over Feisal.

    Must. Look. Away.

  57. Ummm I get distracted easily 😛

  58. Mary W. says:

    How can one guy be soooo talented, well spoken, classy & gorgeous?!!! Before I die, I gotta meet Mr. Jackman! I’ll just settle with a peck on the cheek!

  59. Will the real Hugh Jackman please stand up???!!!

  60. Kawthar A says:

    🙂 <=== just an innocent smile O:-)

  61. Kawthar A says:

    What do you mean python !? 😛 Feisal Kamil 

  62. Feisal Kamil We can’t all bump him at the same time.  We need to pace it out or it’ll get too crowded.

  63. Lacerant Plainer He can’t stand up.  Not with what we’re all doing with him…

  64. Mary T says:

    Hi Kawthar AL ABDALLA I can explain about the Python, it refers to Monty Python, the British comedy group.  Here’s a link:

    Feisal Kamil 

  65. I think he’s fake Kimberly Chapman the only thing which will convince me is if Hugh Jackman comments here. (Tries to use reverse psychology).

  66. Mary T says:

    Feisal Kamil You are most welcome, hehe!

  67. Lacerant Plainer the Hugh on here is clearly a PR person.  And almost certainly has notifications set to Circles Only.

  68. Hmmmm that sucks Kimberly Chapman 😦

    Feisal Kamil, lol I know, it was quite an amateur attempt, but sometimes the most ridiculous things work 😛

  69. Jonas Blom says:

    Awesome post.. Y is rational like the male brain 😉 winning! 

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