Lecture Test 4 Flashcards Preview

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Flashcards in Lecture Test 4 Deck (35):
1

What is a species?

A population of organisms that can, and normally does, interbreed successfully with one another but not with members of other populations (other species).
An evolutionarily independent population or group of populations.

2

Morphospecies concept

Distinguishing features are most likely to arise if populations are independent and isolated from gene flow

3

Pluto's theory of evolution

Each organism as perfect and unchanging
Typological thinking

4

Aristotle's theory of evolution

“Great Chain of Being”
Species are fixed
Higher and lower order
Species immutability

5

Carl Linnaeus

1735 “Systema Naturae”
Classification of all species
Humans as Primates

6

Georges-Louis Leclerc, Comte de Buffon

Used Newton’s physics
Age of Earth is 70,000 years
Earth has history – origins of life
Change through migration

7

Thomas Malthus

Political economist, not biologist
Population effects in humans
Will the food supply keep up?
Will those with the strongest traits survive?

8

Jean-Baptiste Lamarck

Animals seemed to have acquired traits
Giraffe – long neck
Reasoned that through use and effort the neck became longer
Problems (does it explain the facts)?

9

Georges Cuvier

Naturalist
Anatomist and fossil expert
Concept of extinction as ordinary
99% of all species

10

Charles Lyell

Rock cycle, erosion, fossils
Age of the Earth in millions

11

Alfred Russell Wallace

Geographic distribution of animals
Led to exploration of plate tectonics and biogeography

12

Gregor Mendel

Genetic variation
Offspring ratios
Inherited and non-inherited traits

13

Rev JS Henslow

Naturalist and teacher
Encouraged Darwin with field studies
Introduced Darwin to geology
Passed on the opportunity to travel on the HMS Beagle

14

Artificial Selection

by breeders can produce major changes in body form
Variation Choose particular animals to reproduce Develop new breeds with an increase or decrease of particular trait

15

Natural Selection

will also lead to major changes over time

Variation Differences in survival, growth, and reproduction More offspring from those variants that are best adapted to particular environment

16

Geologic time

Vastness
4.6 billion years
Eras
Periods
Earliest life ~3.4-3.8 billion years
24 hour clock
Humans at very end (last few seconds)

17

Fossils

Any evidence of former life forms
Bones/skeletons, teeth, animal tracks, leaves and stems, etc
Rapid covering, right environmental conditions (sedimentary)

18

Transitional Forms

Intermediate between older & younger species
Tiktaalik as example

19

Extinction

Complete loss of a species from Earth
Periodic

20

Vestigial Traits

Human traits
Pseudogenes
Anatomical parts
Other species
Lungfish fins
Cave fish eyes
Dew claws
Wings on flightless birds and insects

21

Geographical distribution

Variation across continents
Similarities of species

22

Homology

Genetic homology
DNA sequences are conserved
Mutations
Developmental homology
Embryonic similarities

23

Darwin’s Postulates

Individual organisms in a population vary
Some of the trait differences are heritable
More offspring are produced than can survive
Some survive to produce offspring, some do not
Those that survive best and reproduce are not a random sample
Individuals with certain traits do better
The environment picks the survivors

24

Today’s Synthesis

Evolution by natural selection occurs when heritable variation leads to differential reproductive success

25

Fitness

Survival of the fittest
reproductive success

26

adaptation

Modification for a certain enviornment
a trait with a current functional role
leads to natural selection

27

Limitiations of natural election

Fitness trade-offs
Pleiotropy
Lack of genetic variation
Cloning?
Historical constraints
All traits have evolved from earlier traits

28

evolution works on populations, not individuals

evolution works on populations, not individuals

29

What is the drving force of microevolution?

changes in alleles

30

n=

total number of individuals

31

for the harvey weinberg law to hold true certain conditions must be met:

Population is very large (infinite?)
Mating is random
Mutations do not occur (or are equal)
Migration is nil or equal
Natural selection is creating no selection pressure
Generations are non-overlapping
Parents produce multiple offspring

32

HW inbreeding

Mating among relatives
Leads to homozygosity
Does not promote evolution

33

sexual selection

Courtship, dominance of a male
Female choice
May leads to sexual dimorphism
May drive evolution

34

immigration

inward

35

emmigration

outword