IB Topic 5.4: Evolution Individuals do not evolve, populations do.
Evolution Chapter 14 p292. Evolution To evolve means to change. All of the changes that have...
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Transcript of Evolution Chapter 14 p292. Evolution To evolve means to change. All of the changes that have...
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
?