Human evolution Intelligent Design Plants

Did sweet potatoes cross the Pacific without humans 100 kya?

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From Dan Garisto at Science News:

New genetic evidence instead suggests that wild precursors to sweet potatoes reached Polynesia at least 100,000 years ago — long before humans inhabited the South Pacific islands, researchers report April 12 in Current Biology. If true, it could also challenge the idea that Polynesian seafarers reached the Americas around the 12th century.

The researchers calculated the average rate of genetic change for the plant, determining that the Polynesian sweet potato diverged from its South American cousin at least 100,000 years ago. That suggests the plants, or their seeds, somehow migrated across the ocean on their own, possibly via wind, water or birds. Precedent exists, the authors note. Two other Ipomoea species crossed the Pacific millions of years ago — to Hawaii in one case, and to islands from Polynesia to Madagascar in the other.

“It could be true,” says biological anthropologist Lisa Matisoo-Smith of the University of Otago in New Zealand. But she and other researchers remain dubious about the findings. Among the issues, the analysis involved just a single historical sample. More.

It does seem a long journey for the humble sweet potato. But we shall see.

See also: Earlier than thought: Dogs lived with humans in the Americas 10 kya Burial of dogs who died from natural causes implies, of course, a level of affection and esteem.

and

Biogeography: Monkeys sailed the ocean blue?

8 Replies to “Did sweet potatoes cross the Pacific without humans 100 kya?

  1. 1
    jdk says:

    I read this a few days ago, and thought it very interesting. Among other things, it stimulated me to re-read Thor Heyerdahl’s “Kin Tiki”, which I loved when I read it many years ago,

  2. 2
    ET says:

    Most likely the people reading the clock made assumptions that didn’t pan out.

    For example the sweet potato in a new environment with different nutrients may (most likely will) evolve at a different rate. Then if any artificial selection and hybridization took place that would also alter the clock

  3. 3
    Allan Keith says:

    Well, sweet potatoes are less dense than seawater and will, therefore, float. I leaned about density and floating in elimentary school. Anything that floats can cross oceans. Boats and construction materials continue to wash ashore on western North America following the Japan tsunami. Whether or not they can remain viable after emmersion in salt water for a long period of time, I have no idea.

  4. 4
    polistra says:

    With seeds no explanation is needed. Birds and clouds are guaranteed free public transit to all destinations. In fact the ABSENCE of a plant propagated by seeds is a fact that needs explanation.

    With larger objects more complex transportation is required, and there’s no guarantee.

  5. 5
    Allan Keith says:

    Well, sweet potatoes are less dense than seawater and will, therefore, float. I leaned about density and floating in elimentary school. Anything that floats can cross oceans. Boats and construction materials continue to wash ashore on western North America following the Japan tsunami. Whether or not they can remain viable after emmersion in salt water for a long period of time, I have no idea .

  6. 6
    mahuna says:

    Allan @ 3 & 5,

    the problem with simply floating is that immersion in saltwater for extended periods will kill a fresh water plant.

    Floating between islands in the Western Pacific is one thing. Perhaps 1 plant in 1,000 might survive, which is still reasonable over several centuries. Floating from Hawaii to Panama and remaining alive is asking a WHOLE lot from the poor plant.

    But in the same vein, no one, most especially Darwin, can explain how land birds got to the Galapagos Islands. They’re not migratory and there are ZERO intermediate landing/breeding sites.

  7. 7
    ET says:

    I wonder if the nomenclature also floated across the ocean?

  8. 8
    ET says:

    mahuna:

    But in the same vein, no one, most especially Darwin, can explain how land birds got to the Galapagos Islands. They’re not migratory and there are ZERO intermediate landing/breeding sites.

    Hurricane/ tropical cyclone.

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