Airmid

I made it through most of the first article. Then I turned to the Literature section to see what their background is. Whatever it is, it's definitely not in genetics.

As to the "proof" they are giving to back up their ideas: their main source is someone, who claims to have invented a machine that can transfer genetic information in the form of some kind of "bioelectric field" from individual to individual. According to our authors, he created a hybrid of a chicken and a duck with his machine.

A quick google search was pretty revealing: it did not return any publications by this person, nor any descriptions of his experiments by others than our authors and the like, nor any patents, nor any kind of biography, nor anything else to show that this person actually ever existed.

So here's my verdict: it's complete nonsense wrapped in lots of jargon, preferably used out of context, to cover up that they have no idea what they're talking about.

Airmid.

I don't think there's any credible evidence showing this, and even if there is, correlation is not the same as causation.

So the folks who invented the words "lunatic" and "moonstruck" were talking moonshine? *grins*

Actually' date=' because you're implying rainforrest destruction for ranching, I'll have to ask you to take note that under my avatar it says Location:Kansas. If my state were a nation, it would be the third leading beef producing nation in the world behind the UK and Argentina. [/quote']

But Brazil is since 2003 the world's leading beef exporter, with Australia as second.

The problem in Brazil is that a substantial portion of this rainforrest destruction is caused for a need for farm land, crops not animals.

Yep, that's why I mentioned soy beans in my previous post. Brazil and Argentina are the top soy exporters at the moment, and alas, a large part of this soy is used to fatten up animals fast.

But they destroy their topsoil and need to destroy more' date=' so they don't get much time on the land they clear. They're not getting much bang for their buck. And, a note should also be made, that the oxygen, and CO2 taken out, produced by cutting down mature rainforest to plant new crops is substantially diminished by the activity. It's an idiotic activity that is slowly but surely screwing us all.[/quote']

I completely agree.

 

Airmid.

We already have such a law in place; it's a law against discrimination and incitement to hatred.

I like it. First as a sign that in my little country things like that are not tolerated. Secondly it gives us a tool to actually get a grip on extremist movements.

So far, if I remember right, the hatred incitement part of the law has been used to prosecute an antisemitic organization, a neo-nazi group, an extremist right-wing political party, and 2 extremist imams, at least, those were the cases that got publicity.

As to loss of free speech: do you really think that people should be allowed to go around shouting that "such-and-so group of people don't deserve to live" or "such-and-so group of people are nothing better than apes" or whatever? That's not free speech, that's crime in my eyes.

Airmid.

I used to be a believer in "elan vital" myself, but I gradually changed my mind.

It started with the realization that there's no way to actually see if a bacterium is alive or dead. There's some exceptions to that: if the cell wall is broken, it's dead; and if it's metabolizing, it's alive. But an intact cell that is not metabolizing might be either.

The death blow to my former belief came from bacteria that had been encased in fossile amber. In a number of experiments, bacterial spores that had been encased for up to 35 million years were made to germinate in laboratories and created viable cultures.

This lead me to the conclusion that bacteria are basically immortal: if the chemical machinery is intact, it's alive. When conditions go bad, they simply start to protect themselves (by creating spores or other structural and chemical adaptations) and shut down completely. In this "dead-but-alive" state they can persist forever, unless for instance radiation damages their chemistry beyond repair.

There was no way I could match this conclusion with my former belief in the "sparkle of life". So, exit "elan vital"!

Airmid.

Plants are not endless C02 soaks. Plants also release a lot of CO2 over it's life time. At best a forrest should have a neutral CO2 input/output.

 

As a forest matures it will have decaying plants that relesae the CO2 that is stored over it's life time.

What are you talking about?

What Edtharan says is true: mature forests do not take up net CO2. Young' date=' growing forests, however, are a great sink for CO2. So what we could do is plant young trees, cut them down as soon as they reach maturity, and make sure their wood never decays or burns, since that would release all the carbon it has trapped again. Burying large amounts of wood would be a good idea, perhaps we would even provide future generations with fossile fuels. An other idea is to use more wood in buildings and furniture. It must be wood that is grown and harvested wisely, of course, and there will be another catch: once you own a nice wooden table you wouldn't be allowed to throw it away when you get sick of it.

On a sideline, but I couldn't help reacting to this:

... and take over Brazil before they ruin the rainforrest with their bizarre farming practices.

You realize this is actually our own fault? We want our burgers, and we want them cheap. Countries like Brazil, where wages are low and where there's no environmental regulations, provide us either with cheap meat, or cheap soy, that's being used to feed cattle elsewhere in the world.

Airmid.

Thanks Moonquake, that was a good read!

The current definition of life (well, I shouldn't call it a definition but rather a description) is "a chemical system that is capable of Darwinian evolution".

What if someone wrote a virus that could have random mutations occure in its code each time it coppied it's self. This would make it act a bit more like a genetic code.

 

However ther would need to be some method to "kill" off other viruses as wellas it's self because in an imortal population (death is imposable) no evolution can take place. Evolution occures because of the posability of death. And selection pressure is strongest amongst peers.

 

This competition amongst peers means that there must be something that have to compete over (proccessor time' date=' memory, avoidance of anti virus software, etc).

 

These programs would evolve, die (get deleted), reproduce, comsume resources (memory and cpu time)... But would they be alive?

[/quote']

 

I think you have the most important bit of the "definition" covered this way, so I wouldn't have a problem calling it life.

In fact, I remember that years ago someone wrote such a program. It ran for months? years? and showed all kinds of interesting Darwinian traits. I don't remember enough of this project to google it for more information, can anyone help out?

 

Airmid.

Today I found this article on my favorite science news site. You're not the only one who thinks that there's more than one kind of life on earth, Sashatheman!

Airmid.

Nice subject and a good read! A good thing this thread has been revived.

Most heavenly smells: cinnamon, cumarin, freshly brewed coffee, freshly baked bread.

Interestingly, last year I had a bad flu, and my smell was really impaired. Now usually the result is you can't smell anything at all, but this time I found I was strangely sensitive to certain odours. I couldn't stand the smell of coffee, fried egg, toast, or anything else that contained heated or burnt organics. I was almost choking as soon as anyone turned on the toaster! Did anything like this ever happen to any of you?

Great smells: anything that reminds me of my childhood, like paper, kid's glue, watercolor paint, clay, ink. That's more psychological than chemical, of course, but if you folks mention gasoline and the "new car" smell and the "new electronics" smell, I guess I can mention these *grins*. Also great: freshly ironed cotton. I wonder what makes it smell so nice.

Very nice in small doses: anything really, as long as the dose is small enough.

Most horrid smell: autoclaved bacteria (like rotten chicken soup, but much much worse)

Airmid.

The birds here are the talk of the town, and on top of that, several parks here look trashed, trees destroyed.

Wow, that doesn't sound like the work of geese. Any idea what kinds of birds they are?

Airmid, are you sure the birds are moving to their breeding areas? It's very cold right now and the birds are moving to even colder places. Shouldn't they move north in March when it gets warmer?

Geese like the Canada Goose don't mind the cold, unless there's still a snow cover. They seem to have a preference for the first fresh shoots that grow after the snow has melted, perhaps because those are more nutritious. Do you still have snow?

Airmid.

That's perfectly normal: the birds are migrating towards their breeding grounds.

Here in northwest Europe the birds are arriving right on time. Bird migration is being watched closely here at the moment because this year the birds bring a nasty surprise - the avian influenza.

Has the disease been spotted in the Americas too?

Airmid.

but yeh if life on another planet is found' date=' could it possly not use DNA like life on earth done, and use something similar to it, or completely different? makes me wonder[/quote']

 

Yep, I'm asking myself the same question. I'm putting myself in some constraints though, since my starting hypothesis is that the building blocks of life originate from space. Following that thought, life on other planets should be built from the same building blocks too. We have amino acids in space, so there's something to work with. Polymerizing doesn't seem to be much of a problem, given some favourable conditions. That's only a first step, but it might lead to RNA/DNA-like structures anywhere to store genetic information.

I haven't been reading up in depth yet about RNA/DNA and potential alternatives, but I will need to do so soon. There's some questions nagging my brains though, and those are: why only 20 (or actually 22) amino acids are used in Earth life; why are only a few bases used in RNA/DNA; why can't life do without RNA/DNA; what exactly is the role of RNA/DNA for Earth life; and, why is RNA/DNA so well fitted to carry out this task.

 

How nice it would be to get those questions answered! The last 2 questions seem to me the ones that might actually be answerable, so that's what I'll focus on for a start. Any suggestions are appreciated!

 

Airmid.

I wonder...... Is “facilitated variation” again a new synomyn for ID? Or is this really something new?

That's exactly the question astrobiologists ask themselves.

Personally, I'd answer this question with "yes", but of course there's no evidence (yet). It will be really hard to find any evidence on Earth, though. Life on Earth is quite old, and in the old days resources that could sustain life were probably pretty rare. Competition must therefore have been fierce, so only the best adapted organisms would have been able to survive.

If a second attempt to create life has been made later in the history of Earth, it would have had very little chance to survive, since it would have to compete with the already well-established and evolved life on Earth.

So prospects to find any evidence of Earth are bleak. There's two tiny sparks of hope left. First, 80% of the microbial life in sea has never been cultured, and so has never been studied genetically. Second, there's Lake Vostok, a lake that lies underneath kilometers of ice on Antarctica, and that has been sealed off from the rest of the world for millions of years. It will be very interesting indeed to see what kind of organisms can be found there!

Still, I think the best chance to find other life forms will be on other planets.

Cool!

Lichens have been taken to the International Space Station and exposed to the space environment, and they survived. Of course lichens aren't exactly plants, and they couldn't grow in space, but they managed to keep their cells intact after being exposed for 14 days, and were able to grow again when back on earth. Here you can find a bit more information about the experiment.

NASA and others are working on the possibility of growing crop plants under Martian conditions. I don't think they have been successful yet. They are able to grow some plants at reduced atmospheric pressure, but nowhere near Martian conditions. This article describes some of the problems they encountered.

Airmid.

You might want to check out the ideas of Rupert Sheldrake, a biologist who used the rats example and others to formulate a controversial theory.

Airmid.

Science is the art of asking the right questions.

To illustrate I'll use bits of Darwin's Origin of Species. During his travels, Darwin was amazed by the variability of plants and animals he encountered. He considered the equally amazing variation seen in domestic breeds, and asked himself if those two phenomena were related. He first examined the relationship between species and domestic breeds in general, but couldn't reach a definite conclusion. He then decided to take up pidgeon breeding as a case study. He asked himself, if it would be possible that all domestic breeds originated from a single wild species. After investigation of the characteristics of domestic pidgeons and the history of pidgeon breeding he became convinced that that was the case.

Then he asked himself: by what means did the huge variety of pidgeon breeds come into existence? After consideration, he concluded that selection of specific traits by breeders was responsible for all the different pidgeon breeds. And this allowed him to formulate the concept of natural selection, and we all know what came from this....

In my opinion, this example shows that Darwin had the knack of asking the right questions. The answers to the questions led to the theory of evolution, of course, but those answers wouldn't have been found if he hadn't asked himself the question first. To ask the right questions wasn't a "mystical" talent of Darwin's, but he was able to do so because he had a thorough knowledge of for instance pidgeon breeding.

And this, in my view, is the relation between, for example, biology and physics. It's the study of biology that allows a scientist to ask the right questions about living beings. The answers to those questions might be supplied by physics, of course, so physics is very important indeed to a biologist. But a physicist wouldn't have been able to ask the right questions in biology, just like biologists wouldn't be able to ask the right questions in the field of physics.

Airmid.

I would help if I could, but I'm afraid I'll have to pass on your questions.

Airmid.

I did a bit more reading on the subject (I'm interested in bacterial metabolism anyway) and I've reached the conclusion that there is no such thing as THE gene for iron reducing. The iron-reducing bacteria are a very diverse group and only two organisms, Geobacter and Shewanella, have been studied in detail.

Here's two examples of relevant studies of Geobacter:

Combining in-situ reverse transcriptase polymerase chain reaction, microscopy and x-ray photoelectron microscopy to investigate mineral surface-associated microbial activities

OmcF, a Putative c-Type Monoheme Outer Membrane Cytochrome Required for the Expression of Other Outer Membrane Cytochromes in Geobacter sulfurreducens

Studies to find evidence for, and characterisation of, iron-reducing bacteria seems to have been undertaken by 16s rRNS analysis, though some have been using more specific primers than the general bacterial ones. For example, I came across this article, Diversity of Geobacteraceae Species Inhabiting Metal-Polluted Freshwater Lake Sediments Ascertained by 16S rDNA Analyses, which uses a Geobacteraceae-specific primer. Of course, you would be missing out on the other iron-reducing groups this way.

I'm afraid this is not really the answer you're looking for. But I hope that you will find a good way to proceed with your work.

Airmid.

I'm not quite sure what you're looking for.

Check out this article please (Phylogenetic Analysis of Dissimilatory Fe(III)-Reducing Bacteria, and see if it fits your subject. Two primers are mentioned in Materials and Methods, are those what you're looking for?

Airmid.

7. hybrid

Wikipedia is great stuff, I always use it when I want to get a start into a new topic. So I would start here (Isozyme) and then check out the references. I hope you can get hold of the articles and books mentioned there!

Airmid.

Rainforests are a unique ecosystem, with huge biodiversity, very high biomass, and the fastest recycling of nutrients ever measured. We definitely need to safe them!

One thing however, they do not, and that is produce net oxygen. Untouched rain forest is in steady state, which means that there is no net increase of biomass: every bit of growth in the system is balanced by decomposition. The oxygen that is produced by growth is lost again through respiration.

Ecosystems that produce net oxygen are oceans (when dead organisms sink to deep waters where they aren't broken down), swamps and peat bogs.

Of course, cutting down the rain forests and burning it will release a lot of CO2 that is normally stored in the system and taken out of circulation.

When a tree dies' date=' it releases its CO2, and I think that it doesn't matter if it dies a natural death, falling down, and rotting in the forest, or it gets burned, the same amount of CO2 gets released. Leaves that die and fall off release their CO2 as well. So it would make sense to burn it to produce energy rather than just let it rot away, especially if it could be burned under controlled conditions, with exhaust stack scrubbers to reduce particulates.

Does that make sense or am I missing something here?[/quote']

It makes sense, but there's a few things to consider. There's a lot of nutrients stored in the dead tree, like nitrogen, sulfur, potassium, etc. If you take those out of the system it can't grow back to its former amount of biomass, and thus decrease the amount of CO2 that's taken out of circulation. Taking the ashes back to the forest helps.

The other thing to consider is that not all carbon in the system can be found in trees and animals: there's a huge amount of carbon present in the microbial population too. Depriving them of food will slow down the recycling of nutrients, and the potential growth of plants.

 

One of the great strenghts of the rain forest, its extreme fast recycling of nutrients, is also its achilles heel. Rain forests typically have very thin soils, since organic material hardly gets the chance to accumulate in the soil. If an area of rain forest is cleared, the soil is very vulnerable to erosion. A thunderstorm can easily wash away the top layer and with it all its nutrients, leaving behind a barren place. It might take ages before a forest can grow there again. I think this makes it extra important to safe the rain forests.

 

Airmid.