Thread: Mutations

Do mutations affect every cell in the body? Can a entire population of organisms get a mutation all at once? How do mutations get into the germ cells?

How many mutations were there when females carried their developing embryo inside the body for the first time from egg layers? It would seem there had to be a lot of modification when placenta's was a new innovation in history. The entire body has to make adjustments for pregnancy.

How do scientists know which mutations are the result of new traits in morphology changes over time in species?

Originally Posted by barbara

Do mutations affect every cell in the body?

No- a mutation occurs in one cell only. If that cell happens to be a dividing cell, then you can get many more cells with the same mutation in your body, but no cell type naturally divides to replace all of the cells in our body.

Originally Posted by barbara

Can a entire population of organisms get a mutation all at once?

No, for the reason stated above.

Originally Posted by barbara

How do mutations get into the germ cells?

The same way they get into any cell- by originating in that cell. Most germ cell mutations would be due to DNA copying errors or chromosomal recombination errors that occur during the division of the germ cell from it's progenitor cell.

If the progenitor cell undergoes a mutation, then obviously there's a chance the germ cells that emerge from it will also carry the mutation.

Both progenitor cells and germ cells can also undergo mutation due to external influences- mutagens such as ionizing radiation and some chemicals.

Originally Posted by barbara

How many mutations were there when females carried their developing embryo inside the body for the first time from egg layers? It would seem there had to be a lot of modification when placenta's was a new innovation in history. The entire body has to make adjustments for pregnancy.

This would have happened in many stages, I personally don't know the order of events.

Originally Posted by barbara

How do scientists know which mutations are the result of new traits in morphology changes over time in species?

Do you mean, how do we know which morphological changes are the results of mutations? I'm no expert, but I would suspect we can infer a lot from what we know about how alleles (gene variants) affect morphology in living organisms, and by what we know about the influence of environment, and about development. Most of this would come from population scale observational studies in humans, and more detailed mechanistic studies in other species, particularly rodents.