Can you compare and contrast gradualism and punctuated equilibrium?

Answer 1

punctuated equilibria accounts for the gaps in the fossil record. Species evolve quickly during relatively short periods. Tiny changes in a species gradually add up to major changes over very long periods of time.

Gradualism proposes that evolution occurs slowly but steadily. These periods of rapid change are separated by long periods of little or no change.

Answer 2

The two contrasting models are actually based on different interpretations of the fossil record.

The gradualism model, or phyletic gradualism, posits that evolutionary change occurs at a slow but constant rate, with small changes accumulating over time. If true, then one would expect to see change in lineages spread uniformly through time, but that isn't what is observed. In the fossil record, one often sees species remaining in stasis, or unchanged, for long periods of time, then bursts of new species quickly at irregular intervals. Supporters of gradualism point to the fossil record as incomplete, so we only have "snapshots" or certain points of evolution, making it appear as though punctuated equilibrium occurs.

Paleontologists Stephen Jay Gould and Niles Eldredge noted this pattern in the fossil record, and proposed the theory of punctuated equilibrium to explain it. Species remain in stasis, they argued, because speciation required certain special conditions for isolation and change to occur, and that these conditions are usually met at the periphery of a species's range, and not all of the time. In addition, they showed, with some very finely graded fossil series, that speciation can occur very rapidly once it gets going--in some cases as quickly as 50,000 years-- far faster than the fossilization process could accurately track in a gradual way. Therefore, one should expect to see long periods of stasis (equilibrium) broken up (punctuated)-- by bursts of speciation.

Answer

Classical Darwinism argued along the lines that evolution is always happening as a gradual accumulated process...(e.g. parents to offspring). Punctuated equilibrium says nothing much happens for a long time and then suddenly there is a burst of evolution. The latter is probably more palatable to people who don't like evolution, since you could argue that the changes in species are caused by external processes (e.g. a meteor), rather than evolution as an intrinsic biological property.

Answer 3

Answer 1

Gradualism usually refers to the discarded notion that evolution occurs at a steady, mostly unvarying rate, and that speciation is a process that takes many millions of generations.

Punctuated equilibrium, on the other hand, proposes that evolution occurs at varying rates: species can exist superficially unchanged for many thousands or millions of years, but then speciate and diverge rapidly, sometimes in the span of less than ten thousand generations.

One should not confuse punctuated equilibrium with saltationism, however: in both gradualism and punctuated equilibrium, evolution and speciation are gradual processes that take many generations to manifest.

Answer 2

Gradualism basically says there is slow change over long periods of time. This was the origional theory of evolution that has since been replaced with punctuated equilibria

Punctuated Equilibria is the theory that there are long periods of no change broken up (or punctuated by) geologically short periods of rapid change. This theory is better supported by the fossil record.
Gradualism is when something happens... well, gradually. Punctuated equilibrium is when something doesn't change over a long period of time then suddenly changes. (Not meaning that punctuated equilibrium is that you see your cat one day, you go to sleep and then the next day your cat has grown fangs). Equilibrium basically means calm, and punctuated means that it's broken. So the calm, unchanging evolution is broken.

• gradualism: roughly constant gradual change over all time.
• punctuated equilibrium: long periods of time with little or no change, separated by short periods of time of large dramatic changes.

Answer 4

Punctuated equilibrium is a long period of no changes in an organism, followed by a period of many changes at once, very quickly. Gradualism is the idea that slow changes are always taking place.

Answer 5

Gradualism is the word used to indicate a more or less uniform rate of divergence. Punctuated equilibrium indicates an extremely variable rate of morphological divergence, to the extent that populations can develop significantly divergent morphologies over the course of only a few thousand generations. They are alike in that they are both gradual.

Answer 6

They are the same by long periods of little change,change over time,evolution takes place,occurs in small and large populations. Punctuated equilibrium- short periods of rapid change,new specied made quick. Gradualism-slow change over time,slow and steady,little change in structure.

Answer 7

• Gradualism is when evolution occurs slowley but steadily. Punctuated equilibria is when species evolve during short periods of quick changes.

Answer 8

Gradualism is when species gradually or slowly change over time. Punctuated equilibrium is when species evolve abruptly over time.

Answer 9

Look in your science book