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Repeated evolution: from egg laying to live-birth and then back to egg laying. Lizards re-evolved laying eggs multiple times
Stuff happens … over and over again … A family of lizards has achieved something very unexpected, evolving to give birth to live young, before going back to egg laying. Most remarkably, the zoologists who observed this think it is possible they rediscovered laying eggs multiple times. https://www.iflscience.com/plants-and-animals/lizards-reevolve-to-lay-eggs-after-having-already-evolved-to-give-birth-to-live-young-/
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Repeated evolution of placenta: at least 100 independent origins across the animal kingdom
First off, let me start with some quotes from mainstream-articles: The placenta is arguably the most important organ of the body, but paradoxically the most poorly understood The placenta: a mysterious organ Despite being critical to a baby’s survival, the placenta remains something of a medical mystery. Detailed understanding about how it carries out all […]
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Repeated evolution: Despite its great advantages, photosynthesis lost multiple times in diverse organisms
It is not easy to understand how natural selection works … Shining Sun – is there any cheaper source of energy ? Despite the great advantages, loss of photosynthesis has occurred in diverse lineages of organisms (e.g. apicomplexans, chlorophytes, cryptophytes, diatoms, dinoflagellates, euglenophytes, and Orobanchaceae species), along with heterotrophic free-living algae, holoparasitic plants, and pathogenic […]
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Repeated evolution: Striated muscles in cnidarians and bilaterians evolved independently
what is left of common ancestry ? Striated muscles are present in bilaterian animals (e.g. vertebrates, insects, annelids) and some non-bilaterian eumetazoans (i.e. cnidarians and ctenophores). The striking ultrastructural similarity of striated muscles between these animal groups is thought to reflect a common evolutionary origin Here we show that a muscle protein core set, including […]
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Key evolutionary innovation lost 1000 times! The ability of flight lost repeatedly in the vast majority of insect orders
Let me repeat that: Evolutionary biologists claim, that after insect-species evolved the key evolutionary innovation – the ability of flight – then the ability got lost, and this happened independently, more than 1000 times in vast majority of insect orders … Here is an older article from 1996: WHY WOULD FLIGHTLESSNESS EVOLVE? Why would natural […]
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Repeated evolution: air bladders or lungs in different groups of fishes evolved multiple times
Stuff happens …. Several times throughout their radiation fish have evolved either lungs or swim bladders as gas-holding structures. Lungs and swim bladders have different ontogenetic origins and can be used either for buoyancy or as an accessory respiratory organ. Therefore, the presence of air-filled bladders or lungs in different groups of fishes is an […]
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Repeated evolution: Appendix evolved more than 30 times!
The appendix may not be useless after all. The worm-shaped structure found near the junction of the small and large intestines evolved 32 times among mammals, according to a new study. The finding adds weight to the idea that the appendix helps protect our beneficial gut bacteria when a serious infection strikes. Now get ready […]
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Repeated evolution: Sex chromosomes evolved independently, many times, in various species
Sex chromosomes evolved not once, but many times, independently … stuff happens … Sex chromosomes are derived from autosomes and have evolved independently many times in different lineages. For example, the human X and Y chromosomes originated about 200-300 million years ago in eutherian mammals after the split of monotremes, and sex chromosomes evolved independently […]
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Repeated evolution: Penis-baculum evolved multiple times and have been lost multiple times
Several hypotheses for the function of the baculum have been proposed which lead to testable predictions in a comparative framework. Unfortunately, comparative studies have failed to yield general and consistent results Here, we specifically test this hypothesis by modeling the presence/absence of bacula of 954 mammalian species across a well-established phylogeny and show that the […]
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Repeated evolution of blood types
interesting stuff happened here … or perhaps not ? The ABO histo-blood group, the critical determinant of transfusion incompatibility, was the first genetic polymorphism discovered in humans. Remarkably, ABO antigens are also polymorphic in many other primates, with the same two amino acid changes responsible for A and B specificity in all species sequenced to […]