+ All Categories
Home > Documents > Chapter 18.1

Chapter 18.1

Date post: 18-Nov-2014
Category:
Upload: fj560
View: 4,051 times
Download: 1 times
Share this document with a friend
Description:
 
Popular Tags:
21
Lesson Overview Lesson Overview Finding Order in Diversity Finding Order in Diversity Lesson Lesson Overview Overview 18.1 Finding Order 18.1 Finding Order in Diversity in Diversity
Transcript
Page 1: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Lesson OverviewLesson Overview18.1 Finding Order 18.1 Finding Order

in Diversityin Diversity

Page 2: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Assigning Scientific NamesWhat are the goals of binomial nomenclature and systematics?

Page 3: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Assigning Scientific NamesThe first step in understanding and studying diversity is to describe and name each species.

By using a scientific name, biologists can be sure that they are discussing the same organism. Common names can be confusing because they vary among languages and from place to place.

For example, the names cougar, puma, panther, and mountain lion can all be used to indicate the same animal— Felis Concolor.

Give me other examples of animals with more than one name or a name that names more than one animal?

Page 4: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Assigning Scientific NamesIn the eighteenth century, European scientists agreed to assign Latin or Greek names to each species. Early scientific names often used long phrases to describe species in great detail.

For example, the English translation of the scientific name of a tree might be “Oak with deeply divided leaves that have no hairs on their undersides and no teeth around their edges.”

It was also difficult to standardize names because different scientists focused on different characteristics

Page 5: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Binomial NomenclatureIn the 1730s, Swedish botanist Carolus Linnaeus developed a two-word naming system called binomial nomenclature.

The scientific name usually is Latin. It is written in italics. The first word begins with a capital letter, and the second word is lowercased.

Page 6: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Binomial NomenclatureThe polar bear, for example, is called Ursus maritimus.

The first part of the name—Ursus—is the genus to which the organism belongs. A genus is a group of similar species. The genus Ursus contains five other species of bears, including Ursus arctos, the brown bear or grizzly bear.

Page 7: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Binomial NomenclatureThe second part of a scientific name—maritimus for polar bears—is unique to each species and is often a description of the organism’s habitat or of an important trait. The Latin word maritimus refers to the sea: polar bears often live on pack ice that floats in the sea.

Panthera leo

Genus Species

Greek Latin

Capital lowercased

Italics Italics

Page 8: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Binomial NomenclatureThe scientific name of the red maple is Acer rubrum.

The genus Acer consists of all maple trees.

The species rubrum describes the red maple’s color.

Page 9: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Classifying Species into Larger GroupsIn addition to naming organisms, biologists try to organize, or classify, living and fossil species into larger groups that have biological meaning. Biologists often refer to these groups as taxa (singular: taxon).

Page 10: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Linnaean Classification SystemHow did Linnaeus group species into larger taxa?

Page 11: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Linnaean Classification SystemLinnaeus also developed a classification system that organized species into a hierarchy, or ranking.

In deciding how to place organisms into larger groups, Linnaeus grouped species according to anatomical similarities and differences.

Page 12: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Seven Levels Linnaeus identified just four levels in his original classification system.

Over time, Linnaeus’s original classification system would expand to include seven taxa: species, genus, family, order, class, phylum, and kingdom.

Page 13: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Seven Levels The scientific name of a camel with two humps is Camelus bactrianus.

This illustration shows how a Bactrian camel, Camelus bactrianus, is grouped within each Linnaean category.

The genus Camelus contains another species, Camelus dromedarius, the dromedary, with only one hump.

Page 14: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Family The South American llama bears some resemblance to Bactrian camels and dromedaries. But the llama is more closely related to other South American species than it is to European and Asian camels.

Therefore, llamas are placed in a different genus, Lama; their species name is Lama glama.

Genera that share many similarities are grouped into a larger category, the family—in this case, Camelidae.

Page 15: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Order Closely related families are grouped into the next larger rank—an order.

Camels and llamas (family Camelidae) are grouped with several other animal families, including deer (family Cervidae) and cattle (family Bovidae), into the order Artiodactyla, hoofed animals with an even number of toes.

Page 16: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Class Closely related orders are grouped into the next larger rank, a class.

The order Artiodactyla is placed in the class Mammalia, which includes all animals that are warm-blooded, have body hair, and produce milk for their young.

Page 17: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Phylum Classes are grouped into a phylum. A phylum includes organisms that are different but that share important characteristics.

The class Mammalia is grouped with birds (class Aves), reptiles (class Reptilia), amphibians (class Amphibia), and all classes of fish into the phylum Chordata. These organisms share important body-plan features, among them a nerve cord along the back.

Page 18: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Kingdom The largest and most inclusive of Linnaeus’s taxonomic categories is the kingdom.

All multicellular animals are placed in the kingdom Animalia.

Page 19: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

How to remember taxonomyThe easiest way to remember how to classify organisms into their taxons is with a saying.

Go from largest taxon to smallest – from general to more specific

King – Phillip – Came – Over – For – Good – Spaghetti

Kingdom – Phylum – Class – Order – Family – Genus – Species

I want you to come up with your own pneumonic device now to help you remember taxonomy.

Page 20: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Problems With Traditional Classification In a way, members of a species determine which organisms belong to that species by deciding with whom they mate and produce fertile offspring.

Ranks above the level of species, however, are determined by researchers who decide how to define and describe genera, families, orders, classes, phyla, and kingdoms.

Linnaeus grouped organisms into larger taxa according to overall similarities and differences. But which similarities and differences are the most important?

Page 21: Chapter 18.1

Lesson OverviewLesson Overview Finding Order in DiversityFinding Order in Diversity

Problems With Traditional Classification For example, adult barnacles and limpets live attached to rocks and have similar-looking shells.

Adult crabs don’t look anything like barnacles and limpets.

Based on these features, one would likely classify limpets and barnacles together and crabs in a different group. However, that would be wrong.

Modern classification schemes look beyond overall similarities and differences and group organisms based on evolutionary relationships.


Recommended