From: rokimoto557@gmail.com   
      
   On 7/9/2025 3:25 AM, jillery wrote:   
   > On Tue, 08 Jul 2025 15:03:35 -0700, Bob Casanova    
   > wrote:   
   >   
   >> On Tue, 8 Jul 2025 07:22:01 -0500, the following appeared in   
   >> talk.origins, posted by RonO :   
   >>   
   >>> On 7/8/2025 4:36 AM, jillery wrote:   
   >>>> On Mon, 07 Jul 2025 08:00:09 -0700, Bob Casanova    
   >>>> wrote:   
   >>>>   
   >>>>> On Mon, 7 Jul 2025 07:01:51 -0500, the following appeared in   
   >>>>> talk.origins, posted by RonO :   
   >>>>>   
   >>>>>> On 7/6/2025 10:09 PM, Pro Plyd wrote:   
   >>>>>>>   
   >>>>>>> https://indiandefencereview.com/its-official-dolphins-and-orcas-have-   
   >>>>>>> now-crossed-the-point-of-no-return-in-their-evolution-of-returning-to-   
   >>>>>>> land-again/   
   >>>>>>>   
   >>>>>>> Dolphins and orcas, revered for their intelligence   
   >>>>>>> and agility, have reached a pivotal point in their   
   >>>>>>> evolutionary journey. New research has revealed   
   >>>>>>> that these marine mammals, once land-dwellers, have   
   >>>>>>> evolved to a stage where returning to life on land   
   >>>>>>> is biologically impossible. A breakthrough study   
   >>>>>>> underscores that after millions of years of   
   >>>>>>> evolutionary change, dolphins and orcas are now   
   >>>>>>> forever bound to the ocean.   
   >>>>>>>   
   >>>>>>> Published in Proceedings of the Royal Society B,   
   >>>>>>> the study scrutinized over 5,600 mammal species   
   >>>>>>> to understand how dolphins and orcas evolved from   
   >>>>>>> semi-aquatic ancestors to fully marine life forms.   
   >>>>>>> The research, led by Bruna Farina, a PhD candidate   
   >>>>>>> at the University of Fribourg in Switzerland,   
   >>>>>>> concludes that the transition from semi-aquatic to   
   >>>>>>> fully aquatic is a one-way path. Once a species   
   >>>>>>> makes this leap, its evolutionary direction becomes   
   >>>>>>> irreversible.   
   >>>>>>>   
   >>>>>>> Farina’s team found that this transition occurred   
   >>>>>>> millions of years ago when mammals returned to the   
   >>>>>>> sea. Unlike their terrestrial predecessors, dolphins   
   >>>>>>> and orcas cannot evolve back to a land-based   
   >>>>>>> lifestyle. Their adaptations—such as specialized   
   >>>>>>> limbs, unique diets, and reproductive systems—have   
   >>>>>>> become so ingrained that reversing these traits is   
   >>>>>>> no longer possible.   
   >>>>>>> ...   
   >>>>>>>   
   >>>>>>> The paper is here   
   >>>>>>>   
   >>>>>>> https://royalsocietypublishing.org/doi/10.1098/rspb.2023.1099   
   >>>>>>> Dollo meets Bergmann: morphological evolution in   
   >>>>>>> secondary aquatic mammals   
   >>>>>>>   
   >>>>>> Never say never.  How did fish adapt to terrestrial life styles?   
   >>>>>> Dolphins already have lungs.   
   >>>>>>   
   >>>>> The whole thing sounds to me like "We can't imagine how this   
   >>>>> could be accomplished, so it can't; simply too many   
   >>>>> simultaneous changes are required", an assertion more   
   >>>>> familiar from evolution denialists than from (supposed)   
   >>>>> scientists. I wonder if they think that cetaceans became   
   >>>>> semiaquatic (not fully; they still can't breathe underwater)   
   >>>>> in one fell swoop? And if not, why the same gradual process   
   >>>>> won't work in reverse?   
   >>>>   
   >>>>   
   >>>> It's a matter of probability.  Between random genetic events and   
   >>>> random environmental events, it's almost impossible for any *exact*   
   >>>> evolutionary pathway to be repeated.  It would be like a broken glass   
   >>>> reassembling itself.   
   >>>>   
   >>>   
   >>> What is stupid about the claim is that they do not acknowledge the   
   >>> possiblity of a new path to terrestrial adaptation.  There is no reason   
   >>> to limit how they might adapt to life on land.  They have a new starting   
   >>> point and have broken a lot of bridges to get to where they are, but   
   >>> there are likely multiple paths back to living on land, especially, just   
   >>> back to an amphibian type life style.   
   >   
   >   
   > It depends on which claim you mean.  A new path would not be a   
   > violation of Dollo's Law:   
   >   
   >    
   >   
   > As I pointed out, it is practically impossible for aquatic mammals to   
   > reverse the traits which make them aquatic and restore their ancestral   
   > land forms.  However, as I also pointed out elsepost, tortoises became   
   > secondarily land animals from ancestral aquatic forms.  So the claim   
   > that aquatic mammals could not evolve back to a completely different   
   > terrestrial form is also incorrect.  Just as with tortoises, these   
   > newly evolved terrestrial forms would necessarily retain traits of   
   > their aquatic past.  That's the point of Dollo's Law.   
      
   My take is that they would not have to take the reverse path.  It is   
   much more likely that they would evolve into a seal like terrestrial   
   animal if we drove pinnipeds to extinction and left that niche open.   
   They would not go back to a lunging croc like animal like ambulocetus.   
   Further terrestrial evolution would depend on what niche was open that   
   they could exploit.   
      
   >   
   >> That was pretty much my thought; while an exact "replay in   
      
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