Thread: Considering OTU as Species

given three OTU of trout, i need to find out if they are the same species or not.

one experiment carried out is to see if they can reproduce

successful fertilisation did occur between sperm and eggs of the different OTU when the it was artificial, milting.

the different OTU did interbreed when given no other choice , but to a lesser extent. but they still did.

finally given a choice using senses other than sight(chemical secretions), a male of one otu did choice his own female otu but occasionally went for a different OTU.

are these OTU of the same species?

my first answer is yes, because they can interbreed they must be. but i have a feeling its not that simple. i have no way to find out if the offspring are fertile, but i assume they might not be. any thoughts?

i know im not giving any real data, and that you cant possibly know. i suppose what im really asking is are there cases where different species do interbreed and produce fertile offspring?, or if you were faced with this would you say they are same species or not?

as an aside...im doing research as part of a Problem based learing, to understand evolution. on one hand i am actually doing the experiments using flash boxes and the like's but we cant go further than what the admin give us. on the other its not really a real experiments at all.

Originally Posted by goodgod3rd

given three OTU of trout, i need to find out if they are the same species or not.

It would have helped me immensely if you had defined OTU. Despite extensive amateur reading in biology I cannot recollect ever hearing this term before.

Originally Posted by goodgod3rd

i know im not giving any real data, and that you cant possibly know. i suppose what im really asking is are there cases where different species do interbreed and produce fertile offspring?, or if you were faced with this would you say they are same species or

The ansewer is a definitive yes. Even mules, the traditionally steril offspring of a horse and donkey mating. are occassionaly fertile.
Recent research, which I cannot currently locate, has emphasised the importance of hybridisation in creating new species.

I think it is important to remember that 'species' is an artificial concept, arising out of the human tendency to classsify things in great detail. (As opposed to say crocodiles which classify things as 'not moving, to be ignored' and 'moving, to be eaten'.)

Consider the example of the two species of gulls in Western Europe - I forget which two particular species. One of them is to be found also in Eastern Canada. The other is found in a chain of colonies around the Arctic ocean, from Scandinavia, through Siberia to North America. Members of these colonies will freely interbreed with adjacent colonies. However, by the time you follow them around from Europe to North America, surprise, surprise they have become the other distinct species to be found in Western Europe.

my bad , i assumed that what our lecturer was using was widespread terms

Operational Taxonomic Unit:
A group of organisms used in a taxonomic study without designation of taxonomic rank


cheers, i understand that the word species has many interpertations, and is very sketch when examined. your answer is kinda what i wanted to hear. that it is possible

The ansewer is a definitive yes. Even mules, the traditionally steril offspring of a horse and donkey mating. are occassionaly fertile.

Granted , some species do interbreed together, and as you said do produce some fertile off spring. you used the word ocasssionaly. dose that mean that the chances are slim?

ok, another question. If there is a great chance, that out of the successful fertilizations, fertile ofspring is produced, dose that give strong evidence that the two OTU's are the same species?

now i'm not too pleased with the results. we arent told if they are fertile or not. so i under stand its kinda pointless, but im only asking your oppinion.
thanks sir,
damien

Originally Posted by goodgod3rd

Operational Taxonomic Unit:
A group of organisms used in a taxonomic study without designation of taxonomic rank

Aha! That is definitely a new one on me, though I work in an industry that abounds in TLAs. (OK. Three Letter Acronyms.)

Originally Posted by goodgod3rd

Granted , some species do interbreed together, and as you said do produce some fertile off spring. you used the word ocasssionaly. dose that mean that the chances are slim?

I don't have any specific figures. I believe I read it in a Biology text, or perhaps a popular science magazine. But my definite impression, was that the chances were slim. (Or, at least slight, whatever that difference may be. :wink: )

Originally Posted by goodgod3rd

ok, another question. If there is a great chance, that out of the successful fertilizations, fertile ofspring is produced, dose that give strong evidence that the two OTU's are the same species?

I would have thought so, but please remember it is four decades since I studied any biology at University, so I am largely self taught in the limited amount I do know.

excelent. we thinkin on the same lines. but i think, there is more to be discovered. thanks for the help sir, and rest assured that the limited amount you know , far surpasses my max! :P

thanks
damien.