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These are just observable facts. Notice that in cases of convergent evolution such as wings, they look alike, but were produced from different parts. Analogous features. On the other hand, human hands, horses hooves, whale flippers and bat wings all evolved from the same parts, even if they look differently. Homlogous features.
Actually, that's a good question. And it was a critical element in Darwin's theory. Evolution is not design. It's opportunistic, taking advantage of variation that actually happens at random. So, while the selective pressures remain very much alike (but not identical for different organisms), the available variation will almost never be the same in different cases. The odds of so many random events happening several times in order are so unlikely as to be practically impossible.
Which was the case when Huxley later made his prediction that birds evolved from other dinosaurs.
No. The archosaur, Ornithosuchus, (named "birdcrocodile" by Huxley) was a clue, as were other known dinosaurs. None of them were remotely mammalian. Cynodonts were unknown at the time, so the affinity between reptiles and mammals was not in evidence in Huxley's time.
No. Huxley, at that time, had not read Darwin's work, and did not think organisms evolved. He was thinking in terms of types, and only later realized what the data meant.
No. "Basic structural similarity" is analogy, not homology.
Yes. It gets difficult and a lot of work involves untangling the anatomical data of fossils. For example, Alan Feduccia argued that birds and dinosaurs evolved from a common ancestor, basing his argument on which digits were reduced in bird and dinosaur forelimbs. Eventually, he was shown to be wrong about which digits, and his theory was refuted.
No, its a mathematical argument. Most YEC arguments on probability are something like "the likelihood of (large number) of amino acids in this order in a protein is so unlikely as to be impossible." Which, if a valid argument, would prove that poker games are impossible. Figures don't lie, but liars often figure. I could show you the math and a simple simulation to test the assumption, if you like.
Well, tell me how many mutations you think would be necessary to convert an archosaur leg into a functional wing. Then we'll do the math. Let's say 100. (obviously a great number of non-useful mutations would occur and be rejected by natural selection during the same time).
The hope for convergence lies in the fenestration occuring precisely in the right place, involving precisely the same bones, connective tissue, muscles and nerves. There is supporting genetic and neurological data, supporting the way this happened:
In evolutionary biology, analogous structures are biological structures having similar or corresponding functions but not from the same evolutionary origin. In other words, species use these biological structures for the same purpose and yet these species are from unrelated evolutionary lines.
Sorry, that's wrong, tool. Depends on evidence. Which is why Feduccia's argument wasn't quickly dismissed. A great deal of work was required to sort out his claims and determine if they were correct or not. Would you like to learn about how it was finally resolved?
It probably seems unfair to YECs that when scientists learn that they were mistaken, they just accept the reality and change their theories to fit. Science looks at the evidence and finds the best their to explain it. YEC assumes a conclusion and tries to make the facts fit the assumption. Nothing better explains the logical differences between science and YEC.
So you've changed your position? The reason that bats and pterosaurs have different wings is that they both had to go through the same process of random mutation and natural selection. The odds of all those random mutations happening would more unlikely than shuffling a deck of cards and getting the same order of cards twice. Creationist arguments on probability are essentially arguing that one can't shuffle a deck of cards once. Would you like me to show you?
You've assumed that the landscape is much simpler than it is. For example, New World and Old World vultures are superficially very similar. But they evolved to fitness in entirely different ways. One example, is that one uses vision and the other uses sense of smell as hunting strategies. But there's more. The confusion between analogy and homology is a function of YECs being unable to comprehend how it all works and how evolution is opportunistic, rather than prescient.
It's pretty simple. You see, the paleontological data predicts that one will see genetic data supporting the divergences of synapsids and diapsids from an anapsid ancestor. And when the genetic basis of these developmental changes were found, that prediction was confirmed. It's been confirmed by other research.
No. "Basic structural similarity" is analogy, not homology.
In evolutionary biology, analogous structures are biological structures having similar or corresponding functions but not from the same evolutionary origin. In other words, species use these biological structures for the same purpose and yet these species are from unrelated evolutionary lines.
Analogous structures - Definition and Examples | Biology Online
Analogous structures have similar functions but with dissimilar evolutionary origins. Know more about its definition, examples, and process here.www.biologyonline.com
pmc.ncbi.nlm.nih.gov
link.springer.com
I showed you the difference between structure and function. Remember? Homologous organs? Same structure, different functions? Human hands, horse feet, whale flippers. Go back and look. One of the major YEC failures is not understanding the difference.
Remember the picture I showed you? Bat wings, bird wings, pterosaur wings. And now you get it, even if you don't remember from where.
That's what I just showed you. But the reason whale flippers and seal flippers are genetically different is that the odds of them evolving in exactly the same way are so great as to be effectively impossible.
You didn't read the article, or you didn't read it very carefully. Do you not realize that the Msx2 homeobox gene is common to all chordates? Indeed, it is found in non-chordate deuterostomes. C'mon.
As you learned, there are a chain of mutations that separate these lineages. And again, it's possible, albeit highly unlikely. However, the genetic data make it clear that such convergence did not happen.
Fortunately, we also have genetics, fossil data, embryology, and so on, to check on the accuracy of anatomical homology. I mentioned New World and Old World vultures as an example where genetics clarified the issue.
I showed you that earlier. Remember the diagram of amniotes. Cladistics is not about common descent. But it can clarify descent.
Kind of like "if matter isn't made of atoms, then it would be said to be made of something else entirely."
The main issue with proposing a hypothetical and then including a wrong conclusion: it's a strawman.
That research was by scientists, not creationists. Didn't you read it?
About the same as the probability of a person with your exact genome being born, given the genes of Adam and Eve. So unlikely as to be effectively impossible. Yet here you are, and the evidence shows that tetrapods evolved from fish. If this puzzles you, here's a way to clear it up:
Read the book. And this won't confuse you further.
Since both evolution and atoms are directly observed, moot point.
Hi BarbarianNo. "Basic structural similarity" is analogy, not homology.
In evolutionary biology, analogous structures are biological structures having similar or corresponding functions but not from the same evolutionary origin. In other words, species use these biological structures for the same purpose and yet these species are from unrelated evolutionary lines.
Analogous structures - Definition and Examples | Biology Online
Analogous structures have similar functions but with dissimilar evolutionary origins. Know more about its definition, examples, and process here.
Yes. It gets difficult and a lot of work involves untangling the anatomical data of fossils. For example, Alan Feduccia argued that birds and dinosaurs evolved from a common ancestor, basing his argument on which digits were reduced in bird and dinosaur forelimbs. Eventually, he was shown to be wrong about which digits, and his theory was refuted.
Sorry, that's wrong, tool. Depends on evidence. Which is why Feduccia's argument wasn't quickly dismissed. A great deal of work was required to sort out his claims and determine if they were correct or not. Would you like to learn about how it was finally resolved?
It probably seems unfair to YECs that when scientists learn that they were mistaken, they just accept the reality and change their theories to fit. Science looks at the evidence and finds the best their to explain it. YEC assumes a conclusion and tries to make the facts fit the assumption. Nothing better explains the logical differences between science and YEC.
It's a mathematical argument. Most YEC arguments on probability are something like "the likelihood of (large number) of amino acids in this order in a protein is so unlikely as to be impossible." Which, if a valid argument, would prove that poker games are impossible. Figures don't lie, but liars often figure. I could show you the math and a simple simulation to test the assumption, if you like.
Well, tell me how many mutations you think would be necessary to convert an archosaur leg into a functional wing. Then we'll do the math. Let's say 100. (obviously a great number of non-useful mutations would occur and be rejected by natural selection during the same time).
Each step in such an evolution depends on the last stage. So 1/100! or about 1/9.3^157. Very small likelihood, um? Which is why we never see a complex adaption form identically in two separate lineages. Just 10 would give us a likelihood of about 1/3,600,000.
So you've changed your position? The reason that bats and pterosaurs have different wings is that they both had to go through the same process of random mutation and natural selection. The odds of all those random mutations happening would more unlikely than shuffling a deck of cards and getting the same order of cards twice. Creationist arguments on probability are essentially arguing that one can't shuffle a deck of cards once. Would you like me to show you?
You've assumed that the landscape is much simpler than it is. For example, New World and Old World vultures are superficially very similar. But they evolved to fitness in entirely different ways. One example, is that one uses vision and the other uses sense of smell as hunting strategies. But there's more. The confusion between analogy and homology is a function of YECs being unable to comprehend how it all works and how evolution is opportunistic, rather than prescient.
The hope for convergence lies in the fenestration occuring precisely in the right place, involving precisely the same bones, connective tissue, muscles and nerves. There is supporting genetic and neurological data, supporting the way this happened:
Devolopment
Volume 144 Issue 22
November 2017
The evolution of cortical development: the synapsid-diapsid divergence
All these mutations happening to fall in exactly the same order, seems very unlikely. Why not just accept the evidence? Understand, the odds aren't for the result happening once. They are for the same result happening twice. And that is why poker games and analogous structures are possible.
It's pretty simple. You see, the paleontological data predicts that one will see genetic data supporting the divergences of synapsids and diapsids from an anapsid ancestor. And when the genetic basis of these developmental changes were found, that prediction was confirmed. It's been confirmed by other research.
Science AdvancesVol. 9, No. 46
Turtle skull development unveils a molecular basis for amniote cranial diversity
Amniote skulls display diverse architectural patterns including remarkable variations in the number of temporal arches surrounding the upper and lower temporal fenestrae. However, the cellular and molecular basis underlying this diversification remains elusive. Turtles are a useful model to understand skull diversity due to the presence of secondarily closed temporal fenestrae and different extents of temporal emarginations (marginal reduction of dermal bones). Here, we analyzed embryos of three turtle species with varying degrees of temporal emargination and identified shared widespread coexpression of upstream osteogenic genes Msx2 and Runx2 and species-specific expression of more downstream osteogenic genes Sp7 and Sparc in the head. Further analysis of representative amniote embryos revealed differential expression patterns of osteogenic genes in the temporal region, suggesting that the spatiotemporal regulation of Msx2, Runx2, and Sp7 distinguishes the temporal skull morphology among amniotes. Moreover, the presence of Msx2- and/or Runx2-positive temporal mesenchyme with osteogenic potential may have contributed to their extremely diverse cranial morphology in reptiles.
gn
Some might deny the evidence, but there it is. No point in fighting the reality.
