Evidence for Evolution

[Curubethion]

Originally Posted by Count Comfect

But I still fail to see why junk DNA would be MORE likely to be a sign of "intelligent" design than of evolution - as I've just proposed an evolutionary mechanic for it, and it doesn't seem intelligent.

It isn't in favor of intelligent design (which sometimes seems to be lacking around here ). The evidence seems more to take a middle ground between atheistic evolution, theistic evolution, and ID.

[Count Comfect]

I think, given how well the differences in junk DNA among species fit evolutionary predictions, it is decent evidence for evolution, scientifically speaking. But metaphysically speaking, literally "who knows"?

[Nurvingiel]

Not to mention, men have nipples. Intelligent Designer eh?

I am being entirely facetious.

[brownjenkins]

Originally Posted by Nurvingiel

Not to mention, men have nipples. Intelligent Designer eh?

I am being entirely facetious.

just 'cause he's intelligent doesn't mean he's a genius

[Spock]

[Nurvingiel]

You spammer Spock, you already posted that! Besides, Brownie and I were already providing levity.

Originally Posted by brownjenkins

just 'cause he's intelligent doesn't mean he's a genius

Haha. Touché.

[Spock]

Actually I hadn't.
not in this topic anyway

[Nurvingiel]

Well, I just saw the other one first then.

Um... I'm not spamming now. Really. This post is 100% on topic.

[Rían]

Originally Posted by Nurvingiel

Not to mention, men have nipples. Intelligent Designer eh?

You obviously never saw my famous "nipple post" ™

(I'll let you search for it - if you dare!!)

[Nurvingiel]

I did dare, and I did find! Right here.

That was awesome! Well, they are fun. There is also a theory that the only reason earlobes exist is for pleasure as well. I mean... they don't really need to be shaped that way.

(I hope your daughter didn't find anything too embarassing! )

[Insidious Rex]

Some details on evolution in humans now. More evidence form our DNA that evolution plays a vital role in making us who we are even today. And the true importance of this is that studying this could help us fight a wide variety of diseases and defects. And so its doubly unfortunate that despite this some people would insist we discount the introduction of this crucial SCIENTIFIC theory in our educational systems because it clashes with their religious notions.

Natural selection has strongly influenced recent human evolution, Cornell/Celera Genomics study finds

ITHACA, N.Y. -- The most detailed analysis to date of how humans differ from one another at the DNA level shows strong evidence that natural selection has shaped the recent evolution of our species, according to researchers from Cornell University, Celera Genomics and Celera Diagnostics.

In a study published in the Oct. 20 issue of the journal Nature, Cornell scientists analyzed 11,624 genes, comparing how genes vary not only among 39 humans but also between the humans and a chimpanzee, whose DNA is 99 percent identical to humans.

The comparisons within and between species suggest that about 9 percent of genes that show some variability within humans or differences between humans and chimpanzees have evolved too rapidly to be explained simply by chance. The study suggests that positive Darwinian natural selection -- in which some forms of a gene are favored because they increase the probability of survival or reproduction -- is responsible for the increased rate of evolution. Since genes are blueprints for proteins, positive selection causes changes in the amino acid sequence of the protein for which the gene codes.

"Our study suggests that natural selection has played an important role in patterning the human genome," said the paper's lead author, Carlos Bustamante, assistant professor of biological statistics and computational biology at Cornell.

The Cornell/Celera team found that genes involved in immune function, sperm and egg production, sensory perception and transcription factors (proteins that control which genes are turned on or off) have been particularly affected by positive selection and show rapid evolution in the last 5 million years, when humans shared a common ancestor with chimps.

Likewise, the researchers found that approximately 13 percent of the genes that may vary show evidence of slightly deleterious or harmful mutations in human populations; these include genes involved in determining the basic structure of cells and muscles as well as genes that control traffic in and out of the cell. These mutations are subject to weak negative selection, according to the study. In general, negative selection eliminates from the population very harmful changes to proteins that kill or stop reproduction. But mutations that have led to slightly deleterious versions of the gene -- mutations that may cause disease or only slightly reduce the average number of children left by those that carried the mutation -- can by chance become quite common in the population.

The authors also found a correlation between genes predicted to be under negative selection and genes implicated in certain hereditary diseases. For example, among the genes the researchers predicted to be under negative selection are those involved in muscular dystrophy and in Usher syndrome, the most common cause of congenital blindness and deafness in developed countries.

"We have a long way to go before we can predict from looking at sequences, which mutations in which genes and under which environmental conditions can ultimately lead to disease. This is a first step in identifying the classes of genes that appear to be particularly vulnerable to these types of changes," said Bustamante.

A team from Celera initiated the project and sequenced more than 20,000 genes in 39 humans and a chimpanzee. By comparing the DNA sequences of the 39 human subjects across the 20,000 genes, the Celera researchers identified DNA sites in the genome where individuals in the sample differed from one another. The chimpanzee sequence was then used to identify which form of the gene was the original ancestral form and which was the derived or new type. The original goal of the project was to identify novel amino acid variants that could then be tested for association with human disease in subsequent studies. The Cornell researchers became involved at the analysis stage in order to make predictions about what types of changes are most likely to be functionally important.

[Rían]

Originally Posted by Nurvingiel

(I hope your daughter didn't find anything too embarassing! )

Well, they would have been embarassing, if I had told her what they really were ... as it was, I was able to make something up, and she bought it!

*reads article*

Natural selection - so who has an issue with that? No one that I know of.

I think that religion/beliefs shouldn't stop people from examining scientific information. That includes atheists and agnostics. Atheists, by definition, think there is no God, and I imagine most of them would not even consider evidence for creationism because of their beliefs.

[Count Comfect]

Atheists believe there is no god. Agnostics are decidedly undecided on the issue.

Well, natural selection's one of those things we base evolution on... if you can prove it happens naturally, it shows the theory explains it (broadly speaking).

[Rían]

whoops, sorry - got my a's mixed up - tired.

[Nurvingiel]

*bump*

Here's an interesting article from the National Geographic. I wish I had had time to read the article in print, because I dislike reading long articles on websites with white backgrounds. It's like staring at a lamp. If this amuses you, here's the link:

Was Darwin Wrong?

This title annoyed me because it struck me as a ploy to sell more magazines. When I saw this title on the front page, I thought "Holy crap, really!?" and immediately picked it up.
On the first page of the article, in huge letters, it said "No." Then the rest of the title was "There's overwhelming evidence for evolution." Personally I think they could have thought of a less sensational title, but this is coming from someone whose opinions probably wouldn't sell a lot of magazines.

I'll read the article myself after my lab exam Friday, but I wanted to get it out there for you guys.

[Jonathan]

I read the article. Good stuff.

[Curubethion]

Very crafty. They cast a little doubt on Darwin, so that they can smash it all the easier. This makes his theory look better. Also, the article is masquerading as an unbiased critique. Yeah right.

[Jonathan]

I hope you actually read the article and just didn't go through it to look for things to criticize. It did explain evolution well and good understanding - be it of evolution, ID or any other theory - is essential if you want to argue against it.

[Nurvingiel]

Originally Posted by Curubethion

Very crafty. They cast a little doubt on Darwin, so that they can smash it all the easier. This makes his theory look better. Also, the article is masquerading as an unbiased critique. Yeah right.

My impression from the title page was that it was a well-researched opinion of a scientific theory.

Why yes, I really should be studying right now...

[BeardofPants]

A language without numbers

With Professor Everett's first steps on Piraha land in 1977, he knew the tribe was remarkable. Their language had no words capable of conveying numbers or of counting to even the most basic of figures. It could be the world's only language without numbers. But he had to wait months before he could say for sure what made the Piraha special, so indecipherable was their language, a kind of sing-song communication which has more in common with whistling and humming than the spoken word.

On one of his first visits, in the late 1970s, he began to understand what the tribespeople were saying. It was a rude awakening. Eavesdropping one night, desperately trying to piece together what little he knew of their words, he realised with a shock that the warriors were planning to murder him by moonlight. Everett ran back to the hut and locked his wife and three children inside. "I grabbed all their weapons, their bows and arrows," he says. It was an act of triumph; the outsider had caught them off guard and proved his worth. The tribe was so amazed he had worked out what they were saying to each other that they treated him with a cautious kind of respect. From then on, neither he nor his family had problems.

In 1980, after many entreaties, Professor Everett set about trying to teach the Piraha. For eight months, he tried to explain rudimentary arithmetic to the more eager men and women keen to learn the skills needed to trade at fair prices with other indigenous tribes who arrived looking for brazil nuts. But after months of painstaking, often excruciatingly slow, evening classes, barely any of the Piraha had managed to count to 10. Even one plus one had proved beyond them. "At first, they wanted to learn to read and write and count," he says. "But by the end, only a few could even manage to get from one to nine. I thought: 'This not working'." Not only did the Piraha use no numbers in their sparse language, they also appeared unable to conceive of them.

During the seven years Professor Everett spent with them, he never heard them use words such as "all", "every" and "more". There is one word, "hoi," which comes close to the number one, but it can also mean "small", or a small amount, such as two small fish as opposed to one large one.

Peter Gordon, a psycholinguist at New York's Columbia University who has also made the journey deep into the rainforest to explore the Piraha's numerical skills, performed experiments with the tribespeople. The results seemed to show the tribe simply did not understand the concept of numbers. The tribe's almost total lack of enumeration skills is just one of the Piraha's many traits which has so fascinated linguists for two decades. The tribe has survived, culture intact, for centuries.

"I tried to transcribe everything I heard," says Professor Everett, now a fluent Piraha speaker. "I tried desperately to find structures I thought every language had but I couldn't find them. I was sure it was my inexperience in not being able to see them, but actually it was that they just weren't there."

He believes the Piraha is the world's only people to have no distinct words for colours. They have no written language, and no collective memory going back further than two generations, meaning few can remember the names of all four grandparents.

The members of the tribe, in villages along a 300km stretch of the Maici, are also believed to be the world's only society to have no creation myth.

Piraha language is simple. For men, it can be pared down to just eight consonants and three vowels. Piraha women have the smallest number of "speech sounds" in the world, with only seven consonants and three vowels. There is no perfect tense, no means of saying, for example, "I have eaten".

They are a unique people living without time or numbers, without colours or a shared past. And, until recently, that was more than enough to unite anthropologists in shared fascination.

Some scientists, including Dr Gordon, interpreted the Piraha's inability to learn to count as evidence for the theory that language shapes the way we think, that we are capable of creating thoughts only for which we already have words. In this theory, espoused initially by the Yale lecturer Benjamin Whorf in the 1930s, the Piraha could not get to grips with numbers in another language, Portuguese, because their own language had no capacity for it.

"A people without terms for numbers doesn't develop the ability to determine exact numbers," Dr Gordon said in Science magazine. "The question is, is there any case where not having words for something doesn't allow you to think about it? I think this is a case for just that."

But Professor Everett did not leave it there. "You could say these features of the language, these absences, are all coincidences. I tried to find a common thread to explain why the Piraha were the way they were."

Rest of the story here

How fascinating! No creation stories, no past tense, no numbers, and colours.