Is Australia’s Dingo Fence Driving Kangaroos to Evolve?

This dingo fence, which not only keeps dingoes away from farm animals but also fragments and reproductively isolates populations of mammals, such as kangaroos, was completed in the 1950s but fell into disrepair until it was fixed in 1975. So, any changes in the kangaroo population “could have come about in as little as 17 kangaroo generations” according to another popular science article.

Now, 17 kangaroo generations is not very long! And yet there have been changes within the “fenced” kangaroo population, specifically that young kangaroos on the inside of the fence, up until they are about four years old, are growing more slowly than their “unfenced,” dingo-exposed counterparts. Of course, this change is being labeled by the press as evolution in action (albeit unexpectedly quick action!).

In a new study, they raise the possibility that within just a few decades the kangaroos have evolved not to hurry their growth to get big enough to escape their main predator.

We’re seeing the effects of natural selection on the kangaroo populations they studied.

But is this really evolution? No, because kangaroos remain kangaroos. No new genetic information has been created and no change in kind has occurred, as they remain the kangaroo kind. Rather, we’re seeing the effects of natural selection (in this case, the lack of predatory pressure) on the kangaroo populations they studied. Interestingly, the first popular science article I mentioned references evolution several times, and yet a keyword search for “evolution” in the actual journal article it’s based on turns up nothing (other than in the titles of some of the cited references). Rather, according to the second popular science article, the paper’s authors state:

This would be unusually fast for an evolutionary adaptation. Instead, we suspect it’s the result of a more immediate response to the absence of dingoes, such as lower concentrations of stress-related hormones. These affect the health of mammals, and might have affected kangaroo growth rates in this case. . . .

But the unprotected kangaroos would have invested a lot more bodily resources into growing so quickly.

This would have left less energy for the animals to develop important functions such as their immune or reproductive systems. Or they might have had less fat reserves.

Conversely, protected kangaroos might have been healthier, or more fertile, because of their slower growth rates.

Again, this is just selection pressures (or lack thereof) impacting the population—but it’s not any change of kind. It’s just variation within the population due to already-existing genetic information. It is not evolution in the molecules-to-animals sense.

Yes, there’s variation within the kangaroo kind, but kangaroos only produce more kangaroos. Don’t let attention-grabbing headlines—meant to brainwash you with evolutionary ideas—fool you.

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This item was discussed Monday on Answers News with cohosts Rob Webb, Avery Foley, and Dr. Tim Chaffey. Answers News is our weekly news program filmed live before a studio audience here at the Creation Museum, broadcast on our Answers in Genesis YouTube channel and posted to Answers TV. We also covered the following topics:

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Thanks for stopping by and thanks for praying,
Ken

This item was written with the assistance of AiG’s research team.