What is a species?

[flobadob]

Every now and then you'll hear that a new species of something has been found, like spider or something. But what differentiates species? Also I'm wondering are there different species of humans? Is someone born and living in the Amazon a different species to someone from Europe?

[flobadob]

So beso, in a nutshell, if one animal can mate with another, and produce fertile offspring then those two animals are of the same species. If the offspring is always infertile or there is never offspring produced from such mating then the animals would be different species? Is that a fair way to decide?

[starone]

Just to add a light note to the discussion - I was watching a tv programme years ago - the scientist there was saying there are still Neanderthals among us. They were recognisable by the following traits - they are short and stocky, they have very bushy eyebrows, they are left-handed and they are unable to separate their toes. My daughter - aged about ten at the time - looked at each other with amazement and then my daughter took off my husband's socks (he was very indulgent) and lo and behold, I discovered I was married to a Neanderthal.

[flobadob]

Perhaps you are part of the missing link, starbuck.

[wildwood]

flobadob. In a nutshell yes. But remember that Nature does not always adhere to the little labeled boxes we like to put things in. Interspecies breeding produces what are know as mules but there is a very small percentage that are able reproduce.
Ofcourse, the chance of those two rarities coming together in Nature is very very small, so mules are gererally considered infertile.
This is how the orange canary was developed but was easier to propagate because of forced breeding pair selections.

In order to produce any type of young the parents have to be at least from the same genus though (see the link). A chicken and a duck can never produce any young because their dna will be completely imcompatable to even form a zygote.

I have no idea why beso is so hung up about sub-species. If humans were non-human the different races would definitely be classed as sub-species. The African and American continents have been separated for over 100 millions of years so genetic drift has not been an option since then.
To illustrate, many folks do not even realise that there are sub-species of the Gorilla because they look so much alike and have no doubt resulted from genetic drift over a relatively short evolutionary period, so why are there sub-species of them?
The human races' ancestors have been separated for much longer so why would there not be sub-species if this was not the 'thing to do' with humans?

[beso]

wildwood
//The African and American continents have been separated for over 100 millions of years so genetic drift has not been an option since then. //

Despite your apparent confidence you obviously haven't a clue about this subject as you clearly don't even known the meaning of genetic drift. (Hint: It is nothing to do with continental drift.)

I am not "hung up" about the issue. I am simply working with the scientific definition. Humans would NOT be classified as having separate sub species for the reasons I clearly described in my previous post. Go and learn about the subject.

[beso]

wildwood
//To illustrate, many folks do not even realise that there are sub-species of the Gorilla because they look so much alike and have no doubt resulted from genetic drift over a relatively short evolutionary period, so why are there sub-species of them? //

If your knowledge matched your confidence you would realise there are two distinct SPECIES of gorilla each with at least two subspecies.

Moreover if you compare the subspecies of the Western Lowland Gorilla it is quite apparent that their differences are far larger than any found among humans.

They are sub species because we don't see a continuum of in-between forms as we do with humans.

[wildwood]

Ok beso, you have obviously taken this personally so please explain a couple of things to make us more informed. How did the people who are now American Natives got there, if not as a part of the genetic drift of the original African humans (via Asia) before total continental separation?

Please explain why, in my example of the Gorillas which have only slightly changed from the nominate species, are separated Gorilla populations now classed as a sub-species?

What is the basis for the formation of sub-species and eventually new species and genera, if not genetic drift?

Thank you.

[wildwood]

//They are sub species because we don't see a continuum of in-between forms as we do with humans.//

You are now starting to talk total rubbish. There NO 'continuum of in-between forms' between the the American and African native peoples.

[beso]

wildwood
// How did the people who are now American Natives got there, if not as a part of the genetic drift of the original African humans (via Asia) before total continental separation? //

Once again you demonstrate you don't even know the meaning of genetic drift. (Hint 2: It isn't about animals floating around on driftwood until they find more land.)

[beso]

And since you are the sole worldwide anthropological expert on the living subspecies of humans perhaps you would care to define these subspecies for us.

If you cannot see the continuum of human forms which closely follow the migration pattern that is not my problem.

[wildwood]

Beso, I see that you've chosen to become sarcastic which is a pity. I am sorry that it seems as if I've upset you, but you really haven't answered any of my questions, just replied a load of gibblygook. In your confusion you forgotten the issue, which is that if humans were a non-human species the different races would be classified as sub-species, but this is not a PC thing to do with people .

Any form of 'continuum of humans' (your words) between the American and African/Asian peoples have long disappeared since the total separation of those two continents, and have changed into individual races.

You further chose to shoot yourself in the foot by bringing to my attention that the Western and Eastern Gorrilas have RECENTLY indeed been separated as two species. This further supports my contribution that an group of life form that is separated from the nominate species long enough to become a variant is termed to be a sub-species or in this case even a totally new species (thank you), hence evolution continues.

I am also sorry about the time lapses but work keeps interfering with my time on Answerbank. Please make yourself a cuppa tea and take a deep breath. It is (was) only a discussion.

[beso]

I genuinely mean that you are the worldwide expert on human subspecies. Perhaps you can correct me by showing a link to a credible anthropologist who shares your opinion.

The gorillas were recently reclassified into different species. This was a change in the knowledge, not the nature of the animals as you have tried to portray it.. It doesn't back your case at all.

Intelligent comment often appears as gobbledygook to those with no knowledge of the subject.

[flobadob]

Well, I for one am conflustered guys.

[jomifl]

Genetic drift describes the change in distribution of genes within a population. It has nothing to do with the physical transport of genes to other geographic regions by mobile organisms.

[Old_Geezer]

From what I have read, the definition of a species seems unclear, with many experts disagreeing whether a particular animal or plant is a different species to, or a sub-species of another.

However, I think it is clear that all humans are, by definition, the same species.

[flobadob]

What do you mean when you say "by definition" geez?

[modeller]

There is one over-riding definition of a species and that it has the ability to reproduce and its progeny also has that ability. There are some closely related animals , horses and donkeys, lions and tigers etc can reproduce but I don't know of a single case where it has gone beyond the second generation in the new form . However this definition does not apply to low level organisms like bacteria.

[Old_Geezer]

Poor choice of phrase my me. I mean by whatever set of rules used to describe a single species, human beings are agreed to be the same species. I don't believe any serious scientist would debate that.