Evolution

Chapter 14 p292

Evolution To evolve means to change. All of the changes that have

transformed life over time.

JB Lamarck Early scientist believed traits and

abilities acquired during an organism’s life-time were passed on to its offspring.

Lamarck cont. This was called

inheritance of acquired characteristics.

Was Lamarck wrong?

AdaptationsAn inherited characteristic that improves an organisms ability to survive and reproduce in it’s environment.

ADAPTATIONS IN ACTION

Charles Darwin In 1831 Darwin took an

exploratory journey on the HMS Beagle to the coast of South America.

Visited and recorded data on an island chain called The Galapagos.

Darwin Cont. Darwin took theories proposed by

other scientists and combined them with what he learned on his voyage.

He published a controversial book called “The Origin of Species”

Darwin cont. Darwin theorized the organisms

adapted to the changing environment.

Darwin’s Finches

Leaves

Seeds

Fruit & Nuts

Insects Grubs

Finds insects using twig

Natural Selection One of Darwin’s main points was a

theory called natural selection. Process by which individuals with

inherited characteristics well-suited to the environment leave more offspring on average than others.

Survival of the fittest.

Evidences of Evolution 5 scientifically studied and

accepted evidences for evolution.

Evidence of Evolution Fossils – preserved remains or

markings left by organisms that lived in the past.

Fossils cont. Fossil record – chronological record of

life’s remains found in layers of rock. By looking at the fossil record we can

see gradual changes over time.

Homologous Structures Similar anatomical structures on

species sharing a common ancestor. Arm bones, WALRUS PELVIS!!

                                                                                                         

                                                          

Vestigial Structures Remnants of structures that may have

had important functions in an ancestral species, but have no function now.

Your tailbone, Whale hip bones

Similarities in Embryonic Development

Closely related organisms look very similar as embryos.

DNA New technologies have allowed for the

comparison of DNA sequences to show similarities.

Black and White Rhino’s Kodiak, Grizzly, Alaskan Brown Bears.

DNA (continued)

Kodiak, Grizzly, Alaskan Brown Bears.

Microevolution Generation – to – generation change

in a localized group of organisms. The peppered moth in England.

Hardy-Weinberg The Hardy – Weinberg Equilibrium Period of time when there is no

change in the local group. It is usually short and rare. It is used to compare and tell if

changes occur.

Macroevolution Bigger, more dramatic concept than

microevolution. New species formation – speciation. Extinction Major new features in organisms.

Species Species – a population whose

members have the ability to breed with one another in nature and produce fertile offspring.

Abrupt speciation can be - Punctuated equilibrium – species

diverge in rapid periods of change, the new species remain unchanged for long periods of time

Speciation?

Liger

Tigon

Zorse

Cama

Beefalo

Leopard-Lion

Wholphin

?

Speciation?