Evolution of Living Things

Chapter 7tree of life

The teaching of Evolution has been controversial

Charles Darwin 1809-1882

British naturalist

Gathered evidence for the theory of evolution during a 5 year Voyage of the Beagle around the world trip from 1831-1836(three years and three months on land; 18 months at sea)

These islands sparked Darwins thoughts that led to his theory of:

Whats so great about the Galapagos?15+ separate islands with different climates and geographyIsolated from South America by 600 miles of ocean Climates are controlled by different ocean currents that bombard the islandsThey lie off the coast of Ecuador on the Equator

Evidence of Evolution?1. Fossils see your text: whale fossils2. Vestigial structures3. Comparison of skeletons4. DNA5. Embryonic structures:

chickencat human

Comparative Anatomy of skeletons:

Fossils: trace or remains of organisms that lived long ago, usually found in sedimentary rocktrilobiteammonite

Fossil T. rex:

Evolution of the whale in fossils:Be sure to read about these fossils in your textbook!

Fossil Record: older fossils are less similar to present day life forms

EVOLUTION-Homer SimpsonTHE PROCESS BY WHICH POPULATIONS ACCUMULATE INHERITED CHANGES OVER TIME

Give some ex. from the Voyage to the Galapagos video:

1. 2. 3.Tap Darwin for Brainpop

ADAPTATIONSSOMETHING THAT HELPS AN ORGANISM SURVIVECan be: structural or behavioral

Darwins Finches:

Section 2:

How Does Evolution Happen?

Natural SelectionThe process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals do

Natural Selection:

Has also been called

Four Parts to Natural Selection

1.Overproduction:Each species produces more offspring than will survive to reproduce.

2.Inherited VariationIndividuals in a population have slightly different traits.

3.Struggle to Survive:Individuals will always have to compete for limited resources. Starvation, disease, and predation will limit survival.

4.Successful Reproduction:Individuals better equipped for the environment survive and reproduce.The KEY to natural selection

Natural Selection (4 steps)1Overproduction2Genetic Variation3Struggle to Survive4Successful Reproduction

Charles Darwin publishes his famous book in 1859:

On the Origins of Species by Means of Natural selection

Section 3Natural Selection in Action

Elephants.African

Asian

Poaching elephants for their tusksThis has resulted in a change in the population where instead of 1% male elephants being born without tusks (1930), now 15% are born without tusks.

Natural Selection in Action:COCKROACHES! Females lay almost 80 eggs.Average colony 1000 roaches .Potential for ________offspring!Genetic variation means_____% will be killed by insecticide.______% will reproduce and produce offspring ____________to insecticide.

eeeeew!

Generation time: the length of time from the birth of one generation to the birth of the next

INSECTS: short generation timeMAMMALS: long generation time

The shorter the generation time(and the more offspring produced),

THE MORE LIKELY ADAPTATIONS WILL ARISE AND NEW SPECIES PRODUCED.

As a rough guide, the numbers of currently identified species can be broken down as follows : 287,655 plants10,000 lichens

1,190,200 invertebrates (including 950,000 insects)

57,739 vertebrates: includes 28,500 fishes, 5,743 amphibians, 8,163 reptiles, 9,917 birds, and 5,416 mammals.

Adaptation to Pollution:Peppered Moth :Lived in England in two colorsdark and light colored. Dark were very RARE.After 1850, industrial revolution brought air pollution.After a while dark colored moths were better adapted. Moth color changed over time.

Conditions of tree bark before 1850:

Conditions after 1850:

A SpeciesA group of organisms that can mate with one another to produce fertile offspring

Horse X Donkey =XMULE (sterile)

How do you get a new species?Florida pantherbobcatkitty cat

Formation of a new Species:1. Separation- part of a population becomes separated from the rest

2. Adaptation- natural selection may act on these groups in different ways

3. Division- separated groups have become so different they can no longer interbreedThis is called speciation

Example in your text book:

Origin of species: Anole lizards living in different habitats on the island of Martinique show distinct shapes and colors, suggesting that they are diverging into new species.

Also, many plants, and some animals, form hybrids in nature. Hooded crows and carrion crows look different, and largely mate within their own groupsbut in some areas, they hybridize. Should they be considered the same species or separate species?

Actual Hybrids

Photo-shopped hybrids

One more cartoon.

Natural Selection: