Just a few questions on evolution...

[JetPilot]

I like the theory a lot, I think it makes sense except for one little fact...

How do things like eyes or wings form. I mean isn't an eye way too complex of a system for it to just be "created" out of a mutation? Or how could some species suddenly morph out a wing and fly? I understand how arms and legs could slowly increase in length and change shape through time; but when evolution suddenly creates things like wings and eyes I don't understand.

 

[cosmictraveler]

I like the theory a lot, I think it makes sense except for one little fact...

How do things like eyes or wings form.

That is what evolution means, to evolve from one form or part of the organism to something new.

 

[iceaura]

but when evolution suddenly creates things like wings and eyes I don't understand.

That never happens, according to Darwinian theory.

 

[cosmictraveler]

Mutations and deviants occur in nature all the time. They don't last that often but sometimes they do and go on to becoming something different than before

 

[Hercules Rockefeller]

I mean isn't an eye way too complex of a system for it to just be "created" out of a mutation?

Yes, eyes are a complex system which is precisely why they weren’t, as you say, “just created out of a mutation”.

Or how could some species suddenly morph out a wing and fly?

Species did not suddenly "morph out a wing and fly".

I understand how arms and legs could slowly increase in length and change shape through time; but when evolution suddenly creates things like wings and eyes I don't understand.

You’ve answered your own question. Eyes and wings have evolved over long periods of time through slow changes in intermediate structures, just as “arms and legs could slowly increase in length and change shape through time”. Evolution did not "suddenly" create things like wings and eyes.

 

[Orleander]

Are we still evolving or have we hit the end of our own evolution?

 

[pilpaX]

Are we still evolving or have we hit the end of our own evolution?

yes we are still evolving... or at least changing. There is not much left of natural selection for humans so I dont think our evolution is going towards "better human" for some time now.
Maybe its the end of biological evolution and start of some other... in silica maybe.

 

[Hercules Rockefeller]

Are we still evolving or have we hit the end of our own evolution?

Yes, humans are still evolving in response to selective pressures.

It's a perennial topic of conversation on biology forums as to whether or not humans are still evolving. Often people try to argue that we are not evolving any more. We are, of course. It’s silly to argue that the widespread migration of humans between different climates and environments, and the dramatic changes in lifestyle that has occurred over the past few millennia as a result of agricultural and industrial revolutions have not resulted in the modification and selection of certain human genetic traits over others. But here is some research that actually helps to pinpoint where that selection might actually have occurred.....

From http://www.nature.com/news/2006/060306/full/060306-8.html

Researchers at the University of Chicago, Illinois, have identified the regions of our genetic sequence that show the strongest marks of natural selection. Their work highlights the genes that have been most important in adapting to new lifestyles, and could help to identify the genetic factors involved in complex medical conditions such as high blood pressure and alcoholism.

Genes that show the most evidence of recent selection include those involved in milk digestion. Although most mammals drink milk only in infancy, humans seem to have adapted genetically to digest it throughout life.

Genes for skin pigmentation also bear the hallmarks of rapid evolution - highlighting the fact that many populations have become more fair-skinned as they have colonized more extreme latitudes with less sunshine.

It's a snip

The team used data from the International HapMap Project, which collates and maps out 'single-nucleotide polymorphisms' (SNPs). These are sites in the genome at which DNA varies between people by just a single letter of genetic code. The team sampled data from more than 200 unrelated individuals in three different racial groups: East Asians, Europeans and the Yoruba of Nigeria.

Genetic mutations that confer an advantage on a given population spread much faster than they would through natural, random mixing of genes. These portions of DNA should carry certain SNPs along with them as they are selected for over time. So if researchers find a string of SNPs that are mostly the same letters within a given population, they can say that the accompanying genes have come under strong selection pressure.

The method reveals changes that have occurred since various populations split to colonize different areas of the globe, says Jonathan Pritchard, who led the research published in the journal PLoS Biology.

Food and sex

Many of the genes that showed evidence of selection involve food metabolism, notes Pritchard. This shows that adapting to different diets has been a key trend in recent human evolution.

Around 20% of the genes identified showed evidence of selection in more than one of the populations. Chief among these were genes involved in reproductive processes such as sperm manufacture, showing that these were equally important in different settings.

All three racial groups showed equal amounts of recent evolution. This is interesting, says Pritchard, given that African populations have remained in the birthplace of our species, while others have moved away. Travelling populations might be expected to encounter challenges favouring more selection pressure than those that stay still.

But, notes Pritchard, the environment can change as much with time as it does with distance. "It is perhaps naive to think of Africans as staying 'in the same place'," he says.

Pritchard is not convinced by the predictions of some experts that advances in medicine will negate evolutionary pressures from now on. "Even today there is plenty of scope for natural selection, such as in genes that impact fertility or fetal survival."

References
Voight B. F., Kudaravalli S, Wen X. & Pritchard J. K.
PLoS Biol, 4 . e72 (2006).

 

[Fraggle Rocker]

I like the theory a lot, I think it makes sense except for one little fact... How do things like eyes or wings form. I mean isn't an eye way too complex of a system for it to just be "created" out of a mutation? Or how could some species suddenly morph out a wing and fly? I understand how arms and legs could slowly increase in length and change shape through time; but when evolution suddenly creates things like wings and eyes I don't understand.

Eyes started out as individual photoreceptor cells, and some organisms still have them. Being able to tell where a particular colored light is coming from, even if you can't focus, is a great help in catching prey or avoiding predators. Compare the eyes of insects and then keep going down the phyla into the lower animals. You'll see a pretty good set of snapshots in the development of the vertebrate eye from the simple light sensors of the primitive animals.

The wing issue was recently explained using high-speed cameras. It's a matter of thinking "outside the box," specifically our notion that wings are for generating the positive lift needed for flying. Wings can also be used for negative lift. Birds that can't fly, like domestic chickens, can climb straight up a cliffside, and even go a little way into the area of reverse slope in order to clamber over the top. This is a great advantage in escaping from a predator. Feathers of course provide warmth and only incidentally shape airfoils. So if the first birdlike creatures had forelegs with stubbly feathers and puny muscles, they could still use them to generate a small amount of negative lift.

 

[leopold]

I like the theory a lot, I think it makes sense except for one little fact...

How do things like eyes or wings form. I mean isn't an eye way too complex of a system for it to just be "created" out of a mutation?

as a non scientist i believe i can help you. first of all you will not find any objective websites on this matter, every single one of them deals either with a scientific view or a religious one. so, what does this mean for people like you and me? it means you must rely on what you know to be facts. what are the facts concerning evolution? to answer this we must first determine what evolution is, so let's define it evolution is a natural process where molecules change. this means that molecules can change from what they are into something else naturally. given this definition we can say that evolution is indeed a fact. next up is one species changing into another. i can only assume since micro evolution is a fact that macro evolution is also a fact. now, how can i make that leap? because i have no evidence that says it can't happen.

Or how could some species suddenly morph out a wing and fly? I understand how arms and legs could slowly increase in length and change shape through time; but when evolution suddenly creates things like wings and eyes I don't understand.

do yourself a favor and stay away from creationist websites and trust your intuition. yes, you do understand, you just don't want to see it.

 

[Fraggle Rocker]

First of all you will not find any objective websites on this matter, every single one of them deals either with a scientific view or a religious one.

Excuse me??? Scientific = objective (observation and logic). Religious = instinctive (archetypes).

 

[leopold]

Excuse me??? Scientific = objective (observation and logic). Religious = instinctive (archetypes).

where did i say i was a genius?
as a matter of fact my first 4 words of the post you quoted is:

as a non scientist . . . .

 

[spuriousmonkey]

How do things like eyes or wings form. I mean isn't an eye way too complex of a system for it to just be "created" out of a mutation? Or how could some species suddenly morph out a wing and fly? I understand how arms and legs could slowly increase in length and change shape through time; but when evolution suddenly creates things like wings and eyes I don't understand.

I find it perplexing that you have no trouble understanding how arms and legs could appear by apparently something as simple as 'extension' when they are derived from something that doesn't look like an arm or a leg, the fin region. It is rather similar in complexity to the evolutionary development of other complex organs such as wings and eyes. Well, and of course wings and eyes developed several times in different lineages in different ways. Hence it cannot really be that impossible to imagine, nor is there one right solution.

Here is a nice article for you to read on limb development and evolution. You might notice that the evolutionary development of limbs is rather complex. Similar to that of the eye and wing.

And in all cases scientists have at a minimum a basic understanding of how which is expanded every day with more insights.

http://www.plosone.org/article/fetchArticle.action?articleURI=info:doi/10.1371/journal.pone.0000754

Open access, so you have no excuses not to read it.

If you have any questions on this article I will be happy to forward them. I know the author.

 

[Idle Mind]

I know the author.

Nice name drop.

(and I'm happy to see you posting in this subforum again)

 

[spuriousmonkey]

Nice name drop.

(and I'm happy to see you posting in this subforum again)

It's not me. I am not Portugese, nor am I a woman. Evo-devo is a small world.

 

[one_raven]

It's not me. I am not Portugese, nor am I a woman. Evo-devo is a small world.

I think you misunderstood the use of the term "name drop".

If, for example, you had dinner at Robert DeNiro's house last week, you might order the same food when at a restaraunt with friends and say, "You know, the Eggplant Rotini I had at Bobby DeNiro's house last week was so much better than this", you would be dropping DeNiro's name.

 

[spuriousmonkey]

Oh, ok. I'm not a native speaker.

She is crazy btw!

You didn't hear it here of course.

But then again, that's probably why we are friends.

 

[s0meguy]

I think he means to say that the problem here is... why would an animal with wings that don't really work survive and evolve further? Because since they can't just 'morph' into existence, they would have to be useless wings first. Not to mention that an animal would have to evolve a lot to actually be able to fly: good wing size, weight, brains capable of using the wings.

Eyes are easy... because early 'eyes' would have been very useful

 

[spuriousmonkey]

The appropriate course of action

On the complexity issue

Legs don't pop out perfect either. If anyone had bothered to read the article you might have noticed trivial things such as:

These early limbs were polydactylous, consisting of six (in Tulerpeton), seven (in Ichthyostega) and eight or more (in Acanthostega) short digits, with comparatively simple or poorly defined wrists and ankles [10]–[14].

Wrists and ankles are highly complex structures. Can they pop out fully functional to a modern standard? hardly

Limb development is just as complex as fin development, the functionality of a limb is just as important as the functionality of a wing. Yet, there is apparently no problem with legs and arms, because probably due to ignorance arms and legs are seen as something simple, and the evolution of them is seen as something straightforward, and the necessity of functional limbs is seen as unimportant.

While as a matter of fact the evolution of limbs was more complicated. Involves much more imagination, had to solve more functional problems, etc than the evolution of wings.

Evolution of wings is in bats merely the extension of digits and the retention of skin between them.

None of these processes are seen as special. The developmental biology behind both is well within reach of the current knowledge.

Now read on the evolution of limbs. Huge changes were made over a long period of time.

Where it went wrong

What we see here is lazy thinking. The curse of modern society. Some people shout that it is impossible that wings can evolve and people start to think that this is a legitimate problem without prior thought.

And this is how the original poster addresses the problem: it makes no sense to him.

Well, of course not. I am not surprised that if you do not know anything on a topic other than some popular memes perpetuated on the web by people with a distinct agenda it cannot be expected that something makes sense.

We can now jump high and low and give likely scenarios on how eyes and wings might have evolved, mostly reiterated from web sites with an agenda, but I feel it is the wrong approach.

What we should do

What we need to do is address the real problem: the original poster has not thought for himself on the topic. He might have given it a cursory thought, 'wow...this doesn't make sense', but he never gave it any real thought.

This can only be achieved by self education. I see no point in giving him a short popular version present on a million websites. He only needed to go to wikipedia to get that version. Hence this cannot be the problem.

What we need to do is point out his error. His error is that he never gave the topic any thought.

Young man/woman, you need to go to the library. You need to start reading books written on evolution and on development, and on evolutionary development. The learning curve will be steep if you really go for it, that is, if you are really curious. You will need to take a dive into the deep end. You will need to start reading books you will not fully comprehend. You will need to start reading scientific articles you will not fully understand. I can promise you though, that although you will not fully understand, you will one day fully understand the error of your post here.

You will understand that you made a post based on wrong assumptions. You will see that your life is enriched by a new level of understanding.

And the world will be a better place (this last line is a lie).

 

[Orleander]

yes we are still evolving... or at least changing. There is not much left of natural selection for humans so I dont think our evolution is going towards "better human" for some time now.
Maybe its the end of biological evolution and start of some other... in silica maybe.

How about longer fingers? The more keyboarding/texting a person is able to do, the better job he may get. More money (ability to support a family), is more attractive which means more reproduction.