The Difference in Macro and Micro Evolution.

No form of evolution ever made a wing overnight. But if you start with just a tiny bit of fuzz, and give about a thousand generations, you might be right there. Micro and macro evolution can be difficult to understand if you think one means that a dog becomes a bear in one generation. That is not only impossible but improbable as well. So how do the scales run over time?

The vital difference between macro and micro evolution are the scales of time in biology. A species can have inter, but not intra, generational mutations. Simple effects such as mutations in pigment genes can create a species which better suits the environment. These happen all the time. If the effect is not beneficial, and predators take note then the mutation will not survive to the next generation, since mutations occur in offspring and show in the juvenile form of the species.

When benefits help the prey or predator species in their environment it is passed on to the next generation. Now mutations like this are small, so they can easily pass on in the DNA strand. When the gametes cross over  in metaphase 1, crossing on this section often passes over small changes and continues them on. Otherwise, if the change had been big,(meaning a mutation to a limb, or other structure), the likelihood of it not being shuffled into an inactive position is very small. This is why some people may have children with genetic disorders and ones without. Many times, unless the same mutation is found in both parents, it is likely to be shuffled. When both parents carry a mutation the offspring will have it, but this is still the micro scale.

Over time mutations like this continue gaining momentum. Just like the giraffe was not always long necked. Over time giraffes with longer necks who could compete for more roughage survived above the other giraffes, with shorter necks. What we have over time is modern giraffes with long necks. It is not only necks, but legs, colors, and food sources. What started as just color can become color and size, not much size just a slight change. Then more slight change in size, over and over. It takes thousands of generations. It could also be an ability to use new resources from the environment as it changes. They are small changes, but small builds on small. Over time it can take one creature and make it so different from others that it is a new species. The new species is considered when one animal/plant is so unlike the original that it can no longer interbreed. Environment plays a large role in this mutations.

Often times, when we as humans are coping with changes in climate, or food growth we think nothing of it, and while we can adjust to these changes well, if they continued over time, we would continue adjusting. Soon we would be adapted to a whole different environment, and no longer able to change back to the old. This has actually happened with our diet. The reason humans have a appendix. At one point in history we survived solely on foliage. Our appendix was used to process large amounts of plant materials, and held many bacteria. As we began eating meat, our appendix shrank. Over thousands of generations it became so unused that it is now inactive and just a lingering remnant of our evolution. All of this took time.

The outcome of all these minor changes is macro evolution. Macro means big, and over millions of years we get species changes. At no point in history was evolution disproportionately large. No one gained a wing over night. No one became human in one generation, but step by tiny step evolution has paved the way to our modern world. 4 billion years ago earth had primitive plants on it. These are found in the fossil record. They were so primitive that they were only able to replicate every leaf petal equal to the other. They were not highly complex, and were under the ocean. The best they could do was filter microbes. Since then plants have adapted to all different environments, and  some of them look like their counter part in the insect world. They have become useful in many ways which benefits their species, by benefiting our species.

The macro would never come to exist if it were not for the micro. Macro only is a sum total of the changes over time. It does nothing else. It does not state a dramatic change over a short period, or in a few generations, but in lengths of millions and billions of years. It is equal to saying millennium, or century. We don't confuse that a millennium is a thousand years, where a century is one hundred. We should not confuse where and how micro, and macro act. It is not a difference we not as two happenings, but an explanation of what happens over time, from the distance of the first change to the last noted one. 

Comments

  1. I think what most people do not realise is that micro evolution is very small. By small I am talking at the chemical bonding level, when two or more chemicals bond to form a molecule. Everything bigger than that can be considered to be macro evolution.

    Now this micro evolution has the advantage of being able to do these small simple mutations many times, and the environment that it is in selects the for the immediate next generation. This show beyond any doubt that there is no purpose beyond the immediate. These simple steps combine to form complex products, which give the illusion of design, but that is wrong. There is no way a reasonable person could suggest that chemical bonding directed long giraffes necks, even if that was the end benefit.

    All you have to look at another animal, such as the zebra, and see that it does not have a long neck. The only evolution is micro evolution at the chemical level, everything is just selection on what is available.

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  2. In an attempt to put geological time scales into perspective for evolution to have taken place, we (Halton Peel Humanist Community) are holding our second annual Ancestor's Trail Hike in Mississauga at the end of June. http://ancestorstrail.ca

    I would encourage anyone interested in public education on evolution to take a look at the event that inspired ours at http://www.ancestorstrail.net

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