Bio Knowledge Check 8

What is evolution in biology?

* process of biological changes by which descendants come to differ from their ancestors

Who was Charles Darwin?

* Wrote “One the Origin of Species”
* Observed many species on the Galapagos Islands

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What were his main observations/studies?

* Noticed the variation of traits among similar species
* Species found on the island looked diff from those found on nearby islands
* Galapagos tortoises and finches
* He believes that these species adapted to their environment

What is the difference between variation and adaptation?

* difference in physical traits of an individual from those of other individuals

vs

* a feature that allows an organism to survive better in its environment

What is biological fitness?

ability to survive and produce more offspring

What is natural selection?

* mechanism of evolution, individuals that have beneficial adaptations produce more offspring

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( environment is selective agent)

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How is it connected to evolution? 

* It can explain how natural selection occurs
* natural selection is the mechanism of evolution

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What is the selective agent in natural selection?

environment

What are some examples of natural selection?

* giraffes evolving long necks for food
* jaguars (check the slides)

What is artificial selection?

* When ***humans*** change a species by breeding it for certain traits

(humans are the selective agent)

What is the selective agent in artificial selection?

humans

What are some examples of artificial selection?

Dog breeding

What are the four principles of natural selection?

* Overproduction - population creates more offspring that can survive and reproduce

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* Variation - individuals in a population differ from each other

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* Adaptation - Some individuals in a population get a trait that makes them better able to survive

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* Descent w Mod. - organisms with a beneficial adaptation are more likely to survive and reproduce and pass on that trait

What are some misconceptions about natural selection and evolution?

* That they are the same thing
* organisms are always getting better through evolution

What are the sources of evidence for evolution and **HOW** do they support the theory of evolution?

* fossils
* embryology
* geography
* anatomy

(HOW) Fossils

* Show the progression of evolution
* prove the existence of now extinct past species which are related to present day species

(HOW) Embryology

* Similar patterns in embryonic development provide evidence that organisms have descended from a common ancestor

(HOW) Biogeography

* grouping of uniquely similar organisms are found in a pattern that prove that they evolved from a common ancestor

(HOW) Anatomy

* provides evidence by **homologous structures**

What are fossils?

* the preserved remains of plants and animals whose bodies were buried in sediments

What is biogeography?

* the study of geographical distribution of organisms

What is comparative anatomy?

* study of the body structures of different species in order to understand the adaptive changes they have undergone

Homologous structure

* similar structures but diff function

(body parts of diff species) Ex: Cat and Human Arm

Analogous structure

* structures that perform a similar function but aren’t similar in origin
* Ex: bat wings and insect wings

Vestigial Structures

* Remnants of organs or structures that had a function in an early ancestor
* Ex: ostrich wings

Which of these structures can serve as evidence for evolution and why?

What are the other sources of evolution besides natural selection?

* Mutations
* Gene Flow
* Genetic Drift
* Sexual Selection

What is allele frequency?

* Ratio of one allele to the total number of the alleles for that gene in the gene pool

How does genetic variation occur in a population?

* Mutation:
* M: can be passed on to offspring
* M: increases genetic variation in a gene pool

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* Gene flow
* increases the genetic variation of receiving population

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What are the two processes that can allow genetic drift to occur?

* Bottleneck effect: genetic drift that occurs after an event greatly reduces the size of a population

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* Founder effect: genetic drift that occurs after a small number of individuals colonize a new area

What is sexual selection?

* occurs when certain traits increase mating success

Intrasexual

* involves competition among males

Intersexual

* Males display certain traits that attract the female

5 factors that lead to Evolution

* Natural Selection
* Genetic Drift
* Gene Flow
* Mutation
* Sexual Selection

Who was Alfred Wallace?

* Helped Darwin research and theorize on evolution

What are the two methods of dating fossils?

* Relative Dating
* Radiometric Dating

What is speciation?

* the rise of two or more species from one existing species

What is reproductive isolation and the three causes of it? (give an example)

* occurs when members of different populations can no longer mate successfully, the final step in becoming two separate species


* Behavioral
* Geographic
* Temporal

Behavioral Isolation

* caused by diffs in courtship or mating behaviors

Geographic Isolation

* physical barriers that divide a population into 2 or more groups

Temporal Isolation

* when timing prevents reproduction between populations

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What are mass extinctions vs background extinctions?

* occurs suddenly, usually because of a catastrophic event

vs

* extinction that occurs continuously but at a very low rate

What is taxonomy?

* a system of naming and classifying organisms based on shared characteristics and universal rules

What is the order of classification? (Kingdom → Phylum → Class, etc.)

* Kingdom
* Phylum
* Class
* Order
* Family
* Genus
* Species

What methods do scientists use to classify species?

* fossil
* dna sequence
* physical features