Comparative Anatomy: What Makes Us Animals - Crash Course Biology #21
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Date: 2022-04-04
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Comments and reviews: 5
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Where are all the evolutionary dead ends in animal structures, fossils or living?
If everything evolved from a single cell then it means that the genetic information of any organism is 100 percent variabled via mutation, albeit generally static after birth. Everything, from the length of your bones, their thickness, etc, all of the specifications of your body plan is contained in your DNA, correct? And mutations may act on any part of that specification -information-, hence every trait of an organism is 100 percent variabled via mutation if a mutation happens. Okay, so what am I getting at? Essentially, why are there no failed nodes in bone structure? I say bone structure specifically, because having a bone anomaly is not necessarily a life ender, but all bone structures are basically smooth and perfect to do what they do, and are not bumpy. Life in general is very not ugly, which it seems it should be according to this line of thinking.
The only explanation for this is also problematic. That is, only traits (which are built on mutations) that cause an organism to be more fit to survive in its current environment are retained, and develop into traits. This is problematic, because then there should be a very visible, non-gapped, progression through all living things. Talk of supposed missing links is missing the real point. Where are all the missing intermediary intermediary forms? The intermediary intermediary intermediary forms, etc? It should be entirely smooth, in the fossil record and in living things, and when I say entirely I mean -very very-.
Also, problematic with this apparently harmonious view (which is essentially what all evolution-accepting people believe) is how can a mutation be retained if its contribution to the survivability of an organism cannot be felt, or if it is just barely apparent? For example, it is said that a wing developed from bird-like tree dwelling animals gliding to the ground via burgeoning wing appendages, but what about the form before it was even able to be used to glide? I've seen one explanation for the bat wing, saying that it could have been used to hold water, previous to being used for gliding. That's fine, but what about before that, and before that? What I mean is, we know now that our cells correct for changes in our DNA (this is not to intone that mutations cannot cause change, but that there is definite impediment to -natural- change, so if you were to take a form to its very origination, when it juuuust started, why would it be retained? We, also, know that changes in features are very small and compiled over time. Often, Darwin's finches are used as an example of such a change happening, and over a relatively short period, but this still misses the point. A beak has a function, (and arguably potential function, but small fluctuations leading to change on an already functioning trait do not explain how the trait originated, or how it was retained. So, what about the very beginning of the formation of the beak? Day one of the beak, if you will. There has to be an apparent advantage on Day One. To say that every burgeoning trait simply did increase fitness from day one seems implausible.
I've also heard that mutations may be stored sometimes, and appear later on, but my research here is very lacking. So, I'll leave it at that.
reply
Where are all the evolutionary dead ends in animal structures, fossils or living?
If everything evolved from a single cell then it means that the genetic information of any organism is 100 percent variabled via mutation, albeit generally static after birth. Everything, from the length of your bones, their thickness, etc, all of the specifications of your body plan is contained in your DNA, correct? And mutations may act on any part of that specification -information-, hence every trait of an organism is 100 percent variabled via mutation if a mutation happens. Okay, so what am I getting at? Essentially, why are there no failed nodes in bone structure? I say bone structure specifically, because having a bone anomaly is not necessarily a life ender, but all bone structures are basically smooth and perfect to do what they do, and are not bumpy. Life in general is very not ugly, which it seems it should be according to this line of thinking.
The only explanation for this is also problematic. That is, only traits (which are built on mutations) that cause an organism to be more fit to survive in its current environment are retained, and develop into traits. This is problematic, because then there should be a very visible, non-gapped, progression through all living things. Talk of supposed missing links is missing the real point. Where are all the missing intermediary intermediary forms? The intermediary intermediary intermediary forms, etc? It should be entirely smooth, in the fossil record and in living things, and when I say entirely I mean -very very-.
Also, problematic with this apparently harmonious view (which is essentially what all evolution-accepting people believe) is how can a mutation be retained if its contribution to the survivability of an organism cannot be felt, or if it is just barely apparent? For example, it is said that a wing developed from bird-like tree dwelling animals gliding to the ground via burgeoning wing appendages, but what about the form before it was even able to be used to glide? I've seen one explanation for the bat wing, saying that it could have been used to hold water, previous to being used for gliding. That's fine, but what about before that, and before that? What I mean is, we know now that our cells correct for changes in our DNA (this is not to intone that mutations cannot cause change, but that there is definite impediment to -natural- change, so if you were to take a form to its very origination, when it juuuust started, why would it be retained? We, also, know that changes in features are very small and compiled over time. Often, Darwin's finches are used as an example of such a change happening, and over a relatively short period, but this still misses the point. A beak has a function, (and arguably potential function, but small fluctuations leading to change on an already functioning trait do not explain how the trait originated, or how it was retained. So, what about the very beginning of the formation of the beak? Day one of the beak, if you will. There has to be an apparent advantage on Day One. To say that every burgeoning trait simply did increase fitness from day one seems implausible.
I've also heard that mutations may be stored sometimes, and appear later on, but my research here is very lacking. So, I'll leave it at that.
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Gamer
If we all share a common ancestor according to evolution, (unless you're a sponge. -, what is it? Cause i have never heard what it is. i just got -We all share a common ancestor. - Well, what is it then!
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If we all share a common ancestor according to evolution, (unless you're a sponge. -, what is it? Cause i have never heard what it is. i just got -We all share a common ancestor. - Well, what is it then!
reply
Michal
Did Hank say that common animal ancestor lived 1. 6 billion years ago? I think that is roughly a time when an eukaryotic cell appeared. Animal ancestor lived about 0. 6 billion years ago.
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Did Hank say that common animal ancestor lived 1. 6 billion years ago? I think that is roughly a time when an eukaryotic cell appeared. Animal ancestor lived about 0. 6 billion years ago.
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Dolandoyle
I'm studying for my Bio Finals tomorrow and just started watching all of your videos, I dont even think Im listening and Im probably just focused on the entertainment wish me luck
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I'm studying for my Bio Finals tomorrow and just started watching all of your videos, I dont even think Im listening and Im probably just focused on the entertainment wish me luck
reply
Sixth
Please stop putting birds in cages for your own fun. Its cruel. Should be criminalized. I love u anyways. But please stop.
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Please stop putting birds in cages for your own fun. Its cruel. Should be criminalized. I love u anyways. But please stop.
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