How could we have stopped evolving?

[Kayra]

What you say implies a moral, ethical or 'judgemental' attitude (not quite the right word sorry).

 

Interesting, but I inferred no such thing intentionally.

What I was speaking of was the two best known mechanisms of evolution, without which the concept could not even exist. Evolution is not driven by purpose or intent, but statistics. The simplest game of odds.

 

Have you ever heard of the saying brain children. This sort of hints upon the evolutionary parallel for the brain.

 

HydrogenBond: Very interesting perspective. Are you saying that ideas that change our environment will likely have an effect on our genetic evolution? I agree but only when there also exists selective pressures for the new environment. What would cause someone who is unfit to be productive in the evening to be statistically less likely to reproduce then someone who is? The bias probably exists, and likely in surprising ways we have not thought of.

 

Or have I missed the point entirely :)

 

If you are speaking of Memes, I personally believe that they exist outside of our chemically driven evolution and exist purely as thought.

 

Hmm, I take that back, as some Memes may drastically affect reproduction if they affect concepts of what a good mate is. In this light, Memes may very well be the single largest driving force for evolution in modern societies in 1st world countries.

[charles brough]

Hello you all, I just peeked back in. . .

 

You know, Darwin was mistaken in applying his theory to us modern humans. He claimed that natural selection occurred among the various races and this process fostered further changes which he assumed were continuing on. It was a natural mistake and does not, to me, cast any shame on him even though it is the type of thinking that eventually led to Adolf Hitler. The fact is that all the races have built or function in or contributed to the various civilizations we study in world history. One the black races seem to get short-shift in history, but they built civilization in North Africa and along the East central coast of Africa.

 

More attention needs to be focused on the subject of epigenetic change. What can too easily be credited to biological evolution in us turns out to be mere epigenetic changes that are eventually reversed. They never get into the genes. They tend to be small and to be passed on only to a few generations or to be eliminated, eventually, through the trials of war, famine and disease. A luxurious society like our own leads to a growing accumulation of weaknesses. We see the growing prevalence of diabetes, autism, poor sight, celiac disease, etc. It is epigenetic, not genetic. When it is reversed by brutal times that hit civilizations in their decline, we cannot then say we are “evolving forward!”

 

I propose that it is the ideologies we agree on that evolve. Those ideologies bind us into societies that compete with each other in a process of natural selection.

 

charles

[Kayra]

Everything I said Charles, but ooh so much more succinct :)

[Michaelangelica]

Tibetans adapted to altitude in under 3,000 years

Friday, 2 July 2010

Agence France-Presse

 

 

WASHINGTON: Tibetans took less than 3,000 years to adapt to living at high altitude,. . .

 

"This is the fastest genetic change ever observed in humans," said biologist Rasmus Nielsen, from University of California Berkeley who led the statistical analysis and genome-wide comparison between the Tibetans and the Han Chinese.

 

. . .Comparing the genes of both ethnic groups, researchers found more than 30 genes with DNA mutations that have become more prevalent in Tibetans than Han Chinese, nearly half of which are related to how the body uses oxygen.

Tibetans adapted to altitude in under 3,000 years | COSMOS magazine

[Eclogite]

In short, I suspect that a population of gorillas, rats, or even birds or other animals dwelling at high altitude for several generations would show an increased frequency of myoglobin genes optimized for the thinner air, and that these genes were present with about the same frequency in our ancestors 10s of thousands and millions of years ago. .

Therefore, implicitly you would expect those inhabitants of the Andes to show the same adaptations. They do not. ergo your postulate is false.

[Michaelangelica]

http://www.livescience.com/14628-mutants-average-human-60-genetic-mutations.html

When parents pass their genes down to their children, an average of 60 errors are introduced to the genetic code in the process, according to a new study. Any of those five dozen mutations could be the source of major differences in a person's appearance or behavior as compared to his or her parents — and altogether, the mistakes are the driving force of evolution.

 

Sixty mutations may sound like a lot, but according to the international team of geneticists behind the new research, it is actually fewer than expected. "We had previously estimated that parents would contribute an average of 100 to 200 mistakes to their child," Philip Awadalla, a geneticist at the University of Montreal who co-led the project, said in a press release. "Our genetic study, the first of its kind, shows that actually much fewer mistakes, or mutations, are made."

 

That means human evolution happens more slowly than they previously thought.

 

[dduckwessel]

I don't think this is true.

There have been a number of genetic changes in the last 10,000 years.

EG:-

1. Ability to digest lactose

2 Loss of ability to manufacture Vitamin C

3. Among those who live in high altitudes, the ability to access oxygen more efficiently.

5. The ability to digest gluten.

6. Resistance to many diseases such eg AIDs, due to exposure to c 10-15C plague virus. Also small pox and measles resistance among Europeans.

 

Possibly I missed the response to this but wouldn't the above changes be considered as adaptation rather than evolving?

[Turtle]

Possibly I missed the response to this but wouldn't the above changes be considered as adaptation rather than evolving?

 

in this regard adaptation is evolution because the changes michaelangelica listed are inherited.

 

http://www.thefreedictionary.com/adaptation

adaptation:

...

4. (Life Sciences & Allied Applications / Biology) Biology an inherited or acquired modification in organisms that makes them better suited to survive and reproduce in a particular environment

[dduckwessel]

in this regard adaptation is evolution because the changes michaelangelica listed are inherited.

 

http://www.thefreedictionary.com/adaptation

 

Land animals adapt to colder temperatures by growing fur - which is an adaptation, not evolution.

 

The human body is highly adaptable (even to poison administered in small doses over time). So then why would adapting to lactose tolerance be considered evolutionary?

 

In my mind adaptation happens for reasons of survival or availability (a certain food is available in abundance). Evolution on the other-hand is where an organism develops a higher trait (the development of speech), which is very different from adaptation. Otherwise why not just call evolution and adaptation the same thing!

[dduckwessel]

http://www.livescience.com/14628-mutants-average-human-60-genetic-mutations.html

When parents pass their genes down to their children, an average of 60 errors are introduced to the genetic code in the process, according to a new study. Any of those five dozen mutations could be the source of major differences in a person's appearance or behavior as compared to his or her parents — and altogether, the mistakes are the driving force of evolution.

 

Sixty mutations may sound like a lot, but according to the international team of geneticists behind the new research, it is actually fewer than expected. "We had previously estimated that parents would contribute an average of 100 to 200 mistakes to their child," Philip Awadalla, a geneticist at the University of Montreal who co-led the project, said in a press release. "Our genetic study, the first of its kind, shows that actually much fewer mistakes, or mutations, are made."

 

That means human evolution happens more slowly than they previously thought.

 

 

Why is the passing on of genes considered 'errors' and 'mistakes'? Is it because genetic code is weakened over time?

[Turtle]

Land animals adapt to colder temperatures by growing fur - which is an adaptation, not evolution.

 

The human body is highly adaptable (even to poison administered in small doses over time). So then why would adapting to lactose tolerance be considered evolutionary?

 

In my mind adaptation happens for reasons of survival or availability (a certain food is available in abundance). Evolution on the other-hand is where an organism develops a higher trait (the development of speech), which is very different from adaptation. Otherwise why not just call evolution and adaptation the same thing!

 

i have come to have low confidence in what is "in your mind" vis à vi scientific understanding. that is a non-evolutionary (genetic evolution) adaptation of mine. you are conflating different definitions of the word "adaptation". it has a specific meaning in regards to evolution and i gave that; moreover the other definitions which i did not give do not apply in regards to evolution. neither does some different definition in your own mind apply. if you want to understand and discuss what is scientifically known about evolution then you must learn & adopt the terminology and methods that scientists use. you don't have to believe it, but you do have to learn it.

/forums/images/smilies/banana_sign.gif

[dduckwessel]

I was simply asking for clarification of something I did not understand. I was curious because it seemed to me there are times when adaptation and evolution appear the same and I was wondering how scientists make the distinction. I didn't think it was an illogical question.

[Turtle]

I was simply asking for clarification of something I did not understand. I was curious because it seemed to me there are times when adaptation and evolution appear the same and I was wondering how scientists make the distinction. I didn't think it was an illogical question.

 

yes well, i directly answered your question about the distinction scientists use and you then argued with my answer. :shrug: no doubt you will argue with this one. arguing from ignorance may be a reason to argue, but it is no excuse. :naughty:

[CraigD]

In my mind adaptation happens for reasons of survival or availability (a certain food is available in abundance). Evolution on the other-hand is where an organism develops a higher trait (the development of speech), which is very different from adaptation.

I think you’re expressing a pretty widespread definition of the term “evolution”, one that’s roughtly synonymous with “progress” – pretty much what this variation of the Darwin fish

(my favorite :)) is saying.

 

The term evolution has a lot of meanings, the most general being close to its etymological meaning “unfolding”. When someone give you a heads-up by saying “we have an evolving situation here”, this is what they mean.

 

As Turtle rightly notes, neither of these meaning is the scientific one for biological evolution, though. It’s fine to use the term evolution in lots of different contexts, but important not to confuse them with the scientific concept of biological evolution. Wikipedia’s wording of this definition, taken verbatim from biologists Douglas J Futuyma’s book Evolution is, IMHO, as good as any:

 

Evolution (also known as biological or organic evolution) is the change over time in one or more inherited traits found in populations of organisms.

 

Note that this definition doesn’t require that trait changes occur due to preferential selection (eg: the long feathers of male peacocks, good-looks in humans, big gonads in primates, etc.), mutations, or any particular factor, only that the changes be heritable – in terrestrial biology, that the traits be due to genes, not, say, handed down via cultural traditions.

 

A really important misconception to dispel (I’ve lost counts of how many times folk have tried dispelling it at hypography) is that evolution always coincides with what we think of as progress, such as humans getting smarter, more peaceful, etc. Biological evolution is determined only by the successful passing on of genes (though “genes” may, possibly and controversially, involve some biochemistry in addition to those in RNA and DNA). Recent human evolution, for example, appears to have more involved the trait of being able to eat what we modern humans eat so much of – domestic grain and domestic animal milk – rather than the mix of hunted and gathered wild foods we ate for most of our pre-history, than a trait like bigger brains (human brains have actually been getting smaller for the past 20,000 to 30,000 years, though it’s unclear if this decreases, increases, or has no significant effect on intelligence – see this thread for more).

 

Otherwise why not just call evolution and adaptation the same thing!

Because the term adaptation refers to a central process of biological evolution, rather than being a synonym for it, in the same way that lift or wing are key concept of, not synonyms for aerodynamics.

 

Dduck, I think you should read through the wikipedia articles above on biological evolution and adaptation. As Turtle noted, you appear to simply be misunderstanding the conventional scientific meaning of these terms. A little (or a lot ;)) of honest study should cure that ill.

[dduckwessel]

yes well, i directly answered your question about the distinction scientists use and you then argued with my answer. :shrug: no doubt you will argue with this one. arguing from ignorance may be a reason to argue, but it is no excuse. :naughty:

 

You always think I'm arguing with you Turtle when sometimes your (and others) answer appears contradictory to me so I have to ask for clarification. I guess I have to use Emoticons more often :rolleyes:

 

I should explain this further: some people on Hypography write above my head and it's not that I'm being rude but that I am simply not understanding. Excepting of course when you're insulting me then your words become fewer and much clearer. <_<

 

It's a communication thing and I don't expect anyone on Hypography to change but there are times I've had to do mental gymnastics just to keep up with some of you ;) .

[dduckwessel]

I think you’re expressing a pretty widespread definition of the term “evolution”, one that’s roughtly synonymous with “progress” – pretty much what this variation of the Darwin fish

(my favorite :)) is saying.

 

Hum! I did read the links both you and Turtle provided. I understand biological adaptation very well but it seemed to me (and I'm sure I'm not the only one) that at times there is a very fine line between evolution and adaptation! I needed clarification of what I thought was a fine line, which it turns out they are quite different. :)

[charles brough]

Before this claim can be accepted, it’s necessary to show that it actually is the consensus of evolutionary biologists that H.Sapiens.S. has not evolved since becoming a species.

 

Aside from the difficulty of defining a distinct event of “becoming a species”, I don’t think this is the conseusus. For example, as described in this World Science article, and discussed in this hypography thread, scientists such as controversial but well-respected anthropologists Gregory Cochran have proposed that not only has human evolution in the past 200,000 years not slowed or stopped, but that it has dramatically accelerated.

 

Charles, what support can you present for your claim? Might your impression of the consensus among evolutionary biologists be based on out-of-date data?

 

I could not believe I had stated that, so I went back and checked! Yes, I had stated it even though I did not intend to say that. As you aver, it is not the consensus! I interpret the consensus to believe there have been slight changes in the last 40,000 years and that they, for lack of any other explanation (social science provides none), feel they must be overlooking something.