Naked Science Forum

Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: neilep on 14/08/2007 17:58:12

Title: Flora & Fauna ...they're the main two eh ?
Post by: neilep on 14/08/2007 17:58:12

Dearest Flora & Fauna Fanatics,

Including insects and all things non-flora that are creature type things !! which has the most species ?

I'm not too sure if I should include bacteria and stuff !!..I'll let you decide !....include them too if you wish....

Thanks

neil

Title: Flora & Fauna ...they're the main two eh ?
Post by: DoctorBeaver on 14/08/2007 21:09:40

I believe it is beetles.

Title: Flora & Fauna ...they're the main two eh ?
Post by: neilep on 14/08/2007 21:22:09

Quote from: DoctorBeaver on 14/08/2007 21:09:40

I believe it is beetles.

Ahhh !!..I have not explained myself correctly !!..what I mean is..are there more species all together?...of planty things against animal/insecty things !!

ie:...are there more varieties of animals than there are varieties of plants ?

Title: Flora & Fauna ...they're the main two eh ?
Post by: DoctorBeaver on 14/08/2007 21:24:55

Oh, sorry. I'm pretty sure the answer is critters. How many new species are discovered each year in Papua/New Guinea alone?

Title: Flora & Fauna ...they're the main two eh ?
Post by: neilep on 14/08/2007 21:29:55

I don't know..I guess we'll have to ask Mamua/New Guinea !


I had a penchant towards planty things myself !!

Title: Flora & Fauna ...they're the main two eh ?
Post by: another_someone on 15/08/2007 00:42:12

Quote from: DoctorBeaver on 14/08/2007 21:24:55

Oh, sorry. I'm pretty sure the answer is critters. How many new species are discovered each year in Papua/New Guinea alone?

But cannot the same be said for plants?

Mostly, it seems rather difficult even to define what a species is (particularly with regard to insects).  Plants also have far more permeable species boundaries, making it fairly easy to create new plants from cross breeds of existing plants (ofcourse, this leaves open the question as to whether they were separate species to start with, but unlike animals, I believe it is possible to cross breed plants with different numbers of chromosomes).

Title: Flora & Fauna ...they're the main two eh ?
Post by: WylieE on 15/08/2007 03:12:54

Right George,

So that is the problem, it gets a bit difficult to say exactly when a plant is a different species from it's neighbors.  Although, I think this is a bit of a challenge for animals too.

However, even being fairly lenient on what we call a species, I think insects would still dominate.

The current estimates on the number of plant species ranges from 40,000 to 400,000 to 4 million.  The estimate on insects is from 1.5 million to 30 million.  This difficulty here is in both what exactly defines a species and the difficulty in sampling.  Plants that look the same when grown next to each other can look quite different if one is grown in a different environment.  The picture below is a famous picture from Dr. Amasino's lab at University of Wisconsin.  The cabbage on the left was always grown in the greenhouse and never saw a winter so it hasn't flowered.  So if cabbages grew in some tropical place that never had a winter and you identified this species would you even think to check if it was the same species as the cabbage in the girl's hands?  Just by looking I would think that these were two different species of plants, but they are the same, the difference is that the little one went through a winter and started to flower.   

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If we look at just identified species there are about 250,000 identified seed plant species and about 850,000 identified animal species.  Again these numbers are contended because there are arguments about whether two identified species are really the same thing or not. 

Good thing you decided to exclude bacteria and fungi from your question, Neil, determining the numbers there gets even more complicated, but I think it would be fairly easy to argue that if you did include them they would probably dominate over all others.

Now, if you want to talk about biomass. . . .

Colleen

Title: Flora & Fauna ...they're the main two eh ?
Post by: another_someone on 15/08/2007 03:36:48

I have yet to be convinced by the arguments about insect numbers.  I have a feeling that the issues regarding insects are probably not a lot different from the issues regarding cabbages.  People go to the tropics, and look down and see something that looks superficially different from any other insect they have seen before, but how can you say it really is a different species without either trying to interbreed with other species, or by gene sequencing - neither of which is commonly done.

Title: Flora & Fauna ...they're the main two eh ?
Post by: WylieE on 15/08/2007 05:18:15

Exactly!

And then if you do sequence them- how similar do the sequences have to be before you call them the same species?  On average there are about 3 million differences between two non-related humans.
 
Tough question Neil!

I still think even with all of the difficulties in getting this number, if you leave out fungi and bacteria, insects still probably have the most species.  Even a conservative estimate of both would give about 10 insect species for every plant species.