Evolution: New Species and Old Species?

[pctopgs]

OK so we all know that when (for example) a population of mammals evolves into something else, whatever it evolves into it will still be a mammal, but it won't be able to produce viable offspring...

This is well understood for taxonomic classes (like mammals) but what about species? What if humans evolved into something else? The new species will still be classified as human, but will the "human" species become a family? if so then will the family "hominidae" become a taxonomic order? Then what about Primates, Mammalia etc?

 

[bobze]

OK so we all know that when (for example) a population of mammals evolves into something else, whatever it evolves into it will still be a mammal, but it won't be able to produce viable offspring...

That's because you are thinking about it wrong. Evolution doesn't work by some organism becoming the "first" of a new species. It works on populations. Specifically the allele frequencies of populations changing over time. No organism is going to give birth to something so different that it will be a new species over night, nor will it not be able to interbreed with the rest of the population. Its a population that evolves: not individuals. Very important concept for understanding evolution.

This is well understood for taxonomic classes (like mammals) but what about species? What if humans evolved into something else? The new species will still be classified as human, but will the "human" species become a family? if so then will the family "hominidae" become a taxonomic order? Then what about Primates, Mammalia etc?

"Class, family, mammal" etc, these are meaningless names given to something real. What is real is the coalescent node it describes.

So like you mentioned above, whatever "it" evolves into will till belong to the "kind" mammal. This is because mammal describes a node, or "parent" populations if you will of all extant populations which descend from that one.

The ancestral population of "mammal" occurs in the past, so any descendents of extant members will always and forever belong to that "kind" no mater what new nodes they create through branching of their lineage and no matter what we decide to name said nodes. Remember the rank is arbitrary, its simply to make it possible for us to converse on the issue. What mattered was that coalescent point--That shared ancestral population who is no longer a live.

 

[pctopgs]

That's because you are thinking about it wrong. Evolution doesn't work by some organism becoming the "first" of a new species. It works on populations. Specifically the allele frequencies of populations changing over time. No organism is going to give birth to something so different that it will be a new species over night, nor will it not be able to interbreed with the rest of the population. Its a population that evolves: not individuals. Very important concept for understanding evolution.

Thanks for the response, but I did say population of mammals. This is besides the point and I thought elaborating on it would be unnecessary since we all know it. :)

"Class, family, mammal" etc, these are meaningless names given to something real. What is real is the coalescent node it describes.

So like you mentioned above, whatever "it" evolves into will till belong to the "kind" mammal. This is because mammal describes a node, or "parent" populations if you will of all extant populations which descend from that one.

The ancestral population of "mammal" occurs in the past, so any descendents of extant members will always and forever belong to that "kind" no mater what new nodes they create through branching of their lineage and no matter what we decide to name said nodes. Remember the rank is arbitrary, its simply to make it possible for us to converse on the issue. What mattered was that coalescent point--That shared ancestral population who is no longer a live.

Yeah thanks again for the reply, but if the human species was to evolve into a new species then does "Human" get reclassified as a genus and whatever humans evolved into will then be classified as "species", or does "human" stay classified as species and whatever the humans evolved into gets a new taxonomic rank? I guess this is more of a taxonomy question..

 

[mishrashubham]

...but if the human species was to evolve into a new species then does "Human" get reclassified as a genus and whatever humans evolved into will then be classified as "species", or does "human" stay classified as species and whatever the humans evolved into gets a new taxonomic rank?...

Are you referring to anagenesis? In that case the 'old humans' are still a species.Check en.wikipedia.org/wiki/Anagenesis

 

[bobze]

Yeah thanks again for the reply, but if the human species was to evolve into a new species then does "Human" get reclassified as a genus and whatever humans evolved into will then be classified as "species", or does "human" stay classified as species and whatever the humans evolved into gets a new taxonomic rank? I guess this is more of a taxonomy question..

I suppose it depends on who is doing the naming. Conventionally the "discovering" biologist gets to name it. In the case of a new taxonomic rank it would probably have to be agreed upon by ICZN (International Commission on Zoological Nomenclature).

If Homo sapiens sapiens split into new "species" they'd probably be classed as new subspecies and eventually we'd vet some new kind of rank (remember though, ranks are arbitrary). Such that their new names would Homo sapiens sapiens new name 1 and Homo sapiens sapiens new name 2

 

[DaveC426913]

If Homo sapiens sapiens split into new "species" they'd probably be classed as new subspecies and eventually we'd vet some new kind of rank (remember though, ranks are arbitrary). Such that their new names would Homo sapiens sapiens new name 1 and Homo sapiens sapiens new name 2

Homo superior
In my interior
But from the skin out I'm
Homo sapiens too
I'm Homo sapiens like you
- Pete Shelley

omg, I've been singing that song at the top of my lungs for decades and only today I discover it is all about homosexuality.