Moderator: Alyrium Denryle
Aren't there also vertebrates whose eyes lack blind spots?Junghalli wrote: Interestingly I've heard the cephalopod eye is actually rather better designed than the vertebrate eye, lacking the blind spot we have in the center of our vision.
it is not just family level stuff. Molecular techniques are shaking up entire orders and even classes.MRDOD wrote:Technically, according to wikipedia (I know, but I'm not an orinthologist), Birds of Prey are defined via habits, not genetics, so New World Vultures are birds of prey- just ones genetically irrelated to actual eagles, falcons, and old world vultures.Darth Yoshi wrote:Really? I didn't know that New World vultures weren't birds of prey. You learn something new everyday.
Nobody really knows- I tried looking it up. Some people tried to class them into storks and herons and so forth, but genetic evidence is overturning the entire old taxonomy in every single study of animals*, so they're in a weird flux. They have their own family called Falconiformes, I believe, which is defined as 'It looks like a falcon'**, making it one of those weird families scientists put animals that they don't know where they go [witness Pongo, for 'apes that aren't humanish', before it was reorganized to be more scientific]
*Take a look at any field of animal study and you'll hear "This used to be classed as X, but genetic evidence now shows".
**This description of bird taxonomy is completely inaccurate and probably insulting to orinthologists, but it's the best I'm willing to do without having to look up and get into what exactly a falcon is.
Not muchI don't know how much water this holds, but I've speculated that the similarities in human and bonobo sexuality is convergent evolution, since bonobos split from chimpanzees more recently than chimps diverged from humans.
Not convergent because the two species are so closely related. It is just a matter of the same equation with slightly different inputs.No. The reason there is a lot of convergence is largely because there is a lot of shared genetic architecture. Gene regulation pathways are similar in most taxa because of a genetic bottleneck that happened after the cambrain explosion. Many Phylum Enter, Very Few Leave. A good part of this was adaptation to similar environments and stochastic forces. After that no more phylum could develop due to competitive exclusion by the survivors. As a result we could not expect that organisms with even vaguely similar body plans would develop. There might be some common solutions to problems (eyes would probably develop for example) but beyond that...Would you expect convergent evolution to produce types of animals that look vaguely familiar to us?
Really? Wow, that is just mindblowing.MRDOD wrote:One of the most striking aspects of convergent evolution to me is that New World and Old World vultures are completely unrelated animals.
The bald head, the scavenging, their circling behavior- it's all convergent evolution, because Old World Vultures are related to birds of prey (how worse of a rap than those they get for being uglier); while New World Vultures are of uncertain origin but possibly more related to Storks and Flamingoes (!).
What modern reptile would be considered closest genetically to mammals?Alyrium Denryle wrote:Birds are fucked up too because they should not even be a class unto themselves. They are nested so deeply within diapsida they are not separate enough for their own class (Aves) and should be nested as an order within Reptilia.
None living. Mammals form the sister group to all other reptilian taxa.Kitsune wrote:What modern reptile would be considered closest genetically to mammals?Alyrium Denryle wrote:Birds are fucked up too because they should not even be a class unto themselves. They are nested so deeply within diapsida they are not separate enough for their own class (Aves) and should be nested as an order within Reptilia.
Does Fetal development show them developing as diapsids and that at some point it closes off?Alyrium Denryle wrote:Turtles for example used to be classified as anapsids, split off from other reptiles before the development of temporal finestrae (the holes in the side of the skull for muscle attachment read: your temple) but now it looks like they lose those secondarily and are in fact diapsids. Snakes too. They are in the suborder Serpentes and used to be thought to have split off from Lacertillia (lizards) so long ago that they were justified in being in a separate suborder. Nope. They are nested very firmly within lacertilla going from genetics. Making Lizards paraphyletic unless we reshuffle the taxonomy..
Honestly I am nor sure. Mind if I look it up and get back to you? I am not even sure the work has been done to be honest. The genetic stuff that made people do a double take was recent.Kitsune wrote:Does Fetal development show them developing as diapsids and that at some point it closes off?Alyrium Denryle wrote:Turtles for example used to be classified as anapsids, split off from other reptiles before the development of temporal finestrae (the holes in the side of the skull for muscle attachment read: your temple) but now it looks like they lose those secondarily and are in fact diapsids. Snakes too. They are in the suborder Serpentes and used to be thought to have split off from Lacertillia (lizards) so long ago that they were justified in being in a separate suborder. Nope. They are nested very firmly within lacertilla going from genetics. Making Lizards paraphyletic unless we reshuffle the taxonomy..
In "Your Inner Fish," there is a lot of discussion about how certain nerves moves from certain positions to where they are in a human from the "Gill Arches" in the Fetus and how the Jawbone, Ear Bones, and other features developAlyrium Denryle wrote:Honestly I am nor sure. Mind if I look it up and get back to you? I am not even sure the work has been done to be honest. The genetic stuff that made people do a double take was recent.
Post hoc edit: Nothing on web of science using the necessary keywords that is recent. The developmental question as far as I know has not yet been asked/published
Yeah but that work has not been done with turtles as far as I am aware. They are not good model organisms for developmental biology unfortunately. Generation times of 10 years and all...Kitsune wrote:In "Your Inner Fish," there is a lot of discussion about how certain nerves moves from certain positions to where they are in a human from the "Gill Arches" in the Fetus and how the Jawbone, Ear Bones, and other features developAlyrium Denryle wrote:Honestly I am nor sure. Mind if I look it up and get back to you? I am not even sure the work has been done to be honest. The genetic stuff that made people do a double take was recent.
Post hoc edit: Nothing on web of science using the necessary keywords that is recent. The developmental question as far as I know has not yet been asked/published
Hedgehogs are part of a group called Insectivores, which I believe also includes shrews. I'm not sure what the latin name is, sorry.MrDOD wrote:Another one- Hedgehogs and Porcupines both have quills, but they are completely different- one of them are rodents and the other is something else. I don't quite remember, but I know they don't share common ancestry for millions and millions of years.
Well first off there is a difference between complex eyes and patches of photosensitive cells. Primitive eyes have evolved independently in many lineages, but complex eyes have only developed a few times.speaker-to-trolls wrote:Hedgehogs are part of a group called Insectivores, which I believe also includes shrews. I'm not sure what the latin name is, sorry.MrDOD wrote:Another one- Hedgehogs and Porcupines both have quills, but they are completely different- one of them are rodents and the other is something else. I don't quite remember, but I know they don't share common ancestry for millions and millions of years.
Another modern example of convergent evolution would be all the things adapted to eat social insects from out of their mounds; Aardvarks, anteaters, pangolins, echidnas, all from completely different mammalian lines, but they all have very similar feeding styles because, really, can you think of a better way to get ants out of their nests in any real numbers?
What's this about the eye evolving 23 times? I knew it evolved at least three times (arthropods, molluscs, chordates), and maybe again in some kinds of worms and some of those extinct things in the silurian, but not 23. Wow. Does anybody have a link to a list of some kind, or somewhere where I could find more information on that?
I had not realized that most turtles had that long a life span. Even smaller ones have a forty year lifespan. Guess if you want a long lived pet, they are close to perfect.Alyrium Denryle wrote:Yeah but that work has not been done with turtles as far as I am aware. They are not good model organisms for developmental biology unfortunately. Generation times of 10 years and all...
That cute little box turtle will have to be put in the will...Kitsune wrote:I had not realized that most turtles had that long a life span. Even smaller ones have a forty year lifespan. Guess if you want a long lived pet, they are close to perfect.Alyrium Denryle wrote:Yeah but that work has not been done with turtles as far as I am aware. They are not good model organisms for developmental biology unfortunately. Generation times of 10 years and all...
Aren't Porcupines a member of the weasel family? Like Skunks, Badgers, and Wolverines?MRDOD wrote:Ah, yes, the fact that Birds are a subgroup of Reptiles is another awesome "Taxonomy Is Changing" fact genetics has brought us. Although we kind of knew this ever since we figured out they're related to dinosaurs.
Another one- Hedgehogs and Porcupines both have quills, but they are completely different- one of them are rodents and the other is something else. I don't quite remember, but I know they don't share common ancestry for millions and millions of years.
Nope! RodentsLadyTevar wrote:Aren't Porcupines a member of the weasel family? Like Skunks, Badgers, and Wolverines?MRDOD wrote:Ah, yes, the fact that Birds are a subgroup of Reptiles is another awesome "Taxonomy Is Changing" fact genetics has brought us. Although we kind of knew this ever since we figured out they're related to dinosaurs.
Another one- Hedgehogs and Porcupines both have quills, but they are completely different- one of them are rodents and the other is something else. I don't quite remember, but I know they don't share common ancestry for millions and millions of years.
I think you mean echidnas and hedgehogs. Echidnas are monotremes, hedgehogs are placentals. The two last shared a common ancestor over 100 million years ago.Another one- Hedgehogs and Porcupines both have quills, but they are completely different- one of them are rodents and the other is something else. I don't quite remember, but I know they don't share common ancestry for millions and millions of years.
While this is true, Insectivora and Rodentia have also seen over 65 million years of evolution since they had a common ancestor; probably longer, I don't know when Insectivora (mish-mash clade that it is) is believed to have originated.hongi wrote:I think you mean echidnas and hedgehogs. Echidnas are monotremes, hedgehogs are placentals. The two last shared a common ancestor over 100 million years ago.Another one- Hedgehogs and Porcupines both have quills, but they are completely different- one of them are rodents and the other is something else. I don't quite remember, but I know they don't share common ancestry for millions and millions of years.
You can thank Linnaeus for that...Darth Yoshi wrote:I always thought Insectivora was a weird class (order? I forget which). I mean, it just strikes me as odd to use eating insects as a criteria for classification, what with convergent evolution and all.
The Original Nex wrote:Insectivora has been considerably trimmed and redefined in recent years. I don't know the most up to date scheme, AFAIK the Tenrecs and Golden Moles have been seperated out into the new order Afrosoricida with the remainder being called order Eulipotyphla; but I know some biologists have talked of doing away with the order all together, placing Hedgehogs in their own order separate from the Moles, Shrews, and the primitive Caribbean Shrews and Solenodons.
So there is still a lot of work to be done with the "Insectivora", but then, no one ever claimed taxonomy was an exact science.
Well that is why class Aves needs to go away and become an order nested with Reptilia.The Original Nex wrote:I agree it should be; fortunately the more genomes we map the better and better our picture of relationships between the species becomes. The large study done on avian genomes a few months ago (I can't recall who did the study) rewrote large swaths of the conventional avian classification system. Of course the concept of Class Aves by itself proves problematic with regards to its relation to Class Reptilia and Super(?)order(s) Archosauria/Dinosauria...I feel like these designations are constantly in a state of flux...
