Questions about evolution

[Tim_Lou]

1. how is new organ developed? mutation?

 

but, a organs is highly organized tissues with unique functions,

how are mutations able to create such?

 

2. does mitochondria evolve?

mitochondria has DNA as we know,

and it only comes from our mom!

 

so, there is no variation, mitochondria stays the same...

[Tim_Lou]

so, if evolution is right,

 

all the DNA in a mitochondria in a cell should be the same!

(except for mutations...but most of them will be the same)

[Uncle Martin]

Tim'

What happened to you while you were gone? You're answering your own questions. Patience.

 

Where have you been by the way?

[Tim_Lou]

i was busy having fun, : )

 

hmm, so, you mean that DNAs in mitochondria are quite the same from a protist to a human?

(i better do a little research)

 

and how is it possible for a mutation to happens that makes,

1. a new type of tissue.

2. with favorable functions

3. highly developed

...(organ)

 

if it takes a while for this organ to developed, tell me how a useless piece of tissue is considered to be favorable to the nature and inherit to offspring.

 

so, that means someone might have an extra organ comes out of mutation,

and possibility lead to super X man!

[Tim_Lou]

im wondering maybe organs could split,

forming new organs over time.....

 

any idea?

[Freethinker]

Tim:

 

One of the most interesting programs I have seen was a few years ago. The group that found the Titanic, that had this mini sub. They did the Titanic thing to fund development of this sub so it could be used for pure research. They also formed the "Jason Project", which is a school based science program that allows schools to interface, thru the internet, to actual projects this group is doing. Great group of people!

 

Anyway, they wanted to research the ocean floor, at it's greatest depths. What they found, at a depth that it had been considered impossible living conditions, extreme cold, no sunlight, extreme pressure, ... what they found was an alien world teaming with life. Being we had never seen before.

 

They found ocean floor bottom sulphur vents spewing hot temp sulphur they found, to temperatures up to 800C. And what did they find around these vents that would rule out any form of life we could imagine?

 

LIFE!

 

Bacteria that lived on the hot sulphur. THRIVED on it!

 

Then they found something more amazing (to me at least), they found some "tubes" waving in the vent jets. They looked like tube worms, but there was not a tube worm know that could survive those conditions. They were able to "harvest" some for examination. What they found was the same bacteria inside with some form of "prokaryotic" organism that lived off of the byproduct of the bacteria from the sulphur. There was a natural tendancy to develope a tube shape to take advantage of natural energy flow. One life from working with another life form for the greatest efficiency of both.

 

Is it hard to imagine the path to a blood vein?

 

More deatils are all over the web, here's one:

 

Far from sunlight, sulfur supports strange life forms

http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/oceanography_recently_revealed1.html

 

which lists all kinds of other resources, including:

 

Hydrothermal Environments on the Ocean Floor

http://www.resa.net/nasa/ocean_hydrothermal.htm

[Tim_Lou]

gresat information, but it is still not the answer that im looking for.

 

what i mean is that like, how is a bird developed?

i mean when the "birds" are in between the flying stat and ground stat,

they dont walk as fast as other organisms, and can not yet fly.

how is it possible that this condition is actually favorable?

 

just like organs,

for example, consider the development of ears,

it must took thousands of years b4 ears come out,

so, is it that a mutation occurs and functional new tissues are formed?

but it cannot be this quick, evolutions take very long...

so, how is it favorable for an organism to have extra not-yet-developed (useless) tissues?

 

the question is: how can it be FAVORABLE when extra features are under development, and it is not yet useful?

 

i was wondering maybe a multi-functional organ becomes separate over generations...

[Freethinker]

Originally posted by: Tim_Lou

gresat information, but it is still not the answer that im looking for.

 

what i mean is that like, how is a bird developed?

i mean when the "birds" are in between the flying stat and ground stat, they dont walk as fast as other organisms, and can not yet fly.

 

how is it possible that this condition is actually favorable?

 

 

"(CNN) -- The feathered forelimbs of some species of small, two-legged dinosaurs may have helped those ancient animals run up hills or other inclines to escape predators. This half running, half flapping may have evolved into an ability to fly, researchers say. "

http://www.cnn.com/2003/TECH/science/01/18/coolsc.coolsc.primitive/

 

just like organs,

 

for example, consider the development of ...

 

You said "ears", but I hope you don't mind if I use eyes instead.

 

Let's say life had evolved to blobs of cells that live in the water. Perhaps the sun's rays are still harmful to this life because the atmosphere has not built up enough yet. In wate5r pools you have a number of blobs. Due to mutations, including something as simple as a slight mutation in cell color, one blob has a cell mutation in a spot that reacts to specific wavelengths of light, that pass thru the water. This blob's mutated cell detects the sun starting to shine on it and causes a reaction that allows that specific blob to move until the cell spot stops being hit by the sun. The blobs that lack this ability to dected the light earlier get trapped and die off. The mutuated cell gives the 1st blob an evolutionary advantage. Thus a genetic predisposition to have color mutated cells is passed on.

 

The eye is born.

 

Dawkins shows with computer simulations that from a light sensitive cell, to a fully functional eye can happen in less than 10,000 generations. This could be less than 100,000 years!

 

Does this mean there is a genetic advantage to color mutated cells? Nope! Not in and of themselves. A color sensitive single celled organism might not have a genetic advantage over a non-sensitive one. But an ORGNAISM which happens to have such a cell, or batch of them, might. Thus color mutated cells, while they do not help "themselves" survive, help their symbiotic host mass survive. So a cell mass with this and other benefitial mutations becomes more prolific.

 

Just as with the "tube worm" structure I posted before functions as a whole, while made up of individual organisms. Our bodies are made up of any variety of cells that in and of themselves are not viable. But when each individual cell type is assembled into a complex mass with each cell type offering a symbiotic advantage, the whole has a genetic advantage.

[Tim_Lou]

so, there has to be mass mutations that lead to the same results?

hmm, i think it makes sense...

since bacteria are so small, mutations can occur in a whole colony...

 

for higher animals, it happens in a rather slower rate...

[Freethinker]

Originally posted by: Tim_Lou

since bacteria are so small, mutations can occur in a whole colony...

 

for higher animals, it happens in a rather slower rate...

to best understand the whole process, it would be better to think of "higher animals" as "a whole colony" of various types of cells working in a symbiotic relationship.

[TeleMad]

One problem is that some look at a complex organ like the four-chambered human heart in isolation. There are many types of hearts out there in the animal world. Some have 3 1/2 chambers, some have 3 chambers, some have 2 chambers, some have a single chamber, and some are just muscular blood vessels that pump. It is not that difficult to form a plausible chain of such hearts leading from a simple muscular blood vessel up to a four-chambered human heart.

 

Some snippets from my zoology class notes...

 

Arthropods have an open circulatory system. ... The heart is either compact or tubular and consists of 1 or more chambers arranged in a linear fashion.

 

Gill-breathing fish have a two-chambered heart that is located just posterior to the gills.

 

Amphibians do not have scales. ... Adults have a three-chambered heart: immatures have a two-chambered heart.

 

Alligators and crocodiles have a four-chambered heart. Snakes, turtles, and lizards have a three-and-one-half-chambered heart.

[Freethinker]

Originally posted by: TeleMad

One problem is that some look at a complex organ like the four-chambered human heart in isolation. There are many types of hearts out there in the animal world. Some have 3 1/2 chambers, some have 3 chambers, some have 2 chambers, some have a single chamber, and some are just muscular blood vessels that pump. It is not that difficult to form a plausible chain of such hearts leading from a simple muscular blood vessel up to a four-chambered human heart.

The same is true for "eyes". There are many very different implemenations of "visible light" detection cells in species on earth. The existing results show multiple paths based on obvious evolutionary advantages to a species having "light sensitive" cells.

 

Thus the notion of some "irreducible complexity" nonsense can not hold water. (or reasoning).

[wisdumn]

been reading over this thread and i have a question, i understand about a blob and it's cells expanding to become an eye(supposing such is possible) but my question is is how do these blobs decide to come together to form humans, i mean are we evolved from the ocean floor or do we evolve on land. best question about evolution i can muster is how does evolution decide what to form and what not to? i mean shouldn't we still have dinosaurs if things happen by evolution?

[Freethinker]

Originally posted by: wisdumn

but my question is is how do these blobs decide to come together to form humans,

Blobs don't "decide" anything.

 

Nor did anyone suggest that light sensitive cells exclusively become a blob which became humans.

 

So much of a succesful discussion is based on establishing common grounds.

i mean are we evolved from the ocean floor or do we evolve on land.

Yes.

best question about evolution i can muster is how does evolution decide

Again, evolution does not "decide" anything.

 

What you are stuck in is called being "Anthropomorphic". You want to pretend that nature has human intellectual thought processes. Things in nature do not DECIDE anything. They do not INTEND for anything to happen. Things happen because that is the way things happen. Water does not CHOOSE, INTEND or DECIDE to freeze at a certain temp. It just DOES.

what to form and what not to?

Evolution functions thru various forms of mutation. The more succesful mutations, those that offer a survival/ procreation advantage continue and those that don't, fade away.

 

Billions of forms spring up. Some catch hold, others fail.

 

e.g. in 1996 there was a large batch of 5 legged frogs being born in various parts of the US. Various reasons were being given. But if having 5 legs would have been a surivial advantage for the frogs, those mutants would have more progeny and 5 legs would become more and more common. But it turned out to be a disadvantage and the phenominon dropped back to just an occasional individual mutation.

i mean shouldn't we still have dinosaurs if things happen by evolution?

And as the environment changes, various evolutionary mutations have greater or lessor advantages and detrements. If a fire hits an area and wipes out all ground and lower vegetation, taller species and those that can climb and fly will have a survival advantage. These that can not reach now exclusively higher food sources will die off.

 

Sparrows live in the Galapagos. Sometimes for some years at a time the water level is higher. Thus insects are in sections of the rocks that do not have as deep of worn away holes. THis gives sparrows with short beaks an advantage. Thus after a few years, generations of short beak sparrows take over.

 

But as the water level sinks, the deeper holes in the rocks become the homes for the insects. Then longer beaks are required and long beak sparrow thrive and grown in number, short beak sparrows dying of starvation.

 

Dino's show an extremely long existence on earth. Many times longer than humans. But something happened that made their size a DISadvantage at some point. One explanation is a meteor that caused massive air polution. Thus taller animals had trouble getting clean air. Higher vegetation died off also and this reduced taller animal survival. While small mammals suddenly had a survival advantage.

 

Thus what happened to the dinos is EXACTLY what we would expect with Evolution.

[clumpymold]

One problem is that some look at a complex organ like the four-chambered human heart in isolation. There are many types of hearts out there in the animal world. Some have 3 1/2 chambers, some have 3 chambers, some have 2 chambers, some have a single chamber, and some are just muscular blood vessels that pump. It is not that difficult to form a plausible chain of such hearts leading from a simple muscular blood vessel up to a four-chambered human heart.

 

Some snippets from my zoology class notes...

One question since you posted this (I know this is an old thread but I searched and it came up with this):

 

For two-chambered hearts, after the gill capillaries, the region of blood vessels are called what? Arteries or veins? Or is it split into two regions? This is the region before the systemic capillaries. I know that arteries go away from the heart and veins return blood to the heart but with a two chambered heart, where does that distinction occur?

[pgrmdave]

I can understand most evolution, but how did organelles come about? I've heard that it is thought that most organelles were individual organisms that ended up having a symbiotic relationship - is there any evidence of this?

[Fishteacher73]

I can understand most evolution, but how did organelles come about? I've heard that it is thought that most organelles were individual organisms that ended up having a symbiotic relationship - is there any evidence of this?

 

 

Mitochondria have their own (and different) DNA than the rest of the host cell and replicate on their own time. Chloroplasts are the same if I recall. As for the rest of the organells, they are constructed by the cell.