Bird Populations Become Separate Species

Actually, that’s a trick question; the mechanism of speciation fits with both the evolution and the creation model. That said, we argue that the creation model better explains the types and speed of speciation we observe. A new study of monarch flycatcher birds gives us a chance to explain.

Coloration is the only known difference (other than habitat) between the populations.

A team led by Syracuse University biologist J. Albert Uy examined two populations of flycatcher birds in the Solomon Islands. One of the populations, on the large island of Makira, have all black feathers. The other population, spread among smaller islands, have some black feathers but also a chestnut-colored underside. Coloration is the only known difference (other than habitat) between the populations.

Uy’s team needed to determine whether the all-black and black-and-chestnut populations of flycatchers were still breeding with one another. If not, then—by one definition of species, anyway—the two populations can each be considered unique.

It would have been impossible for the team to be in all places at once, confirming that members of one population never mated with members of the other. Instead, the scientists looked at territorial rivalry between males in the two populations. The males attack any potential rival that enters their territory. So, the researchers hypothesized, if the all-black flycatcher males reacted less violently to black-and-chestnut flycatchers entering their territory, that could be a sign they no longer see the other population as sexual rivals—and, thus, that interbreeding is uncommon.

Using taxidermic models, Uy and his team “invaded” mating territories—presenting (live) all-black males with both all-black and black-and-chestnut models, then doing the same to (live) black-and-chestnut males. The birds were much less likely to attack models representing members of the opposite population than those representing their own population. The team also found a genetic basis for the difference in plumage coloration: different versions of the gene MC1R, which regulates the production of melanin.

The news release describing the study emphasizes, “Speciation, the process by which different populations of the same species split into separate species, is central to evolution.” That’s true; Darwinian evolution requires a mechanism to create diverse species from a single common ancestor. But creationists believe observed speciation fits much better within the creation model for several reasons:

Both creationists and evolutionists justify their models based on the unobservable past.

• Type of change—When one species becomes two, the biological basis reflects either no change or a loss of genetic information. For example, natural selection generally works to reduce genetic information within a population (only those with certain genotypes survive; others die out). More rarely, a mutation may alter a bird’s plumage color, for example, but otherwise the genetic information remains constant. The effect of natural selection and mutations over time may increase diversity around the globe, but at the cost of reducing the genetic information in each individual—the opposite of what Darwinian evolution would require.
• Speed of change—Scientists often observe new species forming in a relatively short time span, compared to what evolutionists assume has happened over millions of years. Such examples of “rapid” speciation show that the diversity of life we see today is possible given the original created kinds (with representatives on board the Ark) and the elapsed time since the Flood. See also “.”
• Role of kinds—The speciation we observe never transforms a fish into a lizard, for example, or a lizard into a bird; fish remain fish, lizards remain lizards, and birds remain birds. We see a fixity and separation of kinds even though there are minor, information-reducing changes within kinds. Also, successful hybridization (between two different “species”) reminds us of the existence of underlying kinds. See also “Zonkeys, Ligers, and Wolphins, Oh My!”

If the creation model explains speciation better, why is there even a debate? The problem is that both creationists and evolutionists justify their models based on the unobservable past. Creationists’ “kinds” come from Genesis 1. At the same time, evolutionists claim the information-adding genetic changes happen only rarely, too rarely for us to have observed them in the present (they instead point to claimed transitions in the fossil record). Thus, the controversy transitions from a debate over observational science (where both creationists and evolutionists see speciation) to a debate over the interpretation of those observed facts.

In related news, scientists at the National Human Genome Research Institute have discovered that short legs across various breeds of dogs all trace back to the same genetic mutation: “an extra copy of the gene that codes for a growth-promoting protein called fibroblast growth factor 4 (FGF4).” This mutation—a corruption of information—could have happened just once, such as in a dog lineage not long after dogs stepped off Noah’s Ark. As this mutation was passed on, it eventually gave rise to all short-legged dog breeds of today.