Evolution Test Flashcards
Which of Lamarck’s ideas turned out to be true?
Lamarck believed that life had changed gradually over time.
What did Darwin propose to be the “mechanism of evolution”?
Darwin believed that any inheritable variation that improves an individual’s ability to survive and reproduce will tend to be passed on to the next generation.
Why is variation essential to evolution?
Without variation, there would be no changes in a population. Without these changes, there would be no changing over time, because nothing would have ever changed.
What defines the fitness of an organism in evolutionary terms?
It’s ability to survive and reproduce.
In what sense is evolution more of an “editing” process, rather than a “creating” process?
Evolution does not create new organisms, but gradually affects the organisms that already exists.
What are the 5 categories of evidence for evolution?
Biogeography, comparative embryology, the fossil record, molecular biology, and comparative anatomy.
What are homologous structures?
Homologous structures are similar structures in different organisms that serve different functions. For example, the human forearm and the bat wing are homologous structures.
What factors could cause a shift in the allele frequency for a gene in a certain population?
The Founder effect and Bottleneck effect could cause genetic drift.
What are the four types of natural selection?
Directional, stabilizing, sexual, and disruptive.
What is the principle of Hardy-Weinberg equilibrium?
That none of the agents of change for microevolution affect a population, therefore the relative frequencies of alleles will never change
.
What is the Founder effect?
That migration and establishment of a new colony will change the relative frequencies of alleles.
What is the Bottleneck effect?
That a national disaster (or something of that nature) can decrease an overall population, and change the relative frequency.
What is Gene Flow?
The gain or loss of alleles from movement of individuals into or out of a population.
What are the 5 agents of change for microevolution?
Natural selection, DNA mutations, Genetic drift, Gene flow, and Non-random mating.
What is reproductive isolation?
That only organisms within a species can reproduce,
In Lamarck’s opinion, how would evolution occur?
Over an organism’s lifetime, the use and disuse of different organs and the acquiring of different traits would then be passed on to their offspring. The organisms would then, over time, try to aim towards both complexity and perfection.
What has to happen for speciation to occur?
The gene pool of a population has to separate and become isolated.
How do the gene pools of different species maintain separate?
There are usually geographic barriers (like a canyon, or a river) between them.
What is the name of a species formed do to a geographic barrier?
An “Allopatric” species.
What are the two categories of reproductive barriers?
Post-zygotic and pre-zygotic barriers.
What is the difference between post-zygotic and pre-zygotic barriers?
Pre-zygotic barriers prevent the formation of the zygote, and post-zygotic occurs after formation of the zygote.
What are the 5 categories of pre-zygotic barriers?
Temporal, habitat, behaviorial, mechanical, and gametic.
