Genetic Drift
More common in which populations?
Small populations
What am I?
Survival and reproduction of individuals with advantageous traits.
Survival of the fittest
As a result of punctuated equilibrium, the layers of rock may have an inappropriate distribution of ________.
fossils.
What is speciation?
One population diverges and evolves independently into a new species.
What is evolution?
Change in phenotypes over time due to variations of allelic frequency
This phenomenon occurs due to what?
Define fitness
The ability to survive and reproduce
A comparison of the entire human and chimpanzee genome, however, indicates that segments of DNA have also been deleted, duplicated over and over, or inserted from one part of the genome into another. When these differences are counted, there is an additional 4 to 5% distinction between the human and chimpanzee genomes.
What type of evolutionary evidence is this?
Biochemical Evidence
What drives speciation?
Reproductive isolation
The Hardy-Weinberg equilibrium is a mathematical model for detecting evolution. If a population meets five conditions evolution is NOT occurring. What are these conditions and how do they help us detect evolution?
1. Very large population
2. No gene flow (emigration or immigration)
3. Random mating
4. NO natural selection
5. NO mutations
If a populations allelic frequencies are different than the expected than evolution IS occurring in the population.
A random change due to "sampling error" in selecting the alleles for the next generation from the gene pool of the current generation. Smaller populations are effected more strongly by this.
Genetic drift
What are the key principles to Darwin's theory of evolution?
Variation, Overproduction, Competition, Natural Selection, and Descent with Modification
An ostrich and an emu both have wings. However, both are flightless birds and use their strong powerful legs for their main mode of movement and defense. Their wings show common ancestry with birds with flight.
What do these wings represent?
Vestigial structures
Three species of orchids live in the same area. They bloom for only one day each on different days.
What type of reproductive isolation is this?
Temporal isolation
Cephalopods, like octopuses, and vertebrate mammals such as humans both have complex eyes with excellent vision. Explain this phenomena despite completely different evolutionary environments.
Convergent evolution applied similar selective pressures to cephalopods and vertebrate mammals.
Selective crossbreeding of purebred animals will increase the frequency of rare mutations, or alleles, which may cause diseases. This is similar to a natural effect found in nature when a small population breaks off and breeds.
What is this natural phenomenon?
Natural Selection does not always make species stronger and faster. What does natural selection act on?
Pre-existing advantages traits in a population that are heritable.
A technique used to determine the age of materials by measuring the decay of naturally occurring radioactive isotopes within them and comparing the amount of the original radioactive element to the amount of its stable decay product which accumulates at a known constant rate over time.
Radioactive Dating
Male fireflies of a variety of species signal to their female counterparts by flashing their lights in specific patterns. Females will only respond to the signals flashed by their own species.
What type of reproductive isolation is this?
Behavioral isolation
A phylogenetic tree can be used to trace evolution back to the last universal common ancestor. What is most common way phylogenies are used by biologists?
To compare species based on their evolutionary history and common ancestors
Due to an event a millennia ago, a small population of cheetahs became severely inbred and resulted low genetic variation. Despite increasing the population since they are still facing extinction because of this event and the rapid reduction of the population.
Explain what kind of event happened?
Bottleneck effect
Lamarck proposed that individuals can evolve by acquiring traits and passing them down to their offspring. This is false. Darwin proposed populations show descent with modification instead.
What is descent with modification?
Traits and other features of populations change over time from generation to generation. These modifications occur relatively slowly and small incremental changes add up over many generations. This leads to the emergence of new species.
Charles Lyell was a geologist that said Earths features had to have been formed through slow and continuous processes. Current paleontologists can use stratigraphic columns to date fossils based on their depth and location in the rock.
What dating technique is this?
Relative dating
What type of evolution is defined similarly to speciation and what evidence confirms this?
Divergent Evolution and Homologous structures
BT Corn is genetically modified to be resistant to pests like the European corn borer. When the pest feeds on the corn the natural pesticide produced kills the bug. Surviving bugs reproduce and slowly increase the resistant population. What type of evolution is this?
Microevolution