Path: ...!news.mixmin.net!weretis.net!feeder8.news.weretis.net!newsfeed.xs3.de!nntp-feed.chiark.greenend.org.uk!ewrotcd!news.eyrie.org!beagle.ediacara.org!.POSTED.beagle.ediacara.org!not-for-mail
From: Arkalen <arkalen@proton.me>
Newsgroups: talk.origins
Subject: Re: Primary endosymbiosis caught in the act
Date: Thu, 18 Apr 2024 20:21:56 +0200
Organization: A noiseless patient Spider
Lines: 28
Sender: to%beagle.ediacara.org
Approved: moderator@beagle.ediacara.org
Message-ID: <uvroc5$2d43k$1@dont-email.me>
References: <uvrjq4$2c3kt$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Info: beagle.ediacara.org; posting-host="beagle.ediacara.org:3.132.105.89";
	logging-data="41663"; mail-complaints-to="usenet@beagle.ediacara.org"
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.14.0
To: talk-origins@moderators.isc.org
Cancel-Lock: sha1:bUPSsOvey3IZu0JP2rg+fFUQRZ0=
Content-Language: en-US
In-Reply-To: <uvrjq4$2c3kt$1@dont-email.me>
Bytes: 3339

On 18/04/2024 19:04, Chris Thompson wrote:
> Is it true that primary endosymbiosis is thought to have happened only 
> twice? I'm a little dubious about that. But this is still cool.
> 
> "Scientists have caught a once-in-a-billion-years evolutionary event in 
> progress, as two lifeforms have merged into one organism that boasts 
> abilities its peers would envy. Last time this happened, Earth got plants."
> 
> 
> https://newatlas.com/biology/life-merger-evolution-symbiosis-organelle/
> 

One bit I'd found interesting that I didn't know when this article (or 
another one about the same paper) was posted earlier was that apparently 
symbioses of plants with N2-fixing bacteria date back to the Cretaceous 
- both for algae and land plants even though they do it completely 
differently!

I'm also dubious about it having happened twice, I thought plants had 
several plastids corresponding to more than one endosymbiotic event. But 
maybe they simplified things for effect, mitochondria and chloroplasts 
are the big ones everyone knows about. Of course (of course).

Checking that famous drawing of the tree of life with different 
endosymbiosis events that I thought included several, it does seem to 
only have the mitochondria and chloroplast one after all:

https://www.researchgate.net/figure/Schematic-Diagram-of-Symbiosis-in-the-Tree-of-Life-and-the-Union-of-the-Bacterial-and_fig1_332956942