backtop


Print 50 comment(s) - last by PaterPelligrin.. on Mar 14 at 11:14 PM


Deletions of ~510 regulatory genes in humans versus chimpanzees cause humans to lose some traits -- like "bony" penises -- and gain others -- like big brains.  (Source: Gary Wales)

Most primates have spine-filled penises to allow a male to penetrate through dried penis secretions of other males to increase the chance of fertilization when mating with females with multiple partners.  (Source: Philip Reno, Stanford University (left) Bonobos at Arkive.org (right))

The idea that removed regulatory sequences led to increased brain growth in humans was confirmed using testing in transgenic mice (the left embryo has the regulatory sequence removed -- note the blue dye in the brain cortex noting growth).  (Source: Nature/HHMI)
Mankind may have lost spiny penises and whiskers, but it gained far more -- large brains and intelligence

When you look at mankind, for better or worse, we're pretty special.  Arguably no single species has been able to reshape the planet in its image as fully as humans.  So what happened during the course of evolution to make humans so dramatically different in intelligence and abilities from even our closest relatives, say chimpanzees?

That's what a multi-school team set out to answer [press release], with advanced genetic analysis.  The team was led by David Kingsley [profile], a top geneticist at the non-profit Howard Hughes Medical Institute, and included a number of researchers from Stanford University, which is located in Palo Alto, California.

I. The Hunt for Missing Genes

While some find it hard to fathom how a set of small genetic changes could result in dramatically different anatomies -- say growing fins versus arms -- Professor Kingsley has shown in stickleback fish changes to regulatory DNA could have dramatic impact on anatomy and appearance.

Similarly some of the crucial differences between humans and chimps were found to be not actual gene additions or deletions, but rather changes to regulatory DNA.

In total 510 gene sequences can be found in chimps and a variety of other mammal species, but are "surprisingly missing" from humans.  Computer analysis showed that many of these sequence deletions were clustered around steroid hormone genes (which influence sex and anatomy) and neural development genes.

These regulatory changes were thought to grant humans unique traits like bigger brains and erect spines, and cause them to lose other traits such as whiskers and bony penises (more on that later).

But locating potentially important deletions only took the team so far.  They then needed to analyze the deletions.  Describes Professor Kingsley, "We had a team of interested graduate students, postdocs, and developmental biologists poring through this list. It was a fun detective hunt that led to lots of interesting discussions."

II. Penis "Bones" and More -- Intriguing Findings

One inactivation that produced a critical impact in humans was the removal of regulators of the gene GADD45g around neural-specific sequences.  GADD45g triggers cell growth.  So by disabling this regulatory sequence human brains were able to grow larger and more dense, allowing the rich cortex and connecting layers that give rise to intelligence, complex personality, and advanced motor learning.

Other changes revolved around a special sex-specific receptor.

Did you ever stop to wonder why cats and dogs have whiskers and we don't?  Critics of evolutionary theory have long posed such examples.  Well it turns out humans have the genes to potentially grow whisker-like features, but one of the deletions inactivates the growth.

Specifically the deletion is the removal of a regulatory sequence for the androgen receptor, which causes the protein androgen to be produced in that vicinity.  Androgen is responsible for "turning on" male-specific traits.  In this case, knocking out the regulatory sequences knocked out the "on" switch, leaving the genes for whiskers permanently inactivated (barring a rare insertion of an androgen regulatory sequence via future evolution).

A similar male-specific inactivation occurs with the androgen receptor and genes coding for penis bones.

While whiskers may be familiar material, most don't know that chimps and some other mammals actually have "bony" barbs in their penises.  These barbs aren't true bones.  Rather they are made of keratin, the hard material found in human fingernails.

The penis "bones" act as a form of natural male enhancement -- though humans seem to be getting along fine without them.  Gill Bejerano [profile], a developmental biologist at Stanford University in California was responsible for tracking down exactly how humans lost their penile "bones".

Professor Bejerano says we lost our spiny penises approximately 700,000 years ago, around the time humans split from Neanderthals.  A deletion of an androgen receptor regulatory sequence was, once again, to blame.

Increased neural development may have given rise, in part to monogamy, which in turn may have allowed the gene to become non-critical.

Why do chimps and other mammals need bony penises?  In nature, competition is always fierce.  Frequently multiple males try to fertilize the same female over the course of a couple days.  The dried secretions from the first males block entrance to latecomers, in an attempt to increase their chances of being the one to achieve fertilization.

But with a bony penis in hand, such secretory barriers pose little obstacle.  The bony penis is able to break through such obstructions with virtually no damage to the precious male member.

In humans such situations are rare, so sex organs have become simpler.  In other words, because of monogamy we don't need our penises to be spiny any more.

The paper on the changes, including the loss of the penis bones is published [abstract] in the journal Nature, arguably science's most prestigious peer-reviewed journal.

III. The Tip of the Iceberg

Even with a wealth of clues in hand, delving into these mysteries is daunting says Professor Bejerano.  At time the human genome "can be a huge, impenetrable mystery" he says, but, "[Researchers are] beginning to tease out some of the molecular differences that make us human."

A lot more "teasing"/working the data will be necessary if we hope to fully crack that puzzle, though.  The investigation into whiskers, brain development, and penis bones was only the tip of the iceberg.  

Armed with the knowledge of where deleted sequences lie in the human genome, investigators can now perform additional research (one potential target of interest: removed female evolutionary mechanisms dealing with spiny penises) to discover more regulatory differences and how they changed humans and make us look and act far different from our distant monkey relatives.

Outside of scientific interest, learning about how are brains got big and our penises less bony doesn't seem to have a lot of practical applications, but Professor Kingsley explains the methods developed will play a critical role in "solving" the puzzles of genetic-related diseases such as arthritis, cancer, malaria, HIV, Alzheimer's, and Parkinson's (some of which are caused by viruses, but in which genetic dispositions play a major role).

He states, "It's now possible to begin identifying some of the particular molecular changes that contribute to the evolution of human traits. We think that the same sorts of lists and approaches will eventually help illuminate human disease susceptibilities as well. It's a great time to be studying not only where we came from, but also how our genetic history shapes many aspects of current human biology."



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

I don't get the seven reference....
By quiksilvr on 3/10/2011 9:45:12 AM , Rating: 4
Is it regarding to lust as a Sin? Creationism vs evolution? I'm so confused! My tiny brain and bony penis don't get it!




RE: I don't get the seven reference....
By AstroCreep on 3/10/2011 9:56:25 AM , Rating: 2
"Spiney penis", as in the lust murder; the pelvic device with the spear-tip.
An (un)educated-guess, anyway.


RE: I don't get the seven reference....
By AntiM on 3/10/2011 11:19:43 AM , Rating: 2
It is believed that the number 7 has special reverence because there are 7 planets visible in the night sky. Early stargazers looked up into the night sky and thought the lights and their placement and movement had some kind of meaning. Planets move independently of the stars and therefore were considered special.
What this has to do with a spiny penis,, I don't know. If we could grow a bone in our penis, then I suppose Viagra would have never been invented.


RE: I don't get the seven reference....
By maven81 on 3/10/2011 3:39:03 PM , Rating: 2
"It is believed that the number 7 has special reverence because there are 7 planets visible in the night sky. Early stargazers looked up into the night sky and thought the lights and their placement and movement had some kind of meaning."

Huh?! Early stargazers were only aware of 5 other planets. Uranus wasn't discovered until the 18th century and that was with a telescope. (Though technically you may just be able to make it out with the naked eye if your night vision is perfect and your sky pitch black). Neptune was discovered in the 19th century mathematically... So that makes no sense.


RE: I don't get the seven reference....
By AntiM on 3/10/2011 4:19:52 PM , Rating: 2
quote:
Huh?! Early stargazers were only aware of 5 other planets.


True,, I should have said heavenly bodies, 5 planets plus the sun and moon. That's why we have 7 days of the week... SUNday, MOONday, (or monday) ....


RE: I don't get the seven reference....
By Souka on 3/10/2011 5:10:36 PM , Rating: 2
I don't recall a MARSday :)


RE: I don't get the seven reference....
By joeRocket on 3/10/2011 6:04:39 PM , Rating: 2
Well in French it's a little more apparent:

Lundi - Monday
Mardi - Tuesday
Mercredi - Wednesday
Jeudi - Thursday
Vendredi - Friday
Samedi - Saturday
Dimanche - Sunday


RE: I don't get the seven reference....
By kingius on 3/11/2011 9:58:14 AM , Rating: 3
It is actually something a little different to that...

Sunday (Sun)
Monday (moon day)
Tuesday (Tyr's day, the lord of battle)
Wednesday (Wodin -> Odin's Day, the all father)
Thursday (Thor's day, the midguard serpent's foe)
Friday (Frigg's day, the cloud spinner)
Saturday (derives from Sabbath)


By Kurz on 3/12/2011 10:32:14 AM , Rating: 3
Well both are valid.
Depends which culture you come from.


wait wait wait
By InvertMe on 3/10/2011 10:16:21 AM , Rating: 2
My penis isn't supposed to have a spine on it?




RE: wait wait wait
By tastyratz on 3/10/2011 10:26:49 AM , Rating: 3
Does that mean that if this gene turned back on, chiropractors would be the new hooker?


RE: wait wait wait
By kattanna on 3/10/2011 11:31:17 AM , Rating: 4
i had a friend way back in high school that was sure that a bone literally came into the penis and thats what caused it to become erect. because, as he put it.. "thats why they call it a boner"

nice guy though


RE: wait wait wait
By FITCamaro on 3/10/2011 2:20:36 PM , Rating: 2
/facepalm


You just couldn't resist could you?
By Hulk on 3/10/2011 4:32:33 PM , Rating: 2
"But with a bony penis in hand"




By YashBudini on 3/11/2011 12:21:33 AM , Rating: 2
It looks like parents may have right all along when they said, "Don't do that, it will fall off."


What makes Humans Special
By powerover9000 on 3/10/11, Rating: 0
RE: What makes Humans Special
By Parhel on 3/12/2011 12:07:29 AM , Rating: 2
Also, humans can go dual class without an experience point penalty.


monogamy?
By wushuktl on 3/10/2011 10:38:11 AM , Rating: 2
I feel like hygiene and cleanliness would make more sense than monogamy in terms of leftover material




Whoa
By Azethoth on 3/10/2011 11:45:23 AM , Rating: 2
I demand my spiny penis back!




Uhhhh whaaaa?
By YashBudini on 3/11/2011 12:14:59 AM , Rating: 2
quote:
But with a bony penis in hand, such secretory barriers pose little obstacle.


Right, but getting from your hands to the egg presents it's own set of obstacles.

Man, talk about a Freudian slop, err, slip.




Nature may have met its match
By YashBudini on 3/11/2011 12:18:46 AM , Rating: 2
quote:
In other words, because of monogamy we don't need our penises to be spiny any more.


So Liz Taylor and Madonna may in fact eventually lead to the return of the little boners?

And let's not forget " Barb Wire" Pamela Anderson.




Bone Vs. Size
By bleekii on 3/11/2011 11:10:05 AM , Rating: 2
I just want to point out to anyone who is feeling bad about missing a "bone" in their penis, the human penis is 3x larger that other great apes on average.




Bones or spines?
By Parhel on 3/12/2011 12:19:03 AM , Rating: 2
You confused me with all the references to "bones" and "bony." There is no penis bone. It's tiny cactus-like barbs on the outside, like a cat has. Somebody slept through penis class.




Jason, what relevance is this topic?
By Dorkyman on 3/10/11, Rating: -1
RE: Jason, what relevance is this topic?
By kattanna on 3/10/2011 11:56:21 AM , Rating: 1
quote:
Perhaps your next article could examine fecal stool samples and why human samples are brown and firm while others are more like pellets and yet others are watery.


diet and eating habits are the key

and this article makes PERFECT sense when you understand its true intent. page views. it has just enough science/tech to be somewhat relevant, but more importantly it is a topic SURE to drive rants, aka posts, and therefore page views.


By SKiddywinks on 3/10/2011 6:12:03 PM , Rating: 1
Neither of you found the fact that with a simple dose of regulatory sequences, we could give people whiskers?

April Fool's day, here I come.


"Surprisingly missing"
By kingius on 3/10/11, Rating: -1
RE: "Surprisingly missing"
By PaterPelligrino on 3/10/2011 10:40:44 PM , Rating: 3
I hear you babe. I get your meaning. I catch your drift.

From the article:

quote:
Did you ever stop to wonder why cats and dogs have whiskers and we don't? Critics of evolutionary theory have long posed such examples. Well it turns out humans have the genes to potentially grow whisker-like features, but one of the deletions inactivates the growth.


At first glance, it might appear difficult to understand why Yahwei would give us the genes to grow cat-like whiskers and then not activate them. What's that all about you ask.

Well to those godless heathens who will see this as yet more proof that we share a common evolutionary ancestry with other creatures, let me just say right up front that Yahwei has written this inactivated DNA into our genetic code to test our faith. Like what he does with fossils, he deliberately leaves misleading info lying around so that only those of faith will make the difficult effort to overcome doubt and prove themselves worthy of His love. After all, if the fossil and DNA evidence didn't openly contradict the biblical narrative, it wouldn't be necessary to have faith. The test that He demands of each of us is that we chose Him in spite of the evidence.

So rather than threaten my unshakable faith in the literal truth of the biblical narrative, this latest scientific discovery only serves to confirm my belief in our Sacred Text. In fact, with each additional bit of contrary evidence, my belief is only strengthened!

Oh glory hallelujah can you feel the buzz!


RE: "Surprisingly missing"
By kingius on 3/11/2011 10:05:51 AM , Rating: 2
The point that you seem to have missed is that the sequences are not there, so they are assumed to be deleted. That sort of logic would not stand up in court. 'I couldn't find the loot, so he must have destroyed it! It was him, he's the robber, obviously!'

As an aside, here's a quick request, can we have less Biblical references please. Your solitary god has no place in this conversation.


RE: "Surprisingly missing"
By PaterPelligrino on 3/11/2011 7:51:20 PM , Rating: 2
The evolutionary significance of the above study lies in the fact that there exists in the human genome the same DNA found in other species for producing such non-human traits as cat-like whiskers. What distinguishes us from those whiskered species is that we lack the genetic switch to activate those genes and actually grow the whiskers. Obviously the control DNA has been deleted/inactivated; what else could possibly explain the existence of the whisker gene in the human genome - why would we even possess that gene?

Darwin's elegant theory works perfectly here: the existence of the whisker gene proves our kinship to other species; the lack of the on-switch explains how we came to differ from those species. No doubt, more such non-expressed genetic material linking us to other species will be found in the fullness of time; after all, the referenced study is just the first to explore this approach.

If evolution functions as claimed (tho you and I both know - wink, wink, nudge, nudge - it's all bollocks), this makes perfectly good sense. Evolution is driven by random genetic mutation. A chance mutation in the regulatory DNA would have drastic consequences. Most of these simple mutations would prove deadly, but very occasionally, a non-expressed gene would have benefits that would increase the chances of survival. Accordingly, the disappeared regulatory DNA would deactivate/disappear and the stranded (whisker) gene would be left behind as a kind of genetic smoking gun.

quote:
The team found 510 segments that are present in chimps and other animals but missing from the human genome. Only one of the missing segments would actually disrupt a gene; the remaining 509 affect the DNA that surrounds genes, where regulatory sequences lie


The article states that the researchers knew the precise location of the deleted regulatory DNA, so I suspect there were other methods not mentioned in the above summary that were used to identify the deleted info. Most likely the full Nature article has more to say on that topic.

But, as I said in my prior post, all this counter-evidence is just Yahwei fk'g with our heads and testing our faith - the True Believer will not be swayed. (Give me the secret creationist handshake.)


RE: "Surprisingly missing"
By kingius on 3/14/2011 11:44:56 AM , Rating: 2
Basing your argument on a supposition is not a good idea. Unless the researchers can demonstrate what they are saying (read - prove it) then it's just words, ideas and empty air.

It's high time we demanded proof of these claims, as big as they are. If this were aliens being discussed, many would be saying 'extraordinary claims require extraordinary proof'. I don't agree with that sentiment - all facts should be equal - but I do want some semblance of proof from those who make grand claims and want them to be taken as being true.

I see nothing in your post to say that you are equally diligent, just a lot of biblical jokes that probably passes for playground humour these days. If nothing else, consider this; the fool takes what others state at face value.


RE: "Surprisingly missing"
By PaterPelligrino on 3/14/2011 11:14:49 PM , Rating: 4
quote:
Unless the researchers can demonstrate what they are saying (read - prove it) then it's just words, ideas and empty air.


Ah yes, proof. We all know how important proof is to the creationist. So remind me again, where exactly is the proof for all the "words, ideas and empty air" that is the Bible?

quote:
It's high time we demanded proof of these claims, as big as they are. If this were aliens being discussed, many would be saying 'extraordinary claims require extraordinary proof'. I don't agree with that sentiment - all facts should be equal - but I do want some semblance of proof from those who make grand claims and want them to be taken as being true.


Bushes that burn and talk, that a supernatural being no one has ever seen created the world and us in his image, that Yahwei even exists at all, those are certainly the kinds of claims that would require convincing proof - so how about you give us some of that proof you creationists value so highly. Maybe the believers in Christianity's many competing religions would change sides if presented with a little of that proof. A world not divided by waring religions would be nice don't you think? So convince us.

quote:
If nothing else, consider this; the fool takes what others state at face value.


Absolutely priceless. A creationist - someone who thinks that everything written in a 3000 yr-old collection of tribal creation myths is word for word true - telling us that "the fool takes what others state at face value." You're only a Christian because of when and where you were born. If you were Saudi you'd be a Muslim, Tibetan a Buddhist, sub-continent Indian most likely a Hindu, etc., etc. The religion that is so central to your very idea of yourself is something you've been spoon-fed by the society in which you happened to be born.

The genetic material for cat-like whiskers is there in our genome - that's a fact. Even tho it's there, we don't have whiskers because the genetic material is not activated. It's not activated because the regulatory DNA, the on-switch that activates that info, is not there. If it weren't missing, we would grow the whiskers. The only possible explanation for the existence of whisker DNA in our genome is that we are descended from creatures who did grow those whiskers. Now that I've shown you how to think, anything else I can help you out with?

You're an idiot kingus, and like all creationists, a hypocrite as well. You demand absolute proof from the scientists, demand that every tiny detail be accounted for with mathematical certainty, pigheadedly refuse to see all the proof that you are given, yet naively swallow all the superstitious, self-important drivel from the creation myths of a tribe of bronze-age goat herders. You blindly accept all that biblical nonsense, and demand respect for your creed to boot, while you yourself deny the equally dumb gods of all the competition. You live in a airtight, bubble-world of circular reasoning and haven't the smarts to realize how dumb you look when you pontificate that "the fool takes what others state at face value".


Monkey descendents
By Alaa on 3/10/11, Rating: -1
RE: Monkey descendents
By kattanna on 3/10/2011 11:28:54 AM , Rating: 2
quote:
No bigger brains for them too


our ability to cook our food is what really allowed our brain to grow to its current size. the brain uses a lot of energy, but so does digestion of our food. cooked food requires less energy for digestion, so that excess can be used elsewhere. and in our cases allowed our brain to grow.


RE: Monkey descendents
By StevoLincolnite on 3/10/2011 11:38:56 AM , Rating: 5
quote:
and in our cases allowed our brain to grow.


For most people anyway.

/joke (maybe)


RE: Monkey descendents
By MartyLK on 3/10/2011 12:02:57 PM , Rating: 3
You are partly correct. It was the jaw muscles that played the role in allowing a larger brain in humans. We developed weaker jaw muscles, which attach and go around up and over the head, that allowed the skull to grow and the brain to evolve to an ever larger capacity. These weaker jaw muscles made cooking food more favorable because cooked food is easier to chew, requiring less muscular effort. Since the jaw muscles were weaker, the force they applied to the skull was sufficiently less than we see in primates...apes and gorillas...and the reason apes and gorillas don't grow larger brains.


RE: Monkey descendents
By kingius on 3/11/2011 10:10:00 AM , Rating: 2
These explanations don't make sense to me. Cooks and chefs have no bigger brains than any one else, and those with the strongest jaw muscles are the extroverts, yet their brains are no larger than the introverts... so I'm not seeing any evidence to back up these grand, sweeping claims.


RE: Monkey descendents
By mooty on 3/10/2011 4:25:51 PM , Rating: 1
The brain uses depressingly little energy actually.


RE: Monkey descendents
By Iketh on 3/10/2011 5:17:08 PM , Rating: 3
speak for yourself


RE: Monkey descendents
By SKiddywinks on 3/10/2011 5:38:59 PM , Rating: 2
I remember reading in psychology that the brain uses ~20% of the body's energy needs. Hence it has to have been a benefit, despite the energy use, otherwise evolution would have seen fit to chuck it.

Some google-fu also turned up some interesting facts. Such as the brain consumes energy at 10 times the rate of the rest of the body per gram of tissue.

Here you go:

"Although the brain accounts for less than 2% of a person's weight, it consumes 20% of the body's energy."

Drubach, Daniel. The Brain Explained. New Jersey: Prentice-Hall, 2000.


RE: Monkey descendents
By YashBudini on 3/11/2011 12:23:43 AM , Rating: 1
quote:
The brain uses depressingly little energy actually.


Looking at the brain scans of Faux News viewers are we?


RE: Monkey descendents
By Kurz on 3/11/2011 8:11:34 AM , Rating: 2
Nice try Yashbudini... One day you'll make a valid argument.


RE: Monkey descendents
By FITCamaro on 3/11/2011 8:51:32 AM , Rating: 2
Just ignore the troll.


RE: Monkey descendents
By YashBudini on 3/11/2011 12:49:38 PM , Rating: 1
Plenty ignore you.


RE: Monkey descendents
By Kurz on 3/12/2011 10:37:00 AM , Rating: 2
I really wish there was an ignore feature...
you really are a waste of internet space.


RE: Monkey descendents
By YashBudini on 3/14/2011 7:38:14 PM , Rating: 2
Not all of us can be misanthropes, but happy to disappoint you.


RE: Monkey descendents
By Wolfpup on 3/10/2011 1:04:38 PM , Rating: 2
Err...we are those descendants.


RE: Monkey descendents
By maven81 on 3/10/2011 3:32:49 PM , Rating: 2
"If we are the evolution/descendents of monkeys"

We are not! We and the monkeys share a common ancestor that we both descended from.


RE: Monkey descendents
By maven81 on 3/10/2011 3:32:58 PM , Rating: 3
"If we are the evolution/descendents of monkeys"

We are not! We and the monkeys share a common ancestor that we both descended from.


“Then they pop up and say ‘Hello, surprise! Give us your money or we will shut you down!' Screw them. Seriously, screw them. You can quote me on that.” -- Newegg Chief Legal Officer Lee Cheng referencing patent trolls














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki