Did 90% of all animal species arise at the same time as humans?

Recent articles on-line have alleged that about 90% of all animal species came to be at the same time as humans. See this post for references to four such articles.

What is this idea based on? This article is the main reason for such an idea. (The link given is to a summary. The summary includes a link to the full technical article it is based on, which is freely accessible.) A technique known as DNA barcoding was used. DNA barcoding usually compares a small amount, about 600 base pairs, of the mitochondrial DNA of different organisms. Mitochondria have DNA which is separate from the DNA in the cell's nucleus. DNA barcoding has been used, for example, to check the identity of fish sold for food -- are cheaper fish being passed off as more expensive ones? In some cases, the answer has been "yes." Mitochondria are passed on by females, as sperm do not have mitochondria. To quote from the summary of the article: 
Several convergent lines of evidence show that mitochondrial diversity in modern humans follows from sequence uniformity followed by the accumulation of largely neutral diversity during a population expansion that began approximately 100,000 years ago. A straightforward hypothesis is that the extant populations of almost all animal species have arrived at a similar result consequent to a similar process of expansion from mitochondrial uniformity within the last one to several hundred thousand years.

If true, this has important implications for origins. Ken Ham's blog has posted as article about this idea, and, not surprisingly, claims that these findings are consistent with his young-earth creation model, with survival of land animals after the flood, and not consistent with mainstream evolutionary thought. Perhaps so. Ham does note that the time for this increase in diversity suggested, 100,000, or more, years ago is not consistent with his model, which claims that all land animals arose about 6,000 years ago. He says that the difference in time is because of wrong evolutionary assumptions by mainstream biologists.

It seems premature to reach any firm conclusions on this matter. There have been some substantive criticisms of the barcoding method being applied to taxonomy. This article, from an important journal, Systematic Biology, strongly argues that taxonomic conclusions should not be drawn from only one type of data, be that DNA barcoding, the fossil record, or something else. The article isn't against young-earth creationism, in fact doesn't mention it, but it is against not using all types of data in developing taxonomic relationships. "Systematic," in this context, has to do with classifying organisms.

The Systematic Biology article also indicates some possible problems with DNA barcoding, and points out that the original article, quoted above: "... never [claims] that most 'species' came into existence within the past 200,000 years. Rather, what has come into existence within that time frame is the genetic variation observed in one gene in the mitochondrial genome."

DNA barcoding results, although interesting, and sometimes useful, should not be taken as overwhelming scientific proof of young-earth creationism, at least not yet. And, if such proof becomes stronger, the "young" of young-earth creationism may need revision to considerably more than six to ten thousand years ago.

I'm not sure how the remaining 10% of animal species are supposed to have originated, if, indeed, about 90% of them originated close to one time.

Thanks for reading.

Sunspots 521

Things I have recently spotted that may be of interest to someone else:

The Arts: Left Behind is going to be available through Netflix. E. Stephen Burnett does not recommend it, from any source.

Christianity: The New English Translation of the Bible, which can be downloaded free, in various formats. It is not public domain.

A Christianity Today columnist has begun wearing the same outfit to work all week. (In this case, the columnist is a female.)

Computing: Metaflop is a web site that lets you create your own fonts by modifying a pre-existing one.

Wired says that Coolors is a web site that lets you create your own color palettes, easily. It works. I plan to post a poster, with colors selected from that site, tomorrow.

Gizmo's Freeware has a Free Windows Desktop Software Security list, annotated.

The History Blog tells us about the first selfie, taken in 1839.

Health: Christianity Today reviews a book that claims that Christians, historically, have embraced advancements in medicine, and should continue to do so.

Politics: Benjamin L. Corey gives statistics on how much (or little) Christians actually give that goes to help the poor, and says that his support of government assistance isn't because he is a socialist, but because, if the church isn't coming anywhere close to meeting needs, then government should, by default.

Science: Time reports on a baby, conceived in vitro, with mitochondria, taken from the mother, and inserted into the egg.

National Public Radio reports on miscarriages. They are more common than you think, and the most common cause is a chromosomal abnormality. In other words, miscarriage prevents births of severely abnormal babies.

Wired on why, and how, cats purr.

Image source (public domain)

Sunspots 508

Things I have recently spotted that may be of interest to someone else:

Computing: Gizmo's Freeware tells us how to configure Adblock Plus (an add-in for major browsers) so that it does a better job of blocking ads.

Relevant warns of some dangers of social media. They aren't all the same ones you've already heard about.

Politics: Michael Gerson, columnist for The Washington Post, does not think President Obama's response to terrorism has been serious enough. But, he says, the President, nor the one before him, should or could have spoken against Muslims in the way that some people think that they should have.

Science:  Wired reports that the Hubble Space Telescope has captured three of Jupiter's moons, moving in front of the planet's surface. Eclipsing, in other words.

Wired also tells us that the hydra, a common, but nearly-microscopic animal, is potentially immortal.

Wired also tells us how it is possible for a baby to have three parents, in the sense that she gets genetic material from all three of them.

Sports: USA Today, ESPN, and many other outlets tell us that Dean Smith, great men's basketball coach, and greater man, has passed away.

Image source (public domain)