High Speed Evolution In Action

Discussion in 'Science and Nature' started by MelT, Jun 4, 2009.

  1. When Evolution Is Not So Slow And Gradual
    ScienceDaily (June 3, 2009) - What's the secret to surviving during times of environmental change? Evolve…quickly.

    A new article in The American Naturalist finds that guppy populations introduced into new habitats developed new and advantageous traits in just a few years. This is one of only a few studies to look at adaptation and survival in a wild population.
    A research team led by Swanne Pamela Gordon from the University of California, Riverside studied 200 guppies that had been taken from the Yarra River in Trinidad and introduced into two different environments in the nearby Damier River, which previously had no guppies. One Damier environment was predator-free. The other contained fish that occasionally snack on guppies.

    Eight years after their introduction, the team revisited the Damier guppies to see what adaptive changes they might have picked up in their new environments. The researchers found that the females had altered their reproductive effort to match their surroundings. In the environment where predators were present, females produced more embryos each reproductive cycle. This makes sense because where predators abound, one might not get a second chance to reproduce. In less dangerous waters, females produced fewer embryos each time, thus expending fewer resources on reproduction.

    Finally, the researchers wanted to see if these adaptive changes actually helped the new population to survive. So they took more guppies from the Yarra, marked them, and put them in the Damier alongside the ones that had been there for eight years. They found that the adapted guppies had a significant survival advantage over the more recently introduced group.

    In particular, juveniles from the adapted population had a 54 to 59 percent increase in survival rate over those from the newly introduced group. In the long run, survival of juveniles is crucial to the survival of the population, the researchers say.
    The fact that fitness differences were found after only eight years shows just how fast evolution can work-for short-lived species anyway.

    "The changes in survival in our study may initially seem encouraging from a conservation perspective," the authors write. " But it is important to remember that the elapsed time frame was 13-26 guppy generations. The current results may therefore provide little solace for biologists and managers concerned with longer-lived species."
     
  2. Hey Melt! How ya been?




    Interesting articel indeed. I've always been interested in how changes in environment can change the evolution process.


    Isolated islands or habitats tend to show faster evolutionary changes in species than a large area.


    I don't know this for sure, and I can't really find resources to back me up..... but I believe it also has a lot to do with the size of the species' population. Large populations have much more extensive gene pools. And as a direct result, more stable. (?). Smaller populations have less options as far as breeding partners, possibly also kicking off evolution making that species monogomous. (not sure if any of that makses any sense to anyone... or me.)



    I also find it interesting that species must have had more than one 'speed' of their evolution. Lets use islands for an example, since the Galopagos in the mecca of evoltuion.

    The Galopagos weren't always there. Some of the species who now inhabit the islands, came from somewhere else. And there is a good chance that thier previous habitat was not an isolated one, and one that would not speed up the rate of that species evoltuion. Then when they get to the island, by whatever means of transpo, their rate of evolution speeds up.

    For instance, the giant tortoises. I assume that on thier native land, they were a single species with perhaps some geographical variations creating a few subspecies. On the main land, they slowly evolved into their current form. Then when they arrived at the Galopagos, some when to one island and some to another. Some when to a certain habitat and some went to another. Now, the same species of tortoise is sped out over very different habitats, which begins the evolution process. One is taller, one has a bigger shell, one stretches tall and allows birds to pick parasites from its underside.





    I doubt any of this makes sense to you, or anyone else reading. I couldn't quite arange my thoughts well enough this morning.... a fatty wake and bake doobie will do that!
     
  3. that is actually a solid post op

    thanks
     
  4. Good Mate, thanks:) How's the star-gazing going?:)


    All of the above is pretty much on the money. Evolution isn't entirely down to the size of the environment it's held within, it's really more about what stresses affect an organism in any environment. An area well populated with organism 'A' will signify that that area is well-suited to its existence, so evolution will take place more slowly there, if at all. Smaller, remote areas, such as islands, tend to have extreme changes in climate and habitat, and a higher concentration of predators and other organisms to compete with. Evolution is a very large set of variables.:)

    There's also evidence in humans (there was a Swedish study about 9 years ago) that the more densely packed the population, the less likely it is that the population will be able to have children.

    MelT
     

  5. It's going great! I've still yet to get a telescope so all my star-gazing is done through a pair of tri-pod mounted Celestron 25x100 Skymaster binocs.

    I've actually been getting into star photography. I don't have any technology specifically for that, but I got a nice camera for Christmas that I can set to 30second exposures. In a dark area, I can get some really cool photos...... stars show up that I can't see with my binocs, and it brings out the reds and oranes and blues really nicely.

    My favorite objects to photographs have been The Orion nebula, the Pleides, the double cluster in Cassiopeia, Jupiter's moons and various globulars and clusters.





















    You put that in a way that I could understand very well. It makes perfect sense that climate changes and other natural stimuli be the gauge for the speed of evolution. If there is a large area of habitat with relatively no change, than I suppose species A wouldn't need to evolve.... that is if it is already eveolved to fit that habitat.

    I can totally picture a species living in the arctic that has gone unchanged since it's initial evolution. On the reverse, species on a volcanically created island chain with massive swings in weather, tides, and hard land would either be rather new (evolved into current form recently).... or still possess the need for further beneficial changes.





    It still blows my mind to think that a genetic accident is responsible for humans, birds, giraffes. Even further, the ridiculous amount of bird species and genre. Songbirds are the most variant of the bird genres and they evolved much later than other birds.

    I am an avid birder and the range of colors and sizes and shapes and habitats and feeding styles and habits is mind-boggling. Most people who aren't into birds have no clue how many there really are. I live in CT. CT is in the top 10 when it comes to species seen in the state. A group of birders in MA recorded 196 different species in a single 24 hour period the last week of May. I went birding in a small area (maybe 1 square mile) and recorded 77 species.

    Using CT as an example again.... there are 420 bird species that can be seen in CT throughout the year. Not on one day obviously, but through one calander year. I've asked non-birders/nature people to take a guess at that number.... and it is usally somewhere around 50.

    And that is just for CT. The number of bird species in the world is staggering. They have evolved to fit into every nook and cranny in the world. The sheer number of species is one big draw for me. I used to, and still do, enjoy searching for mammals and amphibians/reptiles. On a GOOD day, I could maybe come across 5 different mammal species and 5 amphibian/reptiles species. On that same day, I may record upwards of 70 bird species. My record for one day sits at 102. 102 different species.


    Birds kick ass.

    Picasa Web Albums - Brian

    Check out my (albiet lame) photo gallery if your bored. Lots of bird photos and other nature stuff. I've yet to upload my space photos though. Some are good, some are terrible, some are just bad. A few are really cool.
     
  6. #6 MelT, Jun 10, 2009
    Last edited by a moderator: Jun 10, 2009


    OOOOOOOoooH, nice!:)



    Please post them, seriously, I'd love to see what can come out of this kind of set up. So many nebulae, so little time:) How's the visibility over your way? Rubbish over here, too much low-level haze and street lights:(



    Yup, that's it:) Sharks for example are far more perfect in an evolutionary sense than humans and most other creatures,and they haven't evolved for millions of years. Humans - more or less by the generation.



    I didn't know you were a twitcher too?!?!:) I'm purely an amateur, but we just had a great few days down on the Somerset Levels and saw all kinds of birds that are usually 'rare' here: couple of new Egrets, many more Hobbys and Woodpeckers (mostly black and white) than in past years, and the humble sparrow is finally making a comeback here at last.



    :eek:

    And that is just for CT. The number of bird species in the world is staggering. They have evolved to fit into every nook and cranny in the world. The sheer number of species is one big draw for me. I used to, and still do, enjoy searching for mammals and amphibians/reptiles. On a GOOD day, I could maybe come across 5 different mammal species and 5 amphibian/reptiles species. On that same day, I may record upwards of 70 bird species. My record for one day sits at 102. 102 different species.

    :eek::eek:



    No, MOST are really cool. Thanks for posting, let me know when you update:) I've been through a couple of the galleries and there are some great shots in there (Sasha!:) and some of the wading birds (Yellow Warbler too, nice shot)...really excellent. If you ever need any photo-retouching done let me know, I'd be happy to do it on work like that:)

    MelT
     
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