Viewpoint: Has 'one species' idea been put to bed?

BBC ^ | December 30, 2011 | Clive Finlayson

[decimon]

Here, Prof Clive Finlayson looks back at the year's developments in human evolution research and asks whether recent discoveries rule out a well known idea about our ancestors.

Hobbits on Flores, Denisovans in Siberia, Neanderthals across Eurasia and our very own ancestors.

Given this array of human diversity in the Late Pleistocene, we might well be forgiven for thinking that Ernst Mayr's contention that "in spite of much geographical variation, never more than one species of man existed on Earth at any one time" had finally been put to bed.

It now seems that a high degree of diversity was also present in the Middle Pleistocene, revealed in the latest analysis of human teeth from that period.

Mayr, one of the great evolutionary biologists of modern times, proposed his single species idea in a Cold Spring Harbor Symposium, published in 1950.

The idea of a single species of human has received a great deal of criticism since Mayr's day but it has also had its vociferous advocates.

So, can we really conclude that the concept was fundamentally flawed on the basis of all the new - fossil and genetic - evidence? That depends on how we understand and define species.

[decimon]

Mayr take me home ping.

[razorback-bert]

Liberals are a diffent species.

[762X51]

Some people claim that there are currently more than one species of humans on planet Earth. Any serious research regarding this assertion is of course forbidden due to claims of racism and political correctness. Even if the argument for separate species is debatable it’s hard to argue that several subspecies don’t exist.

[Capt. Tom]

For biologists, like Mayr, species are entities composed of individuals that, in the wild, reproduce among themselves but not with other species.

But palaeontologists use other definitions of species and these have allowed them to classify fossils that cannot be otherwise categorised on the basis of Mayr's biological species concept.

Tom here: The Australian black tip shark (Carcharhinus tilstoni) and the common black tip shark (C. limbatus) have overlapping distributions along the northern and eastern Australian coastline. These shark species have been known to interbreed. -tom

[JimSEA]

As I sit here watching my daughter’s pug play with my Boston bull, I wonder just how clear our idea of species is? Herto man, Neanderthal, Rodesinsis, and others are found over wide areas going back to the earliest Homo Sapiens some 206 k years ago in China no less. The oldest date for Homo Sapiens I’m aware of for Africa is 160 k to 190 k for White’s Awash discoveries.

There are lots of egos involved in human origins research. There are also complications by folks who don’t believe all “people” are human. Am I a Homo Sapiens Sapiens or some lesser creature. It all depends on who is making the definitions.

[Clock King]

Liberals are a diffent species.

Homo parasītos.

[mamelukesabre]

I’ve always thought there’s a strong chance all these ancient hominids are just variations of the same species. I really think a person could recreate a neanderthal or a cro magnon with a breeding program of existing living human beings. Just round up all the individuals with neanderthalish traits and start selectively breeding them. In about 20 generations you will have one.

[Daveinyork]

A species is a group that is capable of creating offspring by mating within the group. Members of different species within a genus can mate and create offspring, but those offspring will be infertile.

I think we can equate subspecies with races, or breeds, if we are talking about horses or dogs. Members of different subspecies can mate and produce fertile offspring. Theoretically, a great dane can mate with a miniature poodle and produce puppies, but I suspect the mechanics would defeat it. And we know for fact that the three acknowledged subspecies of homo sapiens have interbred for generations.

That’s what I remember about this from high school biology, and that was a very long time ago.

[Oratam]

Recent dna testing of an alleged yeti finger turned up as ‘human’; what else would one expect? What is human? Homo Sapiens Sapiens only? Isn’t there evidence of Homo blank blank from the recent past? Didn’t Linneus include Homo Sylvestris in his classification system? Carl was onto something.

[webstersII]

“Some people claim that there are currently more than one species of humans on planet Earth.”

Conservatives. Liberals.

They are as different as night and day.

[Grut]

H. sapiens I don’t know about, but I think p. paniscus deserves its own genus.

[JimSEA]

Agreed. The differences physically, while marked, could be from geographical isolation but short of speciation.

[hinckley buzzard]

Liberals are a diffent species.,p>i think so. I believe they drifted into our atmosphere from outer space in the form of spores. Once on the ground they hatched into the mammalian forms we now know and detest.

[BlueDragon]

Am I a Homo Sapiens Sapiens or some lesser creature. It all depends on who is making the definitions.

Since by the reproductive tests, humans are related enough there has not been found a sub-group that could not produce viable offspring mating with members of any other sub grouping, a better question might be (and this will blow your mind) am I entirely human, or are the lines blurred in other ways?

http://the-scientist.com/2011/09/20/plant-rnas-found-in-mammals/

Plant RNAs Found in Mammals

MicroRNAs from plants accumulate in mammalian blood and tissues, where they can regulate gene expression.

From an embedded link in the above;

http://the-scientist.com/2011/07/01/exosome-explosion/

Exosome Explosion

These small membrane vesicles do much more than clean up a cell’s trash—they also carry signals to distant parts of the body, where they can impact multiple dimensions of cellular life.

Which in light of how humans also are said to have more abundance of cells of other microscopic life, than they have of their own larger-celled human body cells, makes me wonder if instead of saying, "hello, my name is --- " a person could say, "hello, you are speaking with the spokes creature portion of the colony named [insert name here].

Now, it's about time to go tell a little bite of lunch, and another cup of coffee or tea, "you will be assimilated. resistance is futile" hehheh....

[chesley]

But, as I understand it, a race and a subspecies, biologicaly speaking, are the same thing.

And everybody knows that, in humans, “race” is a social construct.

[chesley]

Liberals. I think they are pod people myself.

[Secret Agent Man]

There are two species of humans now.

Makers and Takers.

[SunkenCiv]

GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach	join list or digest view topics view or post blog bookmark post a topic subscribe
Thanks decimon. The Neandertal Enigma by James Shreeve in local libraries Frayer's own reading of the record reveals a number of overlooked traits that clearly and specifically link the Neandertals to the Cro-Magnons. One such trait is the shape of the opening of the nerve canal in the lower jaw, a spot where dentists often give a pain-blocking injection. In many Neandertal, the upper portion of the opening is covered by a broad bony ridge, a curious feature also carried by a significant number of Cro-Magnons. But none of the alleged 'ancestors of us all' fossils from Africa have it, and it is extremely rare in modern people outside Europe." [pp 126-127] To all -- please ping me to other topics which are appropriate for the GGG list.

[blam]

" I really think a person could recreate a neanderthal or a cro magnon with a breeding program of existing living human beings. Just round up all the individuals with neanderthalish traits and start selectively breeding them. In about 20 generations you will have one."

I agree.

I've repeatedly said that all the attributes that make a Neanderthal can be found in the human population today.We are Neanderthals.

The brow ridges of the Australian Aboriginies is more severe than the Neanderthals.