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Joined 1 year ago
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Cake day: August 4th, 2023

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  • This is true for only red and green loght detecting proteins (opsins) - the blue opsin gene is on chromosome 7.

    The red and green detecting proteins have an interesting history in humans.

    Fish, amphibians, lizards and birds have 4 different opsins: for red, green, yellow and blue colours. And the blue opsin sees up into the ultra-violet. Most animals can see waaaay more colours in the world than we (or any mammal) can. So what happened that makes mammal vision so poor?

    It’s thought that all mammals descend from one or a few species of nocturnal mammal that survived the catastrophe that wiped out the dinosaurs at the end of the Cretaceous. The colour detecting cells (the cones) need a lot of light compared to ones that see in black-and-white (the rods) and therefore nocturnal animals frequently lose cones in favour of the more sensitive rods for better night vision. The mammals that survived the Cretaceous extinction had also lost the green and yellow opsins while keeping red and blue - basically the two different ends of the light spectrum.

    Consequently today most mammals still have only 2 opsins so your cat or dog is red-green colourblind.

    Why do humans see green? Probably because our monkey forebears, who lived in trees and ate leaves, needed to distinguish red leaves and red fruit (visible to birds) from the green background.

    But how did we bring back the green opsin? A whole section of the X chromosome (where the red opsin is coded) got duplicated in a dna copying mistake and then there were two genes for red opsins. As there are different alleles (versions), they could be selected for independently and so one red opsin drifted up the spectrum to be specific for green. So our green opsin is a completely different gene to the green opsin in fish, birds, etc. This kind of evolution happens a lot which is why, for example, there are many families of similar hormones like testosterone and estrogen. And steroids too.



  • It is terribly sad - they must live in a world of hurt.

    However so many of these people actively try to hurt LGBTQ+ and trans people by inciting hate and changing laws to harm the non-straight. In particular they have been preaching that being gay/trans equates to being a child molester. This is horrific and needs to stop. Exposing the hypocrisy is essential to reducing the harm they are inflicting to real people right now






  • That was one of the original proposed mechanisms to explain how the (obviously false) autism was caused.

    But since then, since thiomersal was removed, other ‘causes’ and moral issues have been invented, including cells from abortions.

    The one that makes me laugh the most is that it’s terrible that the poor poor baby is exposed to so many illnesses (measles, mumps, rubella, polio, tetanus, notovirus, rotovirus and more) in such a short space of time, it’s no wonder the poor dear’s immune system is compromised. And then the same mother drops the kid off at daycare and exposes the poor dear to all those viruses and more - and live viruses at that.

    There is no bleeding logic, just feels. And they get so angry at the fake harm that medicine is causing, and simultaneously actually causing real harms to real people.