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Why Are Asexual Animals Rare?

The Amazon Molly reproduces without any genetic contribution from a male (click for credit)
Most biology students know that there are two forms of reproduction: sexual and asexual. In sexual reproduction, the genome of the offspring is made from two contributors: the male parent and the female parent. In asexual reproduction, a single organism reproduces, and the offspring are genetically identical (barring any mutations) to the single parent. In general, bacteria reproduce asexually, while most animals and plants reproduce sexually. However, there are some animals that can reproduce asexually. Sea stars, hydra, and planarians are examples.

What most biology students don’t know is that there are examples of individual species of animals that reproduce asexually, even though other very similar animals reproduce sexually. Take, for example, the Amazon molly (Poecilia formosa), which is pictured above. It is thought that this species arose when a female Atlantic molly (P. mexicana) sexually reproduced with a male sailfin molly, (P. latipinna). While both the mother and the father (as well as all other members of the genus) reproduce sexually, the Amazon molly reproduces asexually. So when this interesting fish produces offspring, they are all genetically identical to the parent, except in certain rare instances, such as when mutations occur.

Now interestingly enough, there are a few forms of asexual reproduction in animals, and the one employed by the Amazon molly is called “gynogenesis.” In this form of asexual reproduction, a male is needed, but he contributes nothing to the genetics of the offspring. Essentially, the female produces eggs that have the full complement of genes (technically called a “diploid egg”), but they cannot begin development into offspring until they are stimulated by the presence of a male’s sperm. The problem, of course, is that all Amazon mollys are female. As a result, the Amazon molly “mates” with similar fishes, usually ones from the same genus.

One really interesting question related to all this is, “Why is it rare?” After all, sexual reproduction is annoying. You have to find a member of your own species that is the opposite gender. The Amazon molly’s form of asexual reproduction still requires a male, but it can be from a wide range of species. As a result, it is much easier for the Amazon molly to find a mate. Why, then, isn’t this kind of reproduction found very often in animals?

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The Faith of Some Evolutionists is Mind-Boggling

I just came across an article in the journal Science called “Irremediable Complexity?” 1 In the article, the authors describe an evolutionary idea called “constructive neutral evolution,” which was first proposed in 1993. The paper starts out stating something that is quite obvious:

Many of the cell’s macromolecular machines appear gratuitously complex, comprising more components than their basic functions seem to demand.

Of course the cell seems “gratuitously complex” to an evolutionist, since an evolutionist is forced to believe that everything found in cells (as well as the cells themselves) developed as a result of random processes acted on by natural selection. You would not expect amazingly complex things to be produced that way. Nevertheless, when you look at cells, you see all sorts of amazing complexity. Of course, those of us who understand science know that the cell’s machinery is not gratuitously complex. It is simply very well designed by a Designer who built a lot of adaptability and diversity into His creation.

The paper goes on to ask how we can understand such “gratuitous complexity” in light of evolution. The real answer is that you cannot. However, that’s not the answer an evolutionist likes, so the authors have to come up with something else. They quickly reject the widely-held adaptationist belief that the complexity is just the result of natural selection preserving any random changes that improve basic function. While they admit that this view can explain some of the simpler aspects of the cell, it clearly fails when discussing some of the really complex parts of the cell.

Their reasoning is quite valid, but their proposed solution takes even more faith to believe than the adaptationist view!

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Not So Fast, NASA

I recently commented on NASA’s paper regarding bacteria that can successfully incorporate arsenic into their biochemistry. Well, another blogger who has more expertise related to the paper has posted a very critical analysis. It is worth reading.

Essentially, the blogger believes that it is very possible the bacteria that lived in the arsenic-only cultures might have been scavenging phosphorous from others in the population that had died. As a result, the blogger is skeptical that arsenic was incorporated into the bacteria’s biochemistry to any meaningful extent.

The blogger is especially critical of the analysis claiming to have found arsenic incorporated into the bacteria’s DNA. He thinks the DNA-related data can be explained by contamination:

If this data was [sic] presented by a PhD student at their committee meeting, I’d send them back to the bench to do more cleanup and controls.

Based on the comments, it seems the blogger is sending a modified version of the post to Science as a letter to the editor. It will be interesting to see how the NASA group responds.

Homeschool Graduates Are Amazingly Well-Rounded

I got an E-MAIL from a parent asking if I could recommend any physics books to her. It seems that her son, who is currently majoring in physics and piano performance at a state university, asked for physics books for Christmas. In the E-MAIL she noted:

[My son] has said that your [books] have more than prepared him for his science courses at college, and he has done extremely well in the chemistry and physics classes. He has said many times how thankful he was to have used your programs.

While I am always happy to know how well my books have prepared students for studying science at the university level, what struck me about the E-MAIL was how I wasn’t at all surprised by the fact that her son was majoring in physics and piano performance. I would think most people would do a double-take at that duo of majors. However, it didn’t surprise me at all, since homeschool graduates are amazingly well-rounded.

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Debate: Do Vaccines Cause Autism?

The International Medical Council on Vaccination disseminates a lot of misinformation regarding vaccines. It claims to offer resources that will aid in “critical thinking for a critical dilemma.” Unfortunately, it does quite the opposite. It uses scaremongering and shoddy science in an effort to get people to stop giving critical medical care to their children.

They will be hosting a live debate on Monday, December 13th at 8 PM Central Time. The title of the debate is “Do Vaccines Cause Autism?” I have been asked to defend the scientific answer, which of course, is no. The debate is free, but you should sign up for it in advance. You can do that here.

If you have been deceived by those who want you to believe that vaccines cause autism, you might want to attend the debate so you can learn the actual science behind vaccination. If you know the science behind vaccines and therefore realize that they don’t cause autism, the debate might still be an interesting thing to attend so that you can see the shoddy science used by the anti-vaccination movement.

What Did NASA Really Discover?

“NASA Finds New Life Form” is the headline on the Fox News website. The article says:

NASA has discovered a new life form, a bacteria called GFAJ-1 that is unlike anything currently living in planet Earth. It’s capable of using arsenic to build its DNA, RNA, proteins, and cell membranes. This changes everything…NASA is saying that this is “life as we do not know it”. The reason is that all life on Earth is made of six components: Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. Every being, from the smallest amoeba to the largest whale, share the same life stream. Our DNA blocks are all the same. That was true until today.

While the NASA team has done something quite amazing, Fox News and other similar outlets have really over-hyped it. Not surprisingly, to get the real story, you must read the scientific article, which is groundbreaking indeed, but not in the way that the standard media outlets are saying.

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A Bacterium Walks Into a Restaurant…

We now know that some bacteria can walk
(Click Image for credit)
The hostess says, “Hold on there. We don’t allow bacteria in this fine establishment.” The bacterium says, “It’s okay…I’m staph!” It’s a stupid joke, I know, but at least the beginning isn’t scientifically inaccurate. It turns out that some bacteria can, indeed, walk!

Microbiologists have already shown that bacteria can swim through liquid using their amazingly well-designed flagella. They have also found that bacteria can crawl along a surface. However, no one had ever caught them in the act of walking until a team of UCLA researchers started studying the dynamics of bacterial biofilms.

The researchers were studying Pseudomonas aeruginosa, a species of bacterium found in soil, water, and many human-made environments. It can cause lung, skin, eye, and gastrointestinal infections. Like many bacteria, members of the species can exist as either free-swimming individuals or surface-clinging colonies. The surface-clinging colonies form biofilms.

Interestingly enough, a free-swimming bacterium can be genetically identical to a member of a biofilm. However, because the two different lifestyles have different requirements, some genes are active in the free-swimming bacteria but not in the biofilm bacteria, and vice-versa. This switching on and off of genes produces bacteria that look and behave quite different, even though they have the same genome.

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And I Thought Slime Couldn’t Get Any Better!

Velvet worms make amazing slime! (public domain image)
As a chemist, I have always loved slime. There are so many different kinds of slime and so many different ways to make it! For example, you can make slime at home using glue, water, and borax. You can also make it using water, cornstarch, and some heat. Both slimes are different, and they both bring out the kid in me. Chemistry really can produce great stuff! Of course, nature does a far better job at chemistry than even the best of today’s chemists. Indeed, the best chemists in the most sophisticated chemistry labs on earth cannot begin to make many of the sophisticated chemicals that a “simple” bacterium makes every day!

There is an obvious reason for this, of course. While chemistry has developed over thousands of years and was guided by some incredibly intelligent people, nature was made by God. As a result, you expect nature to be filled with things that put the most amazing achievements of chemistry (and science in general) to shame. Of course, that’s exactly what you find. From the best possible design for the vertebrate eye to the lightning-fast chameleon tongue, nature’s designs are significantly better than anything human science can produce. Indeed, world-renowned atheist Antony Flew had to give up his atheistic faith specifically because of the amazing design he saw in nature.

Well, it turns out that even some of nature’s slime is amazing!

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It’s Too Bad The APS Won’t Learn from This

Dr. Harold Lewis is a giant in physics. At one time, he was the chairman of the physics department at the University of California, Santa Barbara. He is now an Emeritus professor at the same institution. He served in the Navy during World War II, was chairman of the technology panel on the Defense Science Board, chaired that same board’s study on nuclear winter, was on the Advisory Committee on Reactor Safeguards, was a part of the President’s Nuclear Safety Oversight Committee, chaired the American Physical Society’s study on Nuclear Reactor Safety, and was a member of the United States Air Force Scientific Advisory Board. As if that’s not enough, he is a co-founder of JASON, a group of scientists who advise the United States Government on scientific and technological issues.

This giant recently resigned from the American Physical Society (APS). Why? Because he was sick and tired of the APS supporting pseudoscience when it comes to global warming. In his resignation letter, which I urge everyone to read, he specifically says:

…the global warming scam, with the (literally) trillions of dollars driving it, that has corrupted so many scientists, and has carried APS before it like a rogue wave. It is the greatest and most successful pseudoscientific fraud I have seen in my long life as a physicist.

Even though I doubt that the APS will learn from this action, I applaud Dr. Lewis for publicly separating himself from an organization that claims to be scientific but seems happy to throw science under the bus in order to jump onto a politically fashionable and incredibly lucrative bandwagon.

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Cool It!

Bjorn Lomborg is the Skeptical Environmentalist
(Click image for credit)
Because I have written extensively on the topic of global warming and have appeared in a documentary that addresses it from a Christian viewpoint, I was invited to pre-screen Ondi Timoner’s documentary, Cool It. This excellent film is based on a book with the same title, which was written by Dr. Bjorn Lomborg. It also stars Dr. Lomborg himself. Even though I am not a fan of documentaries because it is hard to check their facts, this one is definitely worth watching. If nothing else, it fills the gap between Vice President Gore’s nearly science-free, fear-filled documentary An Inconvenient Truth and the more scientific The Great Global Warming Swindle, which lacks a “take home” message on what should be done when it comes to sane environmental policy.

Dr. Lomborg is an associate professor of statistics in the Department of Political Science at the University of Aarhus in Denmark. He claims to have been a member of Greenpeace who got tired of the hyperbole that is inherent in most radical environmentalist materials. After scientifically investigating a few of the more ridiculous claims of the modern environmentalist movement, he officially left Greenpeace and embarked on a quest for sane environmentalism. Greenpeace, however, says it has no record of Lomborg being an active member. In any event, his scientific investigations led him to author a book called The Skeptical Environmentalist. While Lomborg took a lot of heat for that book, the criticism was often based on falsehoods, and that is the subject of the opening parts of the documentary.

After setting the stage with cute little children explaining the doom that will befall the earth because of global warming, Dr. Lomborg tries to set the record straight regarding the message of his book, The Skeptical Environmentalist. Using old talk-show footage, he shows that unlike many of his critics claim, he never questioned the reality of global warming. He shows that he has always held to the idea that global warming is real and is caused, at least in part, by human activities. The points he stressed in his book (and since then) are that (a) the costs of cutting carbon emissions to stop global warming are astronomical and will do very little good, and (b) there are significantly greater problems that the world faces, and we can do something about some of them.

While I disagree with him on the “global warming is real” issue, I have always appreciated his pragmatic approach and his pursuit of sane environmental policy. Both of these qualities are on full display in Cool It.

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