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?

Adaptations  An 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 InsectsGrubs 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?