Population Dynamics Chap. 4 Flashcards
What is an adaptation?
It is a structural, behaviour or physicological process that helps an organism survive.
What is an inherited trait?
A set of traits that improve the chances of survival and reproduction of an organism.
What is a structural adaptation?
Structures that improve a species’ ability to survive and reproduce. Ex: Camouflauge
What is a behavioural adaptation?
Things that an organism does. ex: migration
What is a physiological adaptation?
Based on chemicals and internal processes. Ex: Pheromones, venom production
How do adaptation deveolp?
- Variation
- Mutations
What are varations?
Differences (visible or otherwise) among members of a population. Created by inheriting different combinations of genetic information from parents.
What are mutations?
Random, spontaneous changes in genetic material that can be passed from parents to offspring.
Are mutatiuons good?
They can be good, bad, or provide no advantage or disadvantage.
What are the requirents for a mutation to be passed on to offspring?
Mutation must occur within a sex cell.
In what situations does a mutation start as a disadvantage or nuetral and then become favourable?
When the organisms environment is changing.
What is selective advantage?
Mutations that help an individual survive.
What is natural selection?
The process by which populations change over time.
What are the 6 distinct ideas of natural selection?
- Overproduction
- Competition
- Variation
- Environmental changes
- Survival of the fittest
- Speciation
What is the idea of overproduction?
More offspring are produced that can possibly survive
What is the idea of competition?
Organisms compete within and between species for limited resources because of overpopulation.
What is the idea of variation?
Inherited differences occur among members of the same species.
What is the idea of survival of the fittest?
Surviving organisms are ones better able to compete, survive, and reproduce.
What is the idea of specitation?
Over numerous generations, new species arise by accumulation of inherited variations of traits; considered new species when member cannot interbreed
How does the enviorment exert selective pressure?
Due to constantly changing environments, individuals that possess variations that allow the to survive in the environmental change will survive and reproduce (survival of the fittest)
What is artificial selection?
Human intervention in the breeding of plants and animals to ensure desirable traits are represtened or magnified in succesive generations.
What are the three types of selection?
- Disruptive
- Stabalizing
- Directional
What is disruptive selection?
The average is disadvantaged.
What is stabilizing selection?
The average has an advantage.
What is directional selection?
One extreme advatage
What are some examples when natural selection is fast?
Quickly reproducing organisms with short life cycles. ex: Bacteria, insects, viruses
Do individuals change within their lifetime?
No
Over what time period does natural selection occur?
Over several generations
How do new traits appear in species?
Mutation
Sexual reproduction
What were the ancient beliefs about species changing?
greek philosophers believed that all life was perfect and unchangeable.
What was Comte De Buffon’s contribution to evolutionary theory?
First to challenge the belief that species were unchangeable
In 1749 he published Histoire Naturelle in which he noted similarities between apes and humans and suggested a possible common ancestor.
What was Georges Cuvier’s contribution to evolutionary theory?
Developed the science of paleontology using fossils to study ancient life.
He was the first to establish extinction as a fact.
By examining layers of rock called strata he noted:
- Each stratum has unique groups of fossil species
- The deeper he looked the more dissimilar the species looked from today
- As he moved from one layer to the next, he found that new species would appear and others would disapper or become extinct
To explain his findings he proposed Catastrophsim
What is Catastrophism
Destructuve narual events such as floods or volcanic eruptions may have killed numerous species each time
What was Thomas Malthus contribution to evolutionary theory?
Wrote an essay which Darwin studied thouroguly called “Essay on Principles of Populaiton”
Argued that populations produce more offspring than their enviorments (food supply) could support and were reduced by starvation (competition).
What was Charles Lyell contribution to evolutionary theory?
Counterd Cuivers theroy of catastrpohsim
Propsed Gradualism; thta geological events are slow and continuos and can result in substantial changes over time.
Concluded that the earth wasn’t just older than 6000 years old it was ancient
What is gradualism?
States that changes are slow, gradual, consistent process which have shaped Eaths surface.
Requires large amounts of time.
What were Cuiver and Lyell’s views on species changing?
They believed they were unchangable.
What did Buffon and Lamark believe in?
Transmuation of species - that species were not fixed as they are, but could change over time.
What was Lamark’s contribution to evolutionary theory?
Believed that in a line of descent each prgrssive ancient life from was more complex and closer to perfection that the last and they eventually lead to the modern species.
Believed mankind was atop the evolutinalt ladder, and every less complex organism was on its way to evolving into man.
Believed that every creature possessed the universl creative principal which is the will to evolve into man.
Believed in the inheritance of aqcuired characteristics.
What is the inheritence of accquired characteristics?
Where traits that an individual acquired during its life would be passed along to its offspring. By the 1800’s this was eventually rejected.
What are the two theroies that comprise inheritance of acquired characteristics?
- Law of use and disuse
- Acquired characteristcs are inherited
What is the law of use and disuse?
The beliefe taht organims can change their body featires during their lifetimes to satisfy needs.
What is the theory of Acquired characteristics are inherited?
That characteristcs changed during the lifetime fo an individual can be passed on to offspring.
Who was Charles Darwin?
A clergyman who went on a five year naval voyage for 5 years. In 1830 he joined the beagle, a british survey ship.
What benefit did the Beagle have on Darwin?
He made obeservations of wildlife and geography of various countires and recoreded the differences and similarites from place to place.
After Darwin’s trip, he began to speculate:
That one species could turn into another
What were Darwin’s contribution to evolutionary theory?
- Made observations of wildlife and geography of various countries and recorded differences and similaritues from place to place.
- Began to speculate that one species could change into another
- Proposed evolution by natural selection in The orgin of species in 1859
Who was Alfred Russell Wallace?
Was inspired by the Voyage of the Beagle and decided to become a naturlist and specimen collector. Came to the conclusion that natural selection was the mechanism that drove the transmutation of species.
What was Alfred Russell Wallace’s contribution to evolutionary theory?
He speculated that natural selection was what drove the transmutation of species.
How did Darwin and Wallace eventully come to similar conclusions concerning evolutinon?
The used ideas and evidence gaterd by other scientists such as lamarcks idea of inheritance. Another key idea was borrowed from Malthus (competition)
What were the two main ideas suggested in the origin of species
- Present day life forms have arisin by descent and modification form an ancesteral species.
- The mechanism for modification is natural selection working for long periods of time
What is evolution?
The process by which populations of living things change over a series of generations.
The cumlitive changes in characteristics of a population in successive generations.
Evolution results in diversity
What is direct evidence for evolution?
Fossils
What are th 4 ways fossils are direct evidence for evolution?
- Palentolgy is the study of fossils which are the remains, impressions, and traces of organisms from past geological ages.
- Radioactive dating attemps to age of rocks based on the decay of radiactive isotopes. The relative quantities of isotopes are measured, and calculations are based on normal amounts of those istopes
- The fossil record shows an increase in complexity of organisms over time. More recent fossils show more complex organsims
- New discoveries of fossils called transitional fossils helf fill in gaps in fossil record
What are 5 indirect sources of evidence towards evolution?
- Embryology
- Morophology
- Vestigal structures
- Molecular biology
- Biogeography
What is embroylogy?
The study of orgnaims in the eary stages of development.
Similarites in embroys suggest a common ancestory
All embroys go through very similar stages
What is Morphology (Homologous Structures)
Structures that originate from same source but develop diffrently. Have common origins in the embryo
Evidence for common ancester
What is Morphology (Analogous Structures)
Similar functinal structures, but develop diffrent from embroylogical structures
Do Not develop from common ancestor
What are vestigal structures?
Are structures present in organisms that have no present day function.
What is molecular biochemistry?
Recent advances in DNA profiling and protein sequencing has allowed us to study the similarites in common molecules.
What is Biogeography
The study of geographical distribution of plants and animals
All continesnts were one joined as a super continent (pangea) and the broke apart
Animals that eveolved before breakd up are widley distributed (reptiles and amphibians)
Animals that evolved after breakup (mammels) are more limited in distribution.
What is a species?
A group of individuals capable of interbreeding and producing fertile offspring
What is Microevolution?
The chaning of an organsim over time without a change in species
I cant delete this :(
I havent found a way yet Zayed stop judging me :(
What is macroevolution?
Species differences become so great that they are no longer able/intrested in interbreeding
Geographical isolatino is often the cause
What is speciation?
The formation of a new species, may result from the accumilation of changes in a population over time.
What two forms can speciation take?
Transformation
Divergence
What is transformation?
The evolution of one species into another as a result of mutations and adaptations to a changing enviorment
What is divergence?
One or more species arise from a parent species
What form of speciation results in greater biodiversity?
Divergence
What are two types of barriers that occur within population to prevent interbreeding?
Geographical barriers
Biological Barriers
What is a geographical barrier
Physical barriers that keep populations apart
What is a biological barrier?
Barriers that prevent populations that are not geographically seperated from reproducing. These barries may be behaviorl or physical.
What is convergent evolution?
When very diffrent species develop similar adaptation due to similar needs in their enviroment.
What is adaptive radiation?
The sudden diversification of a common ancesteral species into a variety of species. Process is usually associated with the intorduction fo a species into a new enviroment.
What is another name for adaptive radiation?
Divergene
What is puncutred equilibrium
Where long periods of equilibrium are intrupted by periods of speciation.
What are the four main points of evolution my natural selection?
- Life froms have developed from ancestral species.
- All living things are related to one another by varying degrees through common desent
- All living things on Earth have a common origin
- The mechanism by which one species evolves into another species involved random heritable genetic mutations
What is Phylogeny?
The study of relationships amoung different groups of organims and their evolutionary development.
