Biodiversity

Diversity Video

Why should Humans (at the top of the Hierarchy of Living things) care about those below?

Scientists have identified 1.75 million different species of organisms. The actual number may be 10 times more. This is Biodiversity

Species Diversity

Biodiversity: The number, variety, and genetic variation of different organisms found within a specified geographic region

How would you classify these?

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The Father of Taxonomy

Carl Linnaeus, also known as Carl von Linné or Carolus Linnaeus, is often called the Father of Taxonomy.

His system for naming, ranking, and classifying organisms is still in wide use today (with many changes).

His ideas on classification have influenced generations of biologists during and after his own lifetime, even those opposed to the philosophical and theological roots of his work.

(1707-1778)

Key factors in Evolution

1. Population is small2. Mating opportunities are nonrandom (preferred

mates will pass on their alleles in greater numbers, ie. The robin with the brightest breast, or the stronger Ram)

3. Mutations Occur (create new alleles, changing frequencies of new and original allele)

4. Migration Occurs (alleles move to a different population)5. Natural Selection Occurs (better suited alleles

reproduce, increasing their frequency in the next generations)

Sexual Selection

Favours the selection of any trait that influences the mating success of the individual

Most common is female selection of the male from male versus male competition… colours, appearance, behaviour, songs, dancing… as they are selected they may exaggerate over time.

Not limited to animals… but also plants, based on attracting insects and birds (smells, colours…)

Beneficial?or

Detrimental?

SpeciationNatural Selection is the same selective mechanism that accounts for speciation

Speciation:The evolutionary formation of new species

The evolution that occurs at the species level is referred to as microevolution

Species:Members of interbreeding groups or population that are reproductively isolated from other groups and evolve independently

What is a Species?

What do you get when you cross a Horse and a Donkey?

A mule, which is sterile!

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Reproductive Isolating Mechanisms

Behaviour, structure or biochemical traits that prevent individuals of different species from reproducing successfully togetherDoesn’t work for asexual organisms such as prokaryotic organisms, some fungi and plants, and even some vertebrates

The Flamingo Dance

Reproductive Isolating Mechanisms

Mechanisms that prevent interspecies mating and fertilization

Mating Prevention1. Ecological isolation2. Temporal Isolation3. Behavioural Isolation

Fertilization Prevention1. Mechanical Isolation2. Gametic Isolation

Taxonomy

The traditional science and methodology of classifying organisms based on physical similarities.

It is criticized for not reflecting patterns of evolutionary relatedness.

Taxonomists classify all organisms into a hierarcy, and give them standardized Latin names.

Increasing

similarity

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PhylumClassOrderFamilyGenus

Species

Levels of Classification

A given organism belongs to one species, which belongs to one genus, which belongs to one family, and so on.

Conversely, a genus can contain one or many species, a family can contain one or many genera, an order can contain one or many families, etc.

Taxonomy

Man Gorilla Chimpanzee Orangutam Gibbon

Within a particular group of organisms, "Latinized" ending are attached to names of all groups at the same taxonomic level.

Divisions of plants end in "-phyta," and Families of animals usually end in "-idae.“

Taxonomy

When referring to a particular species, it is correct to give both genus and species together. As an example, here is the taxonomic classification for the grey wolf:

Kingdom: Animalia Phylum: Chordata Sub-phylum: Vertebrata Class: Mammalia Order: Carnivora Family: Canidae Genus: Canis Species: lupus

When referring to a particular species, it is correct to give both genus and species together. As an example, here is the taxonomic classification for the grey wolf: Canis lupus

Kingdom: Animalia Phylum: MolluscaSub-phylum: Vertebrata Class: GastropodaOrder:Family:Genus: CochlicopaSpecies: lubrica

Binomial nomenclature: system of naming organisms using a two-part scientific name

Example: Castor canadenis, “beaver from Canada” Species: a group of organism that resemble one another physically, behaviourally, or genetically and that can interbreed under natural conditions to produce fertile offspring 

Phylogenetics: the study of how organisms are related to one another. Using the fossil record together with characteristics of living species such as morphology, behavior, and molecular analysis of proteins and DNA, a "best guess" about how closely various species are related.

Try to determine how long ago two or more species had a common ancestor. A "phylogeny" is a sort of family tree, showing how one group of species gave rise to other groups.

More Naming…

Cladistics or Phylogenetic Systematics: the science of classifying organisims strictly on their evolutionary relatedness. The functional grouping unit is a "clade," a group of organisms with a common ancestor.

More Naming…

Dichotomous KeyA two-part key used to identify living things.

The key is constructed so that a series of choices must be made, and each choice leads to a new branch of the key.

If choices are made accurately, the end result is the name of the organism being identified.

Often the choice is hard: conserve a species or feed a community, tourists' dollars or turtles' nests.

In 2003 the World Conservation Union's Red List said more than 12,000 species (out of 40,000 assessed) faced some extinction risk, including: one bird in eight 13% of the world's flowering plants a quarter of all mammals.

The Evolution of Man and Diversity on Earth

FIVE MASS EXTINCTIONS

Cretaceous (About 65 million years ago)

Triassic (About 208 million years ago) Permian (About 245 million years ago) Devonian (About 360 million years ago)

Ordovician (About 438 million years ago)

Science has described 1.75 million species, some experts estimate that there may be 13 or 14 million in the world in total - but until they are catalogued, nobody knows.

The Evolution of Man and Diversity on Earth