Reply to: Evolution in action ?

[dang65]

ok . so why the fuss?
What excited some people is that this fits nicely with the theory of slight changes building up into a major change. This is set against the other side of the coin which is that major changes occur as a result of a single mutation.
You are right that no one was filming when one of the changes actually happened but the excited people would say, 'hey we were close enough'.

It's like hearing a bang, seeing the strike, then saying 'I didn't actually see the bullet leave the barrel, but I am convinced it did'

How does this fit particularly well with either of those theories? I mean, this particular dung beetle might have spent thousands of years finding dead millipedes, sussing out ways of getting in there, mutating its head shape, starting to attack live millipedes etc etc. Or it might have had a head like that already and one day decided to attack a millipede for the first time ever, out of the blue. What the hell does this observation prove?

There are thousands of examples of all kinds of flora and fauna adapting slightly to suit their environment or available food. Some actually have been witnessed, I believe, though more in behaviour than physical changes, such as animals adapting to human habitation and that.

I just don't get at all what is supposed to be so unique about this one. If you believe in evolution - which I do, by-the-way, in case anyone's having doubts! - then you see evidence of it everywhere you look. If you don't believe in evolution then this dung beetle ain't going to prove anything because it might have always eaten millipedes since the day God made it, using spare parts from an old dung beetle... who's to know?

[EternalOptimist]

OK, sure, but the point I'm trying to make is that this particular species has not (as far as I can make out from either of those articles) EVER been observed acting like other dung beetles. This is not a case of a species being observed changing its way of life. It's a type of dung beetle which has a different head shape and feeding habit to other dung beetles, that's all. It might have started eating millipedes 20,000 years ago, or whatever. What makes this different to, say, different bird species which have adapted to open shells of molluscs, or to get nectar from inside flowers, or insects from holes in trees?

Maybe I'm missing something, but this dung beetle thing just seems like a big fuss about nothing.

ok . so why the fuss?
What excited some people is that this fits nicely with the theory of slight changes building up into a major change. This is set against the other side of the coin which is that major changes occur as a result of a single mutation.
You are right that no one was filming when one of the changes actually happened but the excited people would say, 'hey we were close enough'.

It's like hearing a bang, seeing the strike, then saying 'I didn't actually see the bullet leave the barrel, but I am convinced it did'

[dang65]

Didn't read the BBC article, but according to ScienceNow it is still a dung beetle. The parts of the millipede it eats are the dung parts, i.e. the digestive tract.

OK, sure, but the point I'm trying to make is that this particular species has not (as far as I can make out from either of those articles) EVER been observed acting like other dung beetles. This is not a case of a species being observed changing its way of life. It's a type of dung beetle which has a different head shape and feeding habit to other dung beetles, that's all. It might have started eating millipedes 20,000 years ago, or whatever. What makes this different to, say, different bird species which have adapted to open shells of molluscs, or to get nectar from inside flowers, or insects from holes in trees?

Maybe I'm missing something, but this dung beetle thing just seems like a big fuss about nothing.

[EternalOptimist]

That's not what the BBC article says. It says that this whole species (D. valgum) is different from other dung beetle species:


So, it's basically not a dung beetle, but is a variant on a dung beetle which has evolved a different shaped head and different eating habits, presumably over thousands of years??

No one has actually seen this species rolling dung - they just think they should because they're related to dung beetles. But loads of species are closely related to other species which act very differently. What's the particular big deal about this one? This one hasn't even got the right shape head for rolling dung!

Didn't read the BBC article, but according to ScienceNow it is still a dung beetle. The parts of the millipede it eats are the dung parts, i.e. the digestive tract.

'It's a "pretty spectacular finding," says biologist Armin Moczek of Indiana University, Bloomington. But he points out that millipedes have a high proportion of feces inside them because they feed on rotting plants. So if the dung beetles are eating their guts, he speculates, they're essentially still eating dung.'

http://sciencenow.sciencemag.org/cgi...ull/2009/122/1

[NotAllThere]

When a new species comes into being. That's why this might be important.

Trouble is, biologists have difficult defining what "species" is.

This is much more interesting than some purported new species.

[dang65]

You miss the point. The species does roll dung, and their bodies are well suited to it. Some members of the species are slightly different, and it is these differences that make it able to catch and eat the millipedes.

That's not what the BBC article says. It says that this whole species (D. valgum) is different from other dung beetle species:

They found D. valgum fed exclusively on the millipedes, preferring prey which were alive but injured.

[...]

Despite its close relationships with dung feeding species, D. valgum has entirely abandoned its ball-rolling behaviour.

[...]

The beetles were never seen rolling dung balls. Instead, they used their powerful hind legs to drag a killed millipede to a safe site and then begin devouring it.

Dung beetles' heads are usually flat and wide like a shovel in order to roll balls of dung but D. valgum has a narrow, pointy head which it uses to get right inside the millipede's body and feed on its insides.

So, it's basically not a dung beetle, but is a variant on a dung beetle which has evolved a different shaped head and different eating habits, presumably over thousands of years??

No one has actually seen this species rolling dung - they just think they should because they're related to dung beetles. But loads of species are closely related to other species which act very differently. What's the particular big deal about this one? This one hasn't even got the right shape head for rolling dung!

[expat]

I doubt it. Is it more astonishing than the huge variety of dogs that came from a single wolf species?

When does selective breeding become evolution?

When a new species comes into being. That's why this might be important.

[EternalOptimist]

I doubt it. Is it more astonishing than the huge variety of dogs that came from a single wolf species?

When does selective breeding become evolution?

when the dung beetle moves on from millipedes, to millibands, reads the Daily Mail and rolls his own reefers and says
'Now THATS what I call heavy tulip'


?

or when the accumulated changes make it unrecognisable as a former dung beetle ?

[NotAllThere]

I always wondered if I would live long enough to see a fusion reactor, life on other planets, man on mars.

I also wanted to see a species actually evolve into something different


could this be it ?


http://news.bbc.co.uk/1/hi/sci/tech/7840404.stm

I doubt it. Is it more astonishing than the huge variety of dogs that came from a single wolf species?

When does selective breeding become evolution?

[EternalOptimist]

I read this story yesterday and can't get my head round the "evolution in action" bit. It doesn't actually say anywhere in the article that anyone has ever seen this particular species rolling dung. It might be the other way round - that all dung beetles used to eat millipedes but then decided they preferred dung, except for this one.

It's not as if there's loads of footage of D. valgum rolling dung and then suddenly one of them goes for a millipede. They might have been doing this for tens of thousands of years. I thought there were loads of examples like this... like snakes that live in the water and eat lobsters or whatever.

You miss the point. The species does roll dung, and their bodies are well suited to it. Some members of the species are slightly different, and it is these differences that make it able to catch and eat the millipedes.

[dang65]

I read this story yesterday and can't get my head round the "evolution in action" bit. It doesn't actually say anywhere in the article that anyone has ever seen this particular species rolling dung. It might be the other way round - that all dung beetles used to eat millipedes but then decided they preferred dung, except for this one.

It's not as if there's loads of footage of D. valgum rolling dung and then suddenly one of them goes for a millipede. They might have been doing this for tens of thousands of years. I thought there were loads of examples like this... like snakes that live in the water and eat lobsters or whatever.

[expat]

Indeed. Starts with the pants, then the silky underwear, high heels. But whatever makes you happy. Just make sure to think about it before you get the Op.

she was in them at the time

[ace00]

Come to think of it, that was the year I first got in a woman's pants. It's all been downhill from then.

Indeed. Starts with the pants, then the silky underwear, high heels. But whatever makes you happy. Just make sure to think about it before you get the Op.

[EternalOptimist]

I think it's only classed as a different species when interbreeding with the "old species" is either impossible or produces a hybrid animal

Thats the point exactly. At the moment it is not a new species, as you say. It is a mutation, or a variant, still capable of interbreeding with the 'stem' creatures.

If those 'stem' creatures died out (presumably through lack of tulipe) we would be left seeing the evolutionary process in action. This is exactly how 'survival of the fittest' is supposed to work.

[expat]

I think it's only classed as a different species when interbreeding with the "old species" is either impossible or produces a hybrid animal

Indeed, but this may be the start of speciation, since the new lot will start living a different life from the old lot and may become unable to interbreed.

I feel that way about some of the people I went to school with.