Evolution

Question 1

What is Charles Darwin’s book called?

Answer 1

The origin of species

Question 2

what is Charles Darwin’s theory called?

Answer 2

Natural selection

Question 3

Evolution by natural selection

Answer 3

Organisms produce more offspring than can survive

Organisms compete for limited resources

Individuals of a population vary extensively

Much of this variation is heritable

Individuals that are better suited (pre-adapted) to local conditions survive to produce more offspring.

Processes for change are gradual

The changes in populations can be viewed as descent with modification, as the change does not demonstrate progress (improvement). It is simply change.

Question 4

Darwin’s Observations and Questions (Observations)

Answer 4

Some of Darwin’s observations that led to his theory were:

The flora and fauna were different in different regions

He found fossils of extinct animals that looked similar to living animals

Finches found on islands resembled continental finches but were different in some characteristics

Finch beaks were adapted to the food source on each island

Darwin’s Observations and

Question 5

Darwin’s’ Observations and Questions (Questions)

Answer 5

Questions that Darwin considered:

Why were all types of organisms not randomly distributed?

Why would living and fossilised organisms that looked similar be found in the same region?

Why did the Galapagos species so closely resemble organisms on the adjacent South American coastline?

Could species have been modified from an ancestral form that arrived on the Galapagos Islands shortly after the islands were formed?

Question 6

extinct

Answer 6

a species that has completely disappeared from earth completely

Question 7

what is an adaption?

Answer 7

a change in psychological, behavioral, or physical characteristics in a species overtime (helps them survive)

Question 8

how does an adaption occur?

Answer 8

Result of random, heritable mutations in DNA

Accumulate over generations

Question 9

what is a variation within a species?

Answer 9

Structural, functional or physiological differences between individuals

As becomes more common - considered trait of characteristic of population

Question 10

what is mimicry?

Answer 10

a type of structural adaptation. Harmless species physically resemble a harmful species. Predators avoid the harmless species as much as they do the harmful one.

Question 11

What happened to the English Peppered Moth?

Answer 11

They have three colours (greyish/white with black dots, black, or somewhere between these two)

in 1848 the black ones made up of 2% of the population in Manchester

then the brits went through the industrial revolution and the black ones swarmed

they made up 95% in the city and less in rural areas

Question 12

Variation within species

Answer 12

Created by the different combinations of genetic information (alleles) that offspring inherit from their parents.

Source of all those different alleles is mutation

Mutation

Permanent change in the genetic material of an organism

Only source of new genetic variation

Question 13

Selective Advantages

Answer 13

Improves an organism’s chances of survival in changing environment and reproduction

Mutation as become beneficial

Question 14

Rapid Reproduction & Selective Advantage

Answer 14

Species that reproduce quickly adapt quickly to changing conditions.

Bacteria and some insects reproduce quickly

Mutated allele that could be an advantage is passed on to help the population survive

Examples: Staphylococcus aureus bacteria

Question 15

Selective Pressure

Answer 15

An abiotic (non-living) or biotic (living) environmental condition can be said to select for certain characteristics in some individuals and select against certain characteristics in others. This is how the environment exerts a selective pressure on a population.

Selective pressure can result from any number of abiotic or biotic factors

Examples of selective pressures include:
(Temperature change / climate conditions, Diseases, Light level change, Change in predators , Change in competition)

These selective pressures can result in different patterns of natural selection

Question 16

what does natural selection not do?

Answer 16

anticipate change in the environment (that’s why climate change is a no no)

Question 17

fitness

Answer 17

Contribution an individual makes to next generation by producing offspring that will survive long enough to reproduce

High degree of FITNESS, organism survives and reproduces to pass along advantageous genes

Number of re productively viable offspring that organism produces

Question 18

what is directional selection?

Answer 18

This occurs when changing conditions cause allele frequencies to shift so that individuals at one end of the spectrum become more common

Question 19

what is an example of directional selection?

Answer 19

When insect populations develop genetic resistance to being sprayed with pesticides

This type of natural selection occurs during periods of environmental change

Question 20

what is stabalizing selection

Answer 20

When environmental conditions are stable and are not changing much

Most organisms in a population are well adapted to the conditions

Natural selection will tend to eliminate individuals on both ends of the genetic spectrum

Question 21

disruptive or diversifying selection

Answer 21

This occurs when conditions favours individuals at both ends of the genetic spectrum

Organisms that have intermediate traits are at a disadvantage

Can cause populations to split and potentially form new species

Question 22

Artificial Selection

Answer 22

A common example of artificial selection is the food crops produced from the wild mustard plant. With careful selective breeding, the one original plant has been developed into many different crops.

The impact of artificial selection can be enormous

In an experiment begun in 1896, corn was selected for oil content

Corn with the highest and the lowest oil content were both selected for and allowed to reproduce

Question 23

Examples of Artificial Selection

Answer 23

Cats bred for appearance

Cows bred to increase muscle for meat consumption

Chickens bred to produce more eggs

By selecting the parents that carry the genetic material that breeders are interested in, cat breeders have produced cats with distinct features. All the cats shown above carry the same kinds of genes (e.g., fur, size or length) However, the alleles for these genes differ among the cats, allowing humans to select for or against particular traits

Question 24

biotechnology

Answer 24

Use of technology and organisms to produce useful products

Question 25

Consequences of Artificial Selection

Answer 25

When a particular trait is selected for exclusively, often other traits become negatively affected

Example: English bulldogs are bred to have flat faces. Many of the breed suffer from respiratory problems.

Artificial selection often decreases genetic diversity in a population

Makes the population less fit for environmental changes and natural selection

Artificial selection in agriculture is often used in monoculture planting, where a large area has one type of plant with little genetic diversity

Is easier to manage

High risk that any environmental change, such as a new disease, could wipe out the crop

Question 26

Sexual Selection

Answer 26

Variation in ability to obtain mates

Sexual selection is natural selection for mating based on competition between makes and choices made by females

Favouring of any trait that specifically enhances the mating success of an individual

This type of selection often leads to males and females of a species evolving appearances and behaviours that are quite different from each other

Sexual dimorphism

Example: Male mallard vs Female mallard

Mating and courtship behaviours