backtop


Print 93 comment(s) - last by drycrust3.. on Dec 7 at 2:24 AM


  (Source: Matt Groening/Fox)
Crucial gene controls higher brain growth

To the uninformed observer it may seem baffling how geneticists, biochemists, paleontologists, and other researchers can claim that two creatures that look as different as a man and a monkey could not only be "related" but have been produced by evolution over the last couple million years.

I. It's All in the Genes

But the key to understanding evolution is to understand genetics: our body is driven by protein enzymes, which catalyze critical processes inside the body.  Many proteins share common domains.  And the blueprints to all the proteins a creature makes are stored in a special highly-ordered storage construct called DNA.

While living organisms go to great lengths to preserve their genetic code without errors like swapped sections or deletions, occassionally during the process of making sperm and eggs such an error is made.  Most errors result in infertility or death of the offspring.  But occasionally just the right combination of protein domains has accidentally been clumped together, producing something that fundamentally transforms the organism.

Researchers have finally found a gene -- perhaps the gene -- which separates humans from the ancestors they share with apes.

Humans and apes, both members of the order Primates, share 96 percent of their genetic code.  Most of the remaining 4 percent is so-called "junk" DNA; stretches of mostly inactive code.

Rhesus macaque
Humans share 96 percent of their genetic code with primates, like this Rhesus macaque monkey.
[Image Source: Mark Snelson]

Of course, junk DNA is not useless geneticists and biochemists have recently discovered.  It has been shown to in many cases play a key role in regulation of other genes' expression and other "epigenetic" effects.

But researchers had yet to discover a truly active gene that humans have that apes lack -- until now.

II. miR-941 May Hold the Key to How Mankind is so Crafty

Researchers at the University of Edinburgh in Scotland have discovered a gene called miR-941, which is only found in humans and is absent in their primate relatives.

The gene was absent not only in the gorilla and chimpanzee genomes, but also in the genomes of other non-primates, such as mice and rats.  The gene, absent in all the other critters except for man, is mainly active in the brain; particularly in areas of the brain associated with so-called "higher brain" functions.  

The gene was actively being transcribed in the regions of the brain responsiible for language learning and decision making. Researchers hypothesize that it may play a key role in abilities that are largely unique to humans, such as formulating, understanding, and preserving multiple complex communications codes (languages) and developing advanced tools (weapons, machinery).

Human brain activity
The newly discovered human-unique gene is active in areas of the brain associated with higher thinking processes. [Image Source: Neuroimages Tumblr]

Some other creatures -- gorillas, parrots, dolphins, and whales -- show different levels of sign language or spoken/sung language skills.  And chimpanzees, octupi, and other creatures have been shown to use basic implements, like sticks, as tools.  However, only humans are known to manifest these helpful survival skills in more complex manners.

Now, modern genetics may have cracked a key mystery of human evolution and explained why.

The research was published in the prestigious peer-review journal Nature Communications.

Source: Nature Communications



Comments     Threshold


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

RE: Religion and science.
By JediJeb on 11/26/2012 2:23:51 PM , Rating: 3
The only question I see that is unanswered is what came first, the workings of the inside of the cell, or the cell membrane?

If the membrane came first, how did the rest of the nucleus get inside, and if the nucleus came first(DNA,RNA, proteins, protoplasm ect) how did they stay together before the cell membrane formed?

Looking at it as strictly a chemist which I am, the odds of all the components coming together to form the first viable cell are astronomically huge to the point of it never happening, then to have a second or more form is infinitely greater. Biology is nothing more than complex chemistry, and yet it is known in chemistry that things search for the lowest energy state, which is counter intuitive to biology which requires the system to have energy for survival.

After single cell organisms began, what brought them together and made some decide to become skin cells, others brain cells, others bone cells, muscle cells, liver cells ect. Some say that invertebrates developed skeletons to better help them survive, but that would suggest some intelligence behind the development. Did a worm form a single bone and survive, then more mutations later it had more bones that somehow formed into complex shapes that joined perfectly to form a spine? The fact that some frogs develop and extra leg is not evidence of this, since the genetic code for a leg is already present in the frog, it simply deployed incorrectly to form the extra limb. A bee larva becomes a Queen when it is fed Royal Jelly to trigger the development, otherwise it becomes a worker, if a Queen can not exist without that, and a worker can not exist without the Queen to lay the eggs, which came first?

The "overwhelming evidence" to support evolution through mutation alone and refute "intelligent design" fails to explain the things that defy the ability to exist through mutation alone. For the Evolutionist to say that the first cells "just formed from a primordial soup of chemicals" without having a detailed explanation of how it could actually happen is just as bad a Creationist to say "God made it, so it happened". If Evolutionists know how the first cell formed then they should be able to duplicate that procedure and produce viable cells, which they have yet to accomplish. The conditions for forming life can not be so harsh that we can not duplicate them in the laboratory otherwise those conditions would denature the very proteins needed for life to exist. How life began is still a mystery that can not be explained in detail. Until then no one can say for certain just how it did begin.


RE: Religion and science.
By retrospooty on 11/26/2012 6:51:38 PM , Rating: 2
I agree. It all seems way too intelligently designed to have just randomly happened. So long as we agree it did happen. The more you learn about the history of Earth back into deep time and the amazing set of circumstances astrologically, geolocially that have taken place and even more so in the DNA and the attributes and mutations that come from it have all happened in amazing symmetry to bring us where we are. It all actually seems far more miraculous than a magic man just zapping it all into being. LOL.


RE: Religion and science.
By elderwilson on 11/27/2012 8:48:35 AM , Rating: 2
I personally believe in a creator, and I believe that evolution and natural selection are simply the tools used to create life. The understanding of a divine act does not diminish its divinity.

The argument you are using is called “Irreducible Complexity” which basically states that even the sub-components of simple cells are too complex to have given evolutionary advantages. Everything that you mention as being too complex to have evolved has been researched and there are very good answers for all of them (many produced by chemists).

You seem to think that in order for evolution to be valid it must start with an entire modern, eukaryotic (meaning it has an enclosed nucleus) cell. This is simply not true. Most cells on this plant are prokaryotic (no enclosed nucleus) which are significantly simpler. Spontaneous formation of phospholipids has been shown in vitro and self-replicating RNA molecules and proteins have been created. All it takes if for one self-replicating molecule to find its way into a phospholipid bubble and you have a primitive cell. Very simple cells have been created in labs which are capable of performing one or two metabolic reactions.

The problem most people have is the inability to understand the magnitude and power of time. I completely agree that the odds of chemicals spontaneously forming self-replicating molecules is astronomical, but what you don’t understand is that the timeframes evolution deals with are astronomical. Our perspective is so limited that it is difficult to comprehend hundreds of years, but evolution works with millions and billions of years.

I could refute every one of your points, but so could any 101 biology text book. I suggest that you research what you are talking about a little more before you make assertions as to what is or isn’t impossible.


"Spreading the rumors, it's very easy because the people who write about Apple want that story, and you can claim its credible because you spoke to someone at Apple." -- Investment guru Jim Cramer














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