Abstract

A central question in evolutionary biology is whether sponges or ctenophores (comb jellies) are the sister group to all other animals. These alternative phylogenetic hypotheses imply different scenarios for the evolution of complex neural systems and other animal-specific traits1,2,3,4,5,6. Conventional phylogenetic approaches based on morphological characters and increasingly extensive gene sequence collections have not been able to definitively answer this question7,8,9,10,11. Here we develop chromosome-scale gene linkage, also known as synteny, as a phylogenetic character for resolving this question12. We report new chromosome-scale genomes for a ctenophore and two marine sponges, and for three unicellular relatives of animals (a choanoflagellate, a filasterean amoeba and an ichthyosporean) that serve as outgroups for phylogenetic analysis. We find ancient syntenies that are conserved between animals and their close unicellular relatives. Ctenophores and unicellular eukaryotes share ancestral metazoan patterns, whereas sponges, bilaterians, and cnidarians share derived chromosomal rearrangements. Conserved syntenic characters unite sponges with bilaterians, cnidarians, and placozoans in a monophyletic clade to the exclusion of ctenophores, placing ctenophores as the sister group to all other animals. The patterns of synteny shared by sponges, bilaterians, and cnidarians are the result of rare and irreversible chromosome fusion-and-mixing events that provide robust and unambiguous phylogenetic support for the ctenophore-sister hypothesis. These findings provide a new framework for resolving deep, recalcitrant phylogenetic problems and have implications for our understanding of animal evolution.

https://www.nature.com/articles/s41586-023-05936-6 (open access)

On 5/17/23 18:58, erik simpson wrote:
> Abstract
>
> A central question in evolutionary biology is whether sponges or ctenophores (comb jellies) are the sister group to all other animals. These alternative phylogenetic hypotheses imply different scenarios for the evolution of complex neural systems and other animal-specific traits1,2,3,4,5,6. Conventional phylogenetic approaches based on morphological characters and increasingly extensive gene sequence collections have not been able to definitively answer this question7,8,9,10,11. Here we develop chromosome-scale gene linkage, also known as synteny, as a phylogenetic character for resolving this question12. We report new chromosome-scale genomes for a ctenophore and two marine sponges, and for three unicellular relatives of animals (a choanoflagellate, a filasterean amoeba and an ichthyosporean) that serve as outgroups for phylogenetic analysis. We find ancient syntenies that are conserved between animals and their close unicellular relatives. Ctenophores and unicellular eukaryotes share ancestral metazoan patterns, whereas sponges, bilaterians, and cnidarians share derived chromosomal rearrangements. Conserved syntenic characters unite sponges with bilaterians, cnidarians, and placozoans in a monophyletic clade to the exclusion of ctenophores, placing ctenophores as the sister group to all other animals. The patterns of synteny shared by sponges, bilaterians, and cnidarians are the result of rare and irreversible chromosome fusion-and-mixing events that provide robust and unambiguous phylogenetic support for the ctenophore-sister hypothesis. These findings provide a new framework for resolving deep, recalcitrant phylogenetic problems and have implications for our understanding of animal evolution.
>
> https://www.nature.com/articles/s41586-023-05936-6 (open access)

Greatr article! Does either of thesse lineages lead to current cordatges?

<<placing ctenophores as the sister group to all other animals>>

Alien life forms....

On Thursday, May 18, 2023 at 5:45:02 AM UTC-7, Popping Mad wrote:
> On 5/17/23 18:58, erik simpson wrote:
> > Abstract
> >
> > A central question in evolutionary biology is whether sponges or ctenophores (comb jellies) are the sister group to all other animals. These alternative phylogenetic hypotheses imply different scenarios for the evolution of complex neural systems and other animal-specific traits1,2,3,4,5,6. Conventional phylogenetic approaches based on morphological characters and increasingly extensive gene sequence collections have not been able to definitively answer this question7,8,9,10,11. Here we develop chromosome-scale gene linkage, also known as synteny, as a phylogenetic character for resolving this question12. We report new chromosome-scale genomes for a ctenophore and two marine sponges, and for three unicellular relatives of animals (a choanoflagellate, a filasterean amoeba and an ichthyosporean) that serve as outgroups for phylogenetic analysis. We find ancient syntenies that are conserved between animals and their close unicellular relatives. Ctenophores and unicellular eukaryotes share ancestral metazoan patterns, whereas sponges, bilaterians, and cnidarians share derived chromosomal rearrangements. Conserved syntenic characters unite sponges with bilaterians, cnidarians, and placozoans in a monophyletic clade to the exclusion of ctenophores, placing ctenophores as the sister group to all other animals. The patterns of synteny shared by sponges, bilaterians, and cnidarians are the result of rare and irreversible chromosome fusion-and-mixing events that provide robust and unambiguous phylogenetic support for the ctenophore-sister hypothesis. These findings provide a new framework for resolving deep, recalcitrant phylogenetic problems and have implications for our understanding of animal evolution.
> >
> > https://www.nature.com/articles/s41586-023-05936-6 (open access)
> Greatr article! Does either of thesse lineages lead to current cordatges?
> <<placing ctenophores as the sister group to all other animals>>
> Alien life forms....

What is "cordatges"? If you mean dates, thry're hard to come by. Reliable fossil dating, even for sponges is
only available in very late Ediacaran or early Cambrian. It's very likely that the ctenophore - all other metazoan
split happened ~800 Mya, but crown clades' LCA is only a few 100 Mya. It's easier to lose charateristics through
evolutionary processes than to regain them, so we have no idea what the easliest ctenophores and sponges "looked
like".

As for alien life forms, there's no evidence yet for them. I'm hoping Mars or other solar system locations might
provide a glimpse before I leave the stage.

erik simpson <eastside.erik@gmail.com> wrote:
> On Thursday, May 18, 2023 at 5:45:02 AM UTC-7, Popping Mad wrote:
>> On 5/17/23 18:58, erik simpson wrote:
>>> Abstract
>>>
>>> A central question in evolutionary biology is whether sponges or
>>> ctenophores (comb jellies) are the sister group to all other animals.
>>> These alternative phylogenetic hypotheses imply different scenarios for
>>> the evolution of complex neural systems and other animal-specific
>>> traits1,2,3,4,5,6. Conventional phylogenetic approaches based on
>>> morphological characters and increasingly extensive gene sequence
>>> collections have not been able to definitively answer this
>>> question7,8,9,10,11. Here we develop chromosome-scale gene linkage,
>>> also known as synteny, as a phylogenetic character for resolving this
>>> question12. We report new chromosome-scale genomes for a ctenophore and
>>> two marine sponges, and for three unicellular relatives of animals (a
>>> choanoflagellate, a filasterean amoeba and an ichthyosporean) that
>>> serve as outgroups for phylogenetic analysis. We find ancient syntenies
>>> that are conserved between animals and their close unicellular
>>> relatives. Ctenophores and unicellular eukaryotes share ancestral
>>> metazoan patterns, whereas sponges, bilaterians, and cnidarians share
>>> derived chromosomal rearrangements. Conserved syntenic characters unite
>>> sponges with bilaterians, cnidarians, and placozoans in a monophyletic
>>> clade to the exclusion of ctenophores, placing ctenophores as the
>>> sister group to all other animals. The patterns of synteny shared by
>>> sponges, bilaterians, and cnidarians are the result of rare and
>>> irreversible chromosome fusion-and-mixing events that provide robust
>>> and unambiguous phylogenetic support for the ctenophore-sister
>>> hypothesis. These findings provide a new framework for resolving deep,
>>> recalcitrant phylogenetic problems and have implications for our
>>> understanding of animal evolution.
>>>
>>> https://www.nature.com/articles/s41586-023-05936-6 (open access)
>> Greatr article! Does either of thesse lineages lead to current cordatges?
>> <<placing ctenophores as the sister group to all other animals>>
>> Alien life forms....
>
> What is "cordatges"? If you mean dates, thry're hard to come by.
> Reliable fossil dating, even for sponges is
> only available in very late Ediacaran or early Cambrian. It's very
> likely that the ctenophore - all other metazoan
> split happened ~800 Mya, but crown clades' LCA is only a few 100 Mya.
> It's easier to lose charateristics through
> evolutionary processes than to regain them, so we have no idea what the
> easliest ctenophores and sponges "looked
> like".
>
> As for alien life forms, there's no evidence yet for them. I'm hoping
> Mars or other solar system locations might
> provide a glimpse before I leave the stage.
>
Chordates? Echinoderms are much closer as deuterostomes.

On Saturday, May 20, 2023 at 7:36:14 AM UTC-7, *Hemidactylus* wrote:
> erik simpson <eastsi...@gmail.com> wrote:
> > On Thursday, May 18, 2023 at 5:45:02 AM UTC-7, Popping Mad wrote:
> >> On 5/17/23 18:58, erik simpson wrote:
> >>> Abstract
> >>>
> >>> A central question in evolutionary biology is whether sponges or
> >>> ctenophores (comb jellies) are the sister group to all other animals.
> >>> These alternative phylogenetic hypotheses imply different scenarios for
> >>> the evolution of complex neural systems and other animal-specific
> >>> traits1,2,3,4,5,6. Conventional phylogenetic approaches based on
> >>> morphological characters and increasingly extensive gene sequence
> >>> collections have not been able to definitively answer this
> >>> question7,8,9,10,11. Here we develop chromosome-scale gene linkage,
> >>> also known as synteny, as a phylogenetic character for resolving this
> >>> question12. We report new chromosome-scale genomes for a ctenophore and
> >>> two marine sponges, and for three unicellular relatives of animals (a
> >>> choanoflagellate, a filasterean amoeba and an ichthyosporean) that
> >>> serve as outgroups for phylogenetic analysis. We find ancient syntenies
> >>> that are conserved between animals and their close unicellular
> >>> relatives. Ctenophores and unicellular eukaryotes share ancestral
> >>> metazoan patterns, whereas sponges, bilaterians, and cnidarians share
> >>> derived chromosomal rearrangements. Conserved syntenic characters unite
> >>> sponges with bilaterians, cnidarians, and placozoans in a monophyletic
> >>> clade to the exclusion of ctenophores, placing ctenophores as the
> >>> sister group to all other animals. The patterns of synteny shared by
> >>> sponges, bilaterians, and cnidarians are the result of rare and
> >>> irreversible chromosome fusion-and-mixing events that provide robust
> >>> and unambiguous phylogenetic support for the ctenophore-sister
> >>> hypothesis. These findings provide a new framework for resolving deep,
> >>> recalcitrant phylogenetic problems and have implications for our
> >>> understanding of animal evolution.
> >>>
> >>> https://www.nature.com/articles/s41586-023-05936-6 (open access)
> >> Greatr article! Does either of thesse lineages lead to current cordatges?
> >> <<placing ctenophores as the sister group to all other animals>>
> >> Alien life forms....
> >
> > What is "cordatges"? If you mean dates, thry're hard to come by.
> > Reliable fossil dating, even for sponges is
> > only available in very late Ediacaran or early Cambrian. It's very
> > likely that the ctenophore - all other metazoan
> > split happened ~800 Mya, but crown clades' LCA is only a few 100 Mya.
> > It's easier to lose charateristics through
> > evolutionary processes than to regain them, so we have no idea what the
> > easliest ctenophores and sponges "looked
> > like".
> >
> > As for alien life forms, there's no evidence yet for them. I'm hoping
> > Mars or other solar system locations might
> > provide a glimpse before I leave the stage.
> >
> Chordates? Echinoderms are much closer as deuterostomes.

The earliest chordates show up in the lower Cambrian ~540 MYa, but are already quite
derived. The protostome-deauterostome (Echinoderms and we are in there) split occurred
before ~556 MYa since Kimberella (probably a protostome) is found then. Even if Kimberella
is actually a stem Bilaterian, Chordates probably originated in the mid-Ediacaran, ~ 250 My after
the Ctenophore-Sponge divergence.

Considering how long it took (~4Gy) to get to Metazoa at all, subsequent things happened pretty
quickly. If aliens were involved, all bets are off.

On 5/18/23 11:01, erik simpson wrote:
> On Thursday, May 18, 2023 at 5:45:02 AM UTC-7, Popping Mad wrote:
>> On 5/17/23 18:58, erik simpson wrote:
>>> Abstract
>>>
>>> A central question in evolutionary biology is whether sponges or ctenophores (comb jellies) are the sister group to all other animals. These alternative phylogenetic hypotheses imply different scenarios for the evolution of complex neural systems and other animal-specific traits1,2,3,4,5,6. Conventional phylogenetic approaches based on morphological characters and increasingly extensive gene sequence collections have not been able to definitively answer this question7,8,9,10,11. Here we develop chromosome-scale gene linkage, also known as synteny, as a phylogenetic character for resolving this question12. We report new chromosome-scale genomes for a ctenophore and two marine sponges, and for three unicellular relatives of animals (a choanoflagellate, a filasterean amoeba and an ichthyosporean) that serve as outgroups for phylogenetic analysis. We find ancient syntenies that are conserved between animals and their close unicellular relatives. Ctenophores and unicellular eukaryotes share ancestral metazoan patterns, whereas sponges, bilaterians, and cnidarians share derived chromosomal rearrangements. Conserved syntenic characters unite sponges with bilaterians, cnidarians, and placozoans in a monophyletic clade to the exclusion of ctenophores, placing ctenophores as the sister group to all other animals. The patterns of synteny shared by sponges, bilaterians, and cnidarians are the result of rare and irreversible chromosome fusion-and-mixing events that provide robust and unambiguous phylogenetic support for the ctenophore-sister hypothesis. These findings provide a new framework for resolving deep, recalcitrant phylogenetic problems and have implications for our understanding of animal evolution.
>>>
>>> https://www.nature.com/articles/s41586-023-05936-6 (open access)
>> Greatr article! Does either of thesse lineages lead to current cordatges?
>> <<placing ctenophores as the sister group to all other animals>>
>> Alien life forms....
>
> What is "cordatges"?

CORDATES

things with spines?

If you mean dates, thry're hard to come by. Reliable fossil dating,
even for sponges is
> only available in very late Ediacaran or early Cambrian. It's very likely that the ctenophore - all other metazoan
> split happened ~800 Mya, but crown clades' LCA is only a few 100 Mya. It's easier to lose charateristics through
> evolutionary processes than to regain them, so we have no idea what the easliest ctenophores and sponges "looked
> like".
>
> As for alien life forms, there's no evidence yet for them. I'm hoping Mars or other solar system locations might
> provide a glimpse before I leave the stage.

On 5/23/23 8:29 PM, Popping Mad wrote:
> On 5/18/23 11:01, erik simpson wrote:
>> On Thursday, May 18, 2023 at 5:45:02 AM UTC-7, Popping Mad wrote:
>>> On 5/17/23 18:58, erik simpson wrote:
>>>> Abstract
>>>>
>>>> A central question in evolutionary biology is whether sponges or ctenophores (comb jellies) are the sister group to all other animals. These alternative phylogenetic hypotheses imply different scenarios for the evolution of complex neural systems and other animal-specific traits1,2,3,4,5,6. Conventional phylogenetic approaches based on morphological characters and increasingly extensive gene sequence collections have not been able to definitively answer this question7,8,9,10,11. Here we develop chromosome-scale gene linkage, also known as synteny, as a phylogenetic character for resolving this question12. We report new chromosome-scale genomes for a ctenophore and two marine sponges, and for three unicellular relatives of animals (a choanoflagellate, a filasterean amoeba and an ichthyosporean) that serve as outgroups for phylogenetic analysis. We find ancient syntenies that are conserved between animals and their close unicellular relatives. Ctenophores and unicellular eukaryotes share ancestral metazoan patterns, whereas sponges, bilaterians, and cnidarians share derived chromosomal rearrangements. Conserved syntenic characters unite sponges with bilaterians, cnidarians, and placozoans in a monophyletic clade to the exclusion of ctenophores, placing ctenophores as the sister group to all other animals. The patterns of synteny shared by sponges, bilaterians, and cnidarians are the result of rare and irreversible chromosome fusion-and-mixing events that provide robust and unambiguous phylogenetic support for the ctenophore-sister hypothesis. These findings provide a new framework for resolving deep, recalcitrant phylogenetic problems and have implications for our understanding of animal evolution.
>>>>
>>>> https://www.nature.com/articles/s41586-023-05936-6 (open access)
>>> Greatr article! Does either of thesse lineages lead to current cordatges?
>>> <<placing ctenophores as the sister group to all other animals>>
>>> Alien life forms....
>>
>> What is "cordatges"?
>
> CORDATES
>
> things with spines?
Like sea urchins or lionfish?
It's "chordates", and they're thing with notochords, not spines.
> If you mean dates, thry're hard to come by. Reliable fossil dating,
> even for sponges is
>> only available in very late Ediacaran or early Cambrian. It's very likely that the ctenophore - all other metazoan
>> split happened ~800 Mya, but crown clades' LCA is only a few 100 Mya. It's easier to lose charateristics through
>> evolutionary processes than to regain them, so we have no idea what the easliest ctenophores and sponges "looked
>> like".
>>
>> As for alien life forms, there's no evidence yet for them. I'm hoping Mars or other solar system locations might
>> provide a glimpse before I leave the stage.
>