Arcana of life

[STYRBJORN]

I'm starting this post as a result of some people, myself included, going way off theme on another topic. What kicked us off was a comment that "Ladybirds are hardly animals." What the poster meant was clear enough, he meant that insects are not regarded as "animals" by most people who think of only vertebrates as "animals". Some of us went a little bit spare on this.

My position is now informed by comments from other posters, especially Lancashire Lad, aka Mick. There are six kingdoms of life.
Multicellular life consists of:-
Plants
Animals
Fungi
Unicellular life consists of:-
Archaea
Eubacteria
Protista.

Protista include creatures such as Amoeba, which are highly sophisticated single-celled creatures with internal "organs" contained within membranes, specifically the nucleus containing DNA.

My main point stands. If it moves and you can see it it's an animal!

STYRBJORN

[Purplepixii]

Having just done this at college before breaking up for summer hols (yay!) I'm only aware of 5 kingdoms:

Monera
Protista
Fungi
Planatae
Animalia

I've heard of the possibility of 6 in the future (as we learn more) but currently only 5. Or have I been taught incorrectly.......?

[thunder]

Originally Posted by STYRBJORN

My main point stands. If it moves and you can see it it's an animal!

STYRBJORN

What about slime moulds?

henrya

[STYRBJORN]

To the best of my knowledge slime moulds are clones of Protista; there may be several hundred cells in "A slime mould" but they are all geneticelly identical. Dawkins is very informative on this.

STYRBJORN

[STYRBJORN]

Originally Posted by Purplepixii

Having just done this at college before breaking up for summer hols (yay!) I'm only aware of 5 kingdoms:

Monera
Protista
Fungi
Planatae
Animalia

I've heard of the possibility of 6 in the future (as we learn more) but currently only 5. Or have I been taught incorrectly.......?

I regret to say it, but what you are taught at college is last year's orthodoxy.
Latest thinking says 6. The "monera" are now accepted as including 2 distinct kingdoms of prokaryotic unicellular bacteria.

I did head this as "arcana of life"!

STYRBJORN

[thunder]

Originally Posted by STYRBJORN

To the best of my knowledge slime moulds are clones of Protista; there may be several hundred cells in "A slime mould" but they are all geneticelly identical. Dawkins is very informative on this.

STYRBJORN

Indeed, but you can see them (without optical aids), and they do move. Arcane indeed.

henrya

[STYRBJORN]

Originally Posted by thunder

Indeed, but you can see them (without optical aids), and they do move. Arcane indeed.

henrya

Fair comment. You would not be able to see the individual cells though!

[Lancashire Lad]

Originally Posted by STYRBJORN

Fair comment. You would not be able to see the individual cells though!

This can be both true and untrue, depending on the stage in the life cycle of our typical slime mould. I hasten to add, that whilst I find them fascinating, I am certainly no expert, and the undermentioned simplistic view is about the extent of my subject knowledge.

Just after spore germination, the mould exists as a (usually) microscopic single cell “haploid” amoeba, capable of moving around to find and ingest food, and of multiplying asexually by simple cell division.

At some stage, (generally stated as being when the food supply is exhausted), these individual cells come together and form pseudoplasmodia, or coenocyte “colonies”. Such colonies are still single cells, but have many hundreds of nuclei.

At this stage, the colony may be several centimetres large, (colonies covering several square metres have been found, making the slime mould the largest single celled creature in the known world. – Single celled living organisms, yet now very easy to see with the naked eye.

At some stage after this, “aggregation” followed by “axial differentiation” occurs, and the mould continues to develop from here on (towards the formation of a fruiting body) as a multi-cellular organism.

This quote (from Slime Moulds Life Cycle) puts things more authoritatively: -

QUOTE

Slime moulds inhabit forest soil and consume bacteria and yeast, which they track by chemotaxis - chemical gradient sensing (of folic-acid in this case). Starvation, however, prompts the solitary cells to aggregate and develop as a true multicellular organism, producing a fruiting body comprised of cellular, cellulosic stalk supporting a bolus of spores. Thus, slime mould has evolved mechanisms that direct the differentiation of a homogeneous population of cells into distinct cell types, regulate the proportions between tissues and orchestrate the construction of an effective structure of the dispersal of spores. Many of the genes necessary for these processes in slime mould were inherited by Metazoa (animal with specialized cells) and fashioned through evolution for use within many different modes of development.
Analysis of the proteins shows that slime mould diverged from the animal-fungal lineage after the plant-animal split, but it seems to have retained more of the diversity of the ancestral genome than have plants, animals or fungi, i.e., it possesses a level of complexity that is greater than the yeast, but much simpler than plants or animals. It represents one of the earliest branches from the last common ancestor of all eukaryotes.

UNQUOTE

As to whether animal or vegetable - I'm inclined to agree that they should be regarded as being in the animal camp - certainly for a good part of their life cycle anyway. (Cue the spooky music! )

Regards,
Mike.

[STYRBJORN]

I inhabit bars and consume McCoys crisps and yeast derivatives such as BEER. I am not a slime mould, although any of my several ex-wives might want to argue the point.

Seriously tho, how about starting a WAB band. We could call ourselves "The Slime Moulds". I'll play keyboards, Eeyore on brass, Animartco on harmonica, ValleyForge percussion. We just need a good lead guitarist. Any volunteers?

STYRBJORN

[animartco]

Originally Posted by STYRBJORN

I inhabit bars and consume McCoys crisps and yeast derivatives such as BEER. I am not a slime mould, although any of my several ex-wives might want to argue the point.

Seriously tho, how about starting a WAB band. We could call ourselves "The Slime Moulds". I'll play keyboards, Eeyore on brass, Animartco on harmonica, ValleyForge percussion. We just need a good lead guitarist. Any volunteers?

STYRBJORN

No I'm brass. I play the French Horn