Evolution is a Fact #15 - Robinson Crusoe

by cofty 7 Replies latest watchtower beliefs

  • cofty

    There are two sorts of islands. One sort provides powerful evidence of evolution at a species level.

    Firstly there are continental islands. These were once part of larger land masses but they were cut off by rising water levels or the movement of tectonic plates. Great Britain is an example of a continental island, it was cut off from the rest of Europe 300,000 years ago. Continental islands have a large and balanced population of flora and fauna.

    The other sort - the one we are interested in - are oceanic islands. These rise brand new from the ocean due to the effects of volcanoes or the growth of coral reefs. Examples of this sort of island include Hawaii and the Galapagos Islands. Logically these sort of islands have no life at all when they first appear but they end up with an unusual collection of species.

    They get colonised accidently by species that are able to reach them. They lack things like fresh water fish and land mammals and with a few exceptions, reptiles and amphibians.

    The species that do make it to an oceanic island tend to prosper outrageously. With little or no competition the original coloniser ends up being the ancestor of a whole range of species that have adapted to fill the variety of available niches on the island or archipelago. This phenomena is known as "adaptive radiation". Frequently these species are endemic to the oceanic island - in other words they are not found elsewhere.

    For example in the Galapagos Islands there are 28 endemic species of birds. Fourteen of these are closely related and make up the famous Galapagos finches group. Similarly Hawaii had 140 species of native bird. Sixty of these were honeycreepers that had all descended from a single pair that arrived there 4 million years ago. Although these species are similar there is no doubt that they separate species by any definition of the word.

    Similar radiations are found among plants and insects on oceanic islands.

    The really interesting thing about the animals and plants that inhabit oceanic islands is how remarkably similar they are to species found on the nearest mainland. Life on the Galapagos closely resembles life in the west coast of South America. The same is true about Juan Fernandez where the closest relatives of species there can be found in the forests of South America. The same pattern is repeated again and again all over the globe.

    These facts about biogeography is exactly what evolution would predict. It is down to chance which species make it to an oceanic island. Having arrived these Robinson Crusoe species thrive and evolve to fill many different ecological niches, and finally we will find their closest relatives on the nearest mainland.

    Part 1 - Protein Functional Redundancy - - - - - - Part 2 - DNA Functional Redundancy
    Part 3 - ERVsPart 4 - Smelly Genes
    Part 5 - Vitamin CPart 6 - Human Chromosome 2
    Part 7 - Human Egg Yolk GenePart 8 - Jumping Genes
    Part 9 - Less Chewing More ThinkingPart 10 - Non-Coding DNA
    Part 11 - TiktaalikPart 12 - Lenski's E.coli Experiment
    Part 13 - Morris Minor BonnetsPart 14 - Joey Goes to Oz
  • cofty

    The island of Madeira is the exception that proves the rule.

    Unlike most oceanic islands it doesn't have examples of adaptive radiation like the finches of Galapagos or the honeycreepers of Hawaii. In these remote islands the first breeding pair to arrive by accident have the place to themselves. Madeira is situated just 350 miles from the coast of Morocco so all of the environmental niches have been filled by visiting birds.

    The challenge for creationists is to explain how all the species of birds, insects and plants came to be in the same place. Did god choose to create 60 similar species of honeycreepers and put them all on the same island?

  • Half banana
    Half banana

    Excellent information and defense of reality in the attack made by those who who falsely reason that "God must be true".

    You also have covered the territory often called "convergent" evolution. I think that expression is misleading because the principle of evolution by selection cannot literally converge, radiation is better and describes the developmental element in evolution. (Also useful is the word 'exaptation' by implying how it happened?) Variations of organs are induced in one isolated species which happen to echo the role and forms of other species as your illustration shows. Why? For survival.

    If as a species you haven't got the proper biological kit...you die.

    If God created everything six thousand or even a million years ago, why have all the original species died out or everything developed into something else (as geology proves)?

    Creation is a belief for those desperate for a supernatural explanation when all along evolution has the tried and tested reason for how life is today.

  • cofty

    For anybody in the UK there is an excellent three part documentary on I-Player on this very topic.

    Nature's Wonderlands: Islands of Evolution...

  • sir82
    Looks like maybe you have overwhelmed Clambake - no whining (yet, anyway) about "proselytizing".
  • slimboyfat

    Thank you that's really interesting, and for the links to the programmes too. I love islands, and I've visited loads. (Didn't make it to Shetland this year though) One day I really hope to visit Tristan da Cunha, said to be the most remote inhabited island anywhere. It reminds me of that scripture in Isaiah 49. About how Jehovah and his purpose reache everywhere even remote islands.

    Listen to me, you islands,

    And pay attention, you faraway nations.

    Jehovah has called me before I was born.

    From the time I was in my mother’s womb he has made mention of my name.

  • cofty

    Wow that is remote - I don't think you can get there direct from Prestwick. I see it is called "Edinburgh of the Seven Seas". I'm guessing it is more Morningside than Wester Hailes.

  • slimboyfat

    Yeah they've got their own version of English too! The inhabitants are said to consist of the decendents of just a few families with 8 surnames. Without any influx they may be encountering genetic problems never mind the wildlife. I find the idea of modern people who live their whole lives in such a place fascinating. Like living on Lewis except more so, I guess. See this visitor mention YouTube to a young islander.


    Plus the place itself, apart from the people, looks amazing. In terms of wildlife I think it's no Galapagos though. Lots of birds.

Share this