Unit 3 & 4: What Is Evolution? & Mendelian Inheritance Flashcards
Why is studying evolution so important?
In order to make predictions of what will happen, we must understand and study what has happened.
What causes variability among species?
The events of evolution lead to diversity among species.
What interaction does biological diversity reflect?
The forms that preceded them and the ongoing process of change.
What is our definition of evolution?
Change in allele frequencies (genotype) in a population over time.
T/F = Evolution is a theory for the origin of life.
F = Evolution is an explanation for how life has changed since its origin.
T/F = Selection can only operate on the available variations in a population.
T = Evolution does not give species traits needed for survival.
T/F = Bad genes may be maintained by mutation, gene flow, or the late effect onset.
T = Evolution does not progress species toward perfection by removing bad genes.
T/F = Variation from mutation is random but selection favors beneficial traits.
T = Life does not evolve only by random chance.
T/F = Evolution does not affect humans.
F = Humans continue to adapt.
T/F = Species are clear and easy to recognize.
F = Simple view of species as groups that can interbreed doesn’t always apply.
T/F = Usually slow but can also occur in rapid bursts.
T = Evolution is not slow and gradual.
What 4 elements can we use to study evolution?
- ) Genetics or inheritance
- ) Allele frequencies or genotype
- ) The large scale changes overtime - paleobiology
- ) Morphology or investigating evolutionary patterns and growth
What was the main finding of Cuvier?
He observed fossils and found that those organisms that once lived and left these bones behind no longer exist.
What was the main finding of Lyell?
The changes that occur of the landforms that were formed occurs very slowly and since the change is slow the Earth must be very old.
What was the main finding of Lamarckism?
The idea that the acquired traits of an organism are heritable and are passed on.
What did Malthus find?
Survival of the fittest - because the number of people is growing at a faster rate then the amount of food being made thus there is competition.
What is the relationship of the increase of food resources and population growth on a graph?
The amount of people increases geometrically or at a faster rate than the amount of food which increases arithmetically or less fast.
Why is the food resource increasing?
The food resources are increasing because the production of food continues to increase since the amount of people synthesizing the food resources are increasing thus the amount of food will increasing.
What is transmutation?
The belief that species change over time.
What 3 elements are required for natural selection?
- ) Variations
- ) Difference in fitness
- ) Inheritance
What is the fitness difference?
The variation of the phenotype results in a difference in reproductive success.
What is variation?
This is the difference of the phenotype of the organism.
What is inheritance?
This is the process of passing these variations on from one generation to the next.
What are Darwin’s 4 postulates?
- ) Individuals within a species vary
- ) Some variation is heritable
- ) More offspring are produced that can survive and reproduce
- ) Survival and reproduction is not random but related to the phenotypic variation
Why are only some variations heritable?
Not all phenotypic variation can be passed on from one generation to the next because if you look at acquired traits that an organism gains those are not passed on from one generation to the next.
What did Wallace discover?
Wallace came up with the theory of natural selection without knowing that Darwin was exploring the same idea.
What are Darwin’s main ideas?
The mechanism that leads to the biological evolution that changes in species over time.
What is natural selection?
This is the mechanism that leads to the evolution of species over time.
What is adaptive radiation?
A process in which organisms diversity rapidly from an ancestral species to produce new forms.
What is the differentiation that occurs in the islands?
The species that are isolated on the islands are able to evolve and differentiate from their neighbouring species over time, and new species will not be arriving.
What is the differentiation that occurs in the mainland?
There is very little gene flow between the mainland and the species in the islands.
What is the genotype?
The particular combination of alleles present in a given organism is the genotype.
What is the phenotype?
The expression of a trait in an individual.
What is blending inheritance?
Where the offspring has traits that are an intermediate of its parents.
What is Lamarck’s Theory?
Favourable traits acquired by the parents are passed on to offspring.
What happens to blending inheritance over time?
Over time if blending variation will be reduced and traits will be lost.
What did Mendel do?
Mendel observed the phenotypes of the pea plants that he was selectively crossing through the use of true breeding.
What 3 distinctions was Mendel observing?
- ) True breeding strains - these are good phenotypes.
- ) Focused on single traits at a time.
- ) Quantitative findings were a result of counting the progeny.
What is P1?
This is the parental generation.
What is F1?
This is the progeny or daughter generation.
What is the difference between dominant and recessive protein production?
Dominant alleles code for functional proteins while recessive alleles do not code for functional proteins.
What is a monohybrid cross?
- ) Single character trait cross
- ) Using true breeding varieties all offspring have the same phenotype
- ) P Generation: Cross 2 varieties with a different phenotype.
- ) F1 Generation: F1 filials are self fertilized (2 of the same progeny are fertilized)
- ) F2 Generation: Both the phenotype of the parental generations arose.
What was special about the monohybrid cross?
If the cross was only blending inheritance we would not see rise of both phenotypes.
What are homozygous alleles?
The 2 alleles are the same therefore producing only one type of gametes.