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

By JPForums on 11/29/2012 11:01:30 AM , Rating: 2
It seems some people around are confused about what Scientific Theory and Scientific Law are as well as the purpose of each. Wikipedia does well enough for a basic refresher.

Scientific Law
http://en.wikipedia.org/wiki/Scientific_law

Scientific Theory
http://en.wikipedia.org/wiki/Scientific_theory

Scientific Hypothesis
http://en.wikipedia.org/wiki/Hypothesis

quote:
A law is a statement based on repeated observation that describes an aspect of the natural world.
Yes.
quote:
It has no predictive power.
No. A law is demonstrable, always repeatable under the same conditions, and implies a cause effect relationship. Laws are constrained to the conditions under which they are observed. Laws applicability can be expanded when observed to be true under new conditions. If new data legitimately contradicts the law, it may be falsified. It has great predictive power in the sense that you can rely on the fact that if you affect the exact same conditions, the same result will occur. Otherwise the law would be falsified.

quote:
A theory is a statement based on repeated observation that explains an aspect of the natural world.
Yes.
quote:
It makes predictions about the rest of the natural world outside the observed circumstances.
No. Predictions are made based on the theory to test and verify the accuracy of the theory. Let me say that a different way. It has no predictive power. If you could affect the conditions of a theory and observe the result, thus demonstrating reliability, it wouldn't be a scientific theory. If observations are made that contradict the theory, it may be adapted to fit the new data or discarded for a theory that more closely fits the facts. Scientific theories are expected to change from their original conception.

Point of interest: Laws may be observed in the process of testing theories.

quote:
Kindly note that a theory is stronger than a law.
It's not. It is more comprehensive than Scientific Law, but it is also not both observable and repeatable; thus it is less reliable. It is therefore neither stronger nor weaker than Scientific Law. It simply serves a different purpose. Choose the tool appropriate to what you are trying achieve.
quote:
In fact, if a theory is proven false in some circumstances it will be downgraded to a law for the circumstances in which it is proven false.
No. No. No. If a scientific theory is contradicted, the theory is adapted to fit the new data or supplanted by a theory that more closely matches the currently available data. Scientific laws are observable and repeatable. Theories, whether true or false are not both observable and repeatable. They therefore cannot become a law unless for some reason they becomes so. Even then, it is more likely that a small portion of the scientific theory becomes a law or several laws as scientific theories are comprehensive, where scientific laws describe singular relationships. Furthermore, if anything is proven false, it fails the repeatable requirement. So a "false" scientific theory will never be "downgraded to law".

quote:
The reason for the stronger statements with predictive power being labelled theories is because science is obsessed with being correct.
Scientist have an obsession with explaining the world around them. I've seen far more excitement over contradictory observations from scientists than another run of supporting observations as it generally means they've found something new. As a side note, a real scientist will adapt theories to support facts rather than adapt facts to support theories.
quote:
Laws are laws because they make no prediction and are therefore entirely verifiable.
Scientific law starts out as a scientific hypothesis or in other words a testable explanation for a phenomenon. To be testable, you have to be able to define what results would prove or disprove the explanation. You are, therefore, making a prediction that may be proved true or false (true in the case of scientific law). It is not prediction that separates scientific law from scientific theory. It is observability and repeatability.
quote:
It is a very good theory because what it predicts has been shown in every single fossil discovered and in the anatomy of every living being on the planet.
It is actually a very bad theory in its current form as it selectively ignores a preponderance of data. To give a few examples: The fact that measurable levels of carbon14 has been found in fossils that are supposed to be hundreds of million years old. The fact that the supposedly immutable radio radiometric dating methods result in vastly different aging for rocks that should be similarly aged in the grand canyon. The fact that the criteria Darwin himself proposed by which the theory of evolution could be contradicted was actually observed in several places (I'll mention the Flagella). These are just a few of the holes in the Theory of Evolution. Nonetheless, the strength of a scientific theory is measured by its ability to make falsifiable predictions with respect to the phenomena it tries to explain. The fact remains that competing theories fail in regards to making falsifiable predictions with which they may be tested.


"Nowadays, security guys break the Mac every single day. Every single day, they come out with a total exploit, your machine can be taken over totally. I dare anybody to do that once a month on the Windows machine." -- Bill Gates














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