Humans. Here's a list of cranial synapomorphies shared by humans and Australopithecus supporting my argument:Which skull would this fossil most closely resemble?
- simian shelf of mandible absent
- vertical slope of mandibular symphysis
- posteriorly divergent postcanine tooth rows
- incisors much smaller than molars
- diastema absent
- first premolar same size as second premolar
- deep palate
- enlarged external auditory meatus
- reduced supraorbital torus
- reduced protrusion of face
Now here's a list of postcranial synapomorphies shared by humans and Australopithecus further supporting my argument:
- spinous process of thoracic vertebrae angled strongly toward tail
- postzygapophyses displaced beyond caudal margin of centrum in 11th and 12th thoracic vertebrae
- spinous processes of 2nd and 3rd lumbar vertebrae not angled toward tail; square
- transverse width of centrum of 2nd to 5th lumbar vertebrae greater than its length and height
- five fused vertebrae in sacrum
- width of sacrum equal to length of sacrum
- weakly developed lateral supracondylar ridge of humerus
- weakly developed lateral condule of humerus
- radial and ulnar shafts straight
- proximal extension of olecranon process absent
- equal height and width of post-acetabular ilium
- greater sciatic notch forms a tight, narrow curve
- greater trochanter does not extend as far proximally as femoral head when femoral shaft is vertical
- transverse width of medial malleolus of tibia less than 1/4 transverse width of entire distal end of tibia
- medial process of talus medial and plantar to tibial facet absent
Now it's your turn, mark. What suite of shared, derived characters do you think unites chimps and Australopithecus? Let's compare lists and see whose argument is better supported by the evidence.
Again, I'm not ignoring brain size. I admit that Australopithecus had a brain size closer to that of chimps than to modern humans. You're the one ignoring evidence because you're the one who wants to focus solely on brain size while ignoring the rest of the skull and skeleton.The fact that this thing has a chimpanzee size brain is irrelevant even though it's the greatest giant leap in our mythical lineage from the apes. To ignore the size and complexity of the human brain is a deliberate attempt to dodge the null hypothesis even Darwin accepted as a logical disproof of his theory.
And that's another thing: Yes, Darwin thought his theory hinged on slow, gradual change, and if it could be shown that evolutionary change did not occur in small, incremental steps, he thought that his theory of evolution via natural selection would be falsified. But this isn't the case. Darwin was totally ignorant about genetics, which had not established itself as a rigorous field of biology until long after Darwin's death. Darwin particularly had no knowledge of regulatory genes (like Hox genes), which can produce large, quantum changes in phenotype with just small changes to the genes. So it isn't true that large, rapid evolutionary changes in phenotype falsify Darwin's theory after all. Your understanding that it does is long out of date. Please drop that tired old strawman.
I had a feeling.Don't have it available right now but it was published in Nature...sorry.
In the future, if you're going to make a far-out claim, please have the citation handy so we can follow it up. We can't verify your claim, so it's meaningless for the purposes of this discussion.
Which "radical" evolutionary transitions do you accept, mark? And what kind of evidence do you refer to in support of such transitions? You're very critical of the methodology employed by evolutionists for inferring common ancestry, so I want to know how your methodology for inferring common ancestry differs from our own. Please spell it out explicitly.I neither accept nor do I reject the whale evolution thing, my central focus is human evolution since that is the only issue that conflicts with Christian theology. I am pretty consistent, even atheistic materialists catch on to that about me.
Accusing you of committing a logical fallacy is not an attack on your person, mark. It's pointing out a flaw in your line of reasoning. Your reasoning as it applies to the evolution of the human brain isn't flawed because you do not accept evolution; it's flawed because it's an argument based on what we do not know, as opposed to what we do know. By definition, that's an argument from ignorance, or an argument from negative evidence, if you prefer.No, that's a classic ad hominem attack assuming ignorance on the part of Christians that do not swallow Darwinism whole. If you do not make the first a priori assumption of universal common descent you are assumed to be ignorant aka incredulous.
First, homology isn't defined as "things in common". Convergences are also "things in common", but they are most certainly not homologies. Homologies are characters that pass these three tests:First tell me plainly, do you accept that if things in common (homologies) are proof for common ancestry the differences are proof against? Then we can get into these cladistic analysis.
- they must be similar (e.g., developmentally arising from the same germ layers)
- they must not occur more than once in the same organism
- they must define a single clade on a cladogram (i.e., they must be synapomorphies)
Again, read the de Pinna paper here: http://www.ib.usp.br/hennig/depinna1991.pdf
And if you're really serious about learning about homology, read Brian Hall's book on the subject. There's a long history of thought behind the topic of homology that I don't get the impression you appreciate.
Second, I have to question your assertion that differences between individuals are somehow "proof against" common ancestry. After all, we expect to see differences between related taxa. Is the fact that you look different from your brother "proof against" your both being the offspring of your dad? Is the fact that chihuahuas look different from wolves "proof against" their being descended from a common canine ancestor? No.
Again, the best way to infer degree of relatedness is to construct a character matrix that emphasizes both similarities and differences between taxa, and to examine whether the resulting cluster analysis (cladogram) supports our hypothesis about the relatedness of different taxa. This methodology makes use of both differences and similarities when inferring phylogenetic relationships.
I don't want to know someone else's thoughts on homology, mark. I want to know YOUR thoughts on homology because you're the the one who has a problem with homology arguments. And yet you yourself make homology arguments when you compare fossil species to modern ones (like the braincases of chimps and australopithecines). You also must accept homology as applies to your so-called "radical" post-Flood evolutionary scenarios -- how else would you infer them?How about Darwin's?
The theological premise in this argument -- that the apparent uniformity of certain biological patterns is inconsistent with the freedom of a creator to act as he wishes -- is nowhere better illustrated than in Darwin's book on the "contrivances" of orchids. After reviewing the homologies of orchids and ordinary flowers, Darwin appeals to our intuitions about what God would have done in this case:
Can we feel satisfied by saying that each Orchid was created, exactly as we now see it, on a certain "ideal type:" that the omnipotent Creator, having fixed on one plan for the whole Order, did not depart from this plan: that he, therefore, made the same organ to perform diverse functions -- often of trifling importance compared with their proper function -- converted other organs into mere purposeless rudiments, and arranged all as if they had to stand separate, and then made them cohere? Is it not a more simple and intelligible view that all the Orchideae owe what they have in common, to descent from some monocotyledonous plant....? (Charles Darwin, On the Various Contrivances by Which Orchids Are Fertilized by Insects)
The Place of Darwinian Theological Themata in Evolutionary Reasoning
So please tell us about your definition of homology, mark. When is it acceptable to make homology arguments? When is it unacceptable? When do you invoke "inverse logic" arguments? Please detail your rigorous methodology here so we can be clear about your stance on the issue. I want to hear all this in your own words, rather than the words of someone else.
First, we were discussing the cladistic method for inferring phylogenies. The copy-and-paste job you replied with above has nothing to do with what we were talking about. I can't help but wonder whether you even know what we're discussing, here, or if you're purposely trying to confuse the issue by doing the ol' Gish Gallop.How about this one?...
Or these?...
Or this?...
Second, your response is still an argument from ignorance. You're simply pointing to gaps in our knowledge about how evolution happened and concluding that those gaps mean evolution could not have happened. You're not addressing the positive evidence we do have for human evolution; rather, you're pointing to the evidence we don't have. That's a logical fallacy: Argument from ignorance - Wikipedia, the free encyclopedia
Third, the type of argumentation you're applying here is a god-of-the-gaps theology. You're pointing to gaps in our knowledge of the evolutionary past and saying that God therefore must have performed a miracle in order to account for those gaps. That's bad theology because it limits God's actions to what we don't understand as opposed to what we do understand.
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