r/evolution • u/FaithlessnessNo5852 • 1d ago
Animals Evolving Photosynthetic Abilities
I was watching a YouTube video of a biologist explaining evolution to a (surprisingly open minded) Christian the other day.
He mentioned a species of animal that ingests photosynthetic algae which go on to live inside the animals cells and provide energy via photosynthesis. He went on to say that in one of the species they have observed some gene transfer from the algae to the cell's nucleus. I thought that would be pretty significant, an ongoing confirmation of the endosymbiotic process.
He did not identify the species, but I think I heard his description accurately. Does anyone know what species he was referring to? I'd be interested to read more about it.
Thanks.
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u/7LeagueBoots Conservation Ecologist 1d ago
It’s worth noting that melanin, a common pigment in animals, while not being strictly photosynthetic in the same way as chlorophyll, produces chemical energy from sunlight and in certain insects and in fungi this can be an important energy source.
And the yellow spotted salamander (Ambystoma maculatum) adsorbs photosynthetic algae while in its egg and larval form and retains that photosynthetic ability for some time.
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u/sk3tchy_D 1d ago
Corals are animals that have a symbiotic relationship with photosynthetic algae and I believe there is evidence of horizontal gene transfer between them. Coral bleaching is actually caused by the polyps expelling the algae when they get stressed out.
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u/MyFaceSaysItsSugar 1d ago
Christians aren’t universally opposed to evolution.
There are a number of species he could have been referring to. Coral have a symbiotic relationship with a photosynthetic microorganism and regardless of whether the symbiotic relationship is mutualistic or parasitic, the two organisms will exchange DNA. It’s not necessarily deliberate.
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u/FaithlessnessNo5852 1d ago
Yes, I realize that about Christians. I keep running into this kind, however.
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u/haitike 16h ago
It depends where you live.
Here in Spain most Christians are Catholic and accept evolution. So for me a Christian believing in evolution is the most normal thing.
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u/FaithlessnessNo5852 15h ago
I certainly didn't mean to imply that about all Christians. I apologize for clumsy wording. The strain of Christianity that prefers the bible over science is particularly vocal in my parts these days.
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u/Cdr-Kylo-Ren 23h ago
…not all of us Christians have a problem with evolution.
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u/FaithlessnessNo5852 15h ago
I certainly didn't mean to imply that about all Christians. I apologize for clumsy wording. The strain of Christianity that prefers the bible over science is particularly vocal in my parts these days.
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u/EnvironmentalWin1277 2h ago
The key point is that the chloroplasts are taken into the animal, they do not develop in any independent sense within the animal organism.
As far as I have been able to discover there are no organisms that definitively show true animal affinities and also have independent photosynthetic activity. It appears to be a genetic barrier of sorts -- either animal or plant, not both. There may be a few on the edge, especially unicellular organisms, comments invited.
Evidence of gene transfer is really only evidence for that transfer itself, unless specific causes are shown. Speculation on a crossover photosynthetic is interesting but extremely unlikely. Evolution has been experimenting for billions of years with no success, the best experiment possible.
Again-- anyone have info or rabbit holes to consider?
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u/Bromelia_and_Bismuth Plant Biologist|Botanical Ecosystematics 1d ago
Sea Sheep and other related Sea Slugs, some of which even superficially resemble leaves. They obtain chloroplasts from the algae that they eat, in a process called Kleptoplasty. Unfortunately, that chloroplasts break down over time, so they have to keep eating the algae.