BIG IDEA: THE ENVIRONMENT SELECTS THE TRAITS OF ITS INHABITANTS

BIG IDEA:

THE ENVIRONMENT SELECTS THE TRAITS OF ITS INHABITANTS.

Biogenesis: › All living things come from other living things

Spontaneous Generation :› States that life can come from nonliving

matter

Evolution :› the development of new types of organisms

from preexisting organisms over time

Natural Selection: › Is the mechanism for “descent of

modification”

Adaption: › A trait that makes an organism successful

in its environment EX:

thicker fur coats in cold climates

Fitness: › Is a measure of an individual’s hereditary

contribution to the next generation

Homologous Structure: › structures that occur in different species and

originate from a common ancestor Example: human arm and whale’s fin

Analogous Structure: › Structures that are closely related but do not

derive from the same ancestor Example: Wings of butterfly and bird

  Vestigial Structure:

› Structures that serve no function but that resemble structures with functional roles Example: Human appendix

Fossil: › Are the remains of an organism that died

long ago › EX:

Dinosaur bones

Control Group: › the group that doesn’t change

Experimental Group› the group that has the variable

Where does life come from?

A piece of meat was left out.

The next day flies and maggots were seen on the meat.

Where did the flies come from?› The thought the meat.

idea that life can arise from nonliving matter.

There is a “life force”

Francesco Redi

Lazzaro Spallanzani

Louis Pasteur

1668› Francesco Redi

One scientist that performed an experiment that disproved spontaneous generation

Control group:›Put meat in a jar uncovered.

Experimental group:›Put meat in a jar covered.

He let the jars sit out for a couple days Observes……

Flies found on the meat.

No flies on the meat.

Conclusion › Flies do not come from the meat.

Italian scientist 1768

› Performed another experiment that disprove spontaneous generation

Control Group:›Boil broth›Left flask open

Experimental Group:›Boil broth ›Sealed flask

Control: › Broth becomes cloudy bacteria present

Experimental: › Broth remains clearNO bacteria

The bacteria came from the air

French chemist

He disproved spontaneous generation

Invented the Pasteurization method

1862:

Boil broth in a curved-neck flask.› Curved-neck prevented large particles

from getting into the body of the flask.

After a year, › Broth in the not broken neck of

flask clear

› Broth in the broken neck of flask cloudy

Bacteria came from the outside air.

All living things come from the reproduction of other living things.

Change in an organism over time.

Jean Baptiste Lamarck Charles Darwin

French Biologist

Famous for his evolutionary theory of inheritance

1809

Two Theories 1. Use and Disuse 2. Inheritance of Acquired

Characteristics

Body parts that are used more grow stronger and bigger

USE

Body parts that are NOT used deteriorate

DISUSE

Physical traits that were changed in an organism are inherited by their offspring(s).

Giraffe’s neck› They gets longer as it stretches to reach food in trees.

NO!!!!!!

Variations that occur in the:› GAMETES cells are passed to offspring

› SOMATIC (body) cells are NOT inherited

British Naturalist

Set sail on the HMS Beagle

Famous for his studies

with finches on the Galapagos Islands

“Father of Evolution”

Went to the Galapagos Islands

He observed different types of finches

These observation lead to him developing his theory of evolution

British Naturalist Co discover of natural

selection Wallace and Darwin

presented their ideas to the public › Darwinism

States: 1. Descent with modification

2. Evolution occurs by the process of natural selection.

states evolution is the development of new organisms from preexisting organisms over time.

Over production:› In a population, more offspring are produced than can survive.

Competition

› Only some survive long enough to reproduce.

There is variation within a population

these variations are inherited and lead to differences in organisms

traits that are favorable and improve the organism’s ability to function and reproduce.

States that survivors pass on their variations.

Therefore….. a larger proportion in the next

generation will have those variations.

is a measure of an individual’s genetic contribution to the next generation.

Over time, small changes accumulate and populations change.

a group of organisms that can mate and produce fertile offspring.

1. Fossil Evidence 2. Anatomy3. Embryology 4. Molecular Evidence

Fossils:

› remains/traces of organisms that died long ago

› They are often found in strata

Strata layered rock

If undisturbed, › the lowest stratum is the oldest › the highest stratum is the newest

Relative Age: › found by comparing ages of strata

Absolute age › found by using radiometric dating

• Fossil record suggests that different species were present in the past than today.

What about the PACE of evolutionary

change?

Evolution that occurs slowly and continuously throughout time

Gradualism› Fossil record should

show many transitional species, they DON’T

Punctuated Equilibrium › Fossil records seem to

support this › However, the mechanism

is uncertain

States that for long periods of time, the existing species didn’t change Equilibrium

Then, in relatively short periods of time, there is an interruption in the equilibrium

New species emerge. The fossil record supports this!

studies the parts or structures of living things.

Similar internal parts

Different function in different organisms

This suggests descended from COMMON ANCESTORS

Ex:

› Human arm› Cat leg› Whale fin› Bat wing

Similar external form and function

Different internal forms and function

Suggests species came from DIFFERENT ancestral lines

Ex: › Bat Wing › Bird Wing › Insect Wing

Usually reduced iiin size and have no function.

› Suggests that the structure was once used by an evolutionary ancestor.

› Example: human appendix, tailbone.

study of embryos as they develop

Similarities of the development of embryos:

› suggests that the species have a common ancestor

when we analyze chemical similarities between organisms

Ex: a. DNA Comparison b. Protein Comparison

The more DNA is similar the CLOSER the relationship between the organims

Amino acids › The building blocks of proteins

Similarities of amino acids that make proteins suggest a relationship between organisms

EX: › In the protein cytochrome C, the difference

between amino acids is…… Humans vs. monkeys 1 difference Human vs. pigs 10 differences