Evidence of Evolution
When similarities in development of embryos show vertebrate animals have all evolved from a common ancestor.
What is embryological development?
Starlings produce an average of five eggs in each clutch. If there are more than five, the parents cannot adequately feed the young. If there are fewer than five, predators may destroy the entire clutch. As a result, five eggs becomes the most common clutch size.
What is stabilizing selection?
When two populations are kept separate by a river.
What is geographic isolation?
In peacocks, some have bright feathers and some have dull feathers. The females like bright feathers better. Foxes hunt nearby and peacocks are their favorite meal. Over many generations, most peacocks have bright tail feathers. Identify the variations that exist in this population.
What are bright feathers and dull feathers?
The evolution of a new species from an existing species.
What is speciation?
Hip bones in whales, leg bones in snakes, and wings on a penguin are all examples of this.
What are vestigial organs?
Frogs with longer tongues are able to catch more food. Frogs with short tongues can't catch as much food and don't usually survive.
What is directional selection.
When male fireflies signal to female fireflies flash their lights in specific patterns.
What is behavioral isolation?
Tree frogs can have large or small toe pads to give them grip when climbing trees. Snakes will eat some of the tree frogs, but those with large toe pads can escape quicker. Identify the more favorable variation.
What is large toe pads?
Giraffes that have longer necks survive a dry season by eating leaves from the tops of trees. Those giraffes breed more successfully that year. This is an example of
What is Natural Selection
This evidence comes from Earth's crust. It is the timeline of past life, organized by estimated ages and classified by similarities in form.
Light colored oysters blend in with the sand in the shallow water and dark colored oysters blend into the shadows in dark water. Medium colored oysters show up against both backgrounds.
What is disruptive selection.
When a Great Dane and a Chihuahua would not reproduce due to significantly different sizes of reproductive organs
What is mechanical isolation?
In peacocks, some have bright feathers and some have dull feathers. The females like bright feathers better. Foxes hunt nearby and peacocks are their favorite meal. Over many generations, most peacocks have bright tail feathers. Identify the more favorable variation.
What are bright feathers?
When an organism has achieved reproductive success and this reflects how well an organism is adapted to its environment.
What is fitness?
There are features that are very similar in many species. They are similar structures with different functions.
Homologous Structures
A population of birds with various size beaks eats seeds. Small seeds can be eaten by birds with small beaks. Larger, thicker seeds can only be eaten by birds with larger, thicker beaks. During a drought, only large thick seeds exist so only the large, thick-beaked birds survive.
What is directional selection?
When 2 species of frogs live in the same area, but one species only reproduces from January to March, and the other only reproduces from April to June.
What is temporal isolation?
Tree frogs can have large or small toe pads to give them grip when climbing trees. Snakes will eat some of the tree frogs, but those with large toe pads can escape quicker. Identify how the population is expected to change over time.
What is most of the tree frogs would have large toe pads?
The total of all the alleles of all the genes in a population.
What is the gene pool?
When different organisms can evolve similar adaptations for the same environment.
What is analogous structures?
Small lizards have difficulty defending territories so they end up dying out. Large lizards are more likely to be preyed upon by owls. Over time, only medium sized lizards end up surviving.
What is stabilizing selection?
When the chromosome numbers do not match up.
What is postzygotic barriers?
In peacocks, some have bright feathers and some have dull feathers. The females like bright feathers better. Foxes hunt nearby and peacocks are their favorite meal. Over many generations, most peacocks have bright tail feathers. Identify how the population will change over time.
What is most of the peacocks will have bright tail feathers, and few will have dull tail feathers?
When many individuals in a population are killed, the surviving individuals may have a very different allele frequency (typically less variation) than the original population.
What is the bottleneck effect?