The creationists will be screaming about this one. At the website of the largest university in Australia, Monash University in Melbourne, we found this press release: Mouse to elephant? Just wait 24 million generations. Here are some excerpts, with bold font added by us:
Scientists have for the first time measured how fast large-scale evolution can occur in mammals, showing it takes 24 million generations for a mouse-sized animal to evolve to the size of an elephant.
Research published today in the Proceedings of the National Academy of Sciences USA (PNAS) describes increases and decreases in mammal size following the extinction of the dinosaurs 65 million years ago.
We went to the PNAS website, but we can’t locate the paper. It’ll turn up later. [Addendum: here it is: The maximum rate of mammal evolution.] Let’s continue with the press release:
Dr Evans, an evolutionary biologist and Australian Research Fellow, said the study was unique because most previous work had focused on microevolution, the small changes that occur within a species.
“Instead we concentrated on large-scale changes in body size. We can now show that it took at least 24 million generations to make the proverbial mouse-to-elephant size change – a massive change, but also a very long time,” Dr Evans said. “A less dramatic change, such as rabbit-sized to elephant-sized, takes 10 million generations.”
We rarely see a genuine biologist use the word “microevolution.” Let’s read on:
The paper looked at 28 different groups of mammals, including elephants, primates and whales, from various continents and ocean basins over the past 70 million years. Size change was tracked in generations rather than years to allow meaningful comparison between species with differing life spans.
Even so, you know the creationists will be going crazy over the required time spans. One more excerpt:
“The huge difference in rates for getting smaller and getting bigger is really astounding – we certainly never expected it could happen so fast!” Dr Evans said.
Many miniature animals, such as the pygmy mammoth, dwarf hippo and ‘hobbit’ hominids lived on islands, helping to explain the size reduction. “When you do get smaller, you need less food and can reproduce faster, which are real advantages on small islands,” Dr Evans said.
Without the published paper, we can’t determine how this study was conducted, but that will soon be available. Meanwhile, let’s sit back and watch the inevitable fireworks from the usual websites.
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