Biology Ch. 22-24 Evolution, Natural Selection and Speciation

What is species?

A group of individuals that are morphologically similar and are able to interbreed and produce viable fertile offspring

What can make defining species difficult?

Similarities between some species and variation within a species

What is taxonomy?

The branch of biology focused on naming and classifying organisms

When was the binomial naming system introduced?

Linnaeus introduced it in the 18th century

What does taxonomy classify organisms into?

groups

Order of hierarchical classification

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species (Daring king Philip came over for good spaghetti)

Species on hierarchical classification

smallest, only type of organism = leopard

Genus on hierarchical classification

Leopard, tiger, lion, jaguar

Domain on hierarchical classification

Largest, many different types of organisms

Domain for humans

Eukarya

Kingdom for humans

Animalia

Phylum for humans

Chordata

Class for humans

Mammalia

Order for humans

Primates

Family for humans

Hominidae (great apes)

Genus for humans

Homo

Species for humans

Homo sapiens

How many species are there of Hominidae (great apes)?

5 species

Bonobos

live a low stress lifestyle

How long have humans been around?

200,000 years

What are the 3 largest domains?

1. Bacteria

2. Archaea

3. Eukarya

Which domain is the most complex?

Eukarya

Where do the Galapagos Islands get their name?

From the tortoises that live there

What did Charles Darwin observe on the Galapagos Islands?

the diversity of life

What do tortoises vary in?

Variation in shell shape and neck length

• Short neck - food on ground

• Middle length - food higher up

• Long neck - food higher up in vegetation

What did Charles Darwin’s On the Origin of Species by Means of Natural Selection present evidence to support?

• The idea of evolution

• Proposed a mechanism for evolution = natural selection

Who was Alfred Wallace?

Presented with Charles Darwin their ideas of evolution in 1858

What is natural selection?

Change in the frequency of genetic traits in a population through differential survival and reproduction of individuals bearing those traits

What is an example of natural selection?

Peppered moths

• Species dominated by light colored moths

• Small proportion of dark colored moths so it is easier to capture because they are not camouflaged

What was the effect of the Industrial Revolution on peppered moths?

Pollution darkened the tree trunks and killed lichens

• The dark form of the moth became more common because now they were camouflaged

What does natural selection act on?

individual phenotypes

What is a phenotype?

Physical characteristics based off genes

What is evolution?

Process by which different kinds of organisms develop and diversify

What does evolution result in?

Changes in the adaptative characteristics of a population through time

What happens when organisms produce more offspring than the environment can support?

struggle for survival

Individuals do not evolve. What does?

Populations evolve

What are heritable traits?

Characteristics that are passed down from parents to offspring through genes

T/F: Evolution is not goal directed and does not lead to perfection.

True; favorable traits vary as environments change

What is the production of natural selection?

Adaptation

What are adaptations?

Inherited traits that enhance an organism’s ability to survive and reproduce in its environment

What does differential success in reproduction lead to?

A gradual change in the characteristics of a population over generations

What is artificial selection?

The selective breeding of domesticated plants and animals for specific traits (by humans)