difference between two very similar species of t's...

[viper69]

You make a fair point O_O

It's a factual point. I'm not trying to persuade you at all. I'm pointing out facts.

 

[theriumbra]

It's a factual point. I'm not trying to persuade you at all. I'm pointing out facts.

It's just how I speak.

 

[Marijan2]

@viper69
Directly from definition of species:
A species is often defined as the largest group of organisms in which two individuals are capable of reproducing fertile offspring, typically using sexual reproduction. While in many cases this definition is adequate, the difficulty of defining species is known as the species problem. For example, a species complex is a group of closely related species that are very similar in appearance to the point that the boundaries between them are often unclear. Differentiating measures include similarity of DNA, morphology, or ecological niche. Presence of specific locally adapted traits may further subdivide species into "infraspecific taxa" such as subspecies (and in botany other taxa are used, such as varieties, subvarieties, and formae).

 

[theriumbra]

Well, technically both vagans and sabulosum should be the same species, since they can produce viable offspring... It would be taxonomically correct to differentiate them as subspecies

ah, I see. but what do you mean by taxonomically correct?

@viper69
Directly from definition of species:
A species is often defined as the largest group of organisms in which two individuals are capable of reproducingfertileoffspring, typically using sexual reproduction. While in many cases this definition is adequate, the difficulty of defining species is known as the species problem. For example, a species complexis a group of closely related species that are very similar in appearance to the point that the boundaries between them are often unclear. Differentiating measures include similarity of DNA, morphology, or ecological niche. Presence of specific locally adapted traits may further subdivide species into "infraspecific taxa" such as subspecies (and in botany other taxa are used, such as varieties, subvarieties, and formae).

.... why did you send me the definition?

 

[Marijan2]

why did you send me the definition?

@viper69 marked my post with "clarification needed", so i provided it here

 

[theriumbra]

@viper69 marked my post with "clarification needed", so i provided it here

Whoops, sorry, lol I misread and thought it was meant for me, sorry!

 

[viper69]

@viper69
Directly from definition of species:
A species is often defined as the largest group of organisms in which two individuals are capable of reproducing fertile offspring, typically using sexual reproduction. While in many cases this definition is adequate, the difficulty of defining species is known as the species problem. For example, a species complex is a group of closely related species that are very similar in appearance to the point that the boundaries between them are often unclear. Differentiating measures include similarity of DNA, morphology, or ecological niche. Presence of specific locally adapted traits may further subdivide species into "infraspecific taxa" such as subspecies (and in botany other taxa are used, such as varieties, subvarieties, and formae).

Sorry, I should have been more clear as the above provided info I knew over 20 years ago haha..SO much for that clarification icon!!!

What I meant was, why do you think they should be the same species, because offspring from a hybridization can reproduce?

 

[Marijan2]

What I meant was, why do you think they should be the same species, because offspring from a hybridization can reproduce?

Yes, unless i'm missing something big or misunderstood something?

 

[cold blood]

@viper69
Directly from definition of species:
A species is often defined as the largest group of organisms in which two individuals are capable of reproducing fertile offspring, typically using sexual reproduction. While in many cases this definition is adequate, the difficulty of defining species is known as the species problem. For example, a species complex is a group of closely related species that are very similar in appearance to the point that the boundaries between them are often unclear. Differentiating measures include similarity of DNA, morphology, or ecological niche. Presence of specific locally adapted traits may further subdivide species into "infraspecific taxa" such as subspecies (and in botany other taxa are used, such as varieties, subvarieties, and formae).

In the case of tarantulas, it is indeed not adequate, as we know for a fact that different species are in fact, fully capable of reproducing and creating fertile young....which is part of the problem.

 

[viper69]

Yes, unless i'm missing something big or misunderstood something?

This is not always the case, definitely mistaken. Some species can reproduce, producing fertile offspring, but they in fact are different species see this

http://www.slate.com/articles/news_and_politics/explainer/2010/05/pizzly_bears.html

 

[cold blood]

This is not always the case, definitely mistaken. Some species can reproduce, producing fertile offspring, but they in fact are different species see this

http://www.slate.com/articles/news_and_politics/explainer/2010/05/pizzly_bears.html

or...

https://en.wikipedia.org/wiki/Liger

 

[viper69]

or...

https://en.wikipedia.org/wiki/Liger

I didn't know the liger could be fertile in some cases, thanks!

 

[Marijan2]

In the case of tarantulas, it is indeed not adequate, as we know for a fact that different species are in fact, fully capable of reproducing and creating fertile young....which is part of the problem.

So you're telling me either the definition of species needs revision, or hundreds, possible thusands of already described "species"? Holy cow

 

[cold blood]

So you're telling me either the definition of species needs revision, or hundreds, possible thusands of already described "species"? Holy cow

Yeah, I think the "definition" needs revision, as it took us all of 3 minutes to provide multiple examples of its inaccuracies/shortcomings...and we didn't even discuss tarantulas.

 

[AphonopelmaTX]

So you're telling me either the definition of species needs revision, or hundreds, possible thusands of already described "species"? Holy cow

More like there are as many definitions for what constitutes a species as there are evolutionary biologists. There is no one right answer. Sometimes it's worth reminding oneself that the science of taxonomy or phylogenetics is theoretical. For instance, when you read a research paper which presents a relationship between animal species, or specifically spiders, you should read it as the researcher(s) theory on how they are related. Some papers do a better job than others in supporting their theory, but none of it is hard scientific fact.

Tarantulas in particular are especially a challenging group to work out the evolutionary relationships for because they share so many morphological and sometime molecular characters. If one reads enough research papers concerning tarantula taxonomy, it becomes apparent that tarantula classification changes so frequently because additional characters are found through the examination of additional specimens of one species or new taxa is discovered and a phylogeny has to be reworked to support it.

 

[Haksilence]

Well, technically both vagans and sabulosum should be the same species, since they can produce viable offspring... It would be taxonomically correct to differentiate them as subspecies

This is 100% not true in inverts. Yes it fits Webster's definition of "species" but is not scientifically true

Sorry, I should have been more clear as the above provided info I knew over 20 years ago haha..SO much for that clarification icon!!!

What I meant was, why do you think they should be the same species, because offspring from a hybridization can reproduce?

This! The fact that fertile breeding can be done across genus lines discredits that thought process further

 

[cold blood]

@AphonopelmaTX , thanks for your input, you're always a valuable source. Great points.

 

[Marijan2]

This! The fact that fertile breeding can be done across genus lines discredits that thought process further

Shouldn't arthropods have their own way of classification in that case? It is super confusing like this, it just makes it harder for everyone

 

[viper69]

Shouldn't arthropods have their own classification in that case? It is super confusing like this, it just makes it harder for everyone

That's a matter of opinion for some I suspect. IMO, no. When you have an international classification system, you want people using the same standards, otherwise things go off the rails/crazy/haywire.

Imagine if a kilogram wasn't the same in Germany as it is in Switzerland as in Croatia for different products??

 

[Marijan2]

That's a matter of opinion for some I suspect. IMO, no. When you have an international classification system, you want people using the same standards, otherwise things go off the rails/crazy/haywire.

Imagine if a kilogram wasn't the same in Germany as it is in Switzerland as in Croatia for different products??

Oh, you mean something like America with its imperial units? Yeah i guess you have a point there