Flashcards in Evolution/Ecology Test Deck (42):
What are some exceptions to speciation and why?
Dogs and wolves because they can mate, same with horse and donkies, they make a mule. The mules are not fertile though.
What are some reasons speciation occurs?
Geographic or reproductive isolation.
What is gradualism?
The idea that speciation occurs at a regular, gradual rate.
What is puncuated equilibrium?
The idea that "bursts" of evolution can occur. Something may take thousands instead of millions of years.
What is sexual selection?
Where mating is not random in certain groups, when organisms with certain characteristics are more often selected as mates.
What is genetic drift?
Genetic drift provides random changes in the occurrence of genes through random events.
When does genetic drift take place?
When a few individuals of a population break off from the original group and start their own population.
What is another name for genetic drift?
The founder effect.
What is coevolution?
When two or more species have evolved adaptions to each other's influence.
What is an example of coevolution?
An animal evolving to avoid being eaten.
What is convergent evolution?
When the environment selects certain characteristics in animals.
Whay is divergent evolution?
When two or more related populations become more and more different.
What is adaptive radiation?
Related species evolving from a single ancestral species.
What is gene pool?
The total genetic information available in a population.
What is gene frequency?
The percentage of particular genes within a gene pool.
What is the hardy-weinburg genetic equilibrium?
Both scientists showed that genotype frequencies in a population tend to remain the same unless acted upon outside forces.
What is the failure of the hardy-weinberg law?
It is a sign that evolution is occurring.
What is emmigration?
The movement of organisms out of a group.
What is immigration?
The movement of organisms into a group.
What is speciation?
The creation of new species.
What is evolution?
An orderly succession of changes.
What is biological evolution?
The change of populations of organisms over generations.
What is an acquired trait?
A trait that is no determined by genes and arises during lifetime as a result of an organisms experience or behavior.
What was Lemarck's theory?
That acquired traits were passed onto offspring.
What is natural selection?
The fact that organsisms best suited for their environment reproduce more successfully than others.
What was darwins theory?
Darwin proposed a hypothesis that species were modified by natural selection.
What is descent with modification?
A theory of darwins that newer forms in the fossil record are modified descendents of older species.
What are transitional species?
A species which features that are intermediate between those of hypothesized ancestors and later descendant species.
What were darwins two main theories?
1. Descent with modification
2. Fossils of transitional species show evidence
What if the theory of modification by natural selection?
•States how evolution occurs
•Environment affects organisms
•If a trait is beneficial and inhertied, it will be passed on
•Organisms adapt to their environment as favorable genes are passed through generations
•A single organisms contribution to the next generation is called fitness and produces more offspring
What is the principle of superposition?
If layers of rock go undisturbed, the lower layers of rock are older than the top layers.
What is relative age?
Age of a fossil compared to the age of other fossils.
What is absolute age?
The numeric age of an object or event.
What is biogeography?
The study of geographical distribution of fossils and living organisms.
What is adaptation?
An inherited trait that improves chance of survival and reproduction.
What is the evidence of evolution?
What are homologous structures?
Structures that result from modifications
What are analogous structures?
Structures thay have evolved tk serve the same function but have different embryonic developmemt.
What are vestigial structures?
Structures that seem to serve no useful function.
How do fossils serve as evidence for evolution?
We can hae fossils so see what organisms from the past look like and conpare them from different points in time and see that they have evolved.
What is use/disuse in lemarcks theory?
If an organism uses a part of its body enough, it will develop/evolve, vice versa with not using it.