Lesson 1: Introduction to Evolutionary Biology Flashcards
The Origin of Species: The Beak of the Finch (Video):
How many species of finches were found in Galapagos Island?
13
The Origin of Species: The Beak of the Finch (Video):
What small island did the scientists study?
Daphne Major, Galapagos Island
The Origin of Species: The Beak of the Finch (Video):
What finch have a needle-like beak for picking off insects?
Warbler finch
The Origin of Species: The Beak of the Finch (Video):
What finch has a bust beak and eat beetle and termite larvae?
Woodpecker finch
The Origin of Species: The Beak of the Finch (Video):
What finch has a longer and sharp-pointed beak
and feed on cactus flowers?
Cactus finch
The Origin of Species: The Beak of the Finch (Video):
What did they find out about the finches based on the DNA evidence?
All of the finches in the island are more related to each other than the mainland.
- Only one species went to the Galapagos and diversified there.
- Species come from one common ancestor
The Origin of Species: The Beak of the Finch (Video):
What happened in the extreme drought in 1978?
- Medium-ground finches compete for scarce food resources
- Birds with the smallest beaks are vulnerable and over a year they die.
- The larger the beak the higher the chance of surviving the drought.
- Their offspring have larger beaks than the last generation.
The Origin of Species: The Beak of the Finch (Video):
What happened in the El Nino in 1983?
- the strong El Nino brought 10 times more rain than normal
- Larger seeds became scarce.
- Birds with larger beaks have difficulty finding food.
- Birds with small beaks survived more and their offspring inherited small beaks.
The Origin of Species: The Beak of the Finch (Video):
How do finches with different beaks become different species?
- Different species, different mating songs.
–>The same species only responds to songs from the same species
-Males mate with females with similar sizes and beaks.
The Origin of Species: The Beak of the Finch (Video):
What are the keys to the evolution of the Galapagos finches?
Geography and ecology
- causes AIDS
- determined in 1989
- Retrovirus with two single-strand RNA genomes
Human immunodeficiency virus (HIV)
Two distinct HIVs that infect humans. Which caused the pandemic?
- HIV-1 and HIV-2
- HIV-1
Both HIVs are __, a group of retroviruses that infect diverse mammals.
lentiviruses
HIV: In monkeys and other primates, the viruses are called __, or __.
- simian immunodeficiency viruses
- SIVs
HIV-2 recently evolved from an SIV carried by __
sooty mangabey (Cercopithecus atys)
HIV-1 evolved from SIVcpz, the virus that infects __
wild chimpanzees (Pan troglodytes)
Causes of Antimicrobial (Drug) Resistance: Natural (Biological) Causes
- genetic mutation
- gene transfer
flow of genetic mutation
non-resistant bacteria exist
–> bacteria multiply by the billions (a few of these bacteria will mutate)
–> some mutations make the bacterium drug resistant (they survive in the presence of drugs)
–> drug resistant bacteria multiply and thrive.
flow of gene transfer
resistant and non-resistant bacteria exist
–> bacterium multiply by the billions (drug-resistant bacteria may transfer a copy of its genes to other bacteria)
–> non-resistant bacteria receives new DNA
–>drug resistant bacteria multiply and thrive.
Evolutionary biology is concerned with explaining and understanding the diversity of living things and their characteristics. What questions does it answer?
- What has been the history that produced this diversity?
- What have been the causes of this history?
Extends and amplifies the explanation of biological phenomena
Evolutionary biology
Evolutionary biology complement __ (immediate, mechanical causes) of biological phenomena with the __ of those phenomena (their historical causes, especially the action of natural selection).
- proximate causes
- ultimate causes
Quote of Theodosius Dobzhansky (1900-1975)
“Nothing in Biology Makes Sense except in the light of Evolution”
evolution is the increase in fitness over time due to __, or __
- natural selection
- adaptation
evolution is the accumulation of __, which alter fitness over time
mutations
evolution is the change in __ (or the heritable expression of those alleles) in a __ across generations
- allele frequencies
- population
evolution is the progression into more __ forms of life
complex
evolution is the change in __ of genetically different individuals at each generation
proportions
evolution is leading to an average change in characteristics of populations over time → change in allele frequencies (__) or the heritable change in the expression of those alleles (__)
- genetic composition
- epigenetic inheritance
evolution is the acts by removing individuals from the population, or by allowing some to __
leave more offspring
Although, even if allele frequencies in a population remain the same across generations, a population is evolving if it goes out of __ → __ should follow HW expectations, given the allele frequencies.
- Hardy-Weinberg Equilibrium
- genotype frequencies
5 major mechanisms of evolution
- genetic drift
- mutation
- Heritable Epigenetic Modification
- Migration
- Natural Selection
totally random changes in allele frequency from generation to generation
genetic drift
changes in the genetic code, such as errors in DNA replication, gene deletions or duplications, etc.
mutations
heritable changes that are not due to changes in the DNA sequence itself, but the expression of the DNA, such as changes in DNA methylation and histone modifications, etc.
> > changes “epi-alleles” not the genetic code (actual alleles)
Epigenetic Inheritance
alleles moving from one population to another
gene flow
when some alleles favored over others due to an increase in fitness (not random); acts on genetic variation in the population
natural selection
Sources of Genetic Variation
- Mutation generates genetic variation
- Epigenetic Inheritance changes expression of genes
- Genetic Drift reduces genetic variation
__ acts on genetic or epigenetic variation in a population.
Without genetic or epigenetic variation, this* cannot occur
Natural selection
Some aspects of biology where evolutionary concepts permeate
Biotechnology
Agriculture
Medicine
Conservation
Many of our food is a product of intense __or __.
- artificial selection
- human-induced evolution
Modified genetics of wild cabbage:
Selection for terminal buds
Cabbage
Modified genetics of wild cabbage:
Selection for lateral buds
Brussels sprouts
Modified genetics of wild cabbage:
Selection for stem
Kohlrabi
Modified genetics of wild cabbage:
Selection for leaves
Kale
Modified genetics of wild cabbage:
Selection for stems and flowers
Broccoli
Modified genetics of wild cabbage:
Selection for flower clusters
Cauliflower
