Climate change speeds up microbial change

**Mid** · 12-02-2012, 06:58 PM

Climate change speeds up microbial change
11 Feb, 2012

Craig Cary, professor at the University of Waikato, who led the study said that it's important we keep documenting the current biodiversity in Antarctica so we can predict the effects of climate change.

SYDNEY: Climate change could affect Antarctica's Dry Valleys more rapidly than previously expected, particularly the microbial communities in the soil, a study reveals.

"We used to think that microbial change took place slowly over centuries," said Craig Cary, professor at the University of Waikato, who led the study.

"It's important we keep documenting the current biodiversity in Antarctica so we can predict the effects of climate change," said Cary, the journal Nature Communications reported.

To do this, the researchers transferred a 250-year-old carcass to an untouched site and used community DNA fingerprinting and new sequencing techniques to track the changes in microbial composition and structure.

It took only two years for major changes to occur during the five-year study, a university statement said.

"The research we've been doing indicates that the bacteria living in the soil are inherently sensitive to climate variability -- minor temperature variations could lead to cascading changes in hydrology and biogeochemical cycling and could dramatically affect ecosystem function," said Cary.

Polar systems are particularly susceptible to climate change and this study will provide a foundation for future observations on the fate of life in these extreme environments, added Cary.

economictimes.indiatimes.com

**barbaro** · 12-02-2012, 08:39 PM

I've seen some documentaries on scientific studies in Antarctica. Very interesting yet disturbing.

A lot of changes happening.

**kingwilly** · 12-02-2012, 09:34 PM

Originally Posted by Mid

"We used to think that microbial change took place slowly over centuries,"

No, we didnt.

For instance, it is well known that bacteria have developed resistance to many antibiotics over the last few decades.

Anyway, this in ONE study. That's it, one study.

It takes hundreds and thousands of studies to make such a conclusion.

Yet another example of a scientist jumping onto the climate change bandwagon in order to get additional funding and fame.

**Takeovers** · 13-02-2012, 12:30 AM

Originally Posted by Sir Wilson

Originally Posted by Mid

"We used to think that microbial change took place slowly over centuries,"

No, we didnt.

For instance, it is well known that bacteria have developed resistance to many antibiotics over the last few decades.

Anyway, this in ONE study. That's it, one study.

It takes hundreds and thousands of studies to make such a conclusion.

Yet another example of a scientist jumping onto the climate change bandwagon in order to get additional funding and fame.

I firmly believe in climate change as a real and present threat. But you are right on this one. Why would anybody in his right mind believe that bacteria react slowly to changes? Given their fast reproduction rate?

**blue** · 13-02-2012, 02:07 AM

i couldn't care less about polar bears
so bacteria ?
they will cope and so will we

**Umbuku** · 13-02-2012, 04:09 AM

Originally Posted by Takeovers

Why would anybody in his right mind believe that bacteria react slowly to changes?

I suspect the scientist is talking about bacteria in the soil in Antarctica. Low temperatures, limited food supply and isolation from other species in their family group must slow down mutation rates. Hence the 250 year old carcass full of developed but alien microbes used to test mutation rates against the normal environmental conditions.

What it has to do with climate change is a preparatory study with which to compare changes in the microbial environment into the future.

**blue** · 13-02-2012, 04:19 AM

Originally Posted by Umbuku

Low temperatures, limited food supply and isolation from other species in their family group must slow down mutation rates.

surly the opposite is true
nature under pressure tends to mutate more not less

**dirtydog** · 13-02-2012, 04:24 AM

Fuk polar bears, they eat the penguins....

**kingwilly** · 13-02-2012, 06:04 AM

They already have, that's why there's none left in Antarctica.

**Takeovers** · 13-02-2012, 06:19 AM

Originally Posted by Sir Wilson

They already have, that's why there's none left in Antarctica.

What a pity. All the polar bears in the sough eaten by the nasty penguins? That is why the only surviving polar bears live in the north?

**kingwilly** · 13-02-2012, 08:23 AM

Nope,

polar bears south, penguins norf.

**Takeovers** · 13-02-2012, 01:59 PM

Originally Posted by Sir Wilson

Nope,

polar bears south, penguins norf.

Do I understand you correctly? You are saying the polar bears were eaten in the south by the penguins and the penguins eaten by the polar baers in the north?

**FlyFree** · 13-02-2012, 02:22 PM

She's saying that Antarctic Polar bears ate all the Antarctic penguins.

Bastards.

**Takeovers** · 13-02-2012, 03:08 PM

Originally Posted by FlyFree

She's saying that Antarctic Polar bears ate all the Antarctic penguins.

Bastards.

So all those movies and documentaries showing penguins in the south and polar bears in the north are devious fakes to confuse an unsuspecting gullible population.

**FlyFree** · 13-02-2012, 03:38 PM

Originally Posted by Takeovers

Originally Posted by FlyFree

She's saying that Antarctic Polar bears ate all the Antarctic penguins.

Bastards.

So all those movies and documentaries showing penguins in the south and polar bears in the north are devious fakes to confuse an unsuspecting gullible population.

All part of the propaganda by the ruling elite, to keep the masses quiet. Like the moon landing way back when.

And climate change, to tax them more.

**Hampsha** · 13-02-2012, 05:41 PM

You can't beat nature. It's going to kill you.

**Umbuku** · 13-02-2012, 07:22 PM

Originally Posted by blue

surly the opposite is true nature under pressure tends to mutate more not less

Mutation occurs with reproduction. Less contact between species with compatabile genomes means less variation. Think of the genome as a deck of cards that is shuffled with every reproduction. In times of environmental stress those mutations that are beneficial become dominant in the gene pool. If there is no benefecial mutation in the genome then the species dies off. Don't short the deck as it increases the odds.

**Takeovers** · 13-02-2012, 07:31 PM

With bacteria there is another reason for changes. Dormant bacteria of all kinds are everywhere. As soon as the conditions change, the mix of bacteria you find will change almost instantly. Even with cold conditions for bacteria 1 year is plenty of time for major changes with changing conditons.

**kingwilly** · 13-02-2012, 08:22 PM

Originally Posted by Umbuku

Mutation occurs with reproduction. Less contact between species with compatabile genomes means less variation.

Not 100% correct there. Random mutation occurs with reproduction, yes. However, mutation or speciation occurs more quickly in a smaller or isolated population. Larger populations, or non isolate populations tend to have a smoothing effect on mutations.

**Umbuku** · 14-02-2012, 01:07 AM

Except I wasn't refering to the size of the population but the frequency of contact between individuals, which in Antartica is less due to the harsh environment. I should have made that point more clear.

**kingwilly** · 14-02-2012, 04:26 AM

It does't matter how clear you make your point, it was wrong.

However, you've actually made two completely different statements here, the first statement is talking about contact between species, the second contact between individuals of a population. Rather muddled thinking.

Originally Posted by Umbuku

Less contact between species with compatabile genomes means less variation.

Originally Posted by Umbuku

Except I wasn't refering to the size of the population but the frequency of contact between individuals, which in Antartica is less .

**Umbuku** · 14-02-2012, 07:12 AM

Originally Posted by Sir Wilson

It does't matter how clear you make your point, it was wrong.

In any finite population, the process of evolution is well known to be influenced by population size and mutation effects [16]. Beneficial mutations are more frequently fixed in large populations than in small ones, whereas deleterious mutations are more frequently eliminated. Two studies, one based on a theoretical mathematical model [17], and one on experiments of digital organisms [18], arrived at a similar conclusion; namely, that mutational robustness tended to decline with increasing population size, and thus selection in small populations would favor robustness mechanisms. In a population of a given size, the process of evolution will depend on the relative rate of appearance of deleterious and beneficial mutations as well as their actual mutational effects. Selection associated with deleterious mutations will favor lower mutation rates, while beneficial mutations will favor higher mutation rates [9]. Nevertheless, the evolution of extremely high mutation rates is unlikely to occur unless organisms are under special circumstances [19] for the reason that beneficial mutations rarely compensate for deleterious mutations. The importance of this interplay between mutation rate and its effects was pointed out by Keightley [20], who showed that the genome-wide mutation rate and the distribution of fitness effects of mutations could not be simultaneously estimated because they are confounded with one another: a high mutation rate can usually be explained by a low variance in fitness effects, or a low mutation rate with a high variance in fitness effects. Unfortunately, this conclusion is true only for deleterious mutations and further investigation is needed for cases where beneficial mutations also occur.

BMC Evolutionary Biology | Full text | Impacts of mutation effects and population size on mutation rate in asexual populations: a simulation study

The 'smoothing' effect in large populatins that you speak of is only for deleterius mutations.

Originally Posted by Sir Wilson

you've actually made two completely different statements here

Originally Posted by Umbuku

Less contact between "members of" species with compatabile genomes means less variation.

As I said.

Originally Posted by Umbuku

I should have made that point more clear.

**kingwilly** · 14-02-2012, 07:20 AM

Two studies mate.

You should know enough not to quote two studies as your source for what is school kid science.

Originally Posted by Umbuku

Less contact between "members of" species with compatabile genomes means less variation.

nice addition, it completely changes the meaning, so trying to pass your error off as a slightly less than clear statement is farcical.

**Umbuku** · 14-02-2012, 07:44 PM

Originally Posted by Sir Wilson

You should know enough not to quote two studies as your source for what is school kid science.

Since when did a Thai expat forum become a peer reviewed journal.

Wikipedia had the same information by the way.

**kingwilly** · 14-02-2012, 08:03 PM

are you serious ?

I'm not telling you off for poor referencing, I'm pointing out that a single study or two studies does not equal a scientific rule.

I'm sure I could find a study showing that the bacteria came from Mars.

If you knew anything about how science works, you would know this.

Originally Posted by Umbuku

Wikipedia had the same information by the way.

Now I know you're having a lend.

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