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Arch Hades
2014-07-07, 21:22
1. Neanderthals are considered a different species from human.
2. Modern humans have Neanderthal admixture.
3. Since modern humans have Neanderthal admixture that means at one point humans reproduced with Neanderthals and produced fertile offspring.

So why are Neanderthals considered a different species if that's the case?

Rottmayer
2014-07-08, 00:25
Neanderthals (especially the European version) were very different from modern Sapiens. The Neanderthal admixture probably comes from Middle Eastern Neanderthals who were a lot less extreme than the forms living in Europe. That's because nature is not about discrete units, more like a multivariate continuum. Ideas like "species" are arbitary. But not necessarily wrong. But they are not domgas. Think tiger and lion.

"Lumpers and splitters", basically. Both valid concepts and and intelligent guy can have both concepts in mind at the same time.

Arch Hades
2014-07-08, 01:02
So who gets to draw the line on specification if it's not simply the ability to reproduce fertile offspring?

Could Blacks and Whites and Mongolians be considered different species of if that's the case?

Clearly we are just dealing with some arbitrary subjective line of distance here.

Rottmayer
2014-07-08, 03:05
So who gets to draw the line on specification if it's not simply the ability to reproduce fertile offspring?

Could Blacks and Whites and Mongolians be considered different species of if that's the case?

Clearly we are just dealing with some arbitrary subjective line of distance here.

I thought this is a "science" board, instead it feels like Asperger's heaven :D

EliasAlucard
2014-07-09, 21:25
1. Neanderthals are considered a different species from human.
2. Modern humans have Neanderthal admixture.
3. Since modern humans have Neanderthal admixture that means at one point humans reproduced with Neanderthals and produced fertile offspring.

So why are Neanderthals considered a different species if that's the case?Ordinary brown bears and polar bears can reproduce fertile offspring as well, but they can't do that on their own, since they can't live in the same climate. This effectively means that without human intervention, there's no gene flow between brown bears and polar bears, which is one of the justifications for the different species status of polar bears.

So this species status isn't as clear cut as absolute and total genetic incompatibility.

As for the Neanderthals, they were clearly on their way toward full genetic incompatibility, but had not quite reached that point. The view of them as a different species based on infertile or no offspring is an outdated view from before the Neanderthal admixture in extant humans was discovered.


So who gets to draw the line on specification if it's not simply the ability to reproduce fertile offspring?

Could Blacks and Whites and Mongolians be considered different species of if that's the case?

Clearly we are just dealing with some arbitrary subjective line of distance here.All humans today can procreate with one another, regardless of race. Some race deniers have argued that modern human races don't meet Wright's Fst requirements in order to count as different races (0.250):


Wright felt that the primary subdivision within the total species, measured by Fst was equivalent to the subspecies used by taxonomists (or what Mayr would havecalled biological race). Population subdivision can be calculated at individual geneticloci or for numerous genetic loci simultaneously. Wright’s statistic can range between 0 and 1.00. He arbitrarily suggested that the minimal threshold for the existence of great variation was Fst=0.250 and moderate variation Fst=0.15–0.250. He included examinations of individual loci derived from protein electrophoresis from a variety of species in this chapter, including five human blood groups, finding a range of differentiation from 0.023 to 0.501 (average Fst=0.168). Chapters 9 & 10 of this volume focus on variability within human populations and what he described as racial differentiation in mankind. In chapter ten, using six human blood group loci, he calculated average Fst=0.1248. Using this data he showed that variation within the major races of mankind was much less than between them (Fds=0.0715). However, on careful examination we see that Wright, based on his own criteria for the existence of race, contradicted himself. The mean Fst did not exceed, nor did it come close to his pre-established value for the existence of subspecies, which he equated with geographical races, Fst >0.250. If he had followed his own reasoning, he would have concluded that the groups he examined were populations, granted populations with different allele frequencies, but not subspecies. Subsequent studies of multiple loci, including whole genome analyses in humans have generally shown Fst for populations around the globe at much less than Wright’s critical value.
Source: Biological V. Social Definitions of Race: Implicationsfor Modern Biomedical Research

To my knowledge, this racial Fst requirement at 0.250 isn't a standard that is applied on all species, so its validity on humans can be questioned. But the Neanderthals were last I checked if I remember correctly, above 0.250, so you could say they were definitely without any controversy, above the race level, but below the species level.

Speciation doesn't happen instantly anyway. It's not like one day, two populations suddenly become interracially infertile. The Neanderthals represent the way to speciation.

Off topic member discussion deleted.

//mod

Rebel
2014-07-12, 02:57
Neanderthals (especially the European version) were very different from modern Sapiens. The Neanderthal admixture probably comes from Middle Eastern Neanderthals who were a lot less extreme than the forms living in Europe. That's because nature is not about discrete units, more like a multivariate continuum. Ideas like "species" are arbitary. But not necessarily wrong. But they are not domgas. Think tiger and lion.

"Lumpers and splitters", basically. Both valid concepts and and intelligent guy can have both concepts in mind at the same time.

The problem with that is Neanderthal admixture is less than it is in Europeans. If Neanderthals were in closer contact with humans in the Middle East than Humans in Europe,why do Europeans show more admixture?In all actuality the readings for admixture are just noise in humans. If one were to magnify some of this Neanderthal admixture they would find it's indeed human.

M1CR receptor that some scientist thought were to be inherited from Neanderthals are indeed humans,

Ajuran
2014-07-13, 04:31
1. Neanderthals are considered a different species from human.
2. Modern humans have Neanderthal admixture.
3. Since modern humans have Neanderthal admixture that means at one point humans reproduced with Neanderthals and produced fertile offspring.

So why are Neanderthals considered a different species if that's the case?

Don't let these delusional atheist confuse you. Neanderthal were human beings just like you and me. They are a ancient population.

Here is a useful essay (http://www.icr.org/article/neanderthals-are-still-human/)you can read with substantial sources to back up that Neanderthals were human-beings.

Tsoni
2014-11-19, 07:36
Were Neanderthals a sub-species of modern humans? New research says no
12 hours ago

In an extensive, multi-institution study led by SUNY Downstate Medical Center, researchers have identified new evidence supporting the growing belief that Neanderthals were a distinct species separate from modern humans (Homo sapiens), The study looked at the entire nasal complex of Neanderthals and involved researchers with diverse academic backgrounds. Supported by funding from the National Science Foundation and the National Institutes of Health, the research also indicates that the Neanderthal nasal complex was not adaptively inferior to that of modern humans, and that the Neanderthals' extinction was likely due to competition from modern humans and not an inability of the Neanderthal nose to process a colder and drier climate.
Samuel Márquez, PhD, associate professor and co-discipline director of gross anatomy in SUNY Downstate's Department of Cell Biology, and his team of specialists published their findings on the Neanderthal nasal complex in the November issue of The Anatomical Record, which is part of a special issue on The Vertebrate Nose: Evolution, Structure, and Function (now online).
They argue that studies of the Neanderthal nose, which have spanned over a century and a half, have been approaching this anatomical enigma from the wrong perspective. Previous work has compared Neanderthal nasal dimensions to modern human populations such as the Inuit and modern Europeans, whose nasal complexes are adapted to cold and temperate climates.
However, the current study joins a growing body of evidence that the upper respiratory tracts of this extinct group functioned via a different set of rules as a result of a separate evolutionary history and overall cranial bauplan (bodyplan), resulting in a mosaic of features not found among any population of Homo sapiens. Thus Dr. Márquez and his team of paleoanthropologists, comparative anatomists, and an otolaryngologist have contributed to the understanding of two of the most controversial topics in paleoanthropology - were Neanderthals a different species from modern humans and which aspects of their cranial morphology evolved as adaptations to cold stress.
"The strategy was to have a comprehensive examination of the nasal region of diverse modern human population groups and then compare the data with the fossil evidence. We used traditional morphometrics, geometric morphometric methodology based on 3D coordinate data, and CT imaging," Dr. Márquez explained.


Read more at:
http://phys.org/news/2014-11-neanderthals-sub-species-modern-humans.html#jCp
http://www.scienceclarified.com/He-In/Human-Evolution.html#ixzz3JUuawXtq
http://www.reuters.com/article/2014/11/06/us-science-genome-idUSKBN0IQ2QK20141106

An Impeccable Hat
2014-11-25, 19:09
a growing body of evidence that the upper respiratory tracts of this extinct group functioned via a different set of rules as a result of a separate evolutionary history and overall cranial bauplan (bodyplan), resulting in a mosaic of features not found among any population of Homo sapiens. Thus Dr. Márquez and his team of paleoanthropologists, comparative anatomists, and an otolaryngologist have contributed to the understanding of two of the most controversial topics in paleoanthropology - were Neanderthals a different species from modern humans and which aspects of their cranial morphology evolved as adaptations to cold stress.
"The strategy was to have a comprehensive examination of the nasal region of diverse modern human population groups and then compare the data with the fossil evidence. We used traditional morphometrics, geometric morphometric methodology based on 3D coordinate data, and CT imaging," Dr. Márquez explained.





Interesting stuff. But I do question the conclusions they draw from simple physical differences. Look at the various dog breeds, and you'll see radically different bodyplans, ranging from the those evolved in cold climates such as Siberian Huskies, to those evolved in hot climates such as Pharaoh Hounds, to fragile toy breeds purely contrived by man through selective breeding. And for all that, they're still considered the same species. Differences in body plan and nose structure don't make a pug a different species from a German Shepherd. More compelling would be some genetic evidence indicating that Neanderthals significantly differed from Homo Sapiens in their DNA, but as far as I know this is not the case.