2B - Evolution

Question 1

What is an adaptation?

Answer 1

An adaptation is a physical feature,
behaviour, or physiological process that helps an organism survive and reproduce in a particular environment

Question 2

What are the 3 different types of adaptations?

Answer 2

Structural/Physical
Physiological
Behavioural

Question 3

Structural/Physical adaptation

Answer 3

changes in the structures of a living organism that makes it better adapted to its
environment

– Camouflage and colouration
– Morphological features such as changes in
the skeleton, limbs, tails, etc.
– Other physical characteristics of an organism

Question 4

Behavioral adaptations

Answer 4

things an organism does to survive,
usually in response to an external
stimulus

– Nesting and hibernation behaviours
– Collecting and storing food, a food
cache
– Bird calls, songs, mating dances, and
migration

Question 5

Physiological adaptations

Answer 5

• changes in the metabolism and / or physiological activity of organisms that allow them to maintain homeostasis
• These adaptations influence internal
  functioning of the organism

– Breathing rate, temperature regulation in
endotherms, chemical mechanisms
– Odour production in skunks through secretory glands
– Digestive enzymes and the secretion of gastric acid

Question 6

What is genetic variation?

Answer 6

• the difference in
  DNA among individuals or the differences
  between populations among the same
  species
• The multiple sources of genetic variation
  include mutation and genetic
  recombination

– Mutations are the ultimate sources of
genetic variation, but other mechanisms,
such as genetic drift, contribute to it, as well

Question 7

What is genetic variation caused by

Answer 7

Genetic variation is caused by variation in
the order of bases in the nucleotides in
genes

Question 8

What will genetic variation will result in

Answer 8

phenotypic variation if the order of nucleotides in the DNA sequence results in amino acid changes

– Amino acid changes can result in new proteins coded by that DNA sequence

– If resultant differences in amino-acid sequence influence protein shape, it can change function

Question 9

What is phenotypic
variation?

Answer 9

Differences within the observable characteristics among an individual/s within a population.

Question 10

What is variety and what can it cause
/

Answer 10

Variety (in the phenotypic expression of
organisms) within a population exists

• This variation within a particular environment can result in an organism being better or less adapted to their particular situation
• Thus, phenotypic variation is the
  characteristics on which natural selection acts

Question 11

Natural selection

Answer 11

Natural selection is the process by which a population of organisms changes because individuals with certain traits can better survive the local environmental conditions and pass on these traits to their offspring.

Question 12

What is a genetic mutation?

Answer 12

• Changes in the DNA sequence of genes
  can result in the production of new
  proteins
• Mutations can be:
  – Benign (have no effect on the organism)
  – Deleterious (harmful to the organism)
  – Advantageous (helpful to the organism)

Question 13

What is a phenotype

Answer 13

observable characteristics due to thier genes and environment. a difference in phenotype causes variation among a species

Question 14

What do genes code for

Answer 14

proteins/amino acids

Question 15

what do genomes code for

Answer 15

genomes are all your genes combined and they code for the entire organism

Question 16

what are phenotypes the result of

Answer 16

Phenotypes are the result of the genetic
sequence / code and the influence of
environmental factors on gene expression

Question 17

What are selective pressures?

Answer 17

Variable which cause a certain phenotype of an organism to have a better chance at survival
- Organisms possessing a particular characteristic are either eliminated or favoured by an environment
- Selective pressures reduce or increase reproductive success of organisms, which drives natural selection

Question 18

“Fitness”

Answer 18

• Does not mean survival of the fittest
• it is the ability of an organism to survive and reproduce
  • a measure of the average contribution to the gene pool of the next generation of an organism with particular genotype/phenotype

Question 19

Darwins theory of evolution

Answer 19

1. Evolution occurs as organisms change over time
   
   • Descentants diverge from common ancestors in the past
2. Evolution occurs by natural selection
   
   • Process in which living things with beneficial traits produce more offspring than others do. This results in changes in the traits of living things over time
     (gets more common over time)

Question 20

Are environments changing or static

Answer 20

Environments are not static, they change
- Gnetic makeup
- Phenotypes
Like adaptations, mutations all that stuff

Question 21

Heritable traits

Answer 21

Traits or characteristics that can be passed on from parent to child

Genetic

Question 22

Acquired trait

Answer 22

Not heritable
It’s something someone learns in their life and is not genetic

Question 23

Jean Baptiste Lamarck

Answer 23

• “Law of Use and Disuse” = Use it or lose it
  Ind. lose traits their env. doesn’t need and gains traits they need to survive
• Thought aquired traits can be passed down

Question 24

What are the scientific evidences for evolution

Answer 24

• direct observation
• fossil record
• biogeography
• Anatomy, homology and convergent evolution
• Molecular biology and genetics

Question 25

Direct observation

Answer 25

* We can actively see it happening around us ex: bacteria becoming resistant to parasites and vaccines

Question 26

Fossil record

Answer 26

– Fossils are remains or traces of organisms from the past found in sedimentary rock. – Radioactive dating is used to determine the age of fossils and geological principles such as the Law of Superposition. – Darwin’s theory of evolution through natural selection explains the succession of forms in the fossil record. – Transitional fossils have been found that link ancient organisms to modern species, as Darwin predicted.

Question 27

Embryonic Homology

Answer 27

* comparison of early stages of animal dev. reveals many anatomical homologies (morphological similarities) in embryos not visible as an adult

Question 28

Molecular homologies

Answer 28

* shared characteristics on the molecular level * All life forms ise the same genetic language of DNA and RNA * when hox genes are tampered with, legs can replace antennae etc

Question 29

Transitional fossils

Answer 29

* any fossil that possesses characteristics of both ancestral and decsendant groups * show the progression of the dev. of new evo. traits and display the loss of other traits over time

Question 30

Definition of homology

Answer 30

* characteristic in related species can have an underlying similarity even with very different functions

Question 31

Homologous structures

Answer 31

anatomical eviddence for evolution * occurs in species that have a common ancestor * similar functions, although they may have different physical appearences.

Question 32

analogous structures

Answer 32

* perform similair functions but organisms dont have a common ancestor/ evolutionary origin * no evidence of a common ancestor * insect wing vs bat wing

Question 33

Vestigial organs

Answer 33

* structures of minimal importance to the organism * remnants of structures that served important functions in the organisms ancestors

Question 34

Convergent evolution

Answer 34

* taken place when two organisms developed similarities as they adapted to similar environmental challenges * not because they evolved from a common ancestor * similar problem = similar solution

Question 35

divergent evolution

Answer 35

accumullation of differences between closely relates populations within a species, sometimes leading to speciation

Question 36

Biogeography

Answer 36

* geographic distribution of a species * species in discrete geographic area tend to be more closely related to each other than to species than to species somewhere else

Question 37

Adaptive radiation

Answer 37

the diversification of a group of organisms into forms filling different ecological niches. think of darwins finches on galapalos

Question 38

Introduced vs invasive

Answer 38

An introduced species is one that is moved into a new area that it is not naturally found in. An invasive species is an introduced species that disrupts natural ecosystems. may become invasive if environmental pressures are diff in new env. breeding more without a natural predator