Evolution Flashcards
Q: Cornerstone of modern biology?
Evolution.
Q: Mechanism driving evolution? How does it work?
-Natural selection is the mechanism that drives evolution.
-Random genetic mutations increase genetic diversity.
-Advantageous mutations result in the survival of the fittest.
-As a result, species adapt to (changing) environments.
Q: Evidence for evolution?
-Progressions of species changing over time (fossil record shows progression from simple to more complex and specialized organisms over time).
-Similarities between species showing common ancestry.
-Anatomy, e.g., remnants of past generations within species.
-Embryology, e.g., all vertebrate embryos, including humans, exhibit gill slits at some point in early development.
-Biogeography
-DNA analysis
Q: Only evolutionary process that leads to adaptations?
Natural selection
Q: Adaptive radiation
-process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment opens up new niches, making new resources available, creating new challenges.
-e.g., diversified lemur species in Madagascar
-often follows mass extinctions
Q: Does evolution favor generalization or specialization?
Specialization.
There’s a tendency for life forms to fill all available niches.
Specialization often confers an advantage upon a species in its struggle for existence.
Specialization may subdivide a single niche into many new niches.
Q: Advantages/disadvantages of specialists and generalists?
-Specialists thrive when conditions are just right. They fulfill a niche and are very effective at competing with other organisms.
-Generalists respond much better to changes/uncertainty. These species usually survive for very long periods because they deal with unanticipated risks better. But unlike specialists, they don’t maximize their current environment, because they don’t fill a niche where they could be more successful.
-An environment with more competition breeds more specialists. Rainforests have huge diversity and competition and therefore many specialist species.
Q: Analogous structures
similar structures that evolved independently in two living organisms to serve the same purpose.
Q: Biodiversity
Is the variety and variability of flora and fauna on earth.
Q: Biological evolution
any genetic change in a population that is inherited over several generations. These changes may be small or large, noticeable or not so noticeable.
Q: Coevolution
The process of reciprocal evolutionary change that occurs between pairs of species or among groups of species as they interact with one another; two (or more) species reciprocally affect each other’s evolution; the evolutionary change of one species triggered by interaction with another species.
Q: Convergent evolution
unrelated species can develop similar traits as the process of natural selection results in the same solution to a similar problem.
Q: Is extinction natural?
Gradual rates of extinction are natural but rapid rates of extinction are not.
Q: Genetic diversity
the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary.
Q: Genetic drift
a change in the number of times you might see a certain trait in a population due to chance or random events.
Q: Homology
the existence of shared ancestry between a pair of structures, or genes, in different species.
Q: Natural selection
Concept that individuals with mutations resulting in specific attributes may be better suited to conditions in a particular habitat. These better suited individuals survive and reproduce, passing along such favorable traits to their offspring. Such traits become more pronounced over time with succeeding generations, ultimately leading to new sub-species or entirely new species.
Q: Speciation
The evolutionary process by which populations become distinct species. A lineage-splitting event that produces two or more separate species.
Happens when a subset gets isolated from the rest of the population and does not interbreed.
May occur due to geographic isolation or environmental changes.
Slow process, usually involves development of subspecies first.
Example: Madagascar island isolation -> large number of endemic species. E.g., lemurs.
Q: Species
a group of living organisms consisting of similar individuals capable of interbreeding.
Q: Vestigial
a feature of a species that is greatly reduced from the original ancestral form and is no longer functional or is of reduced or altered function.
