Population Genetics Flashcards
Who is carl linneas what did he develop?
- He dveloped a system to organize living things based on traits and shape
- He also created a heiarchial system where organisms are grouped based on shared characteristcs.
Why is the carls system important
How does it help scientist with organisms
What does it standardize?
- It helps scientists classify and study organisms
- Shows evolutionary relationships between species
- Standadarized scientific names
Who is Charles darwin what did he introduce? Decent with what?
- Introduced the idea of decent with modification
What is a phylogenetic tree? What does it contain?
- It is a family tree for species
- It shows how organisms are related and how they evolved from common ancestors
What do the branches mean on a phylogenetic tree?
- Different species evolving over timer
ex; humans and fish areon faster branches
What do the closer branches mean
- a closer related species.
ex; Monkeys and humans ar on closer branches
Why are phylogenetic trees important?
- they explain how life change/es over time\
- help study evolution
- shows how everything is connected
What is it with darwin and natural selection? (PDV)
- wanted to explain how species change over time due to natural selection
- Pre existing Heitable variation
- Differential repordcution
- Variable environments and selction
What is pre-existing heritable variation
Is everyone the same ?
Where are the traits inherited from?
What is an example with giraffes?
- idv in a pop aren’t identical they are genetically different
- traits inherited from parents
ex; some giraffes have longer necks than others
What is differential reproduction?
What is limited?
What is up with traits?
Born vs survive?
- More orgs born than can survive
- limited space, food, and resource which makes competition
- some have traits that allow them to survive better
What is variable envrioments and selection
Different enviroments favor different traits
- over time, pop adapts to their new environment
What is the key takeaway of Darwin’s theme of natural selection?
What can it eventually lead too?
What does the environment choose?
- species change due to natural selection
- environment chooses which traits are beneficial
- can eventually lead to new species
How many people DON’T belive in evolution
53 percent of people in america do not believe in evolution.
What the hell are conserved genes? Why do they do what they do
- genes that stay the same across different species.
- They are essential for life
What is an example of conserved genes? ( flies and mice)
- flies and mice
- they both have genes that control body segmentation ( how their bodies
Why are conserved genes important or matter?
- Conserved genes are important because it show how life is connected through evolution
- Study human genes using animals like flies and mice
What is the basis for heritability?
- It shows how traits are passed from parents to off springs through genes.
What is modern synthesis?
Modernsynthesis combines dawrins theory of natural selction with mendalian genetics
What does natural selection on phenotypes with a genetic basis show?
- natural variation in traits ( fur, color, and height)
- traits come with different alleles of genes
How does allelic variation drive evolution?
- if a peppered mothes.dark colored moth survives in environments more than a light color moth, the entire population will eventually become dark colored.
What is a gene pool?
- sum of all alleles in a population
- includes every version of a gene present in that population
What is a population
- a group of individuals that can mate and produce fertil of spring
What is allele frequency?
- how often an allele appears in the gene pool
What affects allele frequency?
- Adaptive processes and non adaptive processes
What are some non adaptive processes that affect allele frequency
- mutation
- gene flow
- genetic drift
What are some adaptive processes that affect allele frequency
- Natural selection
- Artificial selection
What is positive selection?
- when allele helps survival or reproduction
what are the three modes of natural selection?
- Positive , negative, balancing selections
What is negative selection
When an allele reduces fitness, it is removed from the population
What is balancing selection
- when both allele are kept in the population bc they provide benefit under certain conditions
ex; heterozygous sickle cell trait and malaria
How does positive and negative selction work with plants and animals
( think of cows that produce milk versus the cows that don’t)
Positive:
- famers select big kernels from corn leading to modern corn teosinte
- wolves with friendly traid bred into dogs
Negative:
- cows with low milk production are not used fro breeding
- Wheat drops seded easily but famers selected wheat that holds onto seed so harvesting can be easier.
How would the bottleneck effect affect the sickle cell trait?
- if a small pop with the trait moves to a new location without malaria, the allele can potentially disappear
What principals does human evolution follow?
- the same
- natural selection, genetic drift, and gene flow
What are some examples of the principles that apply to human evolution? what is the advantage? ( milk)
- lactase persistance
- Humans lost ability after childhood, but a mutation appeared in some people allowing lactase persistence to persist into adulthood
- Advantage is that the communities that relied on dairy the mutation was positively selected bc milk provided nutrients during food shortages.
is the everyone was black thing natural selection
- yes it was natural selection
- natural uv
- able to survive in hotter environments
- less skin cancer
amish niggas
- small and isolated
- marry within their community a lot of mutations
