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Mouse to elephant in 24M generations

MONASH (AUS) — A new study says that it would take 24 million generations for a mouse-sized animal to evolve to the size of an elephant.

The Monash University study is the first time that scientists have measured how fast large-scale evolution can occur in mammals. The researchers describe increases and decreases in mammal size following the extinction of the dinosaurs 65 million years ago.

Led by Australian Research Fellow Alistair Evans, a team of 20 biologists and palaeontologists discovered that rates of size decrease are much faster than growth rates. It takes only 100,000 generations for very large decreases, leading to dwarfism, to occur.

Evans, an evolutionary biologist, says 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,” Evans says.

“A less dramatic change, such as rabbit-sized to elephant-sized, takes 10 million generations.”

The paper, published in the journal Proceedings of the National Academy of Sciences, looks 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.

Erich Fitzgerald, senior curator of vertebrate palaeontology at Museum Victoria and a co-author, says changes in whale size occurred at twice the rate of land mammals.

“This is probably because it’s easier to be big in the water—it helps support your weight,” Fitzgerald says.

Evans says he was surprised to find that decreases in body size occurred more than ten times faster than the increases.

“The huge difference in rates for getting smaller and getting bigger is really astounding—we certainly never expected it could happen so fast!” Evans says.

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,” Evans says.

The research furthers understanding of conditions that allow certain mammals to thrive and grow bigger and circumstances that slow the pace of increase and potentially contribute to extinction.

More news from Monash University: www.monash.edu.au/news/

chat16 Comments

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16 Comments

  1. nemo

    Yes but how long before the evolutionists brain becomes logical?

  2. Attomind

    Way too long to wait for Obummer to change into a Republican.

  3. creationist

    Obviously the brains of these evilutionists have evolved into jello.

  4. Bongstar420

    nemo and Attomind are examples of what is wrong with the world

  5. Robert

    Can we model human expansion or regression in the next 100,000 years? Would it be harder since humans are able to cultivate food rather then rely on a natural cycle of growth for food? We certainly are EXPANDING in America. Will we continue to grow due to readily available synthetic “food” supplies? The findings in this article would be helpful to agriculture, as oil ins’t the only thing we are having a shortage of.

    Also, should we look forward to smaller life on other planets with harsher climates or whose sun is of a lower magnitude and may not produce enough vegetation? Or how about enormous animals on planets of all water? Maybe the vast majority of planets with harsh climates have dwarf-like humanoids or mouse sized creatures.

  6. PDixon

    All very interesting, but fails to address the problem of how the information contained in the DNA of complex life forms first originated. The information encoded into the DNA of the mouse and the elephant is more complex than anything humanity has ever conceived, and yet it needed to be present before any life could exist. Evolution is really just a fantastic process that is part of Intelligent Design.

  7. Jon

    really? why do you all want to inject your crappy politics into this?
    Anyway, idiots aside, I understand making the calculatiopns on a generational basis, however, do the calculation take into account environmental changes? In other words, the time it takes to go through 24M generations for a mouse is a relativly short time frame when compared to the same nember of generations for an elephant. an ice age might be stll occurring at the end of the mouse’s 24m generations while 24m generation of elephantst may only be half way through by the end of that same ice age.

  8. donde

    Intelligent design and creationism is what scientists call “not even wrong”. Pons and Fleischmann’s cold fusion experiment was wrong as other scientists failed to recreate it. Intelligent design is not even wrong, as it provides nothing to test and there is no way to disprove anything.

    In order to be a scientific theory, intelligent design would need to provide an explanation as to why Earth has the particular life forms it has. Saying that God is mysterious is not scientific.

  9. Teabagged

    EVOLUTION IS ALL OBAMA’S FAULT!!! IF WE KEPT A REPUBLICAN IN THE WHITEHOUSE THIS WOULD NEVER HAVE HAPPENED!!!

  10. Mike

    Why do creationists (and that includes the idiot design folks) always need to post on scientific evolution articles? It’s not like scientists and rational folks go over to the religious fairy-tale article and plug up the comments section with nonsense.

    Yeah, evolution is so very unbelievable. Much more likely that a sky-daddy that looks just like people poofed into existence and created everything in six days, then changed his mind about dinosaurs. Then the all-knowing guy puts a forbidden fruit in front of people who don’t know right from wrong, and is surprised that they don’t follow his edict. Who woulda guessed?

    Then, in order to forgive people for being, you know, people, he becomes his own son and decides to sacrifice himself to himself so that he forgive people that guess his intentions from an ancient book full of contradictions and boredom (just right!) and forgive them for you know, being people. Because, full of love as he is, he will burn you for all eternity for guessing his intentions wrong. What an example for parenting!

    Makes much more sense. Thanks.

  11. ZelaZinthia

    “A new study says that it would take 24 million generations for a mouse-sized animal to evolve to the size of an elephant.”
    …………………………………………………………………………………………../

    OR, each was Created instantaneously from the mind of the Creator.

    Although science has elevated their Hypothesis of evolotion to a Theory they have not followed their own prescribed “scientific method in doing so. There is not one demonstrable experiment that shows how a man –
    or any other creature for that matter – evolved from any other species. The evidence of separate and distinct species is a fact which lends itself to Creation whereas any evolutionary connection is solely in the imagination of scientists and their followers.

  12. Rumpled4skin

    How funny… and oddly sad at the same time. Pavlov is still the funniest guy ever. Remember, this is supposed to be a non-fiction article.

  13. John

    It took less than 7 days for God to create the whole thing. In fact only 5 days. Genesis 1:31 states – And God saw every thing that he had made, and, behold, it was very good. And the evening and the morning were the sixth day.
    So much for all the money spend researching how long it takes a mouse to become an elephant. But one thing for sure. The value of the research done by theses researchers has a life span of maybe a few days. After that nobody will care or talk about this research.

  14. Mike

    Yep, God did it. Funny about all those fossils and whatnot…but flood…satan’s little joke…something like that. DNA evidence…just a test to see whether we can hold on dearly to a document written by goat herders with heatstroke a couple of thousand years ago. After all, science is hard, believing is easy. Just make sure your version of christianity is the right one out of all the thousand permutations, or burn forever. God loves you!

  15. Edwin Nirdlinger

    The creationists and those arguing against them should read Prof Dawkin’s book “The Greatest Show on Earth” instead of calling each other names and saying nonsensical things.

  16. Edwin Nirdlinger

    Another book, written by a devout Christian..Bishop Spong, is “Rescuing the Bible from Fundamentalism”. The book discusses how, by denying obvious, irrefutable facts, fundamentalists will eventually cause people to give up on Christianity. He thinks that would be a shame because the message of Jesus is beautiful.

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