 Okay, I guess we've sort of like built up to more and more confounding phenomena. And we're going to end with two concepts that relate to external impacts on phenotype. The first one, like, okay, the first one is super obvious. Sometimes the environment impacts phenotype. And that, if it's the environment impacting the phenotype, it's not even heritable at all. It's not passed on to, there's a fruit fly. What? They came to say, hi, go away. Environmental, for a long time, we thought that environmental impacts did not impact heredity at all. Environment can affect phenotype without impacting genotype. So your genotype doesn't change, which means that the environmental impact shouldn't be able to be passed along. There are a jillion good examples of how the environment impacts phenotype. When you go out in the sunshine, if you don't have that much melanin, your skin produces more melanin to try to protect your caratana site DNA and produce little melanin umbrellas. And that's the phenomenon of tanning. If you're the more exposed you are to UV light, the more melanin your body produces. That's not heritable, that's just the environment changing your phenotype, changing the amount of melanin in your skin. Epigenetics, on the other hand, is when the environment, good lord, and by run meant changes the DNA. And all I'm going to say about this is that there is massive research being done on epigenetics. And where we once, where I once was told the environment cannot change DNA, we now know that absolutely things like stress, trauma, diet, sleep, all of those things can actually impact your DNA, which ultimately, yes, it impacts you. But that impacts gametes you produce and the DNA of any possible offspring you produce. Epigenetics is a really interesting, weird, we should all be really nice to each other. I want to show you two pictures of the environment affecting phenotype because it'll make me happy to end on a cool note. Okay, I have pictures of hydrangeas. And hydrangeas are a plant that make a flower and you might look at this and be like, oh yeah, well, these are just different phenotypes. You can have pink flowers or blue flowers. The fact is that's an environmental impact on flower color. And I can't remember which is which and I never can. So I guarantee the last time I talked about this, I also couldn't remember which was which. But one of those pink flowers or blue flowers are found in acidic soils and the others are found in basic soils. What? So the pH of the environment can impact the phenotype. It's not changing the genes. It's not doing anything to the genetics, but it definitely complicates the giddy up. The other example I have is, oh, bun bun. These little funny bunnies, they actually produce melanated hair in cold places. Like their noses and their ears and their fur that's warm. Their warm fur, like everywhere else on their bodies, is not brown. It's not black. It's white. OK, how interesting is that? Now look, their feet are also, you can see the little feet over here. Oh, little tooties. The little tooties are cold, too. So cuddle that little guy. I wonder how long it would take to cuddle the little guy. Put little ear stockings on and the little nose cup so that he can stay warm. And then what is, would everything turn white? I'm not going to do that experiment. But if you want to, would you tell me what happens? And make sure the bunnies happy when you're doing it. OK, that's it. That's the end of our heredity. Next up, sexual reproduction, which totally relates to all of this and links. The next lecture is our link between our little genetics, heredity topic, and polygenetic diversity that leads to evolution. It's going to be fun. OK, bye-bye now.