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If we interbred with them, how are they actually species? It seems more to me you're talking more about racial or breed differences akin to breeds of dogs if tw
by c3534l 7y ago
If we interbred with them, how are they actually species? It seems more to me you're talking more about racial or breed differences akin to breeds of dogs if two species actually successfuly had viable offspring in the wild.
- joe_the_user 7y agoYeah, seems more logical to say ancient human experienced a number genetic divergences which were then folded into the mainline of the genetic stream.
- 0x8BADF00D 7y agoEnvironment plays a huge role. If a nomadic group was in a jungle-like environment, wouldn’t they more likely develop the traits of the other species well suited for jungle living? Over a long enough timescale.
- Haga 7y agoThe habitat also swings, so behavior specialist sub species for every part of the cycle, which allow long term adjustment to circumstances by percentages would be quite beneficial.
- rjf72 7y agoEpigenetics is indicating that our traditional view of genetics is probably just completely wrong, but going with that traditional view - it's not that an environment changes a species, but randomness. And traits randomly evolved that end up beneficial are preserved in the lineage due to increased survivability. Jungle like environments tend to be extremely favorable for the survival of intelligent species which means natural selection starts to play less of a role. Well it does play a role, but in different ways. For instance modern humans are continuing to evolve even though natural selection, in terms of man against environment, is now playing very near 0 role. Instead the factor being selected for now is simple fertility. Humanity will tend to evolve along the characteristics of those families have 3, 4 and more children - while those having 2 or fewer children will gradually fade from the gene pool. So natural selection has in some ways become voluntary, which is quite paradoxical. However in less developed areas, it's still alive in some ways. For instance if an individual in subsahara Africa somehow developed a genetically heritable mutation making him immune to malaria, it's reasonably likely that all subsaharan Africans would, gradually, become immune to malaria. We can only conclude, putting aside epigenetic factors once again, that such mutations are much less common than e.g. those to the shape of a bird's beak.
- thaumasiotes 7y ago> If a nomadic group was in a jungle-like environment, wouldn’t they more likely develop the traits of the other species well suited for jungle living? Yes, and this has already happened. The African jungle has its pygmies; the Southeast Asian peninsula and surrounding islands have their pygmies; and those two groups are totally unrelated.
- Sharlin 7y agoNot at all. For instance, it is thought that H. sapiens × H. neanderthalis hybrids, while viable at least some of the time, were almost never fertile. To explain the Neanderthal contribution to the genome of modern humans, only a very low frequency of successful hybridization events is required.
- keiru 7y ago>mainline of the genetic stream This is a tricky concept. Could it be said over 50,000 years ago that Homo Sapiens' ancestors were the mainline? I wouldn't retroactively call it that because it presumes that it was clear at the time that it would be the definitive dominant subspecies. I think a better phrasing would be "genetic divergences, some of which were preserved by the cross-merging with the only surviving genetic stream", or something of the sort.
- est31 7y agoSuch categories are only an approximation of reality to help with classification. There is stuff like ring species [1] for example or species complex [2]. [1]: https://en.wikipedia.org/wiki/Ring_species https://en.wikipedia.org/wiki/Ring_species [2]: https://en.wikipedia.org/wiki/Species_complex https://en.wikipedia.org/wiki/Species_complex
- peter_retief 7y agoVery helpful links, I didn't know the term ring species
- Doubl 7y agoI thought that unlike what was previously thought, there are no known examples of ring species.
- ethiclub 7y agoAny known ring species where (A + B cannot breed OR B + C cannot breed) AND A + B can breed? Assume not possible?
- garmaine 7y agoYou are asking for both A&B and !(A&B)?
- skrebbel 7y agoThat's logically equivalent to (A + B can breed) AND (B + C cannot breed), not a very exciting question. Did you mean AND (A + C can breed)?
- quickthrower2 7y agoStill not exciting. I think we are looking for non transitivity: A+B & B+C but !A+C
- 7y ago
- avsteele 7y agoInterbreeding isn't a bright line. Zebras can breed with Donkeys! https://en.wikipedia.org/wiki/Zebroid https://en.wikipedia.org/wiki/Zebroid Darwin's Origin of Species had a good section on this; the book is quite readable.
- hanniabu 7y agoThey can breed, but if I'm not mistaken the off-spring can't have off-spring of their own.
- clouddrover 7y agoLions and tigers can interbreed. Ligers and tigons are fertile: https://en.wikipedia.org/wiki/Liger https://en.wikipedia.org/wiki/Liger https://en.wikipedia.org/wiki/Tigon https://en.wikipedia.org/wiki/Tigon https://www.youtube.com/watch?v=JE8Z5Es-M0E https://www.youtube.com/watch?v=JE8Z5Es-M0E
- TheSpiceIsLife 7y agoAre lions and tigers both cats in the same way Border Collies and German Shorthair Pointers are both dogs? Or are there more significant differences?
- pojzon 7y agoI would say your "dogs" example still represent the same spieces but different race. Those dogs can breed normal offsprings. Lions/tigers cannot.
- TheSpiceIsLife 7y agoOh yes, now I’ve read the Wikipedia articles, it seems Ligers and Tigons tend toward weak offspring prone to cancer.
- barry-cotter 7y ago
- corodra 7y agoYou're under the assumption that the current taxonomy structure has hard defined rules that nature follows because we humans told it to. Similar genus (homo is the genus) can interbreed even if they differ by species. But from what I understand, not all genus (gensuses? gensi?(I was educated that it's genera from a commentor)) follow that trait. Most can, some can't. Hell, there's a movement to ditch the current taxonomy structure and pick one of 2 other kinds that seem to follow evolution better than what we have right now. Wasn't subfamily or tribe originally called race back in the day? I could have sworn when I was in school it was called race. But they changed it at some point without sending me a memo.
- stan_rogers 7y agoIt's genera, for future reference.
- corodra 7y agoI raise my beer to you.
- nyolfen 7y agothe categories were made for hominids, not hominids for the categories
- rjf72 7y agoI'm sure you'd agree that a wolf and a chihuahua are different species. Yet they can interbreed and the offspring would likely be fertile as well. Species are primarily created when two groups do not interbreed for a sufficiently long period of time resulting in an accumulation of distinct differences. The crazy thing is that time period is not especially long. The time distance from wolf to chihuahua is only about 15,000 years! Major physical differences (such as wolf) or inability to interbreed or infertile offspring (such as mules) are all just rules of thumb. For instance zebras and horses are clearly distinct species yet they physically appear extremely similar sans their coloring, can interbreed, and there have even been instances of fertile offspring.
- inciampati 7y agoThey are not different species in any traditional biological sense. Yes, they look different due to radical changes in developmental pathways. But the differences are not actually very extreme genetically. They have almost exactly the same basic biology.
- Retric 7y agoSpecie’s definition predates our knowledge about genetics so it’s an imperfect mapping.
- rjf72 7y agoAs a peer mentioned, species predates genetics. But even when you go for a genetic solution it's not clear. How would you propose this? For instance various studies using different metrics put humans and chimps at between 95% and 99% identical. It's the counter intuitive thing about genetics. But then to further confuse the picture is that genome-wide variation between humans can differ by as much as 0.5%. So clearly drawing a genetic boundary between species seems it's subject to the exact same difficulties as our previous phenotypical classifications.
- otabdeveloper4 7y agoBecause "race" is a toxic badthink word. This isn't about science, and what you call this group of hominids is not that important anyways.
- keiru 7y agoNot the reason at all. Even if you left the charge of the word "race" behind, no one ever uses that word to describe such a distant variety of humans as the ones described in the article. I've read they compare to neanderthals and denisovans in their relationship with sapiens, and there's surely a reason why they were classed as Hominins (a two million year old tree) and not some narrower class. I'm still trying to get a better clarification, but the theorized extinct groups seem to require a far stronger word than race by any metric. Maybe subspecies would have preserved the idea of separateness while reconciling the interbreeding, but as you said, what you call this group of hominids is not that important anyways, but race gives the wrong idea in biological terms. And I'm sad so many people just downvoted the comment without clarification. I thought too it was political correctness at first until I looked into the time-frame more closely. It merited a decent reply.
- bregma 7y agoYes. A topic of much debate. Many of the original work regarding Neaderthals was by 19th-century elite-school scientists with a publication history of eugenics and the confidence that comes from the knowledge of innate superiority of their own kind. Anyone who didn't look like them would be obviously inferior. They didn't know what we know today -- Neanderthals were light-skinned fair-hared people who had survived for half a million years in the harsh conditions of glacial and inter-glacial Europe and Asia. They had a rich culture of decorative arts and ceremonial burials. They were as capable of vocal speech as we are (same pharyngeal constructs, highly developed Broca's and Wernicke's regions in the brain). They encountered waves of dark-skinned Homo sapiens coming out of Africa and about 10,000 years later vanished from the scene. That there are light-skinned fair-haired Europeans today is evidence that they didn't vanish completely. The only evidence that H. neanderthalensis and H. sapiens are separate species is the word of 19th-century French aristocrats who were concerned about maintaining racial purity.
- laretluval 7y agoAnd evidence that sapiens x neanderthal offspring were not always fertile, see elsewhere in this thread.
- richardfontana 7y ago> That there are light-skinned fair-haired Europeans today is evidence that they didn't vanish completely. This article suggests otherwise: https://www.newscientist.com/article/dn22308-europeans-did-not-inherit-pale-skins-from-neanderthals/ https://www.newscientist.com/article/dn22308-europeans-did-n...