Science Exam 😒 Flashcards
What are the five conditions for hardy weinberg equilibrium
No types of selection, no mutation, no migration, large population, and random mating
What are the HW equations
p+q=1 and p^2 +2pq+q^2=1
What is p
Frequency of the dominant allele in the population
What is q
Frequency of the recessive allele in the population
What is p^2
Percentage of homozygous dominant individuals
What is q^2
Percentage of homozygous recessive individuals
What is 2pq
Percentage of heterozygous individuals
Cladistics
Method of classifying animals and plants according to the measurable characteristics they have in common
Clade
A group of organisms believed to have evolved from a common ancestor
Node
Point where cladogram branches off, a hypothetical ancestor
Root
Starting point of cladogram or the initial common ancestor
Sister group/taxa
Parts of a cladogram that branch off from a common node and are often considered closely related to
Branch
Lines of a cladogram
Derived characters
A trait/character that a species evolved to have and was passed on to its descendants
Most recent common ancestor
Most recent individual that all the organisms in the set are descended from
Outgroup taxa
A taxa outside the group
How to build a cladogram
Make a chart of organisms and traits, count how many traits the organisms have and how many times that trait occurs, graph lowest scoring taxon first and highest scoring trait first
How do homologous structures provide evidence for evolution
They indicate that species shared a common ancestor
How do vestigial structures provide evidence for evolution
Ancestors had the structures that served a purpose, but evolved them away because of natural selection
How do analogous structures provide evidence for evolution
Shows that animals evolved separately to have similar traits
How do fossils provide evidence for evolution
Fossil record and transitional forms can show how a species evolved and changes over time
How does embryonic development show evidence for evolution
Structures of development can be compared and give information about evolutionary relationships, species with similar development patterns are more closely related
How does direct observation provide evidence for evolution
Selection pressure and beneficial mutations and sometimes make evolution observable, eg rats mutated to have poison resistance
How does biogeography provide evidence for evolution
Unique specie in smaller/isolated show it has occurred, more closely related species are often found in the same geographical area which supports evolutions from a common ancestor
How does molecular evidence provide evidence for evolution
the presence of DNA in all living organisms suggests that we all evolved from a single common ancestor, genes between species can be compared to see how closely related they are
What is speciation
The process of forming a new species
What are prezygotic barriers
Barriers that occur before zygote formation
What are postzygotic barriers
Barriers that occur after zygote formation
What is allopathic speciation
When a species becomes geographically isolated and the populations evolve into two different species
What is sympatric speciation
When species evolves into two different species without isolstion
How can group behaviors help species survive
Protect from physical factors and predation, help get more food, more accuracy when migrating
What are some examples of group behaviors
Defensive behaviors, cooperative food gathering, group hunting, moving as a group
Group defensive bahviors
When a group of animals cooperates to defend against predators, this helps improve chances of survival, eg oxen form a defensive circle, protecting young and increasing chance of survival
Group hunting
When a group of animals work together to hunt other animals or groups, improves chances of success, eg when a pack of wolves hunts together
Cooperative food gathering
Ore efficient, increase chance of finding food/catching prey, eg dolphins cause fish to leap out of water, making them easier to catch
Moving as a group
Helps with migration by finding a more accurate direction, some larger groups can reduce travel time, eg migratory birds or other mammals
Parasitism
When a parasite exploits the resources of its host for its own benefit, harming the host
Mutualism
An intimate association between two species that benefits both
Commensalism
An association between two species in which the commensal benefits and other is unaffected
Competition
When species compete for the same resources, often food, which are dominated by the largest and most aggressive species
Predation
When one species kills and eats another
Amensalism
In which one organism is harmed and the other is unaffected
Herbivory
When an animal feeds off of a plant
Antibiosis
When one organism produces substances that harm another organism
How do adaptations allow species to survive
Adaptation can make a species more suited for its environment and provide advantages to the species, which helps it survive
How is adaptation evidence of evolution
Adaptations show how a species can change over time and can lead to evolution
What are a few examples of adaptation
- Rattlesnakes on Catalina island adapted to become more aggressive and develop a new social language and behavior to let larger animals know they are on the ground near them so they don’t get trampled
- Birds on the Galapagos evolved to have beak shapes suited for the food sources on their islands
