Catastrophism / Gradualism / Punctuated Equilibrium

What are the two causes of punctuated equilibrium?

-A huge and sudden catastrophic change in the environment as what was thought to have occurred causing the great extinctions seen in the fossil record -Random changes in the genetic code or mutations affecting a few individuals

How do scientists think that species that have been on Earth for a longer period of time showing longer evolution evolved?

Mostly by gradualism

How do scientists think that species that have been on Earth for a shorter period of time with shorter evolution evolved?

Mostly by punctuated equilibrium

Who created the Theory of Punctuated Equilibrium?

Niles and Gould

What does microevolution focus on?

Smaller groups of organisms living within well-defined habitats

What is population genetics?

A branch of microevolution that attempts to explain and predict changes in allele frequencies by using statistical models

What are small variations that fit an organism slightly better to its environment selected for in gradualism?

A few more individuals with more of the helpful traits survive, and a few more individuals with less of the healthy trait dies

What were each of the five major extinctions found in the fossil record followed by?

A rapid change in species' diversity

What does punctuated evolution use for one species to evolve traits so to fill the many different habitats?

Adaptive radiation

Why do the proportions of individuals in the populations who have the mutation/trait and those who don't change a lot over a very short period of time?

Because these mutations are so different and so helpful to the survival of those that have them

The big idea behind macroevolution is that of...

common descent; the proposition that all life descends from a single ancestor

What is the Theory of Gradualism?

selection and variation that happens more gradually

Change in gradualism is...

slow, constant, and consistent

What can the rapid genetic change in a population in punctuated equilibrium result in?

the evolution of a new species

What is microevolution concerned with?

Changes on the small scale, to include changes in the frequency of individual alleles within species and populations

Who created the Theory of Gradualism?

Charles Darwin

What does microevolution attempt to do?

Connect changes in the habitat with changes in the genetic makeup of the organisms living within it

What is macroevolution concerned with?

Evolution on the grand scale with the branching out of new species and larger groups, like families and phyla

What are the two ways in which the evolution of a species can occur?

Gradualism and punctuated equilibrium

Is gradualism easy or hard to notice over a short period of time?

Hard

The catastrophic change in the environment, which was one of the causes of punctuated evolution, is thought to be the results of __________?

Harsher natural selection

In punctuated equilibrium, how does change come?

In spurts

Mutations that result in punctuated equilibrium are very helpful to whom?

Individuals in their environments

What is the Theory of Punctuated Equilibrium?

It states that populations remain genetically stable for long periods of time, interrupted by brief periods of rapid genetic change

What do the sources of microevolutionary change include?

The five evolutionary forces: -mutation -natural selection -gene flow -genetic drift -nonrandom mating

What happened to the organisms that could not tolerate the change in the environment, which led to punctuated evolution?

They went extinct

Why would the species that survived the environmental change in punctuated evolution adapt?

To take advantage of the many habitats that were lacking competitors and to form a new species to take advantage of resources

What can the results of population genetics provide?

Useful insights into evolution on the small scale, over shorter periods of time

How do the traits of a population change in gradualism?

Very gradually (small genetic changes over a long period of time)

For gradualism and punctuated equilibrium, can a species evolve by both?

Yes. It can also evolve by only one