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Study helps define the limits of Darwinian natural selection

aphid and clones/M. Turcotte

Not that the authors or their PR team put it that way, but from “Rapid Evolution Within Single Crop-Growing Season Increases Insect Pest Numbers” (ScienceDaily Aug. 15, 2011), we learn the limits. Aphids (pant-sucking pests) Mate once in the fall, and thereafter the females mainly just clone themselves (which explains how they become so numerous so swiftly). Researchers decided to compare the growth rates between a polulation where all members were from a single clone against one where therer were two lineages. They found that hey found that evolving populations grew in number up to 42 percent faster. Their conclusion?

“This shows that even without human interference natural selection acting on aphid populations causes rapid evolution,” said Martin M. Turcotte, who led the research as a graduate student in ecology, evolution and organismal biology at UC Riverside. “Even stronger effects might be expected when pesticides are in use. For decades, evolution was deemed too slow and, hence, it was not considered when studying population growth — an oversight that needs to be corrected.”

Will non-Darwinists be forgiven for asking what this aphid population growth study has to do with evolution, given that it lead to no physical change at all? Change only in numbers hardly counts.

See also: Researchers discover supergene that controls butterfly mimicry patterns

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6 Responses to Study helps define the limits of Darwinian natural selection

  1. What do you mean by “no physical change”?

    If there’s a genetic difference that results in differential population, it’s a physical change.

  2. Are changes to the number, size, and shape of chromosomes in a karyotype – in and of itself – a “physical change” that requires intelligent design?

  3. Were the number, size, and shapes of the letters in your post a “physical change” that required intelligent design?

  4. That’s wasn’t helpful.

    Can we agree that most Intelligent Design proponents do not accept common descent except for very small changes (micro-evolution)? If so, then are changes to the karyotype (see above) considered to be instances of micro-evolution or intelligent design?

    But perhaps I need to ask a more general question.
    The boundaries of evolutionary relationships between “related kinds” appears to be a neglected aspect of Intelligent Design theory. So if design is not specifically detected amongst related flora/fauna, then can one scientifically rule out macro-evolution? In other words, how can one scientifically differentiate between common descent and common design?

    For example, how does ID understand the relationships in the family Canidae (wolves, foxes, jackals, coyotes, dholes, and dogs)? The morphological differences don’t seem to require an intelligent design explanation, so that leaves us with differences in karyotypes.

  5. How about common descent due to/ based on a common design?

    But even more importantly how can we objectively test the premise of universal common descent? I have read Theobald and his “tests” apply equally to common design.

    The point being is that people who do not accept universal common descent do so for scientific reasons. Deal with it.

  6. If it’s wrong to rule out Common Design due to a lack of evidence, then it’s equally wrong to rule out Common Descent for the same reason.

    So what evidence is there, specifically, that the fox species are a product of micro-evolution? And what evidence is there, specifically, that the fox species are a product of Intelligent Design?

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