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Author Topic:   Is everything made of the same material?
taylor_31
Member (Idle past 4031 days)
Posts: 86
From: Oklahoma!
Joined: 05-14-2007


Message 16 of 45 (401543)
05-20-2007 3:06 PM
Reply to: Message 13 by crashfrog
05-20-2007 12:59 PM


Thank you for the effort you put into that post. It was a very interesting read!

crashfrog writes:

What happened was, in the distant past, an organism like a bacteria literally absorbed a smaller, different organism into its cell, but instead of digesting it, they because dependent on each other.

If the bacteria-like organism "absorbed" the smaller organism, how did the smaller organism appear in the descendants? When the bacteria-like organism reproduces , will the smaller organism appear in the new bacteria, or will it have to absorb another one?

My superficial guess is that the mitochondria and chloroplasts have their own reproductive process, and when the bacteria reproduce, the mitochondria and chloroplasts do the same somehow. Is this right?


This message is a reply to:
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Doddy
Member (Idle past 4017 days)
Posts: 563
From: Brisbane, Australia
Joined: 01-04-2007


Message 17 of 45 (401585)
05-20-2007 8:24 PM
Reply to: Message 14 by taylor_31
05-20-2007 2:37 PM


Re: Junk in the trunk
taylor_31 writes:

Would large pieces of junk DNA be selected against? I would think so because competing DNA strands might be more efficient by having less "junk

This is true. However, in terms of large organism, how much DNA you have to replicate is the last of your concerns (that is, growth speed is not as important). What is actually coded for by the DNA (what you look like and how you function) affects your survival and reproduction much more than taking an additional minute for cell division while you replicate the DNA.

However, on the scale of microorganisms, it is very important that you replicate faster than your neighbours, and so you find that single-celled organisms have much less junk DNA, due to the selection acting against it.


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Doddy
Member (Idle past 4017 days)
Posts: 563
From: Brisbane, Australia
Joined: 01-04-2007


Message 18 of 45 (401591)
05-20-2007 8:38 PM
Reply to: Message 16 by taylor_31
05-20-2007 3:06 PM


taylor_31 writes:

If the bacteria-like organism "absorbed" the smaller organism, how did the smaller organism appear in the descendants? When the bacteria-like organism reproduces , will the smaller organism appear in the new bacteria, or will it have to absorb another one?

My superficial guess is that the mitochondria and chloroplasts have their own reproductive process, and when the bacteria reproduce, the mitochondria and chloroplasts do the same somehow. Is this right?

Just to clarify something here: although the organism in the past, the one that absorbed (or was infected by, depending on you point of view)these little bacteria and kept them as mitochondria or chloroplasts, would have looked like a bacteria, modern bacteria do not have these organelles. Only eukaryotes (like us, plants, fungi, amoeba etc) do. Therefore, this means that those bacteria that obtained these organelles must have evolved into the single-celled ancestors of eukaryotes, leaving the bacteria without them to remain as bacteria.

As far as your guess goes, you are exactly right. Both mitochondria and chloroplasts replicate seperately to the host cell, and when the cell divides, half (roughly) of the mitochondria/chloroplasts go to each cell.

This is important to note for sexually reproducing organism, as sperm/pollen cells do not give their mitochondria to the egg cell (they only give their nucleus). Therefore, while you may have your mother's or your father's genes, you can only have your mother's mitochondria!


Help inform the masses - contribute to the EvoWiki today!

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crashfrog
Inactive Member


Message 19 of 45 (401610)
05-20-2007 10:30 PM
Reply to: Message 16 by taylor_31
05-20-2007 3:06 PM


If the bacteria-like organism "absorbed" the smaller organism, how did the smaller organism appear in the descendants?

Organisms that small reproduce by cell division; the smaller endosymbiotes simply divided along with their hosts.

My superficial guess is that the mitochondria and chloroplasts have their own reproductive process, and when the bacteria reproduce, the mitochondria and chloroplasts do the same somehow. Is this right?

Nowadays, the reproduction of mitochondria and chloroplasts is regulated by the host cell itself, but that's basically it. Cells eventually evolved the ability to stimulate mitochondrial reproduction in response to greater energy needs, but I imagine in the beginning, mitochondria reproduced at probably they greatest rate they could without overwhelming the host cell.


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AnswersInGenitals
Member
Posts: 509
Joined: 07-20-2006


Message 20 of 45 (401636)
05-21-2007 12:13 AM
Reply to: Message 6 by taylor_31
05-19-2007 1:01 PM


An excellent beginning reference for molecular biology.
Sorry if I seem twisted in knots. Biology has always had that effect on me.

Let me recommend an excellent book that will propel you miles ahead in understanding all the molecular chemistry that you are curious about: "How LIfe Works", by Mahlon Hoagland. It is just 200 pages long, but 2/3 of that is large pictures and diagrams. It is an easy one day read that could be understood by (almost) any sixth grader. This is not meant to demean anyone's intelligence. It is just written the way any science book should be written, getting to the heart of each topic and revealing its true simplicity. Check it out on amazon.com, where it costs about $20, but any decent city library should have a copy.

An important point to remember about genomes, chromosomes, and DNA is how extremely 'sloppy' they are; or as biologists prefer to phrase it: they are very, very plastic. Your body has about 50 trillion cells and the genomes of no two are identical. Every time cells in your body divide to make new cells or replace dead cells, there are a couple of dozen random point mutations in the 6 billion nucleotides in your genome. Every gene in your genome also occurs in hundreds or even thousands of other species, but it is very rare for the nucleotide sequence of any gene or for the amino acid sequence of the protein it codes for to be identical between any two species. Its like a Chevy and a Ford sedan: they both have pistons, fenders, rear seats, etc., but there are slight differences between the two that make them non-interchangable, even though they have the same basic shape (morphology) and serve the same function (physiology). But this sloppiness or plasticity is exactly what is needed for adaptation and survival in rapidly changing environments.

As far as the preponderance of 'junk' DNA, in recent experiments, researches have removed DNA segments of several million nucleotides from mouse genomes with no apparent effect on the mice when examined over several generations. There appears to be very little cost to an organism (at least a complex one) to carrying around a lot of excess, unused DNA, just as there is very little burden to an architect to carry a bunch of old, unused drawings in his trunk. Remember, every cell in your body has the genes to produce insulin, although only a small number of beta cells in your pancreas actually do so.


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fallacycop
Member (Idle past 3628 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 21 of 45 (401653)
05-21-2007 1:00 AM
Reply to: Message 8 by Coragyps
05-19-2007 1:15 PM


The insides of neutron stars and white dwarfs were once periodic table residents but have been squashed to something else

Actually, the inside of white dwarfs is made of normal nuclei from th familiar periodic table, while neutron stars, as you pointed out, has been squashed into some other (more compact) form of matter.
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taylor_31
Member (Idle past 4031 days)
Posts: 86
From: Oklahoma!
Joined: 05-14-2007


Message 22 of 45 (401763)
05-22-2007 12:34 AM


Thank you everybody for all the help. I believe that I have a stronger understanding of this issue and I will continue in my spare time to research it, and I will also read the information that everybody has provided.

With Zoology looming in the approaching semester, I'm going to need every piece of knowledge I can get. :p


  
IamJoseph
Member (Idle past 1776 days)
Posts: 2822
Joined: 06-30-2007


Message 23 of 45 (409762)
07-11-2007 6:03 AM
Reply to: Message 1 by taylor_31
05-18-2007 1:36 AM


quote:

Let’s start at the beginning of life, with an organism called “X”. Theoretically, you can take the genetic material of X and mutate it, eventually forming a redwood tree, or a dog. This would take billions of years, and it would involve artificial selection instead of natural selection. It would also be improbable due to human constraints, but it's possible.

My question may sound stupid, but here it is: If you start out with X, and you end with a redwood tree, where did all that material come from? How can you go from X to bark and leaves and branches, etc.? Surely trees and bacteria aren’t made of the same material?


Good question, and one which impacts many premises. Yes, IMHO, all life was made from earthly material, and this can be accounted for by a reductionism: calcium and other minerals are earthly components. However, there must also be another factor involved, because the dust of earth's matter does not result in life by itself, even given eons of light years. We have similar conditions on the moon. I see it as an external triggering factor being required to interact with earthly material to activate life - else nothing happens.

The premise life begins in and from inanimate matter of and by itself is unsustained, and never seen here or in other planets. The premise that earth contains a special mix to condone life is also not sustained, including that water is not seen elsewhere. Pineapples are also not seen elsewhere. Life requires a complete and vast array of structures, with each structure intergrated to all others in a critical design, and one which contradicts the chance premise, even an accumulated series of chance occurences, which compound the odss at every treshold - thereby only increasing the odds for life by itself. Vegetation and other food products constitute only one of 100s of 1000s of other intergrated structures required to support life.

The premise that earth is the exact critical distance from the sun, for example, to produce vegetation, is unsustainable: we have vegetation in the deepest recesses of the oceans, where light won't reach it - this affirms that a criticl light is not the factor, and that life could have evolved in different distances from the sun. The principle of life requiring critical conditions, even if correct, does not mean only critical conditions of earth - it means 'critical conditions' - period! IOW, if life could emerge here in prevailing over one million adverse conditions - it aught to prevail over 2 million adverse conditions elsewhere.

The premise life requires water but cannot evolved without it, is as naive and simplistic as saying water creates life. In fact, we can pick out any of a million factors which would negate life if it were not prevailent.

Edited by IamJoseph, : No reason given.


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IamJoseph
Member (Idle past 1776 days)
Posts: 2822
Joined: 06-30-2007


Message 24 of 45 (409764)
07-11-2007 6:27 AM
Reply to: Message 18 by Doddy
05-20-2007 8:38 PM


quote:
doddy
As far as your guess goes, you are exactly right. Both mitochondria and chloroplasts replicate seperately to the host cell, and when the cell divides, half (roughly) of the mitochondria/chloroplasts go to each cell.

This is important to note for sexually reproducing organism, as sperm/pollen cells do not give their mitochondria to the egg cell (they only give their nucleus). Therefore, while you may have your mother's or your father's genes, you can only have your mother's mitochondria!


Mitochondria is tself a derivitive of an already exiting life form, namely bacteria. IOW, life already existed before this product emerged.


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Replies to this message:
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Dr Adequate
Member
Posts: 16093
Joined: 07-20-2006
Member Rating: 9.0


Message 25 of 45 (409780)
07-11-2007 8:04 AM
Reply to: Message 24 by IamJoseph
07-11-2007 6:27 AM


Mitochondria is tself a derivitive of an already exiting life form, namely bacteria. IOW, life already existed before this product emerged.

This may be the first post you've made without a gross error in it. Though a pedant would point out that "mitochondria" is plural.

It's completely irrelevant to the discussion, but at least it's not wildly untrue or written in a private language of your own, so I guess you're improving.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
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IamJoseph
Member (Idle past 1776 days)
Posts: 2822
Joined: 06-30-2007


Message 26 of 45 (409782)
07-11-2007 8:20 AM
Reply to: Message 25 by Dr Adequate
07-11-2007 8:04 AM


quote:

gross error

Is an error gross or is gross an error?


This message is a reply to:
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Replies to this message:
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Dr Adequate
Member
Posts: 16093
Joined: 07-20-2006
Member Rating: 9.0


Message 27 of 45 (409784)
07-11-2007 8:37 AM
Reply to: Message 26 by IamJoseph
07-11-2007 8:20 AM


Is an error gross or is gross an error?

And yet you assure me that English is your native language.

Edited by Dr Adequate, : No reason given.


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New Cat's Eye
Inactive Member


Message 28 of 45 (409808)
07-11-2007 11:57 AM
Reply to: Message 23 by IamJoseph
07-11-2007 6:03 AM


However, there must also be another factor involved, because the dust of earth's matter does not result in life by itself, even given eons of light years. We have similar conditions on the moon.

Ummm... the moon doesn't have an atmosphere. That's quite a difference!

I see it as an external triggering factor being required to interact with earthly material to activate life - else nothing happens.

Yeah, like a lightning bolt, or some radiation.

The premise life begins in and from inanimate matter of and by itself is unsustained, and never seen here or in other planets.

But they have created the building blocks of life from inanimate matter. Its not as far of a leap as you make it out to be for life to arrise naturally.


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crashfrog
Inactive Member


Message 29 of 45 (409823)
07-11-2007 2:15 PM
Reply to: Message 23 by IamJoseph
07-11-2007 6:03 AM


the dust of earth's matter does not result in life by itself, even given eons of light years.

This statement is nonsensical. Light years are a measurement unit of distance, not time.

IOW, if life could emerge here in prevailing over one million adverse conditions - it aught to prevail over 2 million adverse conditions elsewhere.

This is your same old argument, as nonsensical as ever. Life requires Earthlike conditions to evolve and survive. That life has no evolved under conditions that are not Earth-like hardly contradicts this premise; indeed, it supports it.


This message is a reply to:
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IamJoseph
Member (Idle past 1776 days)
Posts: 2822
Joined: 06-30-2007


Message 30 of 45 (409872)
07-11-2007 9:29 PM
Reply to: Message 29 by crashfrog
07-11-2007 2:15 PM


quote:

This statement is nonsensical. Light years are a measurement unit of distance, not time.


These are inter-changeable, relative to its context.

quote:

This is your same old argument, as nonsensical as ever. Life requires Earthlike conditions to evolve and survive. That life has no evolved under conditions that are not Earth-like hardly contradicts this premise; indeed, it supports it.


Conditions to survive, and activation, are two different paradigms. The life seen in a swamp, for example, did not initiate solely because of earth-like conditions, is my point. Further, to survive, conditions have to be intergrated and designed in a way the subject is receptive. A mother can support an off-spring, but the emerging life is condusive - signifying a hovering program which incorporates both. Life is involuntary.


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