1. what is the difference between punctuated equilibrium and gradualism

How did the tiger get its stripes: gradualism or punctuated equilibrium? We don't know whether the tiger got its stripes through gradualism or punctuated equilibrium, but in order to explain both concepts, here is how it could have happened through each. Let's assume that stripes are helpful because they help the tiger to camouflage, blend in with the tall grasses where it lives, so that it can sneak up on its prey what it eats and not be noticed.

Gradualism: A long time ago, there were a lot of tiger-like animals, but without stripes. Most of them were unmarked, but a few had light markings and color variation in their fur. These few blended in with the tall grasses a little bit better, so they were generally able to catch more food, and fewer of the marked than unmarked ones died of hunger, so more of them were able to reproduce. In the next generation, more animals were marked than in the previous generation.

Of those that were marked, some had more, some less, and some the same amount of marks than in the previous generation. Also, the marks were more, less, or the same amount clearly defined. Again, the ones with marks did better than the ones without, and the ones with more, clearly defined marks did better than the ones with fewer or fainter marks. Very gradually, over many, many generations, stripes over the tigers' whole bodies formed and appeared in the whole population, because the tigers that survived in each generation were those whose marks were most clear and contrasted most with the rest of the fur, and those that covered the most area on the bodies of the tigers.

Punctuated equilibrium: A long time ago, there were a lot of tiger-like animals, but without stripes. One time, a mutation occurred in a few of the animals, causing a huge change: they were born with stripes! This was so helpful to survival that out of the whole population, none or almost none of those with stripes died of hunger. Proponents of punctuated equilibrium point out that there are many missing links in the fossil record.

If gradualism is the correct model for the rate of evolution, they argue, there should be fossil records that show evidence of slow, gradual change. Those links never really existed, to begin with, say the proponents of punctuated equilibrium, so that removes the issue of missing links in evolution.

Darwin also pointed to fossil evidence that showed slight changes in the body structure of the species over time, often leading to vestigial structures. Of course, the fossil record is incomplete, leading to the problem of the missing links. Currently, neither hypothesis is considered more accurate.

More evidence will be needed before gradualism or punctuated equilibrium is declared the actual mechanism for the rate of evolution. Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights. Measure content performance.

Develop and improve products. Furthermore, gradualism helps to select better variations to the environment while punctuated equilibrium emphasizes consistent and cumulative changes to the species. Gradualism and punctuated equilibrium are two phenomena that bring variations to a particular species during evolution. What is Gradualism — Definition, Facts, Importance 2. Gradualism is the slow, steady changes of a particular species.

Here, the selection and variation occur more gradually. Hence, gradualism takes a long period of time and the changes are hard to notice within a short period of time. In brief, the population changes over a long period of time while the changes are slow, constant, and consistent. Figure 1: Gradualism and Punctuated Equilibrium. Gradualism is the basis of the classic Neo Darwinism and it is also called uniformitarianism.

It assumes that the tree of life starts with a one-celled organism, which increases its complexity to form modern life forms gradually. But, fossil records do not support this concept of emerging from small, gradual changes.