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We'll see if the inflation in ancient human species stands up to scrutiny. Here's a great TED Talk about dinosaur species being mistakenly identified because '

We'll see if the inflation in ancient human species stands up to scrutiny. Here's a great TED Talk about dinosaur species being mistakenly identified because 'scientists have egos': https://www.youtube.com/watch?v=kQa11RMCeSI&t=102s https://www.youtube.com/watch?v=kQa11RMCeSI&t=102s (well worth a watch, it's a great story)

shahar2k 5y ago
I thought a big part of that was that birds have big variation between juveniles and adults, something that mammalians have less of... (let alone primates) Looking at a time when multiple hominid groups lived in relative isolation over large spans of time, admittedly without expert knowledge, it seems to make sense to me that there would be quite a bit of variation of "species" (though I also suspect the various species are more alike than most breeds of dogs...)
- thaumasiotes 5y ago
  > I thought a big part of that was that birds have big variation between juveniles and adults, something that mammalians have less of... You should see what insects do. It just isn't possible, using fossil records alone, to identify whether two insects belong to the same or different species.
  - shahar2k 5y ago
    yeah and that's what is behind the idea that some "different" dinosaur species (aka birds) are actually juvanile / adult versions of the same species totally amazing that insects basically rearrange themselves on near celular level though at certain points in their lifespan
    - thaumasiotes 5y ago
      > totally amazing that insects basically rearrange themselves on near celular level though at certain points in their lifespan What I find more amazing is that, in the popular culture, this is usually presented as something unusual that butterflies do. When in reality all insects do it and the metamorphosis of butterflies is notable only for its extreme typicality.
- gunapologist99 5y ago
  Interesting point. In the process of adopting a pure-bred Slovakian-line GSD, I've learned that German Shepherd Dogs didn't exist at all until the early 1900's, and the modern Slovakian line (which is related to the DDR line, which is when the two lines became rapidly and visibly diversified when the Iron Curtain divided Germany from the late 40's to the late 80's) is in danger of fading away altogether. And that was only in 40 years -- admittedly with intentional breeding, but it's conceivable that changes in diet, parasites, tumultuous periods of history, seismic changes, or even war/pillaging/violence could rapidly change the makeup of an entire continent within just a few decades. In fact, we've seen that in very recent history.
kypro 5y ago
How is it possible to indentify a new species from just a skull fragment and jawbone? Would there need to be multiple similar bones to rule out the possiblity of a genetic outlier? And even then it's not like there isn't fairly significant variance in bone structure between different populations of human today. Can we really say from two bits of bone that it's a different species? I have no knowledge of anthropology but it just seems a bit crazy to me that from few bits of bone we can declare we found a new species.
- Arnt 5y ago
  This isn't a criminal trial, with failsafe rules about doubt. There are very few generic outliers. They do exist, but at the same time, the chance that the next person you meet will be <1.20m or >2.40m tall is insignificant. The argument is stronger for the past, because generic outliers tend to have worse health than the average and have worse chances of reaching adulthood, so if you find a part of the skeleton of a single adult, the chance that it's someone who's half/twice as tall as the rest of the population is even smaller than for today. https://www.mindprod.com/image/math/livinghistogram.jpg https://www.mindprod.com/image/math/livinghistogram.jpg shows an entire class. They could have had a generic outlier among the pupils, but most people are near the average, see?
  - eloff 5y ago
    But the same logic applies. Instead of innocent until proven guilty it's "not a new species" until there's sufficient evidence to establish that. I'm dubious that they have that evidence, especially given their further unsubstantiated claims that they're ancestors of the neanderthals. The linked article discussed 0 evidence for why it's a new species. Presumably there's a published paper that goes into details.
    - InfiniteRand 5y ago
      It's a new discovery in science, which means it will be about 10 years before we know if it's 90% correct or not. Probably need to wait a year to rule out simple measurement errors. To some degree if a scientific discovery is news, it isn't firmly established, because if the entire field hasn't heard about it, it hasn't been properly vetted.
beerandt 5y ago
Similar thing going on with all sorts of living animals. Sequence DNA, find a population with small, but consistent mutations, declare new species, declare new species endangered because population is so small, declare a 100 mile radius refuge around population, repeat.
kingsuper20 5y ago
> We'll see if the inflation in ancient human species stands up to scrutiny. Not in that business, but could it be simply that a new way of measuring taxonomy is needed? From the outside, it appears that the whole business inherits from a Victorian need for orderly tree structures.
- HelloNurse 5y ago
  While not a tree, there is an indisputable orderly structure: the directed acyclic graph of individuals descending from other individuals. Then we can collapse nodes to obtain species that evolved from one another or more realistic arrangements, respecting some constraints (for example, if A is an ancestor of B and B is an ancestor of C, putting A and C in the same species should imply that B belongs to that species too).
  - deleted 5y ago
    [deleted]
  - AlotOfReading 5y ago
    The problem is that grouping individuals -> species is highly nontrivial. Even your constraint fails with bidirectional admixture. Imagine individuals from species A interbreed with people of species B. The admixture survives in B for a couple hundred thousand years and then back-admixture occurs, producing descendants in A who have intermediate ancestors of a different species. This is a common pattern in genus Homo, which is part of why human taxonomy is insanity. Bonus points if you can explain how to decide which species name to give to the immediate descendants of the admixture event from A->B. There's an older paper by Holliday on this subject that you might find interesting: https://doi.org/10.1086/377663 https://doi.org/10.1086/377663
    - HelloNurse 5y ago
      The idea of species is quite meaningless in any case. Boundaries are arbitrary, genetic similarity can arise by chance, interbreeding is situational, reproductive isolation is rarely perfect, populations are vague; of the different definitions of species surveyed in the article, the "cohesion"-based one is the closest to admitting that taxonomy is a rough model of cohesive genealogical and evolutionary patterns.

shahar2k 5y ago

I thought a big part of that was that birds have big variation between juveniles and adults, something that mammalians have less of... (let alone primates) Looking at a time when multiple hominid groups lived in relative isolation over large spans of time, admittedly without expert knowledge, it seems to make sense to me that there would be quite a bit of variation of "species" (though I also suspect the various species are more alike than most breeds of dogs...)

thaumasiotes 5y ago
> I thought a big part of that was that birds have big variation between juveniles and adults, something that mammalians have less of... You should see what insects do. It just isn't possible, using fossil records alone, to identify whether two insects belong to the same or different species.
- shahar2k 5y ago
  yeah and that's what is behind the idea that some "different" dinosaur species (aka birds) are actually juvanile / adult versions of the same species totally amazing that insects basically rearrange themselves on near celular level though at certain points in their lifespan
  - thaumasiotes 5y ago
    > totally amazing that insects basically rearrange themselves on near celular level though at certain points in their lifespan What I find more amazing is that, in the popular culture, this is usually presented as something unusual that butterflies do. When in reality all insects do it and the metamorphosis of butterflies is notable only for its extreme typicality.
gunapologist99 5y ago
Interesting point. In the process of adopting a pure-bred Slovakian-line GSD, I've learned that German Shepherd Dogs didn't exist at all until the early 1900's, and the modern Slovakian line (which is related to the DDR line, which is when the two lines became rapidly and visibly diversified when the Iron Curtain divided Germany from the late 40's to the late 80's) is in danger of fading away altogether. And that was only in 40 years -- admittedly with intentional breeding, but it's conceivable that changes in diet, parasites, tumultuous periods of history, seismic changes, or even war/pillaging/violence could rapidly change the makeup of an entire continent within just a few decades. In fact, we've seen that in very recent history.

kypro 5y ago

How is it possible to indentify a new species from just a skull fragment and jawbone? Would there need to be multiple similar bones to rule out the possiblity of a genetic outlier? And even then it's not like there isn't fairly significant variance in bone structure between different populations of human today. Can we really say from two bits of bone that it's a different species? I have no knowledge of anthropology but it just seems a bit crazy to me that from few bits of bone we can declare we found a new species.

Arnt 5y ago
This isn't a criminal trial, with failsafe rules about doubt. There are very few generic outliers. They do exist, but at the same time, the chance that the next person you meet will be <1.20m or >2.40m tall is insignificant. The argument is stronger for the past, because generic outliers tend to have worse health than the average and have worse chances of reaching adulthood, so if you find a part of the skeleton of a single adult, the chance that it's someone who's half/twice as tall as the rest of the population is even smaller than for today. https://www.mindprod.com/image/math/livinghistogram.jpg https://www.mindprod.com/image/math/livinghistogram.jpg shows an entire class. They could have had a generic outlier among the pupils, but most people are near the average, see?
- eloff 5y ago
  But the same logic applies. Instead of innocent until proven guilty it's "not a new species" until there's sufficient evidence to establish that. I'm dubious that they have that evidence, especially given their further unsubstantiated claims that they're ancestors of the neanderthals. The linked article discussed 0 evidence for why it's a new species. Presumably there's a published paper that goes into details.
  - InfiniteRand 5y ago
    It's a new discovery in science, which means it will be about 10 years before we know if it's 90% correct or not. Probably need to wait a year to rule out simple measurement errors. To some degree if a scientific discovery is news, it isn't firmly established, because if the entire field hasn't heard about it, it hasn't been properly vetted.

beerandt 5y ago

Similar thing going on with all sorts of living animals. Sequence DNA, find a population with small, but consistent mutations, declare new species, declare new species endangered because population is so small, declare a 100 mile radius refuge around population, repeat.

kingsuper20 5y ago

> We'll see if the inflation in ancient human species stands up to scrutiny. Not in that business, but could it be simply that a new way of measuring taxonomy is needed? From the outside, it appears that the whole business inherits from a Victorian need for orderly tree structures.

HelloNurse 5y ago
While not a tree, there is an indisputable orderly structure: the directed acyclic graph of individuals descending from other individuals. Then we can collapse nodes to obtain species that evolved from one another or more realistic arrangements, respecting some constraints (for example, if A is an ancestor of B and B is an ancestor of C, putting A and C in the same species should imply that B belongs to that species too).
- deleted 5y ago
  [deleted]
- AlotOfReading 5y ago
  The problem is that grouping individuals -> species is highly nontrivial. Even your constraint fails with bidirectional admixture. Imagine individuals from species A interbreed with people of species B. The admixture survives in B for a couple hundred thousand years and then back-admixture occurs, producing descendants in A who have intermediate ancestors of a different species. This is a common pattern in genus Homo, which is part of why human taxonomy is insanity. Bonus points if you can explain how to decide which species name to give to the immediate descendants of the admixture event from A->B. There's an older paper by Holliday on this subject that you might find interesting: https://doi.org/10.1086/377663 https://doi.org/10.1086/377663
  - HelloNurse 5y ago
    The idea of species is quite meaningless in any case. Boundaries are arbitrary, genetic similarity can arise by chance, interbreeding is situational, reproductive isolation is rarely perfect, populations are vague; of the different definitions of species surveyed in the article, the "cohesion"-based one is the closest to admitting that taxonomy is a rough model of cohesive genealogical and evolutionary patterns.