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There are generally accepted scientific theories that have zero predictive power. The theory of evolution is a great explanation of how we got here. But it can'

There are generally accepted scientific theories that have zero predictive power. The theory of evolution is a great explanation of how we got here. But it can't predict what's next.

jhbadger 9y ago
That's not true at all. Yes, you can say that the theory of evolution can't predict what man will be like in the year One Million or other pop culture ideas of how evolution works, but you can make the same claim about physics -- you can't predict what a given particle will be doing then either. But there is lots of predictive power in evolutionary theory. The core of modern evolutionary theory is population genetics which is as mathematical as physics and can make predictions of whether certain alleles will increase or decrease in a population, for example.
craigsmansion 9y ago
All scientific theories should have predictive powers, otherwise they wouldn't be falsifiable, and, as such, not science. Sometimes, as with your example, it's less obvious, but say, if a new species is discovered, evolution predicts there will be genetic differences to its closest cousin or ancestor and that the differences will be related to its fitness to thrive within a particular environment. Also note that "predictive" doesn't need to be about future events. It can also mean new discoveries within existing records (like a feathered dinosaur).
throwaway613834 9y ago
Evolution is probably the wrong example. I think a better example would be something like inflationary cosmology.
rleigh 9y ago
Of course it can. We can apply selective pressure to a population and hypothesise the likely outcome. You can do this on a small scale in a Petri dish by selecting for antibiotic resistance, for example. And then you can validate the hypothesis by sequencing to determine the exact genetic change which led to the outcome. If you wanted to predict the future evolution of a more complex species, that would be harder. Because we don't yet know what the selective pressures in the future will be, and the timescales involved are much longer. But if you define a set of selection criteria you can absolutely test a hypothesis by applying them today.

There are generally accepted scientific theories that have zero predictive power. The theory of evolution is a great explanation of how we got here. But it can't predict what's next.

jhbadger 9y ago

That's not true at all. Yes, you can say that the theory of evolution can't predict what man will be like in the year One Million or other pop culture ideas of how evolution works, but you can make the same claim about physics -- you can't predict what a given particle will be doing then either. But there is lots of predictive power in evolutionary theory. The core of modern evolutionary theory is population genetics which is as mathematical as physics and can make predictions of whether certain alleles will increase or decrease in a population, for example.

craigsmansion 9y ago

All scientific theories should have predictive powers, otherwise they wouldn't be falsifiable, and, as such, not science. Sometimes, as with your example, it's less obvious, but say, if a new species is discovered, evolution predicts there will be genetic differences to its closest cousin or ancestor and that the differences will be related to its fitness to thrive within a particular environment. Also note that "predictive" doesn't need to be about future events. It can also mean new discoveries within existing records (like a feathered dinosaur).

throwaway613834 9y ago

Evolution is probably the wrong example. I think a better example would be something like inflationary cosmology.

rleigh 9y ago

Of course it can. We can apply selective pressure to a population and hypothesise the likely outcome. You can do this on a small scale in a Petri dish by selecting for antibiotic resistance, for example. And then you can validate the hypothesis by sequencing to determine the exact genetic change which led to the outcome. If you wanted to predict the future evolution of a more complex species, that would be harder. Because we don't yet know what the selective pressures in the future will be, and the timescales involved are much longer. But if you define a set of selection criteria you can absolutely test a hypothesis by applying them today.