evolution Flashcards
Define evolution.
The process of organisms developing different traits to be better suited for their environment
Who was responsible for adopting the theory of evolution?
Charles Darwin
The first piece of evidence of evolution is direct observation (modern-day examples of evolution). We discussed many examples of modern-day evolution. Briefly describe what you learned about each:
Insecticide resistance
Bed bugs have become more susceptible to many of our pesticides
MRSA
Bacteria that is susceptible to antibiotics
Bajau people
Larger spleen size
Andes people
Produce more red blood cells so they can pack more oxygen carrying hemoglobin into their blood
Himalayan people
Breathe more rapidly
Lactose persistence
Small pockets of areas that are lactose tolerant, started in northern europe
Peppered moth
Color of the moth let it blend into the environment better
Describe the Galapagos Islands (why is life there so diverse?)
Each island has a slightly different climate due to the variations in elevation. Has a wide range of organisms living on the islands.
Why were Darwin’s ideas so controversial at the time?
Went against the norms beliefs and the bible
What did James Hutton propose? What did Charles Lyell propose?
James: Earth has been slowly shaped by geological processes over millions of years, forces under the surface move up rocks to form mountains, rocks and mountains and valleys are shaped by rain, wind, and temperature, happens slowly, so earth must be millions of years old.
Charles: Geological processes that shaped earth are still happening today, erosion, volcanic eruptions
How did the above scientists help shape Darwin’s theory?
If the earth could change so could life, it would takes many years but it was only possible because of the earth’s age
Describe AND give an example of each of Jean Baptiste Lamarck’s 3 hypotheses about how and why organisms evolve.
Use and disuse, use new organisms or stop using old ones
Inheritance of acquired traits: modifications the organisms acquire during its lifetime can pass that traits on to a offspring.
tendency towards perfection: organisms can force new traits to help them become more effective
Why do we study Lamarck’s ideas if they are flawed?
First person to bring up the fact that organisms change, changed the mind set
Describe struggle for existence.
Organisms struggle to survive when they are competing for the same resources.
Briefly describe what natural selection is.
Populations change over time because individuals who inherit traits best suited for the environment leave more offspring than less effective populations
Other than direct observation, what are other pieces of evidence supporting evolution?
Fossil record, early emroptic structures, homologous & analogous structures, biogeography, DNA
What are homologous structures? Give an example
Common ancestor, different purposes, Bat and human
What are analogous structures? Give an example.
Not common ancestors, same purpose, insect and a bird
What are vestigial organs? Give 3 examples (what they used to do and why we don’t need them anymore). Why do we still have vestigial organs today if they are not useful anymore?
Appendix: digest cellulose, we no longer eat cellulose
Body hair: the keep us warm, we have better clothes now
Tail bone: to help keep balance when climbing, we don’t climb trees for food
They don’t harm us or cause any type of destruction to the fitness of us
What is convergent evolution? Give an example.
Organisms in different parts of the world, but the environments are similar, so organisms evolve the same way, not related,
What is divergent evolution? Give an example.
Started as the same species, but branch out into new species, once related
- For a species to evolve into two (or more) new species, the _____of the two populations must become separated.
Gene pool
Describe how 13 different species of finches throughout the Galapagos Islands distributed from a common ancestry in mainland South America. Hint: There are five steps.
Founders arrive from south america
Geographic isolation results
Changes in the gene pool
reproductive isolation occurs
Continued evolution produces more species
Define species.
Organisms that are so closely related that they will breed and produce a fetal offspring
What are the 3 ways that reproductive isolation happens? For each, define and give an example.
Behavioral: Differences with courtship rituals, bird calls
Geographic: separated by mountains or rivers
Temporal: reproducing times are different, flowers blooming seasons
Define gene pool.
Genes and their alleles found in a population
What does allele frequency mean?
The amount of times a certain allele appears in a population
What are the 3 sources of genetic variation, and for each a) define, and b) give an example
Mutations: a heritable change in the DNA sequence, Sun UV rays can cause skin cancer
Genetic Recombination: Crossing over in prophase 1
Lateral gene transfer: genes pass to a individual that is not a parent or offspring, bacteria can have a conjugation
Differentiate between single gene traits and polygenic traits and give an example of each.
Single: one gene, 2 phenotypes, simple, pea plants
Polygenic: many genes, variety of phenotypes, complex, blood type
Define phylogeny.
The study of the evolutionary history of lineages of organisms
What is a clade?
The groups of organisms that have common ancestors
True or false - In general, the more derived genetic characters two species share, the more recently they shared a common ancestor and the more closely they are related in evolutionary terms.
True
