Repeating a phrase back to me is not a good argument. It is churlish at best.
But it is not conclusive
That is an exaggeration. You have some examples that can be construed. There are more transitions than you have examples for, not the least being chimp (or ancester) to Homo.
I have yet to hear an explanation for Aborigines, or even Native Americans . Seeing as Platypus is now a lynchpin in mammalian development the lack of intermediary mammals would seem to be significant. (When I was taught, Marsupials etc were a divergence)
No, I just queried how that system might evelve.
That really is conjecture based on comparative physiology, which assumes that they are comparable.It is only recent that it was decided that some Dinosaurs were endothermic, a pre-requisite for Birds.
There has never been a means of changing ectotherm to endotherm so you end u with a divergence in Dinosaur physiology early on and a query why mammals did not develop at the same time. IOW In theory during the Dinosaur age there were higher beings that were wiped out before mammals could tae over (There was an interesting Star Trek voyager that proposed highly intelligent dinosaurs feeing the planet before the apocalypse- fun)
We have fossils with a mixture of features from two divergent taxa. They are transitional.
What needs explaining?
What lack of intermediary mammals? There are many known reptile to mammal transitional fossils. A google search should point you in the right direction.
There are dinosaurs that had the same skeletal structures that are associated with the lung system seen in birds.
Ectotherm to endotherm is pretty easy. Tuna do it with just a simple change in their circulatory system.
There has been real advancement in the scanning and imaging of permineralized bone. Dr. Yara Haridy presented this talk to the Royal Tyrrell museum describing some of her work. The video is an hour long and after the introduction is one continuous lecture, but is informative as to how much microscopic and physiological information such as growth, classification, disease, and injury, is preserved even though the original material has been displaced.
Through a combination of recent discoveries in bone physiology and new applied technologies, new hypotheses for the origin of cellular bone can be examined.
The virtual sections produced by the micro-CT scans allow the delineation of the compact cortex and the interior cancellous bone and facilitate a detailed analysis of the mass in the femur
Australasia is now the land that evolution forgot. The fauna are unique. Like i said earlier when i was taught it was classified as divergent, that is evolution taking a different route. That woulld be fine, but if Ornithorhynchus is a stage in mammalian development that either lasted longer or was never realised then there should be no higher mammals. Apart from Aborigines there is no mammal higher than rodent, while Marsupials have taken the place where those mammals would have been. There is no clear ancestor for the Aborigine. To a lesser extent that ight also apply to southern and Northern American homo species. There are no higher apes on those continents.
No matter how you look at it, whether the land mass was separated early or late, the evolutionary development has to be within that continent. Global Evolution does not work.
You are left with parallel development at best and duplication of what is supposed to be a random divergence. Add that to the developments that apparently cannot happen, like winged horses or feathered reptiles and so on, and you end up with a system that is not completely random but guided in some wayâŚ
It is not scientific. But then, who said that science was God?
No, why so? All the evidence Iâm aware of points to migrations of humans out of Africa to the other continents over many thousands of years. Google or Wikipedia will be your friend here.
So Aborigenes came fro the same stock as Red Indians but developed a diffeent culture , not to mention skin and bone structure. Are the North American Indians directly descended from Aztecs then? Dropping off Mexican Gringos en-route?
And at what point did pale skin become a survival advantage? (only in Europe)
There seems to be some wishful thinking here. Human traits are area specific,
And that is ignoring Genetic viability and diversity. Does the human genome contain all human traits worldwide?
Every species is an example of evolution taking a different route.
Evolution isnât a ladder. Itâs a tree.
Modern monotremes are our cousins, not our ancestors.
There is also no such thing as âhigherâ. Thatâs a bias from the Victorian era. All species are at the tips of their branch in the tree of life, so there are no species that are more evolved or higher than any other.
A lot to dissect here.
First, as above, no species is higher than another.
Second, the clear ancestor of Aborigenes are Eastern Eurasians:
Third, the direct lineages for the peoples of the Americas has been a bit murkier, but no one doubts that they descend from Asians.
A cool map of human migration in thousands of years.
There are superficial similarities between some marsupial and placental mammals, but itâs just superficial.
Let me ask you a question. If we compared the DNA of a Tasmanian wolf, a North American wolf, and a human, which two do you think would have the most similar DNA?
Thatâs not what the DNA evidence shows. Australia was populated 50 thousand years before North America.
North American Indians descend from a group that crossed the land bridge that went from Asia to North America. The land bridge existed during the last ice age due to lower ocean levels (water was locked up in continent spanning glaciers). Another land bridge existed 65,000 years ago in SE Asia which allowed the ancestors of the Australian Aborigines to take boats across the short jump from Asia to Australia. See the mtDNA map above, the white areas were land bridges. You will notice that the your own part of the world was connected to mainland Europe at one point. I guess the end of the last Ice Age was the geologic equivalent of Brexit.
Light skin becomes advantageous the closer you are to the poles. It aids in vitamin D production when sunlight is less intense. Protection against the sun and vitamin D production are finely balanced by melanin production in the skin.
Humans migrate to a region, and then develop population specific features after that point. I donât see the problem.
You would have to list the human traits. There are certainly region specific alleles. By tracing these mutations we can actually figure out how humans migrated out of Africa.
Also, African populations are the most genetically diverse, exactly what we would expect to see if humans migrated out of Africa. If you get a chance, search for the Khoisan people. At least to my eyes, they have a wonderful mixture of features from groups across the globe.
Behavior patterns are easier than internal organs because skeletons arenât random bunches of bones, their arrangement indicates how the creature moved. So itâs really just physics with anatomy.
For internal organs the lungs can be deduced from the skeletal structure directly, but thatâs about it. Some can be deduced indirectly; the bones point to how much muscle a creature would have had, and the muscles in turn point to various parameters of internal arrangement, which tell how much space there was and how it was shaped; I missed anatomy in college so I wonât even guess how to proceed from there!
BTW, this has been done with human skeletons from people who activities were known, though the researchers given the skeleton copies werenât told who they were from, they just made their measurements. They correctly identified someone who had been a boxer, one who had been a distance runner, and one who had been a discus thrower, just from the bones (first time I read that I freaked out a little; the idea that my bones adjusted their shapes to match the sports I engaged in in junior high through college was weird).
I visited a Lutheran church once that had vehemently refused to make use of the idea of a lightning rod; they regarded it as not relying on God.
Then came a storm in which the Roman Catholic church across the street wasnât harmed by lightning but the Lutheran churchâs steeple was destroyed . . . .
The elders at the Lutheran church didnât just promptly require a lightning rod in the rebuilt steeple, they but them on their silos, barns, and houses as well!
= - = + = - = â = - = + = - =
I remember as a teen watching birds on the birdfeeder and tree branches just outside the house and had the thought that they were puffing out their chests and relaxing â until I found that was just breathing!
Nice straightforward illustration!
I remember watching birds on a hot day in Texas. They did like the rest of us animals, they sought shade â they didnât go flying around the valley to cool off!
Try old copies of National Geographic, if you can get them over there â late 1980s, IIRC.
You just had to mention tuna â now Iâm hungry!
I think Iâll grab some fried dinosaur for dinner.
= - = + = - = â = - = + = - =
Possibly boats that got carried by currents or storms â island hopping will get one to Australia, especially when the sea levels were lower. Then sea levels rose and the distances over water were too great.
The path from Ukraine to Kamchatka is fascinating!
So there are DNA maps going back thousands of years? How so?
It looked fantastic.and very convincing, But I fail to see how there can be genetic data going back thousands of years when DNA mapping only began very recently. Where on earth can you get genetic samples of generations on any lineages? And how can you know that there was a land bridge joining Asia and America?
It sounds like a mathematical equation.
Clearly the information is beyond me (and any non DNA scientist) which throws up a red flag.
In truth you could be speaking Franglais. or Esperanto (invented languages)
I cannot argue with or even criticise. It is fait accompli.
The genomes of every living person are a direct record of their ancestry. Mutations that happen in the genomes of ancestors are found in modern humans.
You can think of each mutation as a step. Each step adds a mutation to what was already there. By using phylogenetic tools with these mutations you can determine the family human tree and trace how humans migrated out of Africa.
In the genome of every living human.
Thatâs a question for the geologists. From what I have seen, this is a well known land bridge, not something that is at all controversial in geologic circles. The big changes in sea levels between glacial cycles is also not controversial.
I am sorry, but that statement just confirms what I suspected. You have already decided that DNA proves ancestry.ad from then on all your explanations and âstoriesâ work from that, dare I say Assumption.
We observe that mutations are passed on to descendants. It isnât an assumption. MtDNA and other genetic techniques are used to establish relationships between humans all of the time. In fact, it is even used to solve murders. A serial killer called the âGolden State Killerâ was caught using DNA to trace ancestry. They used DNA found at the crime scene, and then scoured DNA ancestry databases to find shared markers. They were able to track down close relatives of the DNA found at the crime scene, and that led them to arresting the serial killer.
The tools arenât based on the theory. If the DNA sequences do not have a tree-like structure then the tools will show you that. The tools donât create the phylogenetic signal in the data. All the tools do is measure the tree-like structure if it is present. For example, if you create multiple random sequences and feed them into the tools it will return a very low score for the phylogenetic signal.
They are part of the old Gondwanan fauna, like the weird taxa present in South America until the Isthmus of Panama closed and the South American extant marsupials. A few members of that fauna spread north out of Gondwana (Opossums and Phorusrhacoids are some of the better-known ones), but most disappeared when Africa, India, and South America ran into other continents after separating from Antarctica.
