THURS. 10/24/13Agenda: Chapter 4 Quiz Species in Danger

Life’s Work:Bring $1 for animal adoption,Read ch. 9 and study for quiz on Tues.

Objective: SWBAT define extinction and identify characteristics that make species vulnerable to extinction.

Do Now:What does it mean for something to go extinct? Name as many extinct species as you can.

Week at a GlanceMonday Tuesday Wednesday

(A)Thursday Friday

Deforestation Invasive Species and Biodiversity

Parent Conferences

Ch. 4 QuizExtinction

Animal $ dueExtinction

EXTINCTION: LIGHTS OUTExtinction: complete disappearance of a species from the Earth

Extinction occurs when the population cannot adapt to changing environmental conditions.

Extinctions have existed long before humans had an influence, but the scientific consensus is that human activities are decreasing the earth’s biodiversity.

The golden toad of Costa Rica’s Monteverde cloud forest has become extinct

because of changes in climate.

EXTINCTION: LIGHTS OUTThe current extinction crisis is the first to be caused by a single species - us!

This is happening faster than ever = a few decades instead of thousands to millions of years.

Humans are eliminating not only the species but the environments as well (ex: tropical rainforests, coral reefs, etc.)

The golden toad of Costa Rica’s Monteverde cloud forest has become extinct

because of changes in climate.

Fig. 4-12, p. 93

Tertiary

Bar width represents relative number of living speciesEra Period

Species and families experiencing

mass extinctionMillions ofyears ago

Ordovician: 50% of animal families, including many trilobites.

Devonian: 30% of animal families, including agnathan and placoderm fishes and many trilobites.

500

345

Cambrian

Ordovician

Silurian

Devonian

Extinction

Extinction

Pale

ozoi

cM

esoz

oic

Cen

ozoi

c

Triassic: 35% of animal families, including many reptiles and marine mollusks.

Permian: 90% of animal families, including over 95% of marine species; many trees, amphibians, most bryozoans and brachiopods, all trilobites.Carboniferous

Permian

Current extinction crisis causedby human activities. Many speciesare expected to become extinctwithin the next 50–100 years.Cretaceous: up to 80% of ruling reptiles (dinosaurs); many marine species including manyforaminiferans and mollusks.

Extinction

Extinction

Triassic

Jurassic

Cretaceous

250

180

65Extinction

ExtinctionQuaternary Today

According to the fossil

record, there have been five major

mass extinctions

over the past 500 million

years.

Some scientists say that we are now in the midst of a 6th mass extinction,

caused by humans.

Globally / Biologically

Ecologically

Locally

Species is no longer found on the Earth

When so few members of a

species are left that they no longer play their ecological role

Species is no longer found in a particular

areaLEVELS OF SPECIES

EXTINCTION

SPECIES IN DANGEREndangered: so few

individual survivors that it could soon become extinct

Threatened: still abundant in its natural range but is

likely to become endangered in the near

future

Rare: a noticeable decline in a species