Evolution Biology Test Review Flashcards
No matter how many times organisms in a species’ tails’ are clipped, their offspring always have normal tails. What is this disproving?
Inheritance of acquired characteristics
Darwin’s theory of evolution did not include the theory that
genetic variation comes from mutations and genetic recombination during sexual reproduction
Lamarck believed in the theory of
Inheritance of acquired characteristics
Natural selection is
survival of those organisms genetically best adapted to their environment
Over time, giraffes’ average neck lengths have increased. What would Lamarck believe this is caused by?
giraffes stretched their necks and their offspring inherited the new trait
Pigs have four toes on each foot, but two of them are small and don’t help the pig walk. How would Lamarck have explained this?
Use and disuse
Weisman’s experiments with mice disproved
Lamarck’s theory of inheritance of acquired characteristics
Gene pool definition
The sum total of all the alleles found in all the individuals of a population
Evolution definition
Change in allele frequency within a population
5 conditions for Hardy Weinburg equilibrium
1) random mating, 2) no migration, 3) no mutation, 4) large population, 5) no natural selection
Genetic drift definition
Chance events that happen in a small population will create the
potential for rapid evolution that may isolate a population genetically
Founder effect
the reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population
Bottleneck effect
when a population is greatly reduced in size, limiting the genetic diversity of the species
why would a small population evolve faster than a large population?
Fewer alleles- easier to alter frequencies
Another name for migration?
Gene flow
What is speciation?
the formation of new and distinct species in the course of evolution
What are the 5 causes of speciation?
1) geographical isolation, 2) behavioral isolation, 3) temporal isolation, 4) mechanical isolation, 5) ecological isolation
Adaptive radiation definition
One ancestral species (often a “pioneer species”) that gradually splits into multiple
species, due to the opening of many available niches
Homologous structures definition
similar physical features in organisms that share a common ancestor, but the features serve completely different functions
Analogous structures definition
When two species have evolved body forms that attempt to solve the same problem, they often look somewhat similar. But these structures do NOT indicate a
recent common ancestor
Gradualism definition
evolutionary change occurs slowly and in small steps
Punctuated equilibrium definition
the view that many evolutionary changes occur
(relatively) quickly
Lamarck’s theory of evolution
Lamarck thought that if a certain characteristic was needed to survive in an environment it would be developed by those organisms. Also, as the trait was used more it would tend to become stronger or enhanced, and that these “Acquired Characteristics” would be passed down to their offspring
