Thursday, February 21, 2008 | Science : Evolution and Biology | print version

Missing link found in Sydney Harbour

by Sydney Morning Herald

Thanks to Clayton Smith for the link.

Reposted from:
http://www.smh.com.au/news/science/missing-link-found-in-sydney-harbour/2008/02/21/1203467216357.html?sssdmh=dm16.303808

Richard Macey
February 21, 2008 - 5:56AM

ONE of evolution's missing links has been found lurking in Sydney Harbour.

Although only a microscopic, single-celled creature, it has excited scientists around the world because it is the nearest relative yet found of a group of deadly parasites.

Its discovery, said Dee Carter, a University of Sydney microbiologist and member of the international team that found the organism, may provide vital clues for researchers seeking new weapons in the war against diseases such as malaria.

Despite being a type of brown algae, an analysis of the new organism's DNA revealed that its closest relatives include cryptosporidium, the parasite which invaded Sydney's water in 1998, and plasmodium, the cause of malaria.

"Scientists have known for some time that these parasites are related to algae," Associate Professor Carter said yesterday.

That is because parasites contain relics of what were once chloroplasts, the mechanisms that allow plants to turn sunlight into energy through photosynthesis.

However, until now, the closest known parasite relatives were a group of simple algae called dinoflagellates, often found living in coral.

But, said Professor Carter, they were very distant relatives indeed. Comparing dinoflagellates with parasites was "like comparing us with ants".

The new organism was much more closely related and appeared to be the long sought "missing link" between the two forms of life.

It was discovered by one of Professor Carter's former students, Bob Moore, while exploring Sydney Harbour for algae living in coral.

Only when then the organism was studied by the team of Australian, US and Czech scientists was it realised that it bridged the evolutionary gap. Their findings have been published in Nature.

Professor Carter said it was amazing that such an important discovery could be made in Sydney Harbour.

She speculated that the first parasites may have evolved long ago from algae which grew inside marine animals. "At some stage [the algae] said: 'Let's stop making our own food. Let's take it from our host"'.

As the organisms invaded the animal cells and evolved into parasites, they gradually lost their ability to convert sunlight into energy.

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1. Comment #130840 by Geoff on February 21, 2008 at 11:35 am

Yeah, but it's not a new "kind"!

And it's just made two gaps instead of one.

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2. Comment #130841 by pulsar1z on February 21, 2008 at 11:38 am

I think that little by little the argument by religious people, "where are the missing links" will go away.

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3. Comment #130847 by Driver on February 21, 2008 at 11:45 am

"I think that little by little the argument by religious people, "where are the missing links" will go away."

After that their argument will be "Well who do you think put the links together to form the chain?"

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4. Comment #130849 by He'sAVeryNaughtyBoy on February 21, 2008 at 11:48 am

Is it odd that recently I've been finding the world of the realy realy small far more interesting than our mundane middle world?

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5. Comment #130867 by D'Arcy on February 21, 2008 at 12:12 pm

I hope someone will send Dinesh D'Souza (self confessed mosquito) an e-mail to say that the ancestor of his parasite, plasmodium, has been found in Sydney. He believes in evolution, but he also believes in miracles. At least part of what he believes appears to have been confirmed - no not the miracle bit!

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6. Comment #130873 by knutsondc on February 21, 2008 at 12:19 pm

I have a small nit to pick here. Granted, it's a loose comment made for publication in a popular medium not meant to be taken literally, but I wish Prof. Carter hadn't said "At some stage [the algae] said: 'Let's stop making our own food. Let's take it from our host.'" This feeds into the common misconception exploited by creationists that evolution teaches that organisms "chose" the manner in which they adapted to their environments. It also smacks of Lysenkoism.

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7. Comment #130885 by HLVenkman on February 21, 2008 at 12:34 pm

Expecting the growth of scientific understanding to effectively curtail religious faith is akin to believing that personal espousement of Thomas Paine moves Richard Littlejohn away from the political right.

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8. Comment #130894 by clementine on February 21, 2008 at 1:08 pm

"This feeds into the common misconception exploited by creationists that evolution teaches that organisms "chose" the manner in which they adapted to their environments."
Yeah, it does!

-sigh-

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9. Comment #130916 by babrock on February 21, 2008 at 1:42 pm

It seams to me that one doesnot evev have to go to t fossil record to see missing links. I saw this thing recently where polar bears can mate w/ grizzly bears. T cubs learn from t mom which to act like but they can sucsesfuly breed w/ either one, I think. It shouldnot be that hard to imagine t two species to otherwise to have evolved such that their offspring become sterile hybrids like those from horses and mules, or lions and tigers, or all t hybrid seed stock, ect.. And then to where they cannot produce offspring at all. And too, there are those birds that Dawkins taked about in "Blind Watchmaker" maybe, ring necked terns (again maybe). They could generaly breed w/ those nearby to both sides but not w/ those too far away.

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10. Comment #130920 by tacitus on February 21, 2008 at 1:44 pm

Actually, who knows what Prof. Carter really said. Note the square brackets:

"At some stage [the algae] said: 'Let's stop making our own food. Let's take it from our host.'"

What Carter may have said is something like "At some stage [it's as if the algae] said..." or something even less confusing but more technical that the reporter removed from the piece. I would blame the reporter in this case.

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11. Comment #130952 by HappyPrimate on February 21, 2008 at 2:34 pm

One of my pet peeves is the language used, even by scientists themselves, when explaining aspects of how organisms evolve. Any reference to modification/adaptation as a choice is just plain wrong and gives the mistaken impression to those who know nothing or very little about the process. Words should be chosen carefully so as not to mislead the general public. There is far too much confusion about evolution by the under-educated to add any seemingly credible doubts about the facts.

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12. Comment #130972 by Robert Maynard on February 21, 2008 at 3:41 pm

Sydney represent!!

...
er, sorry.

Neat discovery.

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13. Comment #130974 by Frankus1122 on February 21, 2008 at 3:54 pm

I noticed the language problem on the weekend while listening to a science radio program. It had to do with the recently discovered bats fossils. I can't exactly remember what was said but I remember thinking that what was said was wrong. It had to do with creatures choosing to evolve in a particular way.
I'm with HappyPrimate and knutsondc; more care is required in discussing evolution so that it is better understood by the general population.

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14. Comment #130979 by BAEOZ on February 21, 2008 at 4:09 pm

ONE of evolution's missing links has been found lurking in Sydney Harbour.

Although only a microscopic, single-celled creature

So that's where John Howard has been hiding since the last election.

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15. Comment #130983 by sarah95 on February 21, 2008 at 4:15 pm

But, said Professor Carter, they were very distant relatives indeed. Comparing dinoflagellates with parasites was "like comparing us with ants".

The new organism was much more closely related and appeared to be the long sought "missing link" between the two forms of life.

She speculated that the first parasites may have evolved long ago from algae which grew inside marine animals. "At some stage [the algae] said: 'Let's stop making our own food. Let's take it from our host"'.

COOL. I hate it when I talk about how fascinating biology is, and people just gape confusedly. It's sad really. I think they all need a dose of Dawkins.

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16. Comment #131043 by Paradigm on February 21, 2008 at 7:21 pm

Comment #130849 by He'sAVeryNaughtyBoy on February 21, 2008 at 11:48 am
Is it odd that recently I've been finding the world of the realy realy small far more interesting than our mundane middle world?

Not at all. That's the coolest part of biology if you ask me.

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17. Comment #131098 by PJG on February 22, 2008 at 12:52 am

I agree that scientists need to start being more careful about how their words may be misinterpreted or, more importantly, mis-USED!

I recently watched The Life of Mammals again and (my awareness raised) felt quite uncomfortable that the first episode was entitled "A Winning Design".

babrock
There are quite a few examples of ring species :-

http://en.wikipedia.org/wiki/Ring_species

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18. Comment #131456 by Vadjong on February 22, 2008 at 12:57 pm

I DO NOT agree that scientists need to start being more careful about how their words may be misinterpreted or, more importantly, mis-USED!

In his books Richard always makes it a point to explain why he may use "as if" language now and again. Everybody uses lies-to-children(TM) to explain things a bit simpler and more direct. The difference is admitting this and taking the opportunity to say: 'Well, ofcourse they didn't really ...., but that's what it just looks like in hindsight.' Repeat this enough times and Joe Public will catch on (and hopefully be a bit more savvy against those who tell the really tall tales).
Lo ... it's meme-inoculation !

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19. Comment #131549 by PJG on February 22, 2008 at 2:37 pm

Vadjong

Of course there is no problem using "as if..."

I don't think it would be a problem using "design" or any of the other examples given above if Joe Public were more aware.

However, when more than 50% (if I remember rightly) of the American and about 95% of the worldwide Muslim population (again, if my understanding is correct) do not believe in evolution, then I think we should all be careful not to use vocabulary that may increase their number.

The word "design" does imply a designer and I think there are more appropriate words to use as a title (in the example I give above) - in the circumstances.

When I said "mis-USED" I meant "used by the creationists to mislead"... not mis-used by the scientists.

EDIT: I used to say "the human body was not designed to...[whatever]". Now I ALWAYS say "The human body did not evolve to...."

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20. Comment #131612 by jo5ef on February 22, 2008 at 5:23 pm

I think the reason that scientists discussing evolution are so prone to using the same kind of language that is used to describe the actions of intelligent agents is that there is some parallel between organic evolution and the process whereby brains develop ideas and concepts. I realize this is a bit hand waving, but I think eventually we'll find organic evolution by NS to be one example of a whole range of natural phenomena that feature a finite set of symbols that can be combined in infinite ways to form larger units that are then subject to some sort of selective pressure.
My question is: can you have intelligence without consiousness?

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21. Comment #132484 by Laurie Fraser on February 24, 2008 at 8:22 pm