December 8, 2014
For the previous installments: part 1, 2, 3.
In the early 1960s, MIT professor Murray Eden set his mind to discover whether neo-Darwinism could account for the origin of new organisms. He knew life was based on a genetic code, and based on our shared experience of all other coded systems, he assumed the sequence of nucleotides was absolutely critical to its function. If you start adding, deleting, or moving pieces of a digital code, for example, the meaning (function) is degraded or even lost. If we can’t create a better program by randomly adding, deleting, and moving pieces of digital code, why think a Darwinian process that makes random changes to the DNA code could build better and novel organisms (indeed, why think a coded system could ever be built by random processes to begin with)?
In 1966, Eden and other colleagues convened a conference at the Wistar Institute in Philadelphia. The conference was titled “Mathematical Challenges to the Neo-Darwinian Interpretation of Evolution.” The conference sought to explore the creative power of natural selection acting on random mutations. Those present recognized that there are an enormous number of ways to combine amino acids together to form protein chains. And while they did not know precisely how many combinations could result in a functional protein compared to those that could not, they did know the number of functional combinations was extremely small.
December 7, 2014
For the previous installments: part 1, 2.
If common ancestry is true, we would expect the evolutionary tree of life (TOL) based on animal morphology to line up with the evolutionary TOL based on molecules, but they don’t. In fact, there is no one TOL based on morphology or one TOL based on molecules. There are multiple TOLs.
Interestingly, a comparison of different genes from the same organism can result in different TOLs for that organism. The same is true of morphology. For example, when the TOL is constructed based on germ-cell formation (which is basic to the evolutionary process because it underlies reproduction, and we would expect for all organisms in a branch of the TOL to have the same germ-cell formation) it leads to one TOL, but this TOL differs radically from TOLs constructed based on body-play symmetry, the number of primary tissues, or the mode of development.
Looking at the Cambrian pyla specifically, there is no one TOL showing what the ancestry looked like leading up to the Cambrian.
Convergent evolution is a word to describe how similar morphological features develop in different species, where that feature was not shared by their common ancestor. There are many examples of so-called convergent evolution. But convergent evolution undermines the presupposition underlying the theory of common descent: similar homology indicates similar ancestry. Convergent evolution demonstrates that homological similarities do not necessarily imply a common ancestry. Convergent evolution negates the logic of the argument for common descent from homology.
Chapter 7 (more…)
December 4, 2014
For the previous installment, see here.
In 1995, Chinese scientists discovered even older Cambrian fossils near Chengjiang, China. At this site, even more Cambrian phyla and species were uncovered. This discovery also put to death the most popular form of the artifact hypothesis. One can no longer claim that the Pre-Cambrian lacks the Cambrian ancestors because the ancestors were too soft (no exoskeleton) or too small given the fact that the Chinese researchers discovered fossilized sponge embryos which are both microscopically tiny and entirely soft-bodied. They were preserved so beautifully that they were even able to see them in the midst of cell-division and identify the nucleus of the cells. Of course, even before this discovery, we knew that soft-bodied animals could be preserved in the fossil record since filament-shaped micro-organisms had already been discovered in the Precambrian, and many other soft-bodies animals, organs, and anatomical structures in both the Cambrian and Precambrian. According to Simon Conway-Morris, the Burgess Shale (Cambrian) contains 70K+ specimens, and 90% of them are either entirely soft-bodied or have a thin skeleton. The fossils discovered by the Chinese contained even more soft-body animals and preserved eyes, intestines, stomachs (and even the contents in the stomachs), mouths, and nerves. Furthermore, it would be impossible for some ancestors of the Cambrian phyla to function without their hard parts (such as an exoskeleton). They would have to have evolved together, and thus we would expect to find those ancestors in the Precambrian. If the Precambrian could preserve soft, tiny organisms, then why don’t we find the transitional forms leading up to the Cambrian phyla in the Precambrian?
December 2, 2014
I may be a bit late to the party, but I’ve finally gotten a chance to read Stephen Meyer’s latest book, Darwin’s Doubt. Having read his previous book, Signature in the Cell, I had high expectations, and Meyer did not disappoint. Darwin’s Doubt takes a look at the longstanding enigma of the Cambrian explosion – a very brief time in history in which the majority of all major animal forms abruptly appear in the fossil record with no trace of simpler ancestral forms. Darwin recognized the problem the Cambrian fossils posed to his theory, but thought future discoveries would solve the problem. After 150 years, the problem hasn’t been solved. Instead, it’s been made more acute.
Scientists are increasingly coming to recognize that Darwin’s theory cannot explain the Cambrian explosion. Some are proposing alternative, naturalistic explanations. Others see the Cambrian explosion as powerful evidence for the intervention of an Intelligent Designer nearly 550 million years ago. Who’s right? Darwin? The Darwin doubters? Intelligent Design theorists? Stephen Meyer walks the reader through the evidence, and then evaluates competing explanations to see how they stack up against the evidence. It should be no surprise to those who know Stephen Meyer where the book concludes. The question is how he gets to his conclusion.
October 1, 2014
If there is no God, there is no morality either. Only a transcendent, personal being like God can serve as the ontological foundation for transcendent moral truths and moral duties. Cultural norms and mores may still exist without God, but not moral truths. Without God to provide the ontological grounding for objective moral values, what we refer to as “morality” is nothing more than expressions of our subjective preferences or human pragmatism. To say “murder is wrong” is no different than saying “chocolate ice-cream is gross” or “you shouldn’t drive on the left side of the road.” Moral obligations fall by the wayside, for in the name of what ought anybody submit to cultural preferences or pragmatic mores?
To believe morals exist but God does not is like believing books exist but authors do not. There wouldn’t be any books in the absence of authors, and there wouldn’t be any moral truths in the absence of a transcendent, personal, holy God to ground those moral truths in reality. Put another way, to believe moral truths exist in the absence of a transcendent source like God is like believing books exist in the absence of authors. And to believe that we are obligated to behave in certain ways in the absence of a moral law maker and judge is tantamount to thinking one is obligated to obey the laws in a nation without legislators.
September 28, 2014
Posted by jasondulle under Odds & Ends
It’s been just over two months since my last post. No, I’m not dead. No, I haven’t given up blogging. I’ve just been working crazy hours at my job. Sleep has been a luxury (to give you an idea of how crazy it’s been, last week I slept five hours between Sunday morning and Thursday night), so blogging has been out of the question. I apologize for not at least posting something a couple months ago notifying everyone that blogging would be next to non-existent for a while. When I have a few minutes I write down some thoughts for a blog post, but then it takes me 10 days to get back to it, and I only have five minutes to write. So I will be posting something in a few days. It’s only a few paragraphs, but it took me more than a month to write!
For those of you who have not already subscribed to my email feed, I would encourage you to do so (click “email notifications” on the top right). Hopefully by December things will be back to normal, and I’ll resume blogging on a regular basis. Until then, I’ll try to post when I can. Thank you for your faithful readership!
July 23, 2014
Former psychiatrist in chief at Johns Hopkins Hospital, Dr. Paul McHugh, recently penned a poignant opinion piece in the Wall Street Journal titled “Transgender Surgery Isn’t the Solution.” John Hopkins was the first medical center to perform sex-reassignment surgery in the 1960s, but based on evidence that such surgeries did not help transgendered people, they ceased performing the surgeries. In light of the recent push to normalize transgenderism, Dr. McHugh has sounded the medical alarm to warn us that in our efforts to help these people we may be having the opposite effect.