Eli5 Favourable mutation



Can someone explain this to me: “we embody a solution, as a consequence of favourable mutation”

In: Other

Where are you finding this? It sounds like a bollocks self-help slogan, so it can’t be explained without knowing the context it’s being used in

I’ll take a stab at explaining this. Mutations are random differences between members of a species caused by genetic variations. There’s no controlling what is impacted by a mutation, no guiding the mutation to a desired goal. However, not every mutation ends up equally impacting members of the species. Any mutation that makes it more difficult to reproduce, or to survive until reproduction occurs is a non-favorable mutation. Which means there’s a flip side to mutations, where it either aids in reproduction, thus passing the genes for that mutation on to the next generation, or aids in survival to reproduction, which will also pass those genes on. These mutations are called favorable mutations, because they act in favor of the individual that possesses them.

So, let’s take a theoretical example. You’re a prehistoric horse-like creature wandering the scrublands. There’s plenty of grass and bushes to graze on and the occasional tree as well. All is great until one day, catastrophe strikes. It could be a wildfire, or locusts, or a plant disease, or whatever, but the end result is that the vast majority of the grass and bushes have died off, leaving bare dirt and the few trees. The herd quickly moves to eating from the lower branches of the trees, but they’re also stripped of leaves and food as well. Members of the herd start to die of starvation. The shorter the herd-member, the faster they cannot reach food and starve. So we have a change in environment, and the species needs a solution to continue to reproduce and survive. Well, what happens is that the natural genetic variation in height becomes a strong factor in the survival of the individual. Over the subsequent generations, taller members of the species tend to survive longer, and are more likely to survive to reproduce. The average height of a herb member begins to grow. Any random mutation that increases the height or reach of the individual makes the more likely to survive, making those mutations favorable. Eventually, a balance point is reached where getting taller no longer has a favorable impact. There’s enough food for the size of the herd at the height they’re at, and being taller than that no longer confers an advantage.

So what happened is that a solution to the change in environment for the species was found as a consequence of favorable mutations, and though the individual members of the herd look quite different from the original form they had, they’re still from the same genetic line.

Genetic mutations are random. When they happen they can do nothing (most of the time this is what happens), they can be detrimental (cancer), or they can be beneficial (low cholesterol)

Over times the creatures that accumulate the beneficial random mutations will out compete the others, and it will appear the are “designed” as a solution to their environment. A giraffe needs a long neck to eat leaves, but it didn’t solve that problem by growing a long neck. Random mutations gave some giraffes long necks, those ones could get to more food, and so out competed the other giraffes, so eventually all the giraffes were long necked. The long necks were an outcome, not a design