Path: ...!3.eu.feeder.erje.net!feeder.erje.net!paganini.bofh.team!news.killfile.org!news.eyrie.org!beagle.ediacara.org!.POSTED.beagle.ediacara.org!not-for-mail
From: John Harshman <john.harshman@gmail.com>
Newsgroups: talk.origins
Subject: Re: Science has a news article up about "living fossils"
Date: Tue, 12 Mar 2024 06:44:41 -0700
Organization: University of Ediacara
Lines: 45
Sender: to%beagle.ediacara.org
Approved: moderator@beagle.ediacara.org
Message-ID: <yr2dnSQUUo3UwW34nZ2dnZfqlJydnZ2d@giganews.com>
References: <uso3e0$3sddr$1@dont-email.me>
 <5uudnTnDGosMDnL4nZ2dnZfqlJydnZ2d@giganews.com> <uspc19$84nb$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Info: beagle.ediacara.org; posting-host="beagle.ediacara.org:3.132.105.89";
	logging-data="42072"; mail-complaints-to="usenet@beagle.ediacara.org"
User-Agent: Mozilla Thunderbird
To: talk-origins@moderators.isc.org
Content-Language: en-US
In-Reply-To: <uspc19$84nb$1@dont-email.me>
Bytes: 5038

On 3/12/24 3:50 AM, Ernest Major wrote:
> On 11/03/2024 23:28, John Harshman wrote:
>> On 3/11/24 4:17 PM, RonO wrote:
>>> https://www.science.org/content/article/these-gars-are-ultimate-living-fossils
>>>
>>> Open access article:
>>> https://academic.oup.com/evolut/advance-article/doi/10.1093/evolut/qpae028/7615529?login=false
>>>
>>> These researchers looked at Gar, but it also applies to sturgeons. 
>>> These two bony fish lineages seem to have a very slow rate of 
>>> molecular evolution.  The changes in their DNA accumulate so slowly 
>>> that two lineages separated for over 100 million years can still form 
>>> fertile hybrids.  3 million years is pushing it for species like 
>>> lions and tigers that can still form hybrids, but the hybrids are 
>>> sterile. Bonobos and chimps are around 3 million years divergent and 
>>> can still form fertile hybrids, but the claim is that these fish 
>>> evolve orders of magnitude more slowly than mammals.
>>>
>>> The Science news article claims that mammals accumulate 0.02 
>>> mutations per site per million years, while these fish averaged only 
>>> 0.00009 mutations per million years.  For the 1100 coding exons that 
>>> they looked at for this study these fish evolve much more slowly than 
>>> mammals.
>>>
>>> The news article notes that other "living fossils" such as 
>>> coelacanths (0.0005) evolve faster, but slower than amphibians 
>>> (0.007).  It sounds like terrestrial animals evolve faster than fish.
>>
>> If it's repair mechanisms they hypothesize as the cause of slow 
>> evolution, they really should be looking at junk sequences rather than 
>> just 4-fold degenerate sites. I suggest introns. And if the introns 
>> aren't alignable, well, that kills the theory right there.
>>
> 
> Tree species thought to be separated by tens of millions of years are 
> known to hybridise. For example Platanus orientalis and Platanus 
> occidentalis, and also with Tilia, Quercus and Aesculus. In the case of 
> Tilia I suspect that multiple rounds of introgression has served to 
> limit the amount of divergence between species. However Tilia does 
> appear as a short branch in cladograms, supporting the hypothesis that 
> forest trees have a lower rate of evolution.
> 
Then again, ducks that are thought to be separated by tens of millions 
of years are also known to hybridize, and their rate of evolution isn't 
particularly slow.