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Grade 11 Bio > Evolution > Flashcards

Flashcards in Evolution Deck (39):
1

What is adaptation?

it is a structure, behaviour or physiological process that helps an organism survive and reproduce in a particular environment. Example: camouflage, hibernation, needle-sharp talons and excellent vision of an owl, white fur and webbed, flat feet of polar bears.

2

What is mimicry?

A structural adaptation in which a harmful species resembles a harmless species in coloration or structure. Predators that avoid the harmful species will also avoid the mimic. For example, the viceroy butterfly is palatable to the predators but the monarch is not (monarch is poisonous), so predator's avoid both because they don't want to get sick.
~type of beetle that look,s like a type of ant and has the same pheromone and gains access to the queen and kills her, then the rest of the beetles come and eat everyone
~scarlet Kingsnake mimics colours of poisonous coral snake

3

What is variation?

differences between individuals, which may be structural, functional, or physiological

4

What is mutation?

a permanent change in the genetic material of an organism; the only source of new genetic variation

5

What are mutagens?

are environmental agents that can also cause mutations in DNA. i.e. ultraviolet radiation, x-ray radiation, toxic chemicals, nuclear energy

6

What are mutations in Gametic Cells?

~if the mutation occurs in a somatic cell, the mutation disappears from the population when the organism dies
~if the mutation alters the DNA in the gamete, the mutation may be passed on to succeeding generations as a new allele

7

What is selective advantage?

a genetic advantage that improves an organism's chance of survival, usually in a changing environment
Ex. the water flea Daphnia, normally lives in water that is around 20 degrees Celsius and it cannot survive in water 27 degrees Celsius `or warmer, but a mutation allows some to survive in temperatures between 25 degrees Celsius and 30 degrees Celsius allowing them to reproduce and survive when temperatures are high

8

What is antibiotic resistant bacteria?

-antibiotics are drugs used to treat infections. When they reproduce asexually (in under 30 minutes in favourable conditions). It allows mutations to occur. When you have all these bacteria inside you and you're treated with antibiotics. It will kill all the bacteria, except for the ones with a mutation that makes it resistant. The antibiotics essentially "choose" the resistant strain, allowing them to reproduce and create many resistant bacteria making it harder to treat.

9

What is natural selection?

the process by which characteristics of a population change over many generations as organisms with heritable traits survive and reproduce, passing their traits to offsprings

10

What is selective pressure?

environmental conditions that select for certain characteristics of individuals and select against other characteristics

11

What is selective advantage?

A genetic advantage that improves an organisms chance of survival, usually in a changing environment

12

What is fitness?

The relative contribution an individual makes to the next generation by producing offspring that will survive long enough to reproduce

13

What is artificial selection?

Selective pressure exerted by humans on populations in order to improve or modify particular desirable traits
~example: cows bred to produce more milk, chickens bred to grow large number of eggs, some chickens are bred to grow rapidly and have large muscles for increased amounts of meat; rice, corn, meat, vegetables, bred crops to be drought- or pest-resistant

14

What is a mono culture?

extensive plantings of the same varieties of species over large expanses of land.
~the big risk for monoculture is that since everything is so similar, if a new disease infests the crop population, most of the individual plants will be affected in the same way and the whole population could be killed or severely damaged

15

What are gene banks?

Contain populations of early ancestors of modern plants.
~our most important food plants came from wild ancestors with genetic combinations that allowed them to survive and reproduce in their environment

16

What is the genetic mutation that may have separated man and apelike kin?

~they may have discovered the mutation that caused they earliest humans to branch off from their apelike ancestors--a gene that led to smaller, weaker jaws and, ultimately, bigger brains
~smaller jaws fundamentally changed the structure of the skull, by eliminating thick muscles that anchor a huge jaw to the crown of the head . The change would have allowed the cranium to grow larger and led ti the development of a bigger brain capable of tool making and language.
~A team isolated a new gene in an overlooked junk DNA sequence on chromosome 7. Their estimate of when this mutation occurred--about 2.4 million years ago, in the grasslands of East Africa

17

Who is Charles Lyell and what is he famous for?

~a famous geologist
~he proposed, based on the work of geologist James Hutton, that geological processes operated at the same rates in the past as they do today in a process called UNIFORMITARIANISM.
~he wrote a book about the Earth being older than 6000
-Darwin took it on his boat (the Beagle)
~he inspired Darwin because if the Earth is slowly changing could slow subtle changes also occur in populations

18

Who is Jean-Baptiste Lamarck and what is he famous?

~wrote a book (philosophic zoologique) which outlined his ideas about changes in species over time
~he observed a "line of descent" or progression, in which a species of fossils (from older to more recent) led to modern species
~thought species increased in complexity overtime until they achieved a level of perfection
~hypothesized that the organisms would become progressively better adapted to their environments
~thoughts giraffes stretched their necks to reach higher leaves and passed this on to their offspring (inheritance of acquired characteristics)
~INHERITANCE OF ACQUIRED CHARACTERISTICS: the idea that characteristics acquired during an organism's lifetime can be passed on to its offspring
~thought body parts that weren't being used would eventually disappear
~inspired Darwin (was credited in his book)

19

Who is Charles Darwin?

~theory of EVOLUTION OF NATURAL SELECTION: a theory explaining how life has changed and continues to change during Earth's history
FIVE OF HIS OBSERVATIONS:
1) The same species would be different in different places/regions (i.e. rodents in South Africa and else where)
2) fossils of extinct animals looked similar to living animals (i.e. armadillo-like gyptodont)
3) Finches and other animals on the Galapagos Islands closely resembled animals he observed on the West Coast of South America
4) Galapagos species (ex. tortoise and finches) looked identical but varied slightly between islands (i.e. each type of Finch had adapted different beaks based on food sources available on the island
5) Noticed natural selection occurring in nature (similar to artificial selection he noticed i.e. pigeons and studying breeds of dogs and varieties of flower)

20

Explain: Darwin, Wallace and the Theory of Evolution by Natural Selection

~survival of the fittest: the idea that the organisms that are the fittest leave the most offspring, so those offspring win the struggle for survival; phrase coined by John Spencer (Darwin called this natural selection)
~The origin of species ideas include:
1) organisms produce more offspring than can survive. Therefore, organisms compete for limited resources
2) Individuals of a population vary extensively, and much of this variation is heritable
3) Individuals that are better suited to local conditions survive to have more offspring
4) Processes for change are slow and gradual
~Descent with modification: Darwin's theory that natural selection does not demonstrate progress, but merely results results from a species' ability to survive local conditions at a specific time

21

What are the 5 sources of Evidence for Evolution?

1) Fossils
2) Biography
3) Evidence from Anatomy
4) Evidence from Embryology
5) Evidence from DNA

22

How are fossils a source of evidence for evolution?

1) fossil found in young layers of rock are much more similar to species alive today than fossils found in older, deeper layers in rock
2) fossils appear in chronological order
3) not organisms appear in the fossil record at the same time
-evidence from transitional fossils
(I. E. Archaeopteryx and tiktaalck)
-vestigial structures

23

What are transitional fossils?

A fossil that shows intermediary links between groups of organisms and shares characteristics common to two now separate groups
i.e. Archaeopteryx is a transitional fossil because it shows a transitional stage in the fossil record because the species had characteristics of both reptiles (dinosaurs) an birds

24

What is a vestigial structure?

A structure that is a reduced version of a structure that was functional in the organisms ancestors (i.e. Whales have pelvic bones)

25

What evidence of evolution is in biography?

1) geographically close environments are more likely to be populated by related species than are locations tat are geographically separate but environmentally similar
2) animals found on islands often closely resemble animals found on the closest continent
3) fossils of the same species can be found on the coastline of neighboring continents
4) closely related species are almost never found in exactly the same location or habitat

26

What is biography?

The study of the past and present geologic distribution of species populations

27

What evidence from Anatomy is there regarding evolution?

-vertebrate forelimbs can be used for flying, swimming and running
-homologous structure: structures that have similar structural elements no origin but may have a different function
-homologous structures are similar because they were inherited from a common ancestor

28

What is the evidence from embryology in pertaining to evolution?

Embryology is the study of early, pre-birth stages of an organisms development
-used to determine evolutionary relationships between animals
-the similarities between embryos in related groups point to a common ancestral origin

29

What DNA evidence is there for evolution?

- since DNA carries genetic information, scientists. An determine how closely related two species are by comparing their DNA
-if two species have similar patterns in their DNA, this indicates that these DNA sequences must have been inherited from a common ancestor
~ DNA shows dogs are related bears and whales and dolphins are related to cows and deers
-current evolutionary theory connects genetics with the theory of natural selection and how natural selection operates on populations

30

What evidence do we have from fossils?

1) fossils found in young layers of rock are much more similar to species alive today than fossils found in older, deeper rocks
2) fossils appear in chronological order
3) not all organisms appear in the fossil records at the same time

31

What is a transitional fossil?

a fossil that shows intermediary links between groups of organisms and shares characteristics common to two now separate groups (i.e. Archaeopteryx and Tiktaalck)

32

What is a vestigal structure?

a structure that is a reduced version of a structure that was functional in the organisms ancestors (i.e. whales still have pelvic bones)

33

What evidence do we have from bio geography?

Biogeography is the study of the past and present geological distribution of species populations

1) Geographically close environments are more likely to be populated by related species than are locations that are geographically separate but environmentally similar
2) Animals found on islands often closely resemble animals found on the closet continent
3) Fossils of the same species can be found on the coastline of neighboring continents
4) closely related species are almost never found in exactly the same location or habitat

34

What evidence do we have from anatomy?

~vertebrate forearms can be used for flying, swimming, and running
~Homologous Structures: structures that have similar structural elements and origin but many have different functions
~homologous structures are similar because they were inherited from a common ancestor

35

What evidence do we have from embryology?

Embryology is the study of early, pre-birth stages of an organisms development
~used to determine evolutionary relationships between animals
~the similarities between embryos in related groups point to a common ancestral origin

36

What evidence do we have from DNA?

due to the genetic information in DNA, scientists can determine how closely related two species are by comparing their DNA
~If two species have similar patterns in their DNA, this indicates that these DNA sequences must have been inherited from a common ancestor
~DNA shows dogs are related to bears and whales and dolphins are related to ungulates (hoofed animals {i.e. cows and deer})
~current evolutionary theory connects genetics with the theory of natural selection, and how natural selection operates on populations

37

Who is Alfred Russel Wallace?

~lived in the jungle and started coming to the same conclusions as Darwin
~him and Darwin presented their theories together and "had each others backs" when being criticized
~became close to Darwin (carried his casket at Darwin's funeral)

38

What is the bottleneck effect?

changes in gene distribution that results from a rapid decrease in population size
~often seen in species driven to the edge of extinction
~since so much of the population died many alleles have been lost
~this decreases the genetic diversity in a population (i.e. colour vision deficiency on Pingelap)

39

What is speciation?

~sometimes called macroevolution
~two populations may become "reproductively isolated" over time (that is, become two species), if there is no gene flow between them
~this was Darwin's "mystery of mysteries" because he did not know how it occurred because he didn't know about DNA