26 Mar '11 19:43>
I've started a new thread on this as the other one has been side tracked, mainly because of my delay in posting this reply.
Right, so we're up to how mutations arise in an organism. The next concept to understand is that these mutations can give that particular organism a slightly better chance of survival, it would subsequently follow that that particular mutation will now be passed onto any offspring it has. I'll give you an example of what i mean below, but first i should explain that not all mutations are of benefit to an organism. Most are harmful, some do nothing and only some are of benefit useful.
Now for an example of a mutation which could arise in an organism and how it could be 'selected' by nature. Take a hypothetical mammal living in a group. A female in this group has a litter of babies, one of the babies has had a 'coding error' during it's conception and has been born with longer hair than normal. At the same time, for whatever reason, the climate is drastically becoming cooler. The long haired baby now has a slighly better survial chance than the rest of it's siblings due to it's 'mutation'. As the generations go by, the long haired baby has a much greater chance of passing it's 'mutation' on to it's children because he would have a greater chance of surviving the colder climate due to his longer hair. In a few generations the group of mammals would now have longer hair as the longer haired ones of the group would be able to survive the cooling climate, the shorter haired ones would have died out taking their genes with them unable to survive the cold.
If we take the same hypothethical situation, but this time we imagine the climate is getting hotter instead of colder then our long haired animals survival chances are reversed. His long hair in the hotter climate is going to be hinderance and he will likely die.
Mutations are random but the way in which nature 'selects' these mutations is not random. Mutations are only passed on if they are of benefit to the animal/organism. Richard Dawkins summed it up best as -
The non-random selection of random variants
That's why when we look at all the animals on the planet they are adapted to the particular environment in which they live. For example, all animals which live in cold climates are equipped to live there. If an animal doesn't adapt to it's changing environment then it will die out, and that is why the fossil record is full of animals that are no longer with us. Survive or go extinct.
But, that doesn't explain how one animal changes into another, that's just micro-evolution not macro-evolution i hear you saying, or Rob is anyhow. You're right, and i'll explain that tomorrow. Firstly does this make sense?
Right, so we're up to how mutations arise in an organism. The next concept to understand is that these mutations can give that particular organism a slightly better chance of survival, it would subsequently follow that that particular mutation will now be passed onto any offspring it has. I'll give you an example of what i mean below, but first i should explain that not all mutations are of benefit to an organism. Most are harmful, some do nothing and only some are of benefit useful.
Now for an example of a mutation which could arise in an organism and how it could be 'selected' by nature. Take a hypothetical mammal living in a group. A female in this group has a litter of babies, one of the babies has had a 'coding error' during it's conception and has been born with longer hair than normal. At the same time, for whatever reason, the climate is drastically becoming cooler. The long haired baby now has a slighly better survial chance than the rest of it's siblings due to it's 'mutation'. As the generations go by, the long haired baby has a much greater chance of passing it's 'mutation' on to it's children because he would have a greater chance of surviving the colder climate due to his longer hair. In a few generations the group of mammals would now have longer hair as the longer haired ones of the group would be able to survive the cooling climate, the shorter haired ones would have died out taking their genes with them unable to survive the cold.
If we take the same hypothethical situation, but this time we imagine the climate is getting hotter instead of colder then our long haired animals survival chances are reversed. His long hair in the hotter climate is going to be hinderance and he will likely die.
Mutations are random but the way in which nature 'selects' these mutations is not random. Mutations are only passed on if they are of benefit to the animal/organism. Richard Dawkins summed it up best as -
The non-random selection of random variants
That's why when we look at all the animals on the planet they are adapted to the particular environment in which they live. For example, all animals which live in cold climates are equipped to live there. If an animal doesn't adapt to it's changing environment then it will die out, and that is why the fossil record is full of animals that are no longer with us. Survive or go extinct.
But, that doesn't explain how one animal changes into another, that's just micro-evolution not macro-evolution i hear you saying, or Rob is anyhow. You're right, and i'll explain that tomorrow. Firstly does this make sense?