GMA Biology
organized (not written) by Julie Thompson Seal coachjulieseal@yahoo.com
Gifts of God - And there are diversities of operations, but it is the same God which worketh all in all. - 1 Corinthians 12
The word "Meiosis" is from the Greek root word "meioun" which means to lessen. (Think minus.) And that is exactly what happens during the process of Meiosis. Remember that during Mitosis (Latin rt. means "to thread" - refering to the threadlike state that the chromatin takes just prior to replication) chromosomes gather together and duplicate and then the cell splits into two, new identical cells.
Meiosis is the process whereby those same cells split into two again, without replicating the genetic contents. The cell which began the Mitosis process is called a Diploid cell - meaning it has two copies of the genetic material. The cells that are produced at the END of Meiosis are known as haploid cells. Meaning that they hold exactly half of the usual genetic material. Why does Meiosis occur? Why do we need cells that only have half of the required genetics to make a human? (or any other living Eukaryote?) Because when the organism reproduces, it is best to mix its genetic code with the code of another independent organism (of the same species of course.) You are a living witness of Meiosis. You have a chromosome from your mother and one from your father. Together they provide a complete set of genetic blueprints for your body. Hopefully, you will be even more genetically durable than either of your parents are on their own. In this way, each species provides the greatest platform to improve and adapt to their physical enviroment.
Meiosis gives us genetic diversity. Genetic diversity is a great thing. If everyone was the exact same, we might all be wiped out by the same disease or the same illness. Maybe we wouln't have the many beautiful different music, art or any other talents we enjoy from one another. We probably wouldn't be as great a friend to our neighbors because we couldn't learn anything from them. Maybe we would feel like we didn't need them. In the end, maybe the human race would be very weak because everyone would only be worried about themselves. If you can just create another person just like the one that recently died, where would the tragedy be in death? Where would the joy be in life? We would all just be clones. Looking exactly alike but being rather alone. Additionally, creating a new person out of halves from two people creates a bond. This bond is physical right down to the very threads of our genetics, in every single cell. Its a lot like an Ionic bond, where atoms borrow electrons from other atoms. We are borrowing electrons too, in the form of chromosomes. :) That ionic bond forms a new compound: a family.
Everytime two organisms combine to form a new offspring, small changes can and do occur. Maybe height, hair color or even skin color can vary in just one generation. These changes can, after time, define an entire population of species. For example, Polynesian traits are distinct from Caucassian or Asian or African traits. This happens in the animal, plant and bacterial worlds as well. This is called microevolution. Microevolution is well documented, reproducible and readily observable. It represents the subtle changes that can happen over time within a population group.
Macroevolution is the term that is sometimes refered to as "evolution. In actuality the two terms are different. Macroevolution means that a species undergoes mutations or additions which prevent that population from reproducing with a cousin population. This would be then labeled a new "species". Evolution is the current theory that all organisms evolved from a common priordial ooze with no divine organization. In this model, one kind of organism can eventually evolve into another kind of organism. I.e. ape ancestors evolve to both apes and humans.
Moses 2
11 And I, God, said: Let the earth bring forth agrass, the herb yielding seed, the fruit tree yielding fruit, after his kind, and the tree yielding fruit, whose seed should be in itself upon the earth, and it was so even as I spake. 12 And the earth brought forth grass, every herb yielding seed after his kind, and the tree yielding fruit, whose seed should be in itself, after his akind; and I, God, saw that all things which I had made were good;
24 And I, God, said: Let the earth bring forth the living creature after his kind, cattle, and creeping things, and beasts of the earth after their kind, and it was so;
25 And I, God, made the beasts of the earth after their kind, and cattle after their kind, and everything which creepeth upon the earth after his kind; and I, God, saw that all these things were good.