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News

Study: biological convergence found in human and squid eye genes

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Christianity and the progress of science
Christianity and the progress of science

We have to start this post with the definition of convergence in biology.

In evolutionary biology, convergent evolution is the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches.

It is the opposite of divergent evolution, where related species evolve different traits.

On a molecular level, this can happen due to random mutation unrelated to adaptive changes; see long branch attraction. In cultural evolution, convergent evolution is the development of similar cultural adaptations to similar environmental conditions by different peoples with different ancestral cultures. An example of convergent evolution is the similar nature of the flight/wings of insects, birds, pterosaurs, and bats.

All four serve the same function and are similar in structure, but each evolved independently.

With that being said, here is an article from Real Clear Science with me.

Eyes and wings are among the most stunning innovations evolution has created. Remarkably these features have evolved multiple times in different lineages of animals. For instance, the avian ancestors of birds and the mammalian ancestors of bats both evolved wings independently, in an example of convergent evolution. The same happened for the eyes of squid and humans. Exactly how such convergent evolution arises is not always clear.

In a new study, published in Nature Scientific Reports, researchers have found that, despite belonging to completely different lineages, humans and squid evolved through tweaks to the same gene.

Like all organs, the eye is the product of many genes working together. The majority of those genes provide information about how to make part of the eye. For example, one gene provides information to construct a light-sensitive pigment. Another gene provides information to make a lens.

Most of the genes involved in making the eye read like a parts list – this gene makes this, and that gene makes that. But some genes orchestrate the construction of the eye. Rather than providing instructions to make an eye part, these genes provide information about where and when parts need to be constructed and assembled. In keeping with their role in controlling the process of eye formation, these genes are called “master control genes”.

The most important of master control genes implicated in making eyes is called Pax6. The ancestral Pax6 gene probably orchestrated the formation of a very simple eye – merely a collection of light-sensing cells working together to inform a primitive organism of when it was out in the open versus in the dark, or in the shade.

Today the legacy of that early Pax6 gene lives on in an incredible diversity of organisms, from birds and bees, to shellfish and whales, from squid to you and me. This means the Pax6 gene predates the evolutionary diversification of these lineages – during the Cambrian period, some 500m years ago.

This is an example of convergence because the same gene is present in animals that DO NOT SHARE A RECENT COMMON ANCESTOR. In short, this is exactly identical to the case where a computer programmer reuses the same library of functions in two completely different programs. Software engineers re-use libraries all the time in different programs. It makes sense in an software engineering paradigm.

But this example of convergence makes no sense on naturalistic evolution – random mutation and selection does not create the same design in two animals with no common ancestry. It screams out design.

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News

New study: DNA requires maintenance from surrounding cell

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Christianity and the progress of science
Christianity and the progress of science

My friend Bruce shared this post from Reasons to Believe about some recent research on DNA.

Naturalists like to argue that DNA somehow came into existence randomly, but it turns out that not only is DNA marvelously improbable for even the simplest living organism, but it also requires a lot of support from other areas of the cell in order to remain stable.

It says:

In 2015, three scientists won the Nobel Prize in Chemistry for decades of research into DNA—research that reinforces the idea that evolution is mythology and makes the modern evolutionary theory of abiogenesis seem more and more indefensible. It turns out that DNA is inherently unstable, and the preservation of genetic information requires a complex symbiotic relationship between the cell and DNA that is so interdependent that neither could have arisen independently of the other.

DNA (deoxyribonucleic acid) is the giant organic molecule which carries and preserves an organism’s genetic information. DNA is essential to the growth and reproduction of life-forms because precise copying and self-replication of DNA is a critical part of the process of cell division.

Tomas Lindahl, the first Nobel laureate, has demonstrated that the rate at which DNA decays should have made the development of life on Earth impossible.1 The Nobel Committee expresses this on a personal level: “you ought to have been a chemical chaos long before you even developed into a foetus.”2

So why doesn’t our genetic material disintegrate into complete chemical chaos? It is because of molecular repair mechanisms within the cell. The three Nobel laureates “mapped, at a molecular level, how cells repair damaged DNA and safeguard the genetic information.”3 They found that a multitude of molecular systems constantly monitor the genome and repair any damage.

One such mechanism discovered by Lindahl is base excision repair, which explains why our DNA doesn’t collapse. A base of a nucleotide often loses an amino group and becomes unable to form a base pair, thus breaking the DNA chain. But an enzymedetects the error, and other enzymes repair it so that the DNA can replicate properly.

Paul Modrich, the second laureate, discovered another molecular mechanism calledmismatch repair. Replication errors often occur as the DNA is copied, but Modrich found that enzymes continually detect most of these errors, and other enzymes repair them. The Nobel Committee says this “reduces the error frequency during DNA replication by about a thousandfold.”4

One further issue that DNA must contend with is mutations, caused by DNA damage due to radiation and a variety of mutagenic substances. For example, radiation might make two base pairs bind to one another incorrectly. But the third laureate, Aziz Sancar, discovered that through a mechanism called nucleotide excision repair, enzymes will cut out, remove, and replace a damaged DNA strand.

We have long known that the cell could not reproduce without DNA, but we now know that DNA would self-destruct without the cell. It is this complex symbiotic relationship between a cell and its DNA that makes the modern evolutionary theory more difficult to defend.

[…]This research shows that for abiogenesis to occur, undirected, random processes must have anticipated the inherent instability of DNA and assembled the cell with the variety of enzymes necessary to prevent the self-destruction of DNA. Additionally, the cell’s chemistry, the self-preservation instinct, and anticipatory DNA repair mechanisms must have all come together at the same instant in time within only 1 billion years; otherwise, any nascent life could not have survived. If the probability barrier to evolution seemed like climbing Mount Improbable before, it has now become climbing Mount Impossible.

Could simple single-celled life-forms emerge and evolve into more complex life? Single-celled life-forms are not so simple. For example, the genome of an aerobic hyper-thermophilic crenarchaeon (a thermophilic archaea, a type of bacteria) consists of 1.7 billion base pairs, which is almost 60 percent of the 2.9 billion base pairs in thehuman genome.5

So, not only is it fantastically improbably to 1) get the building blocks of life, and 2) build the sequence of base pairs in DNA, but 3) you also have to have supporting systems to maintain the DNA in the cell: even more specified complexity.

News

Katie Courie defends deceptive editing in her pro-gun-control documentary

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Why do people think that CNN are biased leftist clowns?
Don’t believe the liberal media

This story from the Washington Free Beacon is very useful for explaining what happens when a person relies on the leftist mainstream media to tell them about reality.

It says:

The makers of a new Katie Couric documentary on gun violence deceptively edited an interview between Couric and a group of gun rights activists in an apparent attempt to embarrass the activists, an audio recording of the full interview shows.

At the 21:48 mark of Under the Gun a scene of Katie Couric interviewing members of the Virginia Citizens Defense League, a gun rights organization, is shown.

Couric can be heard in the interview asking activists from the group, “If there are no background checks for gun purchasers, how do you prevent felons or terrorists from purchasing a gun?”

The documentary then shows the activists sitting silently for nine awkward seconds, unable to provide an answer. It then cuts to the next scene.

However, raw audio of the interview between Katie Couric and the activists provided to the Washington Free Beacon shows the scene was deceptively edited. Instead of silence, Couric’s question is met immediately with answers from the activists. A back and forth between a number of the league’s members and Couric over the issue of background checks proceeds for more than four minutes after the original question is asked.

It’s impossible to purchase a gun in the United States without a background check, unless it is a person to person private sale. Even if you order a gun on the Internet, it has to be shipped to a store where you pick it up – after the background check has been run. However, people on the left love to lie about gun purchases.

Now, the deceptive editing was pointed out to Katie Couric, and what do you think that she did? Did she apologize and pull the documentary?

Of course not, as David French explains in National Review:

At this point, a responsible documentarian either immediately apologizes, promises to investigate exactly how the deception occurred, and pledges to re-edit the film — or they contest the VCDL’s evidence. Instead, Soechtig issued this statement:

There are a wide range of views expressed in the film. My intention was to provide a pause for the viewer to have a moment to consider this important question before presenting the facts on Americans’ opinions on background checks. I never intended to make anyone look bad and I apologize if anyone felt that way.
The Washington Post’s Erik Wemple’s response was exactly right, saying that he’s “scarcely seen a thinner, more weaselly excuse.” But, as he notes, it’s not just an excuse, it reads as an admission. She’s not contesting the VCDL’s claims.

This is exactly the point where a former network anchor — a person who still enjoys respect in the news business — should step in and impose adult supervision. But in her own comment on the controversy, Couric not only said that she was “proud of the film” she also supported Soechtig’s statement.

Dear Yahoo, let me put this in plain English for you. Your premier news personality is “proud” of lying. She “supports” a statement that purports to justify those lies as a form of creative “pause.” This would be a firing offense at any decent opinion journal, much less an organization that purports to objectively report the news. Americans can no longer trust a single news report or a single interview from Couric. They now know that she will unashamedly and proudly deceive them to advance her own ideological agenda.

Previously, I blogged about studies that actually document how far the media is biased to the left. I understand that people on the left want to be lied to, and they are entitled to consume reports from sources that affirm the lies they want to believe. But those who prefer truth should be wiser.