Re: The egg or the chicken

On Thu, 7 Nov 2024 09:39:14 -0600, the following appeared in
talk.origins, posted by RonO <rokimoto557@gmail.com>:

https://www.sciencedaily.com/releases/2024/11/241106132114.htm
>
This news article claims that nature could create eggs long before it
invented chickens.
>
There is a single celled eukaryote (Chromosphaera perkensii) that
branched off from animal cellular life forms a billion years ago before
protists evolved.  It is a single celled organism that can form balls of
two types of cells that look like early stage embryos, and it exists in
these balls for about 1/3 of it's life cycle.
>
The article claims that single celled animals could form embryo like
cellular complexes long before multicellular life forms evolved, but the
most their work indicates is that the genes that could be used to evolve
multicellular life and future embryos may have existed that could allow
the evolution of the convergent trait in two divergent lineages
separated by half a billion years of evolution.  It branched off from
the lineage that led to multicellular life a billion years ago and some
time during it's evolution since splitting off it evolved the means to
form these balls of cells.  A half a billion years after the divergence
the lineage of multicellular animals evolved something similar.  For all
we know the lineage of multicellular animals evolved embryos half a
billion years ago, and the independent lineage of C. perkensii evolved
their ability more recently, unless they have evidence that these embryo
like structures existed a billion years ago.
>

You don't have to go that far back; even if we have no
fossilized eggs of fish or amphibians (due to the lack of
hard shells) we do have fossilized reptile and dino eggs,
which preceded chickens (or any other avians) by quite a few
million years. So I'd rate the article as "interesting, but
nothing really new regarding the old question".

>

--

Bob C.

"The most exciting phrase to hear in science,
 the one that heralds new discoveries, is not
 'Eureka!' but 'That's funny...'"

- Isaac Asimov