Tag Archives: Gene

Polemics

Can you evolve working legs by changing working fins into useless stumps?

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Consider this piece of taxpayer-funded “research” that appeared in the prestigious journal Nature (H/T ECM), and you will know everything you need to know about Darwinism, and whether it is science or mythology.

Excerpt:

The loss of genes that guide the development of fins may help to explain how fish evolved into four-limbed vertebrates, according to a study.

Marie-Andrée Akimenko of the University of Ottawa in Canada and her colleagues may now be able to explain how our ancestors lost their fins: they have discovered a family of genes that code for the proteins that make up fins’ rigid fibres. The actinodin (and) genes are present in the laboratory model zebrafish and in ancient fish, but not in four-legged vertebrates (tetrapods), the team report today in the journal Nature. What’s more, the researchers found that dampening the expression of and genes in zebrafish also disrupts the expression of genes that regulate the growth of limbs and the number of digits in other animals.

These results hint that the loss of and genes is linked to the change from fins to limbs.

[…]But a causal connection is not certain. “The real question is: did we lose these genes because we lost the use of fins, or did we lose fins because we lost the genes?” says Denis Duboule, an evolutionary developmental biologist at the Swiss Federal Institute of Technology in Lausanne (EPFL). “The problem is that when it’s an evolutionary question, you can’t do the experiment.”

You know what? You can’t do the experiment on the evolution of invisible pink unicorns, either. But you might be able to get your taxpayer-funded speculations about how invisible pink unicorns may have evolved published in Nature, as long as it somehow bashes the idea of intelligent design. To be able to explain evolution, you don’t actually have to test anything in an experiment… you just have to tell a fetching just-so story that may have happened. And then it gets published in the prestigious journal Nature. Because you arrived at the right conclusion, and that’s what matters. That’s science.

The Ottawa Citizen explains more about what the intelligent scientists designed using purposeful, non-random interventions during their lab experiments.

Excerpt:

This is a tough one to understand. How could a fish just grow legs? It mystifies us, and so this part of evolutionary theory is a common target for cheap attacks from creationists. Therefore, it’s extremely valuable that a scientist has now found a way in which a genetic tweaking makes a zebrafish embryo stop growing fins, and start growing an appendage that looks like a leg. If she can tweak a gene in the lab, maybe one of the many mutations that pop up in nature could do the same.

[…]To learn what a gene does, one method is to add a chemical that temporarily stops it from working, and see what happens to the animal. Akimenko’s team “knocked down” two of the four actinotrichia genes in a zebrafish embryo, and found that the fish appeared to stop growing fins.

Instead, it began growing features that look like the “buds” (or embryonic beginnings) of legs.

[…]Akimenko was using a chemical which doesn’t destroy the gene, but only stuns it for a short period, leaving the animal’s DNA intact. It’s like a chemical Taser. After three or four days the gene wakes up and does its normal job, and the fish embryo goes back to growing fins.

Got that? Non-functional “buds” are an important discovery for explaining how legs evolved from fins. Experimenter intervention producing an evolutionary dead-end is hailed as a masterful proof of evolution. Don’t even ask about whether non-functional buds convey an evolutionary advantage. Research that confirms Darwinism doesn’t need to be an actual factual account of what really happened. It doesn’t need to be testable or repeatable.

Notice also that no explanation is given about how the bud-enabled fish developed the ability to breathe oxygen, consume and digest food on land, or modify their excretory system to avoid losing water. None of that is necessary – because none of it is testable. It’s not about finding the truth, it’s about telling a story. A story that contradicts the idea that God exists, that there is objective right and wrong, and one day we will be held accountable for our priorities and decisions. And that’s why this is taxpayer-funded research that is published in Nature.

Is this science? Or religion?

News

New study shows that human and chimpanzee DNA are very different

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And this new study is from Nature, the prestigious peer-reviewed journal. (H/T Evolution News via Neil Simpson’s latest round-up)

Excerpt:

A Nature paper from January, 2010 titled, “Chimpanzee and human Y chromosomes are remarkably divergent in structure and gene content,” found that Y chromosomes in humans and chimps “differ radically in sequence structure and gene content,” showing “extraordinary divergence” where “wholesale renovation is the paramount theme.” Of course, the paper attributes these dramatic genetic changes to “rapid evolution during the past 6 million years.”

One of the scientists behind the study was quoted in a Nature news article stating, “It looks like there’s been a dramatic renovation or reinvention of the Y chromosome in the chimpanzee and human lineages.” The news article states that “many of the stark changes between the chimp and human Y chromosomes are due to gene loss in the chimp and gene gain in the human” since “the chimp Y chromosome has only two-thirds as many distinct genes or gene families as the human Y chromosome and only 47% as many protein-coding elements as humans.” According to the news piece, “Even more striking than the gene loss is the rearrangement of large portions of the chromosome. More than 30% of the chimp Y chromosome lacks an alignable counterpart on the human Y chromosome, and vice versa, whereas this is true for less than 2% of the remainder of the genome.”

I’m sure this will make it into the public school textbooks and PBS/Discovery Channel documentaries right away. Right! Away!

Commentary

Is universal common ancestry based on established facts?

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Casey Luskin wrote a wonderful article called “A Primer on the Tree of Life” that will help you to consider whether universal common ancestry is true.

Excerpt:

Evolutionists often claim that universal common ancestry and the “tree of life” are established facts. One recent opinion article argued, “The evidence that all life, plants and animals, humans and fruit flies, evolved from a common ancestor by mutation and natural selection is beyond theory. It is a fact. Anyone who takes the time to read the evidence with an open mind will join scientists and the well-educated.”1 The take-home message is that if you doubt Darwin’s tree of life, you’re ignorant. No one wants to be ridiculed, so it’s a lot easier to buy the rhetoric and “join scientists and the well-educated.”

But what is the evidence for their claim, and how much of it is based upon assumptions? The truth is that common ancestry is merely an assumption that governs interpretation of the data, not an undeniable conclusion, and whenever data contradicts expectations of common descent, evolutionists resort to a variety of different ad hoc rationalizations to save common descent from being falsified.

Here are two of the four evidences he looks at:

Molecular phylogenies

…the cover story of the journal New Scientist… titled, “Why Darwin was wrong about the tree of life.” …reported that “The problem was that different genes told contradictory evolutionary stories.” The article observed that with the sequencing of the genes and proteins of various living organisms, the tree of life fell apart…

You get completely different molecular phylogenies depending on which gene or protein you analyze from the organism. If UCA were true, all the genes and proteins would have to give similar molecular phylogenies. Casey also addresses horizontal gene transfer.

Convergent evolution

One data-point that might suggest common design rather than common descent is the gene “pax-6.” Pax-6 is one of those pesky instances where extreme genetic similarity popped up in a place totally unexpected and unpredicted by evolutionary biology. In short, scientists have discovered that organisms as diverse as jellyfish, arthropods, mollusks, and vertebrates all use pax-6 to control development of their very distinct types of eyes. Because their eye-types are so different, it previously hadn’t been thought that these organisms even shared a common ancestor with an eye.

Here, you have the same gene being used for the same function in different organisms that do not share a common ancestor.

Homologies and Morphological phylogenies

Casey goes on to look at the evidence from homologies and the disparities between molecular phylogenies and morphological phylogenies, (e.g. – Cytochrome B). Casey’s article is worth looking at, especially if you have never considered the case against universal common ancestry.