Unit 7: Natural Selection (copy)

________ can occur between different populations of the same species if individuals migrate.

________ and Harold Urey simulated the conditions of primitive Earth in a laboratory.

________ called phylogenetic trees, or cladograms, are used to study relationships between organisms.

Stabilizing selection means that organisms in a population with ________ are eliminated.

________ is a change in a population over time.

________ is defined in terms of populations but occurs in terms of individuals.

________ based on biotic and abiotic factors; different genetic variations can be selected for in different generations.

________ is measured by reproductive success.

________ is the process by which two unrelated and dissimilar species come to have similar traits, often because they have been exposed to similar selective pressures.

________ are often drawn with even spacing between species, but phylogenetic trees are often drawn with different distances between species and as a result they look more like a tree with uneven branches.

________ and abiotic factors can affect the direction of evolution.

________, or the study of the anatomy of various animals: scientists discovered that some animals have similar structures that serve different functions.

________ that occurs quickly after a period of stasis is called punctuated equilibrium.

The ________, or those with the most favorable traits, are the most likely to survive and therefore produce a second generation.

As long as a mutation does not kill an organism before it reproduces it may be passed on to the ________.

The ________ states that even with all the shuffling of genes that goes on, the relative frequencies of genotypes in a population are constant over time.

If the population is small, the population will be more susceptible to random ________ than if the population is large.

A(n) ________ is related to the inability of a hybrid organism to produce offspring.

If mutations are present in a population, new alleles will be introduced into the population and hence ________ will be disturbed.

________ of the fittest is the name of the game, and any trait that causes an individual to reproduce better gives that individual evolutionary fitness.

________ simply means that a population becomes separated from the rest of the species by a geographic barrier so the two populations cant interbreed.

Some ________ is the common ancestor to all life.

________ is something that causes a change in the genetics of a population, but it is not natural selection.

________: The most compelling proof of all is the similarity at the molecular level.

________ is the very foundation of evolution.

________ are built using data from the fossil record or molecular record.

________ requires genetic variation and an environmental pressure.

________ occurs only if some individuals have more evolutionary fitness and can be selected.

If there is ________, organisms better adapted to their environment will be more likely to survive and reproduce, and thus their alleles will be preferentially propagated to the next generation.

paleontology revealed the various organisms and the major lines of evolution

scientists found related species in widely separated regions of the world

All the vertebrates-including fish, amphibians, reptiles, birds, and even mammals such as humans-show fishlike features called gill slits

scientists discovered that some animals have similar structures that serve different functions

The most compelling proof of all is the similarity at the molecular level

Evolution is constantly occurring