Vestigial Traits and Evolutionary Misconceptions

by Jason Amores Sumpter
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now just because birds evolved from dinosaurs doesn't mean that one day a dinosaur just gave birth to a bird. No, there were many transitional states along the way. And we call these transitional features. That's a trait that has a form somewhere between the ancestral one and that of the descendants. A great example of a transitional feature. Transitional organism, Actually. Is this the R key optics? This is kind of the missing link or one of those missing links between birds and dinosaurs. And you can see that the R key optics was a type of dinosaur, but had this feather had these feathers and it was starting to gain that bird form. So this is just an example of a transitional feature, the dinosaur turning into the bird. Some organisms have what are called vestigial traits, though, and these air structures their attributes that have lost their ancestral functionality but still stick around. Great example of this are whales back legs. Yeah, I bet you didn't know whales actually have the bones for back legs Now. Whales actually evolved from four legged mammals, so they lost the need for those back legs because their tails took over as their main mode of transit. What? But the bones for those back legs are still formed in Wales, and that is because they are a vestigial trait. They're kind of an evolutionary hangover from where they came from from their ancestors. Now some traits it's worth noting are non adaptive, meaning that these traits don't appear to be adaptive. And instead they have some sort of neutral or occasionally Della teary ISS effect on fitness. So basically, some evolved traits are not good for the organism, necessarily. And this really gets at some of the main evolutionary misconceptions. First and foremost, it's very often that we throw around the word complexity. This organism is mawr complex than that organism. Humans are higher order organisms than lowly bacteria. Guess what? Those aren't scientific terms, and in fact, those air really not scientific ideas. There's no definition for complexity. I mean, what really makes you more complex than a bacteria? Scientifically, it's very hard to define that term. Complexity is a very vague term that gets thrown around. Additionally, this sort of higher order, lower order hierarchy is also just kind of made up. There's no riel scientific basis for any of those ideas. I mean, really, what makes you so much higher order than a bacteria? Those bacteria have been around for a heck of a lot longer than you have. And, you know, assuming something terrible were to happen to the Earth and humans were to die out well, it probably be some bacteria that are still sticking around those air hardy, very resistant little guys. So in addition to that, it's important to know that evolution is constrained by genetic variation and what's already evolved. I you know, if there is not a lot of genetic variation in your population, then there won't be a lot of wiggle room for some traits to become more desirable than others. If if all the organisms or just all alike. Additionally, evolution is constrained by what's already evolved Now. What do I mean by that? I mean that every step that occurs in evolution is based on the previous step. So humans, for example, we could continue evolving in our form, could continue to train, but it would have to be based on the form we have now, right? We came from primates. Look at us. We still have a lot of the same kind of features that primates do because we can Onley modify what already exists. You can't create some completely new thing in evolution. It's always a modification of something that already existed. And lastly, evolution is not progressive. I mean, evolution will not continue to go along until it makes the perfect organism. There will never be the perfect organism, and that's because of fitness trade offs. These air basically compromises between traits. So imagine chicken, for example, and it evolves to produce more eggs. Yeah, that's a good evolutionary advantage, right? But guess what? There's a fitness trade off because now that it's producing mawr eggs, it means that it has to make the shells of those eggs a little thinner. So even though it's making mawr eggs, those eggs are more fragile. That's a fitness trade off, and that's the way things work in evolution. You make a little improvement on this thing, and often it's at the detriment of this other thing. So you can't create the perfect organism between from evolution and no such thing as complexity or higher order. And, of course, evolution is always just based on what came before it. So that's the reality of evolution. That's all I have for this video. I'll see you guys next time