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Flashcards in Evolution Deck (46):
1

Theory

Explanation, supported by observations/ experiments

Used to explain related occurrences

2

Evolutional theory

Gradual CHANGE in a POPULATION over TIME

3

Trends shown by evolution

Organisms change over time
Life evolved from SIMPLE to COMPLEX forms
Life went form UNICELLULAR to MULTICELLULAR

4

Misconceptions of evolution

1.only the strong will survive
-survival of the FITTEST (not always strength) FIT = ADAPTED

2.humans evolved from apes
-humans and apes evolved from a COMMON ANCESTOR

3.organisms change bc they need to
-populations change due to VARIATION passed on genetically from one generation to the next

5

Lamarack was WRONG

You can't pass on traits you acquire during your lifetime

6

Lamarack's law of use and disuse

The more an animal uses a certain part of his body, the stronger/ more developed that part of its body becomes

7

Lamarck's inheritance of acquired characteristics

If you develop a characteristic during your life you can pass it of to your offspring

8

According to Lamarck

Ancestors of giraffes short necks, as food decreased they stretched their necks, necks became longer, long necks passed on to offspring

9

Charles Darwin was RIGHT, his theory:

Sailed to SA, studied Galapagos finches

Overproduction--Competition--Variation--Adaptations--Natural selection--Speciation

10

Natural selection

Organisms with favorable variations survive/produce more offspring than less well-adapted organisms

Survival of the fittest

11

Speciation

Formation of a new species

Time frame; millions of years

12

Darwin's finches

Evolved bc limited niches

Niche= role in environment / how they get their food

Speciation

13

How fast does evolution occur?

Gradualism (Darwin's theory, gradual changes, millions of years)
Vs.
Punctuated equilibrium (rapid evolution in a short interval, supported by fossils)

14

So environmental changes always cause evolution?

NO:
Times when there is NO SELECTION means that the organisms' traits are still fit for the environment (already adapt)

15

Organisms that don't resemble their ancestors?

= DRASTIC CHANGE IN ENVIRONMENT
Ex: elephants

16

Survival of the fittest

=Natural selection
The ENVIRONMENT selects individuals with the best traits

17

Sources of Variation

Sexual Reproduction (the one that's more fun) : meiosis (crossing over) and fertilization, new genes produced each time,
Asexual Reproduction (not as fun): mutation, random (change in genetic info)

Multicellular organisms: mutation: rare/random has to be in GAMETES to go to offspring and sexual repro

Unicellular organisms: mutation only (they don't have fun)

18

Examples of Adaptations that = best fit

Camouflage, mimicry, warning coloration (poisonous)

19

Types of Camouflage

Cryptic coloration (checkered fish)
Disruptive coloration (zebra)
Counter shading (squirrel)

20

Modern day evolutionary theory

Darwin's theory + knowledge on genetics

21

Results of genetic variation

•Structural change (thick furred polar bears)
•Functional change (electric eel, poisonous snake, antibiotic resistant bacteria, digesting certain foods)
•Behavioral change (nocturnal animals, firefly blinking, octopus)

22

Isolation

Anything preventing two groups WITHIN A SPECIES form interbreeding

23

Types of Isolation

Geographic isolation (natural barrier: mountains, river, lava)

Reproductive isolation (loss in the ability to interbreed, diff in courtship behavior -ex the dance- and mating times)

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Species

Organisms
Share characteristics
Can mate/ produce offspring

Isolation often leads to speciation

25

Adaptive radiation

=Darwin's fiches
=Divergent evolution

One species evolved into several diff species each having their own NICHE (role)

26

Convergent evolution

Organisms that are non related develop similar characteristics and look alike

Koala (marsupial) an bears

27

Variation vs no variation

Variation (sex + mutations) + change in environment = evolution (ex:horses)

No variation + change in environment = endangered / extinction (ex:panda bears)

28

IMPORTANT

⬆️variation= ⬆️survival

⬇️variation= ⬆️ extinction

You CANT develop a trait that you NEED, you either have it or you don't

29

Supporting evidence of evolution

Comparative anatomy (homologous analogous vestigial structures), comparative embryology and comparative biochem

30

Comparative anatomy

The study of structural similarities and diff among living species

31

Homologous structures

SAME STRUCTURE and embryonic development, DIFF FUNCTION

Ex: human arm, whale fin, cat leg, bat wing, bird wing

Shows that organisms are adapted to diff environments bc they're being used for diff things (diff niches)

32

Analogous structures

SAME FUNCTION DIFF STRUCTURE

Ex: bird and insect wings

Shows that they have a similar niche/environment but a DIFF COMMON ANCESTOR

33

Vestigial structures

Remnants of a structure that was FUNCTIONAL in ANCESTRAL FORM

more than 100 in humans

Tail bone, appendix, wisdom teeth, muscles with nose and ears

34

Comparative embryology

Similarities during the earliest stage of development
*Common Ancestry

35

Comparative biochem

Similar DNA, RNA and protein like enzymes

MOST RELIABLE

36

Antibiotic resistance

Antibiotics treat bacteria
Natural variation=ability to resist antibiotic
Variation= gene carried on by bacteria
Least resistant bacteria die 1st
Stoping antibiotic=greater proportion resistant
Pop of resistant⬆️
Diff antibiotic requires

37

Preventing antibiotic resistance

Avoid using antibiotics unnecessarily
Follow prescription : finish taking it
Use the most specific antibiotic possible

38

Population

Same species, same time, same place

39

Population Genetics

The study in the changes in the genetic makeup of a population

40

GENE POOL

All the alleles in the individual that make up a population at any given time

"Reservoir" of genes for next generation

Where genetic variation is stored

41

Shift in the gene pool

= evolution

42

Allelic Frequency

How often can certain genes be expressed in a gene pool
Mathematic formula (%)

43

Hardy-Weinberg

NON EVOLVING
Hardy-Weinberg theory describes a non evolving pop, pop @ equilibrium

Generation after generation, gene pool stays the same

44

Hardy-Weinberg Equation

Each variable represents a diff type of allele

45

Need page 18 and 19 in pkt

Look at those pages in packet

46

Need page 18 and 19 in pkt

Look at those pages in packet